Internet Draft                                       ETSI TC-SEC (ETSI)
S/MIME Working Group                         J Ross (Security & Standards)                                   D. Pinkas (Bull)
expires in six months                                      D Pinkas (Bull)                    J. Ross (Security & Standards)
Target Category: Informational               N           N. Pope (Security & Standards)
                                                                March
                                                              July 2000

                     Electronic Signature Formats
                  for long term electronic signature
                   <draft-ietf-smime-esformats-00.txt> signatures
                  <draft-ietf-smime-esformats-01.txt>

Status of this Memo

   This document is an Internet-Draft and is NOT offered in
   accordance with section of RFC 2026, and the author does not
   provide the IETF with any rights other than to publish as an
   Internet-Draft.

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   http://www.ietf.org/ietf/1id-abstracts.txt

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Abstract

The informational RFC defines the format of an electronic signature
that can remain valid over long periods. This includes evidence as to
its validity even if the signer or verifying party later attempts to
deny (repudiates) (i.e. repudiates, see [ISONR]) the validity of the signature.

The format can be considered as an extension to RFC 2630 [CMS] and RFC
2634 [ESS], where, when appropriate additional signed and unsigned
attributes have been defined.

The contents of this Informational RFC is technically equivalent to
ETSI ES 201 733 V.1.1.1 V.1.1.3 Copyright (C). Individual copies of this
ETSI deliverable can be downloaded from http://www.etsi.org

1.  Introduction

This document is intended to cover electronic signatures for various
types of transactions, including business transactions (e.g. purchase
requisition, contract, and invoice applications) where long term
validity of such signatures is important.

Internet Draft                             Electronic Signature Formats

Electronic signatures can be used for any transaction between an
individual and a company, between two companies, between an individual
and a governmental body, etc. This document is independent of any
environment. It can be applied to any environment e.g. smart cards, GSM
SIM cards, special programs for electronic signatures etc.

Internet Draft                                   Electronic Signature Formats

An electronic signature produced in accordance with this document
provides evidence that can be processed to get confidence that some
commitment has been explicitly endorsed under a Signature signature policy, at a
given time, by a signer under an identifier, e.g. a name or a
pseudonym, and optionally a role.

The European Directive on a community framework for Electronic
Signatures defines an electronic signature as: "data in electronic form
which is attached to or logically associated with other electronic data
and which serves as a method of authentication".  An electronic
signature as used in the current document is a form of advanced
electronic signature as defined in the Directive.

The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "MAY", and "OPTIONAL" in this document (in uppercase,
as shown) are to be interpreted as described in [RFC2119].

TABLE OF CONTENTS

1.  Introduction                                                    1
2  Overview                                                         4
2.1  Aim

The aim                                                            4
2.2  Basis of this document is to define an Present Document                                      4
2.3  Major Parties                                                  5
2.4  Electronic Signature (ES) that
remains valid over long periods. This includes evidence as to its
validity even if the signer or verifying party later attempts to deny
(repudiates) the validity of the signature.

A signer is the entity that creates an electronic signature.

This document specifies use of trusted service providers (e.g.
TimeStamping Authorities (TSA)), and the data that needs to be archived
(e.g. cross certificates Signatures and revocation lists) to meet the requirements Validation Data                      6
2.5  Forms of long term electronic signatures. An electronic signature defined by
this document can be used for arbitration in case Validation Data                                       7
2.6  Extended Forms of a dispute between
the signer and verifier, which may occur at some later time, even years
later. This document uses a signature policy, referenced by the signer,
as the basis for establishing the validity Validation Data                              9
2.7  Archive Validation Data                                       11
2.8  Arbitration                                                   12
2.9  Validation Process                                            12
2.10  Example Validation Sequence                                  13
2.11  Additional optional features                                 18
3. Data structure of an electronic signature.

A Trusted Service Provider (TSP) is an entity that helps to build trust
relationships by making available or providing some information upon
request.

A verifier is an entity that verifies an evidence. (ISO/IEC 13888-1
[13]). Within the context of this document this is an entity that
validates an electronic signature.

A signature policy is a set of rules for the creation and validation of
an electronic signature, under which the signature can be determined to
be valid

2.2	Basis of Electronic Signature                       19
3.1  General Syntax                                                19
3.2  Data Content Type                                             19
3.3  Signed-data Content Type                                      19
3.4  SignedData Type                                               19
3.5  EncapsulatedContentInfo Type                                  20
3.6  SignerInfo Type                                               20
3.6.1  Message Digest Calculation Process                          20
3.6.2  Message Signature Generation Process                        20
3.6.3  Message Signature Verification Process                      20
3.7  CMS Imported Mandatory Present Document

This document is based on the use of public key cryptography to produce
digital signatures, supported by public key certificates. Attributes                     21
3.7.1  Content Type                                                21
3.7.2  Message Digest                                              21
3.7.3  Signing Time                                                21

Internet Draft                             Electronic Signature Formats

A Public key certificate is a public keys of a user, together with some
other information, rendered unforgeable by encipherment with the
private key of the Certification Authority (CA) which issued it (ITU-T
Recommendation X.509 [1]).

This document also uses timestamping services to prove the validity of
a signature long after the normal lifetime of critical elements of an
electronic signature and to support non-repudiation. It also, as an
option, uses additional timestamps to provide very long-term protection
against key compromise or weakened algorithms.

This document builds on existing standards that are widely adopted.
This includes:

     * RFC 2630 [9] Crytographic Message Syntax (CMS);
     * ITU-T Recommendation X.509 [1] Authentication framework;
     * RFC 2459 [7]  Internet X.509 Public Key Infrastructure (PKIX)

3.8  Alternative Signing Certificate and CRL Profile;
     * RFC (to be published) PKIX Timestamping protocol.

NOTE:	See clause 2 Attributes                    21
3.8.1  ESS Signing Certificate Attribute Definition                21
3.8.2  Other Signing Certificate Attribute Definition              22
3.9  Additional Mandatory Attributes                               23
3.9.1  Signature policy Identifier                                 23
3.10  CMS Imported Optional Attributes                             24
3.10.1  Countersignature                                           25
3.11  ESS Imported Optional Attributes                             25
3.11.1 Content Reference Attribute                                 25
3.11.2  Content Identifier Attribute                               25
3.12   Additional Optional Attributes                              25
3.12.1  Commitment Type Indication Attribute                       25
3.12.2  Signer Location attribute                                  27
3.12.3  Signer Attributes attribute                                28
3.12.4  Content Timestamp attribute                                28
3.13  Support for a full set Multiple Signatures                              29
3.13.1  Independent Signatures                                     29
3.13.2  Embedded Signatures                                        29
4.  Validation Data                                                29
4.1  Electronic Signature Timestamp                                30
4.1.1  Signature Timestamp Attribute Definition                    30
4.2  Complete Validation Data                                      31
4.2.1  Complete Certificate Refs Attribute Definition              32
4.2.2  Complete Revocation Refs Attribute Definition               32
4.3  Extended Validation Data                                      34
4.3.1  Certificate Values Attribute Definition                     34
4.3.2  Revocation Values Attribute Definition                      35
4.3.3  ES-C Timestamp Attribute Definition                         35
4.3.4  Time-Stamped Certificates and CRLs Attribute Definition     36
4.4  Archive Validation Data                                       36
4.4.1  Archive Timestamp Attribute Definition                      37
5.  Security considerations                                        38
5.1  Protection of references.

2.3	Major Parties Private Key                                     38
5.2  Choice of Algorithms                                          38
6.  Conformance Requirements                                       38
6.1  Signer                                                        38
6.2  Verifier                                                      39
7. References                                                      40
8. Authors' Addresses                                              40
9. Full Copyright Statement                                        41
Annex A (normative): ASN.1 Definitions                             43
A.1  Definitions Using X.208 (1988) ASN.1 Syntax                   43
A.2  Definitions Using X.680 1997 ASN.1 Syntax                     52
Annex B (informative): General Description                         61
B.1  The following are the major parties involved in a business transaction
supported by electronic signatures as defined in this document:

     * Signature Policy                                          61
B.2  Signed Information                                            62
B.3  Components of an Electronic Signature                         62
B.3.1  Reference to the Signer;
     * Signature Policy                           62
B.3.2  Commitment Type Indication                                  63
B.3.3  Certificate Identifier from the Verifier;
     * Trusted Service Providers (TSP);
     * Signer                      64

Internet Draft                             Electronic Signature Formats

B.3.4.  Role Attributes                                            64
B.3.4.1  Claimed Role                                              65
B.3.4.2  Certified Role                                            65
B.3.5  Signer Location                                             66
B.3.6  Signing Time                                                66
B.4  Components of Validation Data                                 67
B.4.1  Revocation Status Information                               67
B.4.2  CRL Information                                             67
B.4.3  OCSP Information                                            68
B.4.4  Certification Path                                          69
B.4.5  Timestamping for Long Life of Signature                     69
B.4.6  Timestamping before CA Key Compromises                      70
B.4.6.1  Timestamping the Arbitrator. ES with Complete validation data         71
B.4.6.2  Timestamping Certificates and Revocation Information      72
B.4.7  Timestamping for Long Life of Signature                     72
B.4.8  Reference to Additional Data                                73
B.4.9  Timestamping for Mutual Recognition                         73
B.4.10  TSA Key Compromise                                         74
B.5  Multiple Signatures                                           74
Annex C (informative):  Identifiers and roles                      75
C.1  Signer Name Forms                                             75
C.2  TSP Name Forms                                                75
C.3  Roles and Signer Attributes                                   75

2  Overview

2.1  Aim

The arbitrator aim of this document is to define an entity Electronic Signature (ES) that may be used
remains valid over long periods. This includes evidence as to arbitrate a dispute
between a its
validity even if the signer and verifier when there is a disagreement on or verifying party later attempts to deny
(repudiates) the validity of a digital signature.

The Signer is the entity that creates the electronic signature. When
the signer digitally signs over data using the prescribed format, this
represents a commitment on behalf

This document specifies use of the signing entity to trusted service providers (e.g.
TimeStamping Authorities (TSA)), and the data
being signed.

The Verifier is the entity that validates needs to be archived
(e.g. cross certificates and revocation lists) to meet the requirements
of long term electronic signature, it
may signatures. An electronic signature defined by
this document can be used for arbitration in case of a single entity or multiple entities.

The Trusted Service Providers (TSPs) are one or more entities that help
to build trust relationships dispute between
the signer and verifier. They
support verifier, which may occur at some later time, even years
later. This document uses a signature policy, referenced by the signer and verifier signer,
as the basis for establishing the validity of an electronic signature.

2.2  Basis of Present Document

This document is based on the use of public key cryptography to produce
digital signatures, supported by means public key certificates.

A Public key certificate is a public keys of supporting services
including: user certificates, cross-certificates, timestamping tokens,
CRLs, ARLs, OCSP responses. a user, together with some
other information, rendered unforgeable by encipherment with the
private key of the Certification Authority (CA) which issued it (ITU-T
Recommendation X.509 [1]).

Internet Draft                             Electronic Signature Formats

The following TSPs are used

This document also uses timestamping services to support the
functions defined in this document:

     * Certification Authorities;
     * Registration Authorities;
     * Repository Authorities (e.g. a Directory);
     * TimeStamping Authorities;
     * Signature Policy Issuers.

Certification Authorities provide users with public key certificates.

Registration Authorities allows prove the registration validity of entities before
a
CA generates certificates.

Repository Authorities publish CRLs issued by CAs, signature policies
issued by Signature Policy Issuers and optionally public key
certificates.

TimeStamping Authorities attest that some data was formed before a
given trusted time.

Signature Policy Issuers define long after the technical and procedural
requirements for normal lifetime of critical elements of an
electronic signature creation and validation, in order to meet a particular business need.

In some cases the following support non-repudiation. It also, as an
option, uses additional TSPs are needed:

     * Attribute Authorities.

Attributes Authorities provide users with attributes linked timestamps to public provide very long-term protection
against key certificates

An Arbitrator is an entity compromise or weakened algorithms.

This document builds on existing standards that arbitrates disputes between a signer are widely adopted.
This includes:

     * RFC 2459 [RFC2459]  Internet X.509 Public Key Infrastructure
       Certificate and CRL Profile (PKIX);
     * RFC 2630 [CMS] Crytographic Message Syntax (CMS);
     * RFC 2634 [ESS] Enhanced Security Services (ESS);
     * RFC 2439 [OCSP] One-line Certificate Status Protocol (OCSP);
     * ITU-T Recommendation X.509 [1] Authentication framework;
     * RFC (to be published) [TSP] PKIX Time Stamping protocol (TSP).

NOTE:  See clause 8 for a verifier.

A signature policy issuer is an entity that defines full set of references.

2.3  Major Parties

The following are the technical and
procedural requirements for electronic signature creation and
validation, major parties involved in order to meet a particular business need

2.4	Electronic Signatures and Validation Data

Validation of an transaction
supported by electronic signature signatures as defined in accordance with this document
requires: document:

     * The electronic signature; this includes:
        - the signature policy;
        -  the signed user data;
        - Signer;
     * the digital signature;
        -  other signed attributes provided by Verifier;
     * the signer.

Internet Draft                                   Electronic Signature Formats Arbitrator;
     * Validation data which Trusted Service Providers (TSP).

A Signer is an entity that creates the additional electronic signature. When
the signer digitally signs over data needed to validate using the electronic signature; prescribed format, this includes:

        -  certificates;
        -  revocation status information,
        -  trusted time-stamps from Trusted Service Providers (TSPs).

     * The signature policy specifies the technical requirements
represents a commitment on
      signature creation and validation in order behalf of the signing entity to meet a particular
      business need. the data
being signed.

A given legal/contractual context may recognize a
      particular signature policy as meeting its requirements.

For example: a specific signature policy may be recognized by court of
law as meeting verifier is an entity that verifies an evidence. (ISO/IEC 13888-1
[13]). Within the requirements context of the European Directive for this document this is an entity that
validates an electronic
commerce. A signature policy may be written using a formal notation like
ASN.1 (see 6.1) or in signature.
An arbitrator, is an informal free text form provided the rules of
the policy are clearly identified. However, for a given signature policy
there shall be one definitive form entity which has arbitrates disputes between a unique binary encoded
value.

Signed user data signer
and a verifier when there is a disagreement on the user's data validity of a
digital signature.

Trusted Service Providers (TSPs) are one or more entities that is signed.

The Digital Signature is help
to build trust relationships between the digital signer and verifier. Use of
some specific TSP services MAY be mandated by signature applied over policy. TSP
supporting services may provide the following attributes provided by the signer:

    * hash of the information: user data;
    * signature Policy Identifier;
    * other signed attributes
certificates, cross-certificates, timestamping tokens, CRLs, ARLs,
OCSP responses.

Internet Draft                             Electronic Signature Formats

The other signed attributes include any additional information which
must be signed to conform following TSPs are used to support the signature policy validation or this document
(e.g. signing time).

The Validation Data may be collected by the signer and/or the verifier
and must meet
the requirements of the signature policy.  Additional
data includes CA certificates as well as revocation status information
in the form verification of electronic signatures :

     * Certification Authorities;
     * Registration Authorities;
     * Repository Authorities (e.g. a Directory);
     * TimeStamping Authorities;
     * One-line Certificate Revocation Lists (CRLs) or certificate
status information provided by an on-line service.  Additional data
also includes timestamps and other time related data used to Status Protocol responders;
     * Attribute Authorities;
     * Signature Policy Issuers.

Certification Authorities provide
evidence of users with public key certificates.

Registration Authorities allows the timing registration of given events.  It is required, as a minimum,
that either the signer or verifier obtains a timestamp over the
signer's signature.

A Certificate Revocation List (CRL) is signed list indicating entities before a set of
CA generates certificates.

Repository Authorities publish CRLs issued by CAs, cross-certificates
(i.e. CA certificates) issued by CAs, signature policies issued by
Signature Policy Issuers and optionally public key certificates that are no longer considered valid (i.e.
leaf certificates) issued by the certificate
issuer [X.509 FPAM]digital signature: CAs.

TimeStamping Authorities attest that some data appended to, or was formed before a
cryptographic transformation of,
given trusted time.

One-line Certificate Status Protocol responders (OSCP responders)
provide information about the status (i.e. revoked, not revoked,
unknown) of a data unit particular certificate.

A Signature Policy Issuer issues signatures policies that allows a recipient of
the data unit to prove define the source
technical and integrity of the data unit procedural requirements for electronic signature
creation, validation and
protect against forgery, e.g. by the recipient (ISO 7498-2 [12])

Internet Draft verification, in order to meet a particular
business need.

Attributes Authorities provide users with attributes linked to public
key certificates

2.4  Electronic Signature Formats

2.5	Forms of Signatures and Validation Data

An

Validation of an electronic signature may exist in many forms including: accordance with this document
requires:

     * The electronic signature; this includes:

        -  the Electronic Signature (ES), which includes the digital signature and policy;
        -  the signed user data;
        -  the digital signature;
        -  other basic information signed attributes provided by the signer;

    * the ES with Timestamp  (ES-T), which adds a timestamp to
.       -  other unsigned attributes provided by the
       Electronic Signature, to take initial steps towards providing
       long term validity; signer.

    * the ES with Complete validation Validation data (ES-C), which adds to the
      ES-T references to is the complete set of additional data supporting the
      validity of needed to validate
      the electronic signature (i.e. signature; this includes:

        -  certificates references;
        -  certificates;

Internet Draft                             Electronic Signature Formats

        -  revocation status
      information). information references;
        -  revocation status information;
        -  time-stamps from Time Stamping Authorities (TSAs).

     * The signer must provide at least the ES form, but in some cases may
decide to provide signature policy specifies the ES-T form technical requirements on
       signature creation and validation in the extreme case could provide
the ES-C form. If the signer does not provide ES-T, the verifier must
create the ES-T on first receipt of an electronic signature. The ES-T
provides independent evidence order to meet a particular
       business need. A given legal/contractual context may recognize a
       particular signature policy as meeting its requirements.

For example: a specific signature policy may be recognized by court
of law as meeting the existence requirements of the European Directive for
electronic commerce. A signature at the
time it was first verified which should policy may be near the time it was
created, and so protects against later repudiation of written using a formal
notation like ASN.1 or in an informal free text form provided the existence
rules of the signature. If the signer does not provide ES-C the verifier must
create the ES-C when policy are clearly identified. However, for a given
signature policy there shall be one definitive form which has a unique
binary encoded value.

Signed user data is the complete set of revocation and other validation user's data that is available. signed.

The ES satisfies the legal requirements for electronic signatures as
defined in the European Directive on electronic signatures, see Annex C
for further discussion on relationship of this document to the
Directive. It provides basic authentication and integrity protection
and can be created without accessing on-line (timestamping) services.
However,  without the addition of a timestamp Digital Signature is the electronic digital signature
does not protect against applied over the threat that
following attributes provided by the signer later denies having
created signer:

    * hash of the electronic user data (message digest);
    * signature (i.e. does not provide non-repudiation
of its existence). Policy Identifier;
    * other signed attributes

The ES-T time-stamp should other signed attributes include any additional information which
must be created close to the time that ES was
created signed to provide maximum protection against repudiation. At this time
ll the data needed conform to complete the validation may not be available but
what information is readily available signature policy or this document
(e.g. signing time).

The Validation Data may be used to carry out some of collected by the initial checks. For example, only part signer and/or the verifier
and must meet the requirements of the signature policy.  Additional
data includes CA certificates as well as revocation status information may be available for verification at that point
in time.

Generally, the ES-C form cannot be created at the same time as the ES,
as it is necessary to allow time for any revocation information to be
captured. Also, if a of Certificate Revocation Lists (CRLs) or certificate is found to be temporarily suspended,
it will be necessary
status information provided by an on-line service.  Additional data
also includes timestamps and other time related data used to wait until provide
evidence of the end timing of given events.  It is required, as a minimum,
that either the suspension period.

The signer should only create or verifier obtains a timestamp over the ES-C in situations where it was
prepared
signer's signature.

A digital signature (not to wait for be confused with an electronic signature)
is data appended to, or a sufficient length of time after creating the ES
form before dispatching the ES-C. This, however, has the advantage cryptographic transformation of, a data unit
that allows a recipient of the verifier can be presented with data unit to prove the complete set source and
integrity of the data supporting unit and protect against forgery, e.g. by the validity
recipient (ISO 7498-2 [12])

2.5  Forms of Validation Data

An electronic signature may exist in many forms including:

    * the ES.

Internet Draft Electronic Signature Formats

Support for ES-C (ES), which includes the digital
      signature and other basic information provided by the verifier is mandated (see clause 14 for
specific conformance requirements).

An signer;

Internet Draft                             Electronic Signature (ES), Formats

    * the ES with Timestamp (ES-T), which adds a timestamp to the additional
      Electronic Signature, to take initial steps towards providing
      long term validity;

    * the ES with Complete validation data forming (ES-C), which adds to the
      ES-T and ES-C is illustrated in Figure 1:

+------------------------------------------------------------ES-C-----+
|+--------------------------------------------ES-T-----+              |
||+------Elect.Signature (ES)----------+ +------------+| +-----------+|
|||+---------+ +----------+ +---------+| |Timestamp   || |Complete   ||
||||Signature| |  Other   | | Digital || |over digital|| |certificate||
||||Policy ID| |  Signed  | |Signature|| |signature   || |and        ||
||||         | |Attributes| |         || +------------+| |revocation ||
|||+---------+ +----------+ +---------+|               | |references ||
||+------------------------------------+               | +-----------+|
|+-----------------------------------------------------+              |
+---------------------------------------------------------------------+

Figure 1: Illustration references to the complete set of an ES, ES-T and ES-C

2.6	Extended Forms data supporting the
      validity of Validation Data the electronic signature (i.e. revocation status
      information).

The complete validation data  (ES-C) described above signer must provide at least the ES form, but in some cases may be extended
decide to provide the ES-T form an ES with eXtended validation data (ES-X) to meet following
additional requirements.

Firstly, when and in the verifier extreme case could provide
the ES-C form. If the signer does not has access to,

     * provide ES-T, the signer's certificate,
     * all verifier must
create the CA certificates that make up ES-T on first receipt of an electronic signature. The ES-T
provides independent evidence of the full certification
       path,
     * all existence of the associated revocation status information, as referenced
       in signature at the ES-C.

then
time it was first verified which should be near the values of these certificates time it was
created, and revocation information may be
added to so protects against later repudiation of the ES-C. This form existence of extended
the signature. If the signer does not provide ES-C the verifier must
create the ES-C when the complete set of revocation and other
validation data is called a
X-Long.

Secondly, if there is a risk that any CA keys used in available.

The ES satisfies the certificate
chain may be compromised, then it is necessary legal requirements for electronic signatures as
defined in the European Directive on electronic signatures, see Annex C
for further discussion on relationship of this document to additionally the
Directive. It provides basic authentication and integrity protection
and can be created without accessing on-line (timestamping) services.
However, without the addition of a timestamp the validation data by either:

     * timestamping electronic signature
does not protect against the threat that the signer later denies having
created the electronic signature (i.e. does not provide non-repudiation
of its existence).

The ES-T time-stamp should be created close to the time that ES was
created to provide protection against repudiation. At this time all
the validation data as held with needed to complete the ES(ES-C),
       this eXtended validation data may not be available but
what information is called a Type 1 X-Timestamp; or
     * timestamping individual reference data as readily available may be used for complete
       validation.

This form to carry out some of eXtended validation data is called a Type 2 X-Timestamp.

Internet Draft                                   Electronic Signature Formats

NOTE:	The advantages/drawbacks for Type 1 and Type 2 X-Timestamp are
discussed in this document (see clause 4.4.6.)

If all
the above conditions occur then a combination initial checks. For example, only part of the two formats
above revocation
information may be used. This form of eXtended validation data is called
a X-Long-Timestamped.

Support available for verification at that point in time.
Generally, the extended forms of validation data is optional.

An Electronic Signature (ES) , with ES-C form cannot be created at the additional validation data
forming same time as the ES-X long is illustrated ES,
as it is necessary to allow time for any revocation information to be
captured. Also, if a certificate is found to be temporarily suspended,
it will be necessary to wait until the end of the suspension period.

The signer should only create the ES-C in situations where it was
prepared to wait for a sufficient length of time after creating the ES
form before dispatching the ES-C. This, however, has the advantage that
the verifier can be presented with the complete set of data supporting
the validity of the ES.

Support for ES-C by the verifier is mandated (see clause 6 for
specific conformance requirements).

Internet Draft                             Electronic Signature Formats

An Electronic Signature (ES), with the additional validation data
forming the ES-T and ES-C is illustrated in Figure 2:

+------------------------------------------------------- ES-X Long--+
|+--------------------------------------- EC-C --------+            |
||+---- Elect.Signature (ES)----+            +--------+| +--------+ |
|||+-------+-+-------+-+-------+| +---------+|Complete|| |Complete| |
||||Signa- | |Other 1:

+------------------------------------------------------------ES-C-----+
|+--------------------------------------------ES-T-----+              | |Digital|| |Timestamp||certi-
||+------Elect.Signature (ES)----------+ +------------+| +-----------+|
|||+---------+ +----------+ +---------+| |Timestamp   || |certi-  | |Complete   ||
||||Signature| |
||||ture  Other   | |Signed | |Signa- Digital || |over     ||ficate  || |ficate  | | digital|| |certificate||
||||Policy ID| | |Attri-  Signed  | |ture   || |digital  ||and |Signature|| |signature   || |and        ||
||||         | |
||||ID     | |butes  | |Attributes| |         || |signature||revoc. +------------+| |revocation || |revoc.  |
|||+---------+ +----------+ +---------+|               |
|||+-------+ +-------+ +-------+| +---------+|refs |references || |data    | |
||+-----------------------------+            +--------+| +--------+
||+------------------------------------+               | +-----------+|
|+-----------------------------------------------------+              |
+-------------------------------------------------------------------+
+---------------------------------------------------------------------+

Figure 2: 1: Illustration of an ES ES, ES-T and ES-X long.

An Electronic Signature (ES) , with the additional ES-C

2.6  Extended Forms of Validation Data

The complete validation data
forming the (ES-C) described above may be extended to
form an ES with eXtended Validation Data - validation data (ES-X) to meet following
additional requirements.

Firstly, when the verifier does not has access to,

     * the signer's certificate,
     * all the CA certificates that make up the full certification
       path,
     * all the associated revocation status information, as referenced
       in the ES-C.

then the values of these certificates and revocation information may be
added to the ES-C. This form of extended validation data is called a
X-Long.

Secondly, if there is a risk that any CA keys used in the certificate
chain may be compromised, then it is necessary to additionally
timestamp the validation data by either:

     * timestamping all the validation data as held with the ES(ES-C),
       this eXtended validation data is called a Type 1 X-Timestamp; or
     * timestamping individual reference data as used for complete
       validation.

This form of eXtended validation data is called a Type 2 X-Timestamp.

NOTE:  The advantages/drawbacks for Type 1 and Type 2 X-Timestamp are
discussed in this document (see clause B.4.6.)

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If all the above conditions occur then a combination of the two formats
above may be used. This form of eXtended validation data is called
a X-Long-Timestamped.

Support for the extended forms of validation data is optional.

An Electronic Signature (ES) , with the additional validation data
forming the ES-X long is illustrated in Figure 3:

+---------------------------------------------------------- 2:

+------------------------------------------------------- ES-X 1 -+
|+---------------------------------------- Long--+
|+--------------------------------------- EC-C --------+            |
|| +----
||+---- Elect.Signature (ES)----+            +--------+| +-------+ +--------+ |
|| |+-------+ +-------+ +-------+|
|||+-------+-+-------+-+-------+| +---------+|Complete|| |Complete| |       | |
|| ||Signa-
||||Signa- | |Other  | |Digital|| |Timestamp||certifi-|| | Time- |Timestamp||certi-  || |certi-  | |
|| ||ture
||||ture   | |Signed | |Signa- || |over     ||cate and||     ||ficate  || |ficate  | |
||||Policy | |Attri- | |ture   || |digital  ||and     || |and     | |
||||ID     | |butes  | |       || |signature||revoc.  || |revoc.  | |
|||+-------+ +-------+ +-------+| +---------+|refs    || |data    | |
||+-----------------------------+            +--------+| +--------+ |
|+-----------------------------------------------------+            |
+-------------------------------------------------------------------+

Figure 2: Illustration of an ES and ES-X long.

An Electronic Signature (ES) , with the additional validation data
forming the eXtended Validation Data - Type 1 is illustrated in
Figure 3:

+---------------------------------------------------------- ES-X 1 -+
|+---------------------------------------- EC-C --------+           |
|| +---- Elect.Signature (ES)----+            +--------+| +-------+ |
|| |+-------+ +-------+ +-------+| +---------+|Complete|| |       | |
|| ||Signa- | |Other  | |Digital|| |Timestamp||certifi-|| | Time- | |
|| ||ture   | |Signed | |Signa- || |over     ||cate and|| | stamp | |
|| ||Policy | |Attri- | |ture   || |digital  ||revoc.  || | over  | |
|| ||ID     | |butes  | |       || |signature||refs    || | CES   | |
|| |+-------+ +-------+ +-------+| +---------+|        || |       | |
|| +-----------------------------+            +--------+| +-------+ |
|+------------------------------------------------------+           |
+-------------------------------------------------------------------+

Figure 3: Illustration of ES with ES-X Type 1

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An Electronic Signature (ES) , with the additional validation data
forming the eXtended Validation Data - Type 2 is illustrated in
Figure 4:

+-------------------------------------------------------- ES-X 2 ---+
|+--------------------------------------- EC-C --------+            |
||+---- Elect.Signature (ES)----+            +--------+| +--------+ |
|||+-------+ +-------+ +-------+| +---------+|Complete|| |Times   | |
||||Signa- | |Other  | |Digital|| |Timestamp||certs   || |Stamp   | |
||||ture   | |Signed | |Signa- || |over     ||and     || |over    | |
||||Policy | |Attri- | |ture   || |digital  ||revoc.  || |Complete| |
||||ID     | |butes  | |       || |signature||refs    || |certs   | |
|||+-------+ +-------+ +-------+| +---------+|        || |and     | |
||+-----------------------------+            +--------+| |revoc.  | |
||                                                     | |refs    | |
|+-----------------------------------------------------+ +--------+ |
+-------------------------------------------------------------------+

Figure 4: Illustration of ES with ES-X Type 2

2.7  Archive Validation Data

Before the algorithms, keys and other cryptographic data used at the
time the ES-C was built become weak and the cryptographic functions
become vulnerable, or the certificates supporting previous timestamps
expires, the signed data, the ES-C and any additional information
(ES-X) should be timestamped.  If possible this should use stronger
algorithms (or longer key lengths) than in the original timestamp.

This additional data and timestamp is called Archive Validation Data
(ES-A).  The Timestamping process may be repeated every time the
protection used to timestamp a previous ES-A become weak. An ES-A
may thus bear multiple embedded time stamps.

Support for ES-A is optional.

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An example of an Electronic Signature (ES), with the additional
validation data for the ES-C and ES-X forming the ES-A is illustrated
in Figure 5.

+-------------------------------- ES-A --------- ----------+
|  +-------------------- ES-A -----------------+           |
|  |  +--------- ES-X -------------- +         |           |
|  |  |..............................| +-----+ |  +-----+  |
|  |  |..............................| |Time | |  |Time |  |
|  |  |..............................| |Stamp| |  |Stamp|  |
|  |  |                              | +-----+ |  +-----+  |
|  |  +----------------------------- +         |           |
|  +-------------------------------------------+           |
+----------------------------------------------------------+

Figure 5: Illustration of ES -A

Support for ES-A is optional.

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2.8  Arbitration

The ES-C may be used for arbitration should there be a dispute between
the signer and verifier, provided that:

      * a copy of the signature policy referenced by the signer is
        available;

      * the arbitrator knows where to retrieve the signer's certificate
        (if not already present), all the cross-certificates and the
        required CRLs and/or OCSPs responses referenced in the ES-C;

      * none of the issuing key from the certificate chain have ever
        been compromised;

      * the cryptography used at the time the ES-C was built has not
        been broken at the time the arbitration is performed.

When the first second condition is not met, then the plaintiff must provide
an ES-X Long.

When it is known by some external means that the second third condition is
not met, then the plaintiff must provide an ES-X Timestamped.

When the two previous conditions are not met, the plaintiff must
provide the two above information (i.e. an ES-X Timestamped and Long).

When the last condition is not met, the plaintiff must provide an ES-
A.
ES-A.

It should be noticed that a verifier may need to get two time stamps
at two different instants of time: one soon after the generation of
the ES and one soon after some grace period allowing any entity from
the certification chain to declare a key compromise.

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2.9  Validation Process

The Validation Process validates an electronic signature in accordance
with the requirements of the signature policy. The output status of
the validation process can be:

     * valid;
     * invalid;
...
     * incomplete verification.

A Valid response indicates that the signature has passed verification
and it complies with the signature validation policy.

A signature validation policy is a part of the signature policy which
specifies the technical requirements on the signer in creating a
signature and verifier when validating a signature signature.

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An Invalid response indicates that either the signature format is
incorrect or that the digital signature value fails verification
(e.g. the integrity checks on the digital signature value fails or
any of the certificates on which the digital signature verification
depends is known to be invalid or revoked).

An Incomplete Validation response indicates that the format and
digital signature verifications have not failed but there is
insufficient information to determine if the electronic signature
is valid under the signature policy. This can include situations
where additional information, which does not effect the validity of
the digital signature value, may be available but is invalid.

In the case of Incomplete Validation, it may be possible to request
that the electronic signature be checked again at a later date when
additional validation information might become available. Also, in the
case of incomplete validation, additional information may be made
available to the application or user, thus allowing the application or
user to decide what to do with partially correct electronic signatures.

The validation process may also output validation data :

     * a signature timestamp;
     * the complete validation data;
     * the archive validation data.

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2.10  Example Validation Sequence

As described earlier the signer or verifier may collect all the
additional data that forms the Electronic Signature. Figure 6, and
subsequent description, describes how the validation process may build
up a complete electronic signature over time.

+---------------------------------------- ES-C ----------+
|+----------------------------- ES-T -------+            |
||+--- Elect.Signature (ES) ----+           | +--------+ |
|||+-------+ +-------+ +-------+|+---------+| |Complete| |
||||Signa- | |Other  | |Digital|||Timestamp|| |certifi-| |
||||ture   | |Signed | |Signa- |||over     || |cate and| |
||||Policy | |Attri- | |ture   |||digital  || |revoca- | |
||||ID     | |butes  | |       |||signature|| |tion    | |
|||+-------+ +-------+ +-------+|+---------+| |referen-| |
||+------------\----------------+    ^      | |ces     | |
||              \                    |      | +--------+ |
||               \ 1                /       |      ^     |
|+----------------\----------------/--------+      |     |
+------------------\--------------/-------------- /------+
                    \            /2    ----3-----/
 +----------+        |          /     /
 | Signed   |\       v         /     |
 |User data | \     +--------------------+     +------------+
 +----------+  \--->| Validation Process |---> |- Valid     |
                    +---|--^-------|--^--+ 4   |- Invalid   |
                        |  |       |  |        |- Validation|
                        v  |       v  |        |  Incomplete|
                    +---------+ +--------+     +------------+
                    |Signature| |Trusted |
                    | Policy  | |Service |
                    | Issuer  | |Provider|
                    +---------+ +--------+

Figure 6: Illustration of an ES with Complete validation data (ES-C)

Soon after receiving the electronic signature

Soon after receiving the electronic signature (ES) from the signer (1),
the digital signature value may be checked,  the validation process
must at least add a time-stamp (2), unless the signer has provided one
which is trusted by the verifier. The validation process may also
validate the electronic signature, as required under the identified
signature policy, using additional data (e.g. certificates, CRL, etc.)
provided by trusted service providers. If the validation process is not
complete then the output from this stage is the ES-T.

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When all the additional data (e.g. the complete certificate and
revocation information) necessary to validate the electronic signature
first becomes available, then the validation process:

     * obtains all the necessary additional certificate and revocation
       status information;

     * completes all the validation checks on the ES, using the
       complete certificate and revocation information  (if a timestamp
       is not already present, this may be added at the same stage
       combining ES-T and ES-C process);

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     * records the complete certificate and revocation references (3);

     * indicates the validity status to the user (4).

+---------------------------------------- ES-C ----------+
|+----------------------------- ES-T -------+            |
||+--- Elect.Signature (ES) ----+           | +--------+ |
|||+-------+ +-------+ +-------+|+---------+| |Complete| |
||||Signa- | |Other  | |Digital|||Timestamp|| |certifi-| |
||||ture   | |Signed | |Signa- |||over     || |cate and| |
||||Policy | |Attri- | |ture   |||digital  || |revoca- | |
||||ID     | |butes  | |       |||signature|| |tion    | |
|||+-------+ +-------+ +-------+|+---------+| |referen-| |
||+------------\----------------+    ^      | |ces     | |
||              \                    |      | +--------+ |
||               \ 1                /       |      ^     |
|+----------------\----------------/--------+      |     |
+------------------\--------------/-------------- /------+
                    \            /2    ----3-----/
 +----------+        |          /     /
 | Signed   |\       v         /     |
 |User data | \     +--------------------+     +------------+
 +----------+  \--->| Validation Process |---> |- Valid     |
                    +---|--^-------|--^--+ 4   |- Invalid   |
                        |  |       |  |        |- Validation|
                        v  |       v  |        |  Incomplete|
                    +---------+ +--------+     +------------+
                    |Signature| |Trusted |
                    | Policy  | |Service |
                    | Issuer  | |Provider|
                    +---------+ +--------+

Figure 6: Illustration of an ES with Complete validation data (ES-C)

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At the same time as the validation process creates the ES-C, the
validation process may provide and/or record the values of certificates
and revocation status information used in ES-C, called the ES-X Long
(5). This is illustrated in figure 7:

+---------------------------------------------------- ES-X ---------+
|+--------------------------------------- ES-C --------+ +--------+ |
||+--- Elect.Signature (ES) ----+           +--------+ | |Complete| |
|||+-------+ +-------+ +-------+|+---------+|Complete| | |certifi-| |
||||Signa- | |Other  | |Digital|||Timestamp||certifi-| | |cate    | |
||||ture   | |Signed | |Signa- |||over     ||cate and| | |and     | |
||||Policy | |Attri- | |ture   |||digital  ||revoca- | | |revoca- | |
||||ID     | |butes  | |       |||signature||tion    | | |tion    | |
|||+-------+ +---|---+ +-------+|+---------+|referen-| | |Data    | |
||+--------------\--------------+    ^      |ces     | | +--------+ |
||                \                  |      +--------+ |      ^     |
||                 \ 1             2/          ^       |      |     |
|+------------------\--------------/-----------|-------+     /      |
+--------------------\------------/-----------/-------------/-------+
                      \          /    ---3---/             /
 +----------+          |        /    /   -----------5-----/
 | Signed   |\         v       |     |  /
 |User data | \     +--------------------+     +-----------+
 +----------+  \--->| Validation Process |---> | - Valid   |
                    +---|--^-------|--^--+ 4   | - Invalid |
                        |  |       |  |        +-----------+
                        v  |       v  |
                    +---------+ +--------+
                    |Signature| |Trusted |
                    | Policy  | |Service |
                    | Issuer  | |Provider|
                    +---------+ +--------+

Figure 7: Illustration ES with eXtended validation data (Long)

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When the validation process creates the ES-C it may also create
extended forms of validation data. A first alternative is to timestamp
all data forming the Type 1 X-Timestamp (6). This is illustrated in
figure 8:

+---------------------------------------------------- ES-X -------+
|+--------------------------------------- ES-C --------+ +------+ |
||+--- Elect.Signature (ES) ----+           +--------+ | |Time- | |
|||+-------+ +-------+ +-------+|+---------+|Complete| | |stamp | |
||||Signa- | |Other  | |Digital|||Timestamp||certifi-| | |over  | |
||||ture   | |Signed | |Signa- |||over     ||cate and| | |CES   | |
||||Policy | |Attri- | |ture   |||digital  ||revoca- | | +------+ |
||||ID     | |butes  | |       |||signature||tion    | |     ^    |
|||+-------+ +--|----+ +-------+|+---------+|referen-| |     |    |
||+-------------|---------------+     ^     |ces     | |     |    |
||              |                     |     +--------+ |     |    |
||               \ 1                 2/        ^       |     |    |
|+----------------\------------------/---------|-------+     |    |
+------------------\----------------/----------/-------------/----+
                    \              /   ----3--/             /
 +----------+        |            /   /  --------------6---/
 | Signed   |\       v           |   |  /
 |User data | \     +--------------------+     +-----------+
 +----------+  \--->| Validation Process |---> | - Valid   |
                    +---|--^-------|--^--+ 4   | - Invalid |
                        |  |       |  |        +-----------+
                        v  |       v  |
                    +---------+ +--------+
                    |Signature| |Trusted |
                    | Policy  | |Service |
                    | Issuer  | |Provider|
                    +---------+ +--------+

Figure 8: Illustration of ES with eXtended validation data - Type 1 X-
Timestamp

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Another alternative is to timestamp the certificate and revocation
information references used to validate the electronic signature (but
not the signature) (6'); this is called Type 2 X-Timestamped. This is
illustrated in figure 9:

+---------------------------------------------------- ES-X ----------+
|+--------------------------------------- ES-C --------+ +---------+ |
||+--- Elect.Signature (ES) ----+           +--------+ | |Timestamp| |
|||+-------+ +-------+ +-------+|+---------+|Complete| | |over     | |
||||Signa- | |Other  | |Digital|||Timestamp||certifi-| | |Complete | |
||||ture   | |Signed | |Signa- |||over     ||cate and| | |Certifi- | |
||||Policy | |Attri- | |ture   |||digital  ||revoc.  | | |cate and | |
||||ID     | |butes  | |       |||signature||refs    | | |revoc.   | |
|||+-------+ +---^---+ +-------+|+----^----++---^----+ | |refs     | |
||+--------------\--------------+     |         |      | +---------+ |
|+----------------\------------------/----------|------+      ^      |
+----------------1-\----------------/----------/--------------|------+
                    \              /  -----3--/               |
 +----------+        |           2/  /   --------------6'-----/
 | Signed   |\       v           |  |   /
 |User data | \     +--------------------+     +-----------+
 +----------+  \--->| Validation Process |---> | - Valid   |
                    +---|--^-------|--^--+ 4   | - Invalid |
                        |  |       |  |        +-----------+
                        v  |       v  |
                    +---------+ +--------+
                    |Signature| |Trusted |
                    | Policy  | |Service |
                    | Issuer  | |Provider|
                    +---------+ +--------+

Figure 9: Illustration of ES with eXtended validation data - Type 2 X-
Timestamp

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Before the algorithms used in any of electronic signatures become or
are likely, to be compromised or rendered vulnerable in the future, it
is necessary to timestamp the entire electronic signature, including
all the values of the validation and user data as an ES with Archive
validation data (ES-A)

  An ES-A is illustrated in figure 10:

-------------------------------------------- ES-A --------------------+
----------------------------------------------------------------+     |
+------------------------------- EC-C --------++-----+          |     |
|                                             ||Time-|          |     |
|+-- Elect.Signature (ES) -+        +--------+||stamp|  +-------+     |
||+------++-------++-------|+------+|Complete|||over |  Complete|     |
|||Signa-||Other  ||Digital||Time- ||certifi-|||CES  |  |certi- |+----|
|||ture  ||Signed ||Signa- ||stamp ||cate and||+-----+  |ficate |Arch-|
|||Policy||Attri- ||ture   ||over  ||revoca- ||+------+ |and    |ive  |
|||ID    ||butes  ||       ||digit.||tion    |||Time- | |revoca-|Time |
||+------++---|---++-------||signa-||referen-|||stamp-| |tion   |stamp|
|+------------|------------+|ture  ||ces     |||over  | |data   |+----|
|             |             +------++--------+|Complete\+-------+  ^  |
|             |                ^         ^    ||cert.  |        |  |  |
+-------------|----------------|---------|----+|and rev|        |  |  |
               \               |         /     |refs.  |        |  |  |
                \              |        /      +-------+        |  |  |
-----------------\-------------|-------/------------------------+  |  |
+----------+      \            |      /                            /  |
| Signed   |       \2          |3    /     /--------------7-------/   |
|User data |        \          |    |     /                           |
+-------\--+         \         |    |    /                            |
---------\------------|--------|----|---/-----------------------------+
          \           v        |    |   |
          1\        +--------------------+     +-----------+
            \------>| Validation Process |---> | - Valid   |
                    +---|--^-------|--^--+ 4   | - Invalid |
                        |  |       |  |        +-----------+
                        v  |       v  |
                    +---------+ +--------+
                    |Signature| |Trusted |
                    | Policy  | |Service |
                    | Issuer  | |Provider|
                    +---------+ +--------+

Figure 10: Illustration of an ES with Archive validation data (ES-A)

2.11  Additional optional features

This document also defines additional optional features to:

     * indicate a commitment type being made by the signer;
     * indicate the role under which a signature was created;
     * support multiple signatures.

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3. Data structure of an Electronic Signature

This clause uses and builds upon the Crypographic Cryptographic Message Syntax
(CMS), as defined in RFC 2630, REF [CMS] , 2630 [CMS], and Enhanced Security Services
(ESS), as defined in RFC 2634 [10], REF [ESS] . [ESS]. The overall structure
of Electronic Signature is as defined in [CMS]. The Electronic
Signature (ES) uses attributes defined in [CMS], [ESS] and
this document. This document defines in full the ES attributes which it
uses and are not defined elsewhere.

The mandated set of attributes and the digital signature value is
defined as the minimum Electronic Signature (ES) required by this
document. A signature policy MAY mandate other signed attributes are to be
present.

3.1  General Syntax

The general syntax of the ES is as defined in [CMS].

3.2  Data Content Type

The data content type of the ES is as defined in [CMS].

The data content type is intended to refer to arbitrary octet strings,
such as ASCII text files; the interpretation is left to the
application.  Such strings need not have any internal structure
(although they could have their own ASN.1 definition or other
structure).

3.3  Signed-data Content Type

The Signed-data content type of the ES is as defined in [CMS].

The signed-data content type consists of a content of any type and zero
or more signature values. Any number of signers in parallel can sign
any type of content. The typical application of the signed-data content
type represents one signer's digital signature on content of the data
content type.

To make sure that the verifier uses the right signers key, certificate, this
document mandates that the hash of the signers certificate is always
included in the Signing Certificate signed attribute.

3.4  SignedData Type

The syntax of the SignedData type of the ES is as defined in [CMS].

The fields of type SignedData have the meanings defined [CMS] except
that:

     * version is the syntax version number. The value of version must
       be 3.

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     * The identification of signer's certificate used to create the
       signature is always signed. The validation policy may specify
       requirements for the presence of certain certificates. present as a signed attribute.

     * The degenerate case where there are no signers is not valid in
       this document.

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3.5  EncapsulatedContentInfo Type

The syntax of the EncapsulatedContentInfo a type of the ES is as
defined in [CMS].

For the purpose of long term validation as defined by this document, it
is advisable that either the eContent is present, or the data which is
signed is archived in such as way as to preserve the any data encoding.
It is important that the OCTET STRING used to generate the signature
remains the same every time either the verifier or an arbitrator
validates the signature.

The degenerate case where there are no signers is not valid in this
document.

3.6  SignerInfo Type

The syntax of the SignerInfo a type of the ES is as defined in [CMS].

Per-signer information is represented in the type SignerInfo. In the
case of multiple independent signatures, there is an instance
of this field for each signer.

The fields of type SignerInfo have the meanings defined in [CMS} [CMS]
except
that: that signedAttributes must, as a minimum, contain the following
attributes:

* ContentType as defined in clause 3.7.1.
* MessageDigest as defined in clause 3.7.2.
* SigningTime as defined in clause 3.7.3.
* SigningCertificate as defined in clause 3.8.1.
* SignaturePolicyId as defined in clause 3.9.1.

3.6.1  Message Digest Calculation Process

The message digest calculation process is as defined in [CMS].

3.6.2  Message Signature Generation Process

The input to the digital signature generation process is as defined in
[CMS].

3.6.3  Message Signature Verification Process

The procedures for CMS signed data validation are as defined in
[CMS] and enhanced in this document.

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The input to the signature verification process includes the signer's
public key verified as correct using either the ESS Signing
Certificate attribute or the Other Signing Certificate attribute.

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3.7  CMS Imported Mandatory Present Attributes

The following attributes MUST be present with the signed-data defined
by this document. The attributes are defined in [CMS].

3.7.1  Content Type

The syntax of the content-type attribute type of the ES is as defined
in [CMS].

3.7.2  Message Digest

The syntax of the message-digest attribute type of the ES is as defined
in [CMS].

3.7.3  Signing Time

The syntax of the message-digest attribute type of the ES is as defined
in [CMS]and [CMS] and further qualified by this document.

The signing-time attribute type specifies the time at which the signer
claims to have performed the signing process.

This present document recommends the use of GeneralizedTime.

3.8  Alternative Signing Certificate Attributes

One, and only one, of the following two alternative attributes MUST be
present with the signed-data defined by this document to identify the
signing certificate. Both attributes include an identifier and a hash
of the signing certificate. The first, which is adopted in existing
standards, may be only used if with the SHA-1 hashing algorithm. The
other
hall shall be used for when other hashing algorithms are to be supported.

The signing certificate attribute is designed to prevent the simple
substitution and re-issue attacks, and to allow for a restricted set of
authorization certificates to be used in verifying a signature.

3.8.1  ESS Signing Certificate Attribute Definition

The syntax of the signing certificate attribute type of the ES is as
defined in [ESS], and further qualified and profile in this document.

The ESS signing certificate attribute must be a signed attribute.

This document mandates the presence of this attribute as a signed CMS
attribute, and the sequence must not be empty. The certificate used to
verify the signature must be identified in the sequence, the Signature
Validation Policy may mandate other certificates certificate references to be
present, that may include all the certificates up to the point of

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trust. The encoding of the ESSCertID for this certificate must include
the issuerSerial field.

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The issuerAndSerialNumber present in the SignerInfo must be
consistent with issuerSerial field. The certificate identified must be
used during the signature verification process. If the hash of the
certificate does not match the certificate used to verify the
signature, the signature must be considered invalid.

The sequence of policy information field is not used in this document.

NOTE: Where an attribute certificate is used by the signer to associate
a role, or other attributes of the signer, with the electronic
signature this is placed in the Signer Attribute attribute as defined
in clause 3.12.3.

3.8.2  Other Signing Certificate Attribute Definition

The following attribute is identical to the ESS SigningCertificate
defined above except that this attribute can be used with hashing
algorithms other than SHA-1.

This attribute must be used in the same manner as defined above for
the ESS SigningCertificate attribute.

The following object identifier identifies the signing certificate
attribute:

id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 19 }

The signing certificate attribute value has the ASN.1 syntax
OtherSigningCertificate

OtherSigningCertificate ::=  SEQUENCE {
    certs        SEQUENCE OF OtherCertID,
    policies     SEQUENCE OF PolicyInformation OPTIONAL
                 -- NOT USED IN THIS DOCUMENT
}

OtherCertID ::= SEQUENCE {
     otherCertHash            OtherHash,
     issuerSerial             IssuerSerial OPTIONAL
}

OtherHash ::= CHOICE {
    sha1Hash OtherHashValue,  -- This contains a SHA-1 hash
    otherHash OtherHashAlgAndValue} OtherHashAlgAndValue
}

OtherHashValue ::= OCTET STRING

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OtherHashAlgAndValue ::= SEQUENCE {
  hashAlgorithm  AlgorithmIdentifier,
  hashValue      OtherHashValue
}

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3.9  Additional Mandatory Attributes

3.9.1  Signature policy Identifier

This document mandates that a reference to the signature policy, which
defines the rules for creation and validation of an electronic
signature, is included as a signed attribute with every signature. The
signature policy identifier must be a signed attribute.

The following object identifier identifies the signature policy
identifier attribute:

id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 15 }

Signature-policy-identifier attribute values have ASN.1 type
SignaturePolicyIdentifier.

SignaturePolicyIdentifier ::= SEQUENCE {
        sigPolicyIdentifier   SigPolicyId,
        sigPolicyHash         SigPolicyHash,
        sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                              SigPolicyQualifierInfo OPTIONAL}      OPTIONAL
}

The sigPolicyIdentifier field contains an object-identifier which
uniquely identifies a specific version of the signature policy. The
syntax of this field is as follows:

   SigPolicyId ::= OBJECT IDENTIFIER

The sigPolicyHash field contains the identifier of the hash algorithm
and the hash of the value of the signature policy.

If the signature policy is defined using ASN.1 (see 6.1) a computer processable
notation like ASN.1, then the hash is calculated on the value without
the outer type and length fields and the hashing algorithm must be as
specified in the field signPolicyHshAlg.

If the signature policy is defined using another structure, the type of
structure and the hashing algorithm must be either specified as part
of the signature policy, or indicated using a signature policy
qualifier.

   SigPolicyHash ::= ETSIHashAlgAndValue

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A signature policy identifier may be qualified with other information
about the qualifier. The semantics and syntax of the qualifier is as
associated with the object-identifier in the sigPolicyQualifierId
field. The general syntax of this qualifier is as follows:

   SigPolicyQualifierInfo ::= SEQUENCE {
        sigPolicyQualifierId  SigPolicyQualifierId,
        sigQualifier          ANY DEFINED BY sigPolicyQualifierId
}

This document specifies the following qualifiers:

    * spuri: This contains the web URI or URL reference to the
      signature policy

    * spUserNotice: This contains a user notice which should be
      displayed whenever the signature is validated.

-- sigpolicyQualifierIds defined in this document

SigPolicyQualifierId ::=  OBJECT IDENTIFIER

    id-spq-ets-uri OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 1 }

   SPuri ::= IA5String

    id-spq-ets-unotice OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 2 }

   SPUserNotice ::= SEQUENCE {
        noticeRef        NoticeReference OPTIONAL,
        explicitText     DisplayText OPTIONAL} OPTIONAL
}

   NoticeReference ::= SEQUENCE {
        organization     DisplayText,
        noticeNumbers    SEQUENCE OF INTEGER
}

   DisplayText ::= CHOICE {
        visibleString    VisibleString  (SIZE (1..200)),
        bmpString        BMPString      (SIZE (1..200)),
        utf8String       UTF8String     (SIZE (1..200))
}

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3.10  CMS Imported Optional Attributes

The following attributes MAY be present with the signed-data defined by
this document. The attributes are defined in ref [CMS] and are imported

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into this specification and were appropriate qualified and profiling by
this document.

3.10.1  Countersignature

The syntax of the countersignature attribute type of the ES is as
defined in [CMS]. The countersignature attribute must be an unsigned attribute
attribute.

3.11  ESS Imported Optional Attributes

The following attributes MAY be present with the signed-data defined by
this document. The attributes are defined in ref [ESS] and are imported
into this specification and were appropriate qualified and profiling
by this document.

3.11.1	Signed Content Reference Attribute

The content reference attribute is a link from one SignedData to
another. It may be used to link a reply to the original message to
which it refers, or to incorporate by reference one SignedData into
another.

The content reference attribute MUST be used as defined in [ESS].  The
content reference MUST be a signed attribute.

The syntax of the content reference attribute type of the ES is as
defined in [ESS].

3.11.2  Content Identifier Attribute

The content identifier attribute provides an identifier for the signed
content for use when reference may be later required to that content,
for example in the content reference attribute in other signed data
sent later.

The content identifier must be a signed attribute.

The syntax of the content identifier attribute type of the ES is as
defined in [ESS].

The minimal signedContentIdentifier should contain a concatenation of
user-specific identification information (such as a user name or public
keying material identification information), a GeneralizedTime string,
and a random number.

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3.12   Additional Optional Attributes

3.12.1  Commitment Type Indication Attribute

There may be situation were a signer wants to explicitly indicate to a
verifier that by signing the data, it illustrates a type of commitment
on behalf of the signer. The commitmentTypeIndication attribute conveys
such information.

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The commitmentTypeIndication attribute must be a signed attribute attribute.

The commitment type may be:

    * defined as part of the signature policy, in which case the
      commitment type has precise semantics that is defined as part of
      the signature policy.

    * be a registered type, in which case the commitment type has
      precise semantics defined by registration, under the rules of the
      registration authority. Such a registration authority may be a
      trading association or a legislative authority.

The signature policy specifies a set of attributes that it
"recognizes". This "recognized" set includes all those commitment types
defined as part of the signature policy as well as any externally
defined commitment types that the policy may choose to recognize. Only
recognized commitment types are allowed in this field.

The following object identifier identifies the commitment type
indication attribute:

id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

Commitment-Type-Indication attribute values have ASN.1 type
CommitmentTypeIndication.

CommitmentTypeIndication ::= SEQUENCE {
   commitmentTypeId            CommitmentTypeIdentifier,
   commitmentTypeQualifier     SEQUENCE SIZE (1..MAX) OF
                               CommitmentTypeQualifier
OPTIONAL}      OPTIONAL
}

CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

CommitmentTypeQualifier ::= SEQUENCE {
    commitmentTypeIdentifier   CommitmentTypeIdentifier,
    qualifier                  ANY DEFINED BY
                               commitmentTypeIdentifier
}

The use of any qualifiers to the commitment type is outside the scope
of this document.

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The following generic commitment types are defined in this document:

       id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= { iso(1) member-
       body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
       cti(6) 1}

       id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1) member-
       body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
       cti(6) 2}

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       id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::= { iso(1)
       member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
       smime(16) cti(6) 3}

       id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1) member-
       body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
       cti(6) 4}

       id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::= { iso(1)
       member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
       smime(16) cti(6) 5}

       id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::= { iso(1)
       member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
       smime(16) cti(6) 6}

These generic commitment types have the following meaning:

Proof of origin indicates that the signer recognizes to have created,
approved and sent the message.

Proof of receipt indicates that signer recognizes to have received the
content of the message.

Proof of delivery indicates that the TSP providing that indication has
delivered a message in a local store accessible to the recipient of the
message.

Proof of sender indicates that the entity providing that indication has
sent the message (but not necessarily created it).

Proof of approval indicates that the signer has approved the content of
the message.

Proof of creation indicates that the signer has created the message
(but not necessarily approved, nor sent it).

NOTE:	See clause A.3 for a full description of the commitment types
defined above.

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3.12.2  Signer Location attribute

The signer-location attribute is an attribute which specifies a
mnemonic for an address associated with the signer at a particular
geographical (e.g. city) location. The mnemonic is registered in the
country in which the signer is located and is used in the provision of
the Public Telegram Service (according to ITU-T Recommendation F.1
[5?????]).
[PTS]).

The signer-location attribute must be a signed attribute.

The following object identifier identifies the signer-location
attribute:

id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 17}

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Signer-location attribute values have ASN.1 type SignerLocation: SignerLocation.

   SignerLocation ::= SEQUENCE {
        -- at least one of the following must be present
      countryName          [0] DirectoryString      OPTIONAL,
        -- As as used to name a Country in X.500
      localityName         [1] DirectoryString      OPTIONAL,
         -- As as used to name a locality in X.500
      postalAdddress       [2] PostalAddress        OPTIONAL
}

   PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString

3.12.3  Signer Attributes attribute

The signer-attributes attribute is an attribute which specifies
additional attributes of the signer (e.g. role).

It may be either:

     * claimed attributes of the signer; or
     * certified attributes of the signer;
     * the signer-attribute

The signer-attributes attribute must be a signed attribute
       attributes.

The signer-attributes attribute must be a signed attribute. attribute.

The following object identifier identifies the signer-attribute
attribute:

id-aa-ets-signerAttr OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}

signer-attribute attribute values have ASN.1 type SignerAttribute.

   SignerAttribute ::= SEQUENCE OF CHOICE {
      claimedAttributes      [0]  ClaimedAttributes,
      certifiedAttributes    [1]  CertifiedAttributes
}

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ClaimedAttributes ::= SEQUENCE OF Attribute

CertifiedAttributes ::= AttributeCertificate
         -- As as defined in X.509 : see section 10.3

NOTE:  The claimed and certified attribute are imported from ITU-T
Recommendations X.501 [16] and ITU-T Recommendation X.509 : Draft
Amendment on Certificate Extensions, October 1999.

3.12.3

3.12.4  Content Timestamp attribute

The content timestamp attribute is an attribute which is the timestamp
of the signed data content before it is signed.

The content timestamp attribute must be a signed attribute.

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The following object identifier identifies the signer-attribute
attribute:

     id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::= { iso(1)
     member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 20}

Content timestamp attribute values have ASN.1 type ContentTimestamp:
ContentTimestamp::= TimeStampToken

The value of messageImprint field within TimeStampToken must be a hash
of the value of eContent field within encapContentInfo within the
signedData.

For further information and definition of TimeStampToken see ref .. temp
note; need to add the reference to the timestamping RFC. [TSP].

3.13  Support for Multiple Signatures

3.13.1  Independent Signatures

Multiple independent signatures (see clause 55) are supported by independent SignerInfo
from each signer.

Each SignerInfo must include all the attributes required under this
document and must be processed independently by the verifier.

3.13.2  Embedded Signatures

Multiple embedded signatures (see clause B.6) are supported using the counter-signature
unsigned attribute (see clause 10.1). 3.10.1). Each counter signature is
carried in Countersignature held as an unsigned attribute to the
SignerInfo to which the counter-signature is applied.

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4.  Validation Data

This clause specifies the validation data structures which builds on
the electronic signature specified in clause 3. This includes:

    * Timestamp applied to the electronic signature value.

    * Complete validation data which comprises the timestamp of the
      signature value, plus references to all the certificates and
      revocation information used for full validation of the electronic
      signature.

The following optional eXtended forms of validation data are also
defined:

     * X-timestamp: There are two types of timestamp used in extended
       validation data defined by this document.

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        - Type 1 -Timestamp which comprises a timestamp over the ES
          with Complete validation data (ES-C).

        - Type 2 X-Timestamp which comprises of a timestamp over the
          certification path references and the revocation information
          references used to support the ES-C.

               * X-Long : This comprises a  Complete validation data
                 plus the actual values of all the certificates and
                 revocation information used in the ES-C.

               * X-Long-Timestamp: This comprises a Type 1 or Type 2
                 X-Timestamp plus the actual values of all the
                 certificates and revocation information used in the
                 ES-C.

This clause also specifies the data structures used in Archive
validation data:

      * Archive validation data comprises a  Complete validation data,
        the certificate and revocation values (as in a X-Long
        validation data), any other existing X-timestamps, plus the
        Signed User data and an additional archive timestamp over all
        that data. An archive timestamp may be repeatedly applied
        after long periods to maintain validity when electronic
        signature and timestamping algorithms weaken.

The additional data required to create the forms of electronic
signature identified above is carried as unsigned attributes
associated with an individual signature by being placed in the
unsignedAttrs field of SignerInfo (see clause 6????). SignerInfo. Thus all the attributes defined
in clause 9?? 4 are unsigned attributes.

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NOTE:  Where multiple signatures are to be supported, as described in
clause 3.13, each signature has a separate SignerInfo. Thus, each
signature requires its own unsigned attribute values to create ES-T,
ES-C etc.

4.1  Electronic Signature Timestamp

An Electronic Signature with Timestamp is an Electronic Signature for
which part, but not all, of the additional data required for validation
is available (i.e. (e.g. some certificates and revocation information is
available but not all).

The minimum structure Timestamp validation data
is:
     * The is the Signature
Timestamp Attribute as defined in clause 4.1.1 over the ES signature
value.

4.1.1  Signature Timestamp Attribute Definition

The Signature Timestamp attribute is timestamp of the signature value.
It is an unsigned attribute. Several instances of this attribute from
different TSAs may occur with an electronic signature, from different TSAs. signature.

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The Signature Validation Policy specifies, in the
signatureTimestampDelay field of TimestampTrustConditions, an a maximum
acceptable time difference which is allowed between the time indicated
in the signing time attribute and the time indicated by the Signature
Timestamp attribute. If this delay is exceeded then the electronic
signature must be considered as invalid.

The following object identifier identifies the Signature Timestamp
attribute:

     id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::= { iso(1)
     member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
     id-aa(2) 14}

The Signature timestamp attribute value has ASN.1 type
SignatureTimeStampToken:
SignatureTimeStampToken.

SignatureTimeStampToken ::= TimeStampToken

The value of messageImprint field within TimeStampToken must be a hash
of the value of signature field within SignerInfo for the signedData
being timestamped.

For further information and definition of TimeStampToken see [TSP]
Temp note ;ref to timestamping doc required

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4.2  Complete Validation Data

An electronic signature with complete validation data is an Electronic
Signature for which all the additional data required for validation
(i.e. all certificates and revocation information) is available.
Complete validation data (ES-C) build on the electronic signature
Timestamp as defined above.

The minimum structure of a Complete validation data is:

     * the Signature Timestamp Attribute, as defined in clause 4.1.1;
     * Complete Certificate Refs, as defined in clause 4.2.1;
     * Complete Revocation Refs, as defined in clause 4.2.2.

The Complete validation data MAY also include the following additional
information, forming a X-Long validation data, for use if later
validation processes may not have access to this information:

     * Complete Certificate Values, as defined in clause 4.2.3;
     * Complete Revocation Values, as defined in clause 4.2.4.

The  Complete validation data MAY also include one of the following
additional attributes, forming a X-Timestamp validation data, to
provide additional protection against later CA compromise and provide
integrity of the validation data used:

     * ES-C Timestamp, as defined in clause 4.2.5; or
     * Time-Stamped Certificates and CRLs references, as defined in
       clause 4.2.6.

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NOTE 1: As long as the CA's are trusted such that these keys cannot
be compromised or the cryptography used broken, the ES-C provides long
term proof of a valid electronic signature.

A valid electronic signature is an electronic signature which passes
validation according to a signature validation policy.

NOTE 2: The ES-C provides the following important property for long
standing signatures; that is having been found once to be valid, must
continue to be so months or years later. Long after the validity period
of the certificates have expired, or after the user key has been
compromised.

4.2.1  Complete Certificate Refs Attribute Definition

The Complete Certificate Refs attribute is an unsigned attribute. It
references the full set of CA certificates that have been used to
validate a ES with Complete validation data (ES-C) up to (but not
including) the signer's certificate. Only a single instance of this
attribute must occur with an electronic signature.

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Note: The signer's certified is referenced in the signing certificate
attribute (see clause 3.1).

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

The complete certificate refs attribute value has the ASN.1 syntax
CompleteCertificateRefs.

CompleteCertificateRefs ::=  SEQUENCE OF ETSICertID

ETSICertID OTHERCertID

OTHERCertID is defined in clause 3.8.2.

The IssuerSerial that must be present in ETSICertID. OTHERCertID. The certHash
must match the hash of the certificate referenced.

NOTE:  Copies of the certificate values may be held using the
Certificate Values attribute defined in clause 4.3.1.

4.2.2  Complete Revocation Refs Attribute Definition

The Complete Revocation Refs attribute is an unsigned attribute. Only a
single instance of this attribute must occur with an electronic
signature. It references the full set of the CRL or OCSP responses that
have been used in the validation of the signer and CA certificates
used in ES with Complete validation data.

The following object identifier identifies the CompleteRevocationRefs
attribute:

id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 22}

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The complete revocation refs attribute value has the ASN.1 syntax
CompleteRevocationRefs
CompleteRevocationRefs.

CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

CrlOcspRef ::= SEQUENCE {
    crlids           [0] CRLListID        OPTIONAL,
    ocspids          [1] OcspListID       OPTIONAL,
    otherRev         [2] OtherRevRefs     OPTIONAL
}

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CompleteRevocationRefs must contain one CrlOcspRef for the signing
certificate, followed by one for each ETSICertID OTHERCertID in the
CompleteCertificateRefs attribute. the The second and subsequent CrlOcspRef
fields must be in the same order as the ETSICertID OTHERCertID to which they
relate. At least one of CRLListID or OcspListID or OtherRevRefs should
be present for all but the "trusted" CA of the certificate path.

CRLListID ::=  SEQUENCE {
    crls        SEQUENCE OF CrlValidatedID}

CrlValidatedID ::=  SEQUENCE {
     crlHash                   ETSIHash,
     crlIdentifier             CrlIdentifier OPTIONAL}

CrlIdentifier ::= SEQUENCE {
    crlissuer                 Name,
    crlIssuedTime             UTCTime,
    crlNumber                 INTEGER OPTIONAL
                                            }

OcspListID ::=  SEQUENCE {
    ocspResponses        SEQUENCE OF OcspResponsesID}

OcspResponsesID ::=  SEQUENCE {
    ocspIdentifier              OcspIdentifier,
    ocspRepHash                 ETSIHash    OPTIONAL
                                            }

OcspIdentifier ::= SEQUENCE {
     ocspResponderID    ResponderID,
                       -- As in OCSP response data
     producedAt      GeneralizedTime
                       -- As in OCSP response data
                                             }

When creating an crlValidatedID, the crlHash is computed over the
entire DER encoded CRL including the signature. The crlIdentifier would
normally be present unless the CRL can be inferred from other
information.

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The crlIdentifier is to identify the CRL using the issuer name and the
CRL issued time which must correspond to the time "thisUpdate"
contained in the issued CRL. The crlListID attribute is an unsigned
attribute. In the case that the identified CRL is a Delta CRL then
references to the set of CRLs to provide a complete revocation list
must be included.

The OcspIdentifier is to identify the OSCP response using the issuer
name and the time of issue of the OCSP response which must correspond
to the time "producedAt" contained in the issued OCSP response. Since
it may be needed to make the difference between two OCSP responses
received within the same second, then the hash of the response
contained in the OcspResponsesID may be needed to solve the ambiguity.

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NOTE: Copies of the CRL and OCSP responses values may be held using
the Revocation Values attribute defined in clause 4.3.2.

OtherRevRefs ::= SEQUENCE {
   otherRevRefType      OtherRevRefType,
   otherRevRefs         ANY DEFINED BY otherRevRefType
}

OtherRevRefType ::= OBJECT IDENTIFIER

The syntax and semantics of other revocation references is outside the
scope of this document.  The definition of the syntax of the other form
of revocation information is as identified by OtherRevRefType.

4.3  Extended Validation Data

4.3.1  Certificate Values Attribute Definition

The Certificate Values attribute is an unsigned attribute. Only a
single instance of this attribute must occur with an electronic
signature. It holds the values of certificates referenced in the
CompleteCertificateRefs attribute.

Note: If an Attribute Certificate is used, it is not provided in this
structure but must be provided by the signer as a signer-attributes
attribute (see clause 12.3).

The following object identifier identifies the CertificateValues
attribute:

id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

The certificate values attribute value has the ASN.1 syntax
CertificateValues
CertificateValues.

CertificateValues ::=  SEQUENCE OF Certificate

Certificate is defined in clause 10.1 (which is as defined in RFC2459 and ITU-T Recommendation X.509 [1])

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4.3.2  Revocation Values Attribute Definition

The Revocation Values attribute is an unsigned attribute. Only a single
instance of this attribute must occur with an electronic signature. It
holds the values of CRLs and OCSP referenced in the
CompleteRevocationRefs attribute.

The following object identifier identifies the CertificateValues Revocation Values
attribute:

    id-aa-ets-revocationValues OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 24}

The revocation values attribute value has the ASN.1 syntax
RevocationValues
RevocationValues.

RevocationValues ::=  SEQUENCE {
   crlVals           [0] SEQUENCE OF CertificateList     OPTIONAL,
   ocspVals          [1] SEQUENCE OF BasicOCSPResponse   OPTIONAL,
   otherRevVals      [2] OtherRevVals
}

OtherRevVals ::= SEQUENCE {
   otherRevValType       OtherRevValType,
   otherRevVals          ANY DEFINED BY otherRevValType
}

OtherRevValType ::= OBJECT IDENTIFIER

The syntax and semantics of the other revocation values is outside the
scope of this document. The definition of the syntax of the other form
of revocation information is as identified by OtherRevRefType.

CertificateList is defined in clause 10.2 (which as defined RFC 2459 [RFC2459] and in ITU-T
Recommendation X.509 [1]). [X509]).

BasicOCSPResponse is defined in clause 10.3 (which as defined in ??? RFC 2560 [8] ???). [OCSP].

4.3.3  ES-C Timestamp Attribute Definition

This attribute is used for the Type 1 X-Timestamped validation data.
The ES-C Timestamp attribute is an unsigned attribute. It is timestamp
of a hash of the electronic signature and the complete validation data
(ES-C). It is a special purpose TimeStampToken Attribute which
timestamps the ES-C. Several instances instance of this attribute may
occur with an electronic signature from different TSAs.

The following object identifier identifies the ES-C Timestamp
attribute:

    id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1) member-body(2) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 25}

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The ES-C timestamp attribute value has the ASN.1 syntax
ESCTimeStampToken.

ESCTimeStampToken ::= TimeStampToken

The value of messageImprint field within TimeStampToken must be a hash
of the concatenated values (without the type or length encoding for
that value) of the following data objects as present in the ES with
Complete validation data (ES-C):

     * signature field within SignerInfo;

     * SignatureTimeStampToken attribute;

     * CompleteCertificateRefs attribute;

     * CompleteRevocationRefs attribute.

For further information and definition of the Time Stamp Token see
clause
[TSP].
Temp note ;ref to timestamping doc required.

4.3.4  Time-Stamped Certificates and CRLs Attribute Definition

This attribute is used for the Type 2 X-Timestamp validation data. A
TimestampedCertsCRLsRef attribute is an unsigned attribute. It is a
list of referenced certificates and OCSP responses/CRLs which are been
timestamped to protect against certain CA compromises. Its syntax is as
follows:

The following object identifier identifies the TimestampedCertsCRLsRef
attribute:

    id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 26}

The attribute value has the ASN.1 syntax TimestampedCertsCRLs.

TimestampedCertsCRLs ::= TimeStampToken

The value of messageImprint field within TimeStampToken must be a hash
of the concatenated values (without the type or length encoding for
that value) of the following data objects as present in the ES with
Complete validation data (ES-C):

* CompleteCertificateRefs attribute;
* CompleteRevocationRefs attribute.

Internet Draft                                   Electronic Signature Formats

4.4  Archive Validation Data

Where an electronic signature is required to last for a very long time,
and a the timestamp on an electronic signature is in danger of being
invalidated due to algorithm weakness or limits in the validity period
of the TSA certificate, then it may be required to timestamp the

Internet Draft                             Electronic Signature Formats

electronic signature several times. When this is required an archive
timestamp attribute may be required. This timestamp may be repeatedly
applied over a period of time.

4.4.1  Archive Timestamp Attribute Definition

The Archive Timestamp attribute is timestamp of the user data and the
entire electronic signature. If the Certificate values and Revocation
Values attributes are not present these attributes must be added to
the electronic signature prior to the timestamp. The Archive Timestamp
attribute is an unsigned attribute. Several instances of this attribute
may occur with on electronic signature both over time and from
different TSAs.

The following object identifier identifies the Nested Archive Timestamp
attribute:

    id-aa-ets-archiveTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 27}

Archive timestamp attribute values have the ASN.1 syntax
ArchiveTimeStampToken

ArchiveTimeStampToken ::= TimeStampToken

The value of messageImprint field within TimeStampToken must be a hash
of the concatenated values (without the type or length encoding for
that value) of the following data objects as present in the electronic
signature:

     * encapContentInfo eContent OCTET STRING;
     * signedAttributes;
     * signature field within SignerInfo;
     * SignatureTimeStampToken attribute;
     * CompleteCertificateRefs attribute;
     * CompleteRevocationData attribute;
     * CertificateValues attribute
       (If not already present this information must be included in
       the ES-A);
     * RevocationValues attribute
       (If not already present this information must be included in
       the ES-A);
     * ESCTimeStampToken attribute if present;
     * TimestampedCertsCRLs attribute if present;
     * any previous ArchiveTimeStampToken attributes.

Internet Draft                                   Electronic Signature Formats

For further information and definition of TimeStampToken see see [TSP]
Temp note ;ref to timestamping doc required

The timestamp should be created using stronger algorithms (or longer
key lengths) than in the original electronic signatures and weak
algorithm (key length) timestamps .

5. signatures.

Internet Draft                             Electronic Signature Policy Specification

This document mandates that:
     * an Formats

5.  Security considerations

5.1  Protection of Private Key

The security of the electronic signature must be processed by the signer and
       verifier mechanism defined in accordance with the signature policy as identified
       by this
document depends on the signature policy attribute (see clause 4.1);
     * privacy of the signature policy signer's private key.
Implementations must take steps to ensure that private keys cannot be identifiable by an Object
       Identifier;
     * there must exist a specification
compromised.

5.2  Choice of Algorithms

Implementers should be aware that cryptographic algorithms become
weaker with time. As new cryptoanalysis techniques are developed and
computing performance improves, the signature policy;
     * for work factor to break a given signature policy there must particular
cryptographic algorithm will reduce. Therefore, cryptographic algorithm
implementations should be one definitive form
       of modular allowing new algorithms to be readily
inserted. That is, implementers should be prepared for the specification which has a unique binary encoding;
     * set of
mandatory to implement algorithms to change over time.

6.  Conformance Requirements

This document only defines conformance requirements up to a hash ES with
Complete validation data (ES-C). This means that none of the definitive specification, using an agreed
       algorithm, must be provided by the signer and checked by the
       verifier (see clause 4.1).

A signature policy specification includes general information about the
policy, the validation policy rules extended
and other signature policy
information.

Clause 6 describes the kind archive forms of information Electronic Signature (ES-X, ES-A) need to be included in a
signature policy.

The current
implemented to get conformance to this standard.

This document does not mandate the form mandates support for elements of the signature policy
specification. The policy.

6.1  Signer

A system supporting signers according to this document must, at a
minimum, support generation of an electronic signature policy may be specified either: consisting of
the following components:

      * The general CMS syntax and content type as defined in a free form document for human interpretation; or RFC 2630
        (see clauses 4.1 and 4.2).

      * CMS SignedData as defined in a structured form using an agreed syntax RFC 2630 with version set to 3
        and encoding.

This document defines an ASN.1 based syntax that may at least one SignerInfo must be used to define
a structured signature policy.

5.1	Overall ASN.1 Structure present
        (see clauses 4.3, 4.4, 4.5, 4.6).

      * The overall structure of a signature policy following CMS Attributes as defined using ASN.1 is
given in this clause. Use of this ASN.1 structure is optional. RFC 2630 :

             - ContentType; This ASN.1 syntax is encoded using the Distinguished Encoding Rules
(DER).

Internet Draft                                   Electronic Signature Formats

In this structure the policy information is preceded by an identifier
for the hashing algorithm used to protect the signature policy and
followed by the hash value which must always be re-calculated and checked
whenever the policy is passed between the issuer and signer/verifier.
The hash is calculated without the outer type and length fields.

SignaturePolicy ::= SEQUENCE {
	signPolicyHashAlg      AlgorithmIdentifier,
	signPolicyInfo         SignPolicyInfo,
	signPolicyHash         SignPolicyHash     OPTIONAL }

SignPolicyHash ::= OCTET STRING

SignPolicyInfo ::= SEQUENCE {
	signPolicyIdentifier            SignPolicyId,
	dateOfIssue                     GeneralizedTime,
	policyIssuerName                PolicyIssuerName,
	fieldOfApplication              FieldOfApplication,
	signatureValidationPolicy       SignatureValidationPolicy,
	signPolExtensions	        SignPolExtensions
	                                           OPTIONAL
	                                                 }

SignPolicyId ::= OBJECT IDENTIFIER

The policyIssuerName field identifies the policy issuer in one or more
of the general name forms.

PolicyIssuerName ::= GeneralNames

The fieldofApplication is a description of the expected application of
this policy.

FieldOfApplication ::= DirectoryString

The signature validation policy rules are fully processable to allow
the validation of electronic signatures issued under that signature
policy. They are described in the rest of this clause.

5.2	Signature Validation Policy

The signature validation policy defines for the signer which data
elements present
               (see clause 3.7.1);

             - MessageDigest; This must always be present in the electronic signature he provides and
for the verifier which data elements
               (see clause 3.7.2);

             - SigningTime; This must always be present under that
signature policy for an electronic signature to be potentially valid.
               (see clause 3.7.3).

Internet Draft                             Electronic Signature Formats

      * The signature validation policy is described following ESS Attributes as follows:

SignatureValidationPolicy ::= SEQUENCE {
	signingPeriod          SigningPeriod,
	commonRules            CommonRules,
	commitmentRules        CommitmentRules,
	signPolExtensions      SignPolExtensions	OPTIONAL
                                                }

The signingPeriod identifies the date and time before which the
signature policy should not defined in RFC 2634 :

              - SigningCertificate: This must be used for creating signatures, set as defined
                in clauses 3.8.1 and an
optional date after which it should not be used for creating
signatures.

SigningPeriod ::= SEQUENCE {
	notBefore	GeneralizedTime,
	notAfter	GeneralizedTime OPTIONAL }

5.3	Common Rules 3.8.2.

      * The CommonRules define rules that are common to all commitment types.
These rules are following Attributes as defined in terms of trust conditions for certificates,
timestamps and attributes, along with any constraints on attributes
that may clause 3.9:
             - SignaturePolicyIdentifier; This must always be included present.

      * Public Key Certificates as defined in the electronic signature.

CommonRules  ::= SEQUENCE {
	signerAndVeriferRules          [0]  SignerAndVerifierRules
                                                        OPTIONAL,
	signingCertTrustCondition ITU-T Recommendation
        X.509 [1]  SigningCertTrustCondition
                                                        OPTIONAL,
	timeStampTrustCondition        [2]  TimestampTrustCondition
                                                        OPTIONAL,
	attributeTrustCondition        [3]  AttributeTrustCondition
                                                        OPTIONAL,
	algorithmConstraintSet         [4]  AlgorithmConstraintSet
                                                        OPTIONAL,
	signPolExtensions	       [5]  SignPolExtensions
                                                         OPTIONAL
                                                       }

If a field is present in CommonRules then the equivalent field must
not be present and profiled in any of the CommitmentRules RFC 2459 [7] (see below). If any clause 9.1).

6.2  Verifier

A system supporting verifiers according to this document must, at a
minimum, support:

       * Verification of the
following fields are not present mandated components of an electronic
         signature, as defined in CommonRules then it must be
present clause 14.1.

       * Signature Timestamp attribute, as defined in each CommitmentRule: clause 4.1.1.

       * Complete Certificate Refs attribute, as defined in
         clause 4.2.1.

       * signerAndVeriferRules; Complete Revocation Refs Attribute, as defined in
         clause  4.2.2.

       * signingCertTrustCondition; Public Key Certificates, as defined in ITU-T
         Recommendation X.509 and profiled in RFC 2459.

       * timeStampTrustCondition. Either of:

             - Certificate Revocation Lists. as defined in ITU-T
               Recommendation X.509 [1] and profiled in RFC 2459 [7];
               or

             - On-line Certificate Status Protocol responses, as
               defined in RFC 2560.

Internet Draft                             Electronic Signature Formats

5.4	Commitment Rules

The CommitmentRules consists of the validation rules which apply to
given commitment types:

CommitmentRules ::= SEQUENCE OF CommitmentRule

The CommitmentRule

7. References

[RFC2119] Bradner, S., "Key words for given commitment types are defined use in terms of
trust conditions RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[ESS] P. Hoffman, "Enhanced Security Services for certificates, timestamps S/MIME",

[CMS] R. Housley, "Cryptographic Message Syntax", RFC 2630,
June 1999.

[OCSP] M. Myers, R. Ankney, A. Malpani, S. Galperin, C. Adams.
On-line Status Certificate Protocol, RFC 2560.

[TSP] C. Adams, P. Cain, D. Pinkas, R. Zuccherato. Time Stamp Protocol
(TSP), (under progress). June 2000.

[PTS] Public Telegram Service. ITU-T Recommendation F1. XXXX

[RFC2459] R. Housley, W. Ford, W. Polk, D. Solo, "Internet X.509 Public
Key Infrastructure, Certificate and attributes, along
with any constraints on attributes that may be included in the
electronic signature.

CommitmentRule  ::= SEQUENCE {
	selCommitmentTypes                  SelectedCommitmentTypes,
	signerAndVeriferRules          [0]  SignerAndVerifierRules
                                                          OPTIONAL,
	signingCertTrustCondition      [1]  SigningCertTrustCondition
                                                          OPTIONAL,
	timeStampTrustCondition        [2]  TimestampTrustCondition
                                                          OPTIONAL,
	attributeTrustCondition        [3]  AttributeTrustCondition
                                                          OPTIONAL,
	algorithmConstraintSet         [4]  AlgorithmConstraintSet
                                                          OPTIONAL,
	signPolExtensions	       [5]  SignPolExtensions
                                                          OPTIONAL
                                                       }

SelectedCommitmentTypes ::= SEQUENCE OF CHOICE {
	empty                        NULL,
	recognizedCommitmentType     CommitmentType }

If the SelectedCommitmentTypes indicates "empty" then this rule applied
when a commitment type is not present  (i.e.the type of commitment is
indicated CRL Profile," RFC 2459, January
1999.

[PKCS9] RSA Laboratories, "The Public-Key Cryptography Standards
(PKCS)", RSA Data Security Inc., Redwood City, California, November
1993 Release.

[ISONR] ISO/IEC 10181-5:  Security Frameworks in the semantics of the message). Otherwise, the electronic
signature must contain a commitment type indication that must fit one Open Systems.
Non-Repudiation Framework. April 1997.

[ES201733] ETSI Standard ES 201 733 V1.1.3 (2000-05) Electronic
Signature Formats. Note: copies of ETSI ES 210 733 can be freely
downloaded from the commitments types that are mentioned in CommitmentType.

A specific commitment type identifier must not appear ETSI web site www.etsi.org.

8. Authors' Addresses

This Informational RFC has been produced in more than one
commitment rule.

CommitmentType ::= SEQUENCE {
	identifier			CommitmentTypeIdentifier,
	fieldOfApplication	[0] FieldOfApplication OPTIONAL,
	semantics		[1] DirectoryString OPTIONAL }

The fieldOfApplication and semantics fields define the specific use and
meaning of the commitment within the overall field of application
defined for the policy. ETSI TC-SEC.

ETSI
F-06921 Sophia Antipolis, Cedex - FRANCE
650 Route des Lucioles - Sophia Antipolis
Valbonne - France
Tel: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16
secretariat@etsi.fr
http://www.etsi.org

Internet Draft                             Electronic Signature Formats

5.5	Signer and Verifier Rules

The SignerAndVerifierRules consists of signer rule and verification
rules as defined below:
SignerAndVerifierRules ::= SEQUENCE {
	signerRules      SignerRules,
	verifierRules    VerifierRules }

5.5.1	Signer Rules

Contact Point

Harri Rasilainen
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis, Cedex
FRANCE
harri.rasilainen@etsi.fr

Denis Pinkas
Bull S.A.
12, rue de Paris
B.P. 59
78231 Le Pecq
FRANCE
Denis.Pinkas @bull.net

John Ross
Security & Standards
192 Moulsham Street
Chelmsford, Essex
CM2 0LG
United Kingdom
ross@secstan.com

Nick Pope
Security & Standards
192 Moulsham Street
Chelmsford, Essex
CM2 0LG
United Kingdom
pope@secstan.com

9. Full Copyright Statement

Copyright (C) The signer rules identify:

     * if the eContent is empty Internet Society (2000). All Rights Reserved.
This document and the signature is calculated using
       a hash translations of signed data external it may be copied and furnished to CMS structure.

     * the CMS signed attributes
others, and derivative works that must comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided by that the signer
        under above copyright notice and this policy;

     * the CMS unsigned attribute that must paragraph are
included on all such copies and derivative works. However, this
document itself may not be provided modified in any way, such as by removing
the signer
        under this policy;

     * whether the certificate identifiers from the full certification
       path up copyright notice or references to the trust point must be provided by Internet Society or other
Internet organizations, except as needed for the signer purpose of developing
Internet standards in which case the SigningCertificate attribute;

     * whether a signer's certificate, or all certificates procedures for copyrights defined
in the
       certification path to the trust point Internet Standards process must be provided by the
       signer in the certificates field of SignedData.

SignerRules ::= SEQUENCE {
	externalSignedData         BOOLEAN	OPTIONAL,
		    -- True if signed data is external to CMS structure
			-- False if signed data part of CMS structure
			-- not present if either allowed
	mandatedSignedAttr         CMSAttrs,
                                 -- Mandated CMS signed attributes
	mandatedUnsignedAttr       CMSAttrs,
                                 -- Mandated CMS unsigned attributed
	mandatedCertificateRef     [0] CertRefReq DEFAULT signerOnly,
				 -- Mandated Certificate Reference
	mandatedCertificateInfo    [1] CertInfoReq DEFAULT none,
				 -- Mandated Certificate Info
	signPolExtensions	   [2] SignPolExtensions	OPTIONAL
                                                }

CMSAttrs ::= SEQUENCE OF OBJECT IDENTIFIER

The mandatedSignedAttr field must include the object identifier for
all those signed attributes required by this document as well followed, or as
additional attributes required by this policy. to
translate it into languages other than English.

Internet Draft                             Electronic Signature Formats

The mandatedUnsignedAttr field must include the object identifier for
all those unsigned attributes required by this document as well as
additional attributes required this policy. For example, if a signature
timestamp (see clause 1.1) is required by the signer the object
identifier for this attribute must limited permissions granted above are perpetual and will not be included.

The mandatedCertificateRef identifies whether just
revoked by the signer's
certificate, Internet Society or all its successors or assigns.

This document and the full certificate path must be information contained herein is provided by the
signer.

CertRefReq ::= ENUMERATED {
				signerOnly (1),
           -- Only reference to signer cert mandated
				fullPath (2)

           -- References for full cert path up to a trust point required
					}

The mandatedCertificateInfo field identifies whether on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN
WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Internet Draft                             Electronic Signature Formats

Annex A (normative): ASN.1 Definitions

This annex provides a signer's
certificate, or summary of all certificates in the certification path to the trust
point must be provided by the signer ASN.1 syntax definitions for
new syntax defined in this document.

A.1  Definitions Using X.208 (1988) ASN.1 Syntax

NOTE:  The ASN.1 module defined in clause A.1 has precedence over that
defined in Annex A-2 in the certificates field case of
SignedData.

CertInfoReq ::= ENUMERATED any conflict.

    ETS-ElectronicSignatureFormats-88syntax {
				none (0)	, iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-mod(0) 5}

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

-- No mandatory requirements
				signerOnly (1)	, EXPORTS All -

IMPORTS

-- Only reference to signer cert mandated
				fullPath (2) Crypographic Message Syntax (CMS): RFC 2630

  ContentInfo, ContentType, id-data, id-signedData, SignedData,
  EncapsulatedContentInfo, SignerInfo, id-contentType,
  id-messageDigest, MessageDigest, id-signingTime, SigningTime,
  id-countersignature, Countersignature

  FROM CryptographicMessageSyntax
    { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) modules(0) cms(1) }

-- References for full cert path up to a ESS Defined attributes: RFC 2634
-- trust point mandated (Enhanced Security Services for S/MIME)

  id-aa-signingCertificate, SigningCertificate, IssuerSerial,
  id-aa-contentReference, ContentReference,
  id-aa-contentIdentifier, ContentIdentifier

  FROM ExtendedSecurityServices
     { iso(1) member-body(2) us(840) rsadsi(113549)
       pkcs(1) pkcs-9(9) smime(16) modules(0) ess(2) }

5.5.2	Verifier Rules

The verifier rules identify:
* The CMS unsigned attributes that must be present under this policy

-- Internet X.509 Public Key Infrastructure
-- Certificate and must be added by the verifier if not added by the signer.

VerifierRules ::= SEQUENCE {
		mandatedUnsignedAttr	MandatedUnsignedAttr,
		signPolExtensions		SignPolExtensions  OPTIONAL
		                                                   }

MandatedUnsignedAttr ::=  CMSAttrs
                                   -- Mandated CMS unsigned attributed CRL Profile: RFC 2459

  Certificate, AlgorithmIdentifier, CertificateList, Name,
  GeneralNames, GeneralName, DirectoryString,Attribute,
  AttributeTypeAndValue, AttributeType, AttributeValue,
  PolicyInformation, BMPString, UTF8String

Internet Draft                             Electronic Signature Formats

5.6	Certificate and Revocation Requirement

  FROM PKIX1Explicit88
  {iso(1) identified-organization(3) dod(6) internet(1)
   security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-explicit-
   88(1)}

-- X.509 '97 Authentication Framework

AttributeCertificate

  FROM AuthenticationFramework
  {joint-iso-ccitt ds(5) module(1) authenticationFramework(7) 3}

-- The SigningCertTrustCondition, TimestampTrustCondition and
AttributeTrustCondition (defined in subsequent sub-clauses) make use of
two ASN1 structures which are imported AttributeCertificate is defined below: CertificateTrustTrees and
CertRevReq.

5.6.1	Certificate Requirements

The certificateTrustTrees identifies a set of self signed certificates
for using the trust points used to start (or end) certificate path processing
and X.680 1997
-- ASN.1 Syntax,
-- an equivalent using the initial conditions for certificate path validation as defined
RFC 2459 [7] section 5. This ASN1 structure is 88 ASN.1 syntax may be used.

-- OCSP 2560

BasicOCSPResponse, ResponderID

  FROM OCSP {-- OID not assigned -- }

-- Time Stamp Protocol Internet Draft

TimeStampToken

  FROM PKIXTSP
  {iso(1) identified-organization(3) dod(6) internet(1)
  security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-tsp(13)}

-- S/MIME Object Identifier arcs used to define policy
for validating the signing certificate, the TSA's certificate and
attribute certificates.

CertificateTrustTrees in this document
-- ===================================================

-- S/MIME  OID arc used in this document
-- id-smime OBJECT IDENTIFIER ::=   SEQUENCE OF CertificateTrustPoint

CertificateTrustPoint { iso(1) member-body(2)
--             us(840) rsadsi(113549) pkcs(1) pkcs-9(9) 16 }

-- S/MIME Arcs
-- id-mod  OBJECT IDENTIFIER ::= SEQUENCE {
	trustpoint				Certificate, id-smime 0 }
-- self-signed certificate
	pathLenConstraint	[0] PathLenConstraint   OPTIONAL,
	acceptablePolicySet	[1] AcceptablePolicySet OPTIONAL, modules
-- If not present "any policy"
	nameConstraints		[2] NameConstraints     OPTIONAL,
	policyConstraints	[3] PolicyConstraints   OPTIONAL id-ct   OBJECT IDENTIFIER ::= { id-smime 1 }

The trustPoint field gives the self signed certificate for the CA that
is used as the trust point for the start of certificate path
processing.

The pathLenConstraint field gives the maximum number of CA certificates
that may be in a certification path following the trustpoint. A value
of zero indicates that only the given trustpoint certificate and an
end-entity certificate may be used. If present, the pathLenConstraint
field must be greater than or equal to zero. Where pathLenConstraint
is not present, there is no limit to the allowed length of the
certification path.

PathLenConstraint    ::=   INTEGER (0..MAX)

The acceptablePolicySet field identifies the initial set of certificate
policies, any of which are acceptable under the signature policy.
AcceptablePolicySet
-- content types
-- id-aa   OBJECT IDENTIFIER ::= SEQUENCE OF CertPolicyId

CertPolicyId { id-smime 2 }
-- attributes
-- id-spq  OBJECT IDENTIFIER ::= { id-smime 5 }
-- signature policy qualifier
-- id-cti  OBJECT IDENTIFIER ::= { id-smime 6 }
-- commitment type identifier

Internet Draft                             Electronic Signature Formats

The nameConstraints field indicates a name space within which all
subject names in subsequent certificates in a certification path must
be located. Restrictions may apply to the subject distinguished name or
subject alternative names. Restrictions apply only when the specified
name form is present. If no name

-- Definitions of the type is in the certificate, the
certificate is acceptable.

Restrictions are defined Object Identifier arcs used in terms this document
-- ===========================================================

-- The allocation of permitted or excluded name
subtrees. Any name matching a restriction in OIDs to specific objects are given below with the excludedSubtrees field
is invalid regardless of information appearing in
-- associated ASN.1 syntax definition

-- OID used referencing electronic signature mechanisms based on this
-- standard for use with the ermittedSubtrees.

 NameConstraints IDUP API (see annex D)

id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::= SEQUENCE
  {
           permittedSubtrees       [0]     GeneralSubtrees OPTIONAL,
           excludedSubtrees        [1]     GeneralSubtrees OPTIONAL itu-t(0) identified-organization(4) etsi(0)
     electronic-signature-standard (1733) part1 (1)
         idupMechanism (4)etsiESv1(1) }

      GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree

      GeneralSubtree ::= SEQUENCE {
           base                    GeneralName,
           minimum         [0]     BaseDistance DEFAULT 0,
           maximum         [1]     BaseDistance

-- CMS Attributes Defined in this document
-- =======================================

-- Mandatory Electronic Signature Attributes

-- OtherSigningCertificate

    id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 19 }

OtherSigningCertificate ::=  SEQUENCE {
    certs        SEQUENCE OF OtherCertID,
    policies     SEQUENCE OF PolicyInformation OPTIONAL
                 -- NOT USED IN THIS DOCUMENT
}

      BaseDistance

OtherCertID ::= INTEGER (0..MAX)

The policyConstraints extension constrains path processing in two ways.
It can be used to prohibit policy mapping or require that each
certificate in SEQUENCE {
     otherCertHash            OtherHash,
     issuerSerial             IssuerSerial OPTIONAL
}

OtherHash ::= CHOICE {
    sha1Hash     OtherHashValue,  -- This contains a path contain an acceptable policy identifier.

The policyConstraints field, if present specifies requirement for
explicit indication of the certificate policy and/or the constraints on
policy mapping.

PolicyConstraints SHA-1 hash
    otherHash    OtherHashAlgAndValue
}

OtherHashValue ::= OCTET STRING

OtherHashAlgAndValue ::= SEQUENCE {
        requireExplicitPolicy           [0] SkipCerts
  hashAlgorithm    AlgorithmIdentifier,
  hashValue        OtherHashValue
}

-- Signature Policy Identifier

    id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 15 }

Internet Draft                             Electronic Signature Formats

SignaturePolicyIdentifier ::= SEQUENCE {
        sigPolicyIdentifier   SigPolicyId,
        sigPolicyHash         SigPolicyHash,
        sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                              SigPolicyQualifierInfo OPTIONAL
}

SigPolicyId ::= OBJECT IDENTIFIER

SigPolicyHash ::= ETSIHashAlgAndValue

SigPolicyQualifierInfo ::= SEQUENCE {
        sigPolicyQualifierId  SigPolicyQualifierId,
        sigQualifier          ANY DEFINED BY sigPolicyQualifierId
}

SigPolicyQualifierId ::=
        OBJECT IDENTIFIER

    id-spq-ets-uri OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 1 }

   SPuri ::= IA5String

    id-spq-ets-unotice OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 2 }

   SPUserNotice ::= SEQUENCE {
        noticeRef        NoticeReference   OPTIONAL,
        inhibitPolicyMapping            [1] SkipCerts
        explicitText     DisplayText       OPTIONAL
}

SkipCerts

   NoticeReference ::= SEQUENCE {
        organization     DisplayText,
        noticeNumbers    SEQUENCE OF INTEGER (0..MAX)

If the inhibitPolicyMapping field is present, the value indicates the
number of additional certificates that may appear in the path
(including the trustpoint's self certificate) before policy mapping is
no longer permitted. For example, a value of one indicates that policy
mapping may be processed in certificates issued by the subject of this
certificate, but not in additional certificates in the path.

If the requireExplicitPolicy field is present, subsequent certificates
must include an acceptable policy identifier. The value of
requireExplicitPolicy indicates the number of additional certificates
that may appear in the path (including the trustpoint's self
certificate) before an explicit policy is required. An acceptable
policy identifier is the identifier of a policy required by the user of
the certification path or the identifier of a policy which has been
declared equivalent through policy mapping.
}

   DisplayText ::= CHOICE {
        visibleString    VisibleString  (SIZE (1..200)),
        bmpString        BMPString      (SIZE (1..200)),
        utf8String       UTF8String     (SIZE (1..200))
}

Internet Draft                             Electronic Signature Formats

5.6.2	Revocation Requirements

The RevocRequirements field specifies minimum requirements for
revocation information, obtained through CRLs and/or OCSP responses, to
be used in checking the revocation status of certificates. This ASN1
structure is used to define policy for validating the signing
certificate, the TSA's certificate and attribute certificates.

CertRevReq

-- Optional Electronic Signature Attributes

-- Commitment Type

id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

CommitmentTypeIndication ::= SEQUENCE {
	endCertRevReq	RevReq,
	caCerts	    [0] RevReq
  commitmentTypeId                 CommitmentTypeIdentifier,
  commitmentTypeQualifier          SEQUENCE SIZE (1..MAX) OF
                                   CommitmentTypeQualifier   OPTIONAL
}

Certificate revocation requirements are specified in terms of checks
required on:
     * endCertRevReq: end certificates (i.e. the signers certificate,
     the attribute certificate or the timestamping authority
     certificate).

     * caCerts: CA certificates.

        RevReq

CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

CommitmentTypeQualifier ::= SEQUENCE {
         enuRevReq  EnuRevReq,
         exRevReq    SignPolExtensions OPTIONAL}

An authority certificate is certificate issued to an authority (e.g.
either to a certification authority or to an attribute authority (AA)).

A TimeStamping Authority (TSA) is a trusted third party that creates
time stamp tokens in order to indicate that a datum existed at a
particular point in time (RFC??: "Internet X.509 Public Key
Infrastructure - Time Stamp Protocol").

EnuRevReq
    commitmentTypeIdentifier   CommitmentTypeIdentifier,
    qualifier                  ANY DEFINED BY commitmentTypeIdentifier
}

    id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= ENUMERATED {
	clrCheck	(0),
                   --Checks must be made against current CRLs
		   -- (or authority revocation lists (ARL))
	ocspCheck	(1), -- The revocation status must be checked
                  -- using the Online Certificate Status Protocol
                  -- (OCSP),RFC 2450.
	bothCheck	(2), iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    cti(6) 1}

    id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    cti(6) 2}

    id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::= { iso(1) member-
    body(2)  us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    cti(6) 3}

    id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
   cti(6) 4}

    id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    cti(6) 5}

    id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    cti(6) 6}

Internet Draft                             Electronic Signature Formats

-- Both CRL and OCSP checks must be carried out
	eitherCheck	(3), Signer Location

   id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-
   body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
   id-aa(2) 17}

SignerLocation ::= SEQUENCE {
       -- At at least one of CRL or OCSP checks the following must be present
      countryName      [0]  DirectoryString    OPTIONAL,
       -- carried out
	noCheck		(4),
                  -- no check is mandated
	other		(5)
                  -- Other mechanism as defined by signature poilicy used to name a Country in X.500
      localityName     [1]  DirectoryString    OPTIONAL,
       -- extension
	  }

Internet Draft                                   Electronic Signature Formats

Revocation requirements are specified as used to name a locality in terms of:
     * clrCheck: Checks must be made against current CRLs (or
       authority revocation lists);
     * ocspCheck: The revocation status must be checked using the
       Online Certificate Status Protocol (RFC 2450);
     * bothCheck: Both OCSP and CRL checks must be carried out;
     * eitherCheck: Either OCSP or CRL checks must be carried out;
     * noCheck: No check is mandated.

5.7	Signing Certificate Trust Conditions

The SigningCertTrustCondition field identifies trust conditions for
certificate path processing used to validate the signing certificate.

SigningCertTrustCondition X.500
      postalAdddress   [2]  PostalAddress      OPTIONAL
}

  PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString

-- Signer Attributes

    id-aa-ets-signerAttr OBJECT IDENTIFIER ::= {
     signerTrustTrees              CertificateTrustTrees,
     signerRevReq                  CertRevReq
                                             }

5.8	TimeStamp Trust Conditions

The TimeStampTrustCondition field identifies trust conditions for
certificate path processing used to authenticate the timstamping
authority and constraints on the name of the timestamping authority.
This applies to the timestamp that must be present in every ES-T.

TimestampTrustCondition iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}

SignerAttribute ::= SEQUENCE OF CHOICE {
    ttsCertificateTrustTrees
      claimedAttributes     [0]	CertificateTrustTrees
                                           OPTIONAL,
    ttsRevReq ClaimedAttributes,
      certifiedAttributes   [1]		CertRevReq
                                           OPTIONAL,
    ttsNameConstraints  	[2]		NameConstraints
                                           OPTIONAL,
    cautionPeriod		[3]		DeltaTime
                                           OPTIONAL,
    signatureTimestampDelay	[4]		DeltaTime
                                           OPTIONAL CertifiedAttributes
}

DeltaTime

ClaimedAttributes ::= SEQUENCE {
	deltaSeconds	INTEGER,
	deltaMinutes	INTEGER,
	deltaHours	INTEGER,
	deltaDays	INTEGER }

If ttsCertificateTrustTrees is not present then the same rule OF Attribute

CertifiedAttributes ::= AttributeCertificate  -- as defined in certificateTrustCondition applies to certification of the
timestamping authorities public key. X.509 :
see section 10.3

-- Content Timestamp

    id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 20}

ContentTimestamp::= TimeStampToken

-- Validation Data

-- Signature Timestamp

    id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 14}

SignatureTimeStampToken ::= TimeStampToken

Internet Draft                             Electronic Signature Formats

The tstrRevReq specifies minimum requirements for revocation
information, obtained through CRLs and/or OCSP responses, to be used in
checking the revocation status of the time stamp that must be present
in the ES-T.

If ttsNameConstraints is not present then there are no additional
naming constraints on the trusted timestamping authority other than
those implied by the ttsCertificateTrustTrees.

The cautionPeriod field specifies a caution period after the signing
time that it is mandated the verifier must wait to get high assurance
of the validity of the signer's key and that any relevant revocation
has been notified. The revocation status information forming the ES
with

-- Complete validation data must not be collected and used to
validate the electronic signature until after this caution period.

The signatureTimestampDelay field specifies a maximum acceptable time
between the signing time and the time at which the signature timestamp,
as used to form the ES Timestamped, is created for the verifier. If the
signature timestamp is later that the time in the signing-time
attribute by more than the value given in signatureTimestampDelay, the
signature must be considered invalid.

5.9	Attribute Trust Conditions

If the attributeTrustCondition field is not present then any certified
attributes may not considered to be valid under this validation policy.
The AttributeTrustCondition field is defined as follows:

AttributeTrustCondition Certificate Refs.

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= SEQUENCE {
	attributeMandated            BOOLEAN, iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

CompleteCertificateRefs ::=  SEQUENCE OF OTHERCertID

-- Attribute must be present
	howCertAttribute             HowCertAttribute,
	attrCertificateTrustTrees Complete Revocation Refs

   id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-
   body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
   id-aa(2) 22}

CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

CrlOcspRef ::= SEQUENCE {
    crlids           [0] CertificateTrustTrees CRLListID      OPTIONAL,
	attrRevReq
    ocspids          [1] CertRevReq OcspListID     OPTIONAL,
	attributeConstraints
    otherRev         [2] AttributeConstraints OtherRevRefs   OPTIONAL
}

If attributeMandated is true then an attribute, certified within the
following constraints, must be present. If false, then the signature
is still valid if no attribute is specified.

The howCertAttribute field specifies whether attributes uncertified
attributes "claimed" by the signer, or certified in an attribute
certificate or either  using the signer attributes attribute defined
in 4.12.3.

HowCertAttribute

CRLListID ::= ENUMERATED  SEQUENCE {
	claimedAttribute       (0),
	certifiedAttribtes     (1),
	either                 (2) }

Internet Draft                                   Electronic Signature Formats

The attrCertificateTrustTrees specifies certificate path conditions for
any attribute certificate. If not present the same rules apply as in
certificateTrustCondition.

The attrRevReq specifies minimum requirements for revocation
information, obtained through CRLs and/or OCSP responses, to be used in
checking the revocation status of Attribute Certificates, if any are
present.

If the attributeConstraints field is not present then there are no
constraints on the attributes that may be validated under this policy.
The attributeConstraints field is defined as follows:

AttributeConstraints
    crls        SEQUENCE OF CrlValidatedID}

CrlValidatedID ::=  SEQUENCE {
	attributeTypeConstarints	[0] AttributeTypeConstraints
                                                 OPTIONAL,
	attributeValueConstarints	[1] AttributeValueConstraints
     crlHash                   ETSIHash,
     crlIdentifier             CrlIdentifier OPTIONAL
}

If present, the attributeTypeConstarints field specifies the attribute
types which are considered valid under the signature policy. Any value
for that attribute is considered valid.

AttributeTypeConstraints

CrlIdentifier ::= SEQUENCE OF AttributeType

If present, the attributeTypeConstraints field specifies the specific
attribute values which are considered valid under the signature policy.

AttributeValueConstraints {
    crlissuer                 Name,
    crlIssuedTime             UTCTime,
    crlNumber                 INTEGER OPTIONAL
}

OcspListID ::=  SEQUENCE {
    ocspResponses        SEQUENCE OF AttributeTypeAndValue

5.10	Algorithm Constraints

The algorithmConstrains fields, if present, identifies the signing
algorithms (hash, public key cryptography, combined hash and public key
cryptography) that may be used for specific purposes and any minimum
length. If this field is not present then the policy applies no
constraints.

AlgorithmConstraintSet OcspResponsesID}

OcspResponsesID ::=  SEQUENCE {   -- Algorithm constrains on:
signerAlgorithmConstraints	[0] 	AlgorithmConstraints OPTIONAL,
                                -- signer
eeCertAlgorithmConstraints	[1] 	AlgorithmConstraints OPTIONAL,
                                -- issuer of end entity certs.
caCertAlgorithmConstraints	[2] 	AlgorithmConstraints OPTIONAL,
                                -- issuer of CA certificates
aaCertAlgorithmConstraints	[3] 	AlgorithmConstraints OPTIONAL,
                                -- Attribute Authority
tsaCertAlgorithmConstraints	[4] 	AlgorithmConstraints
    ocspIdentifier              OcspIdentifier,
    ocspRepHash                 ETSIHash    OPTIONAL
}

OcspIdentifier ::= SEQUENCE {
  ocspResponderID    ResponderID,
                    -- TimeStamping Authority as in OCSP response data
  producedAt      GeneralizedTime
                    -- as in OCSP response data
}

Internet Draft                             Electronic Signature Formats

AlgorithmConstraints ::= SEQUENCE OF AlgAndLength

AlgAndLength

OtherRevRefs ::= SEQUENCE {
	algID
   otherRevRefType         OtherRevRefType,
   otherRevRefs            ANY DEFINED BY otherRevRefType
}

OtherRevRefType ::= OBJECT IDENTIFIER,
	minKeyLength	INTEGER 	OPTIONAL, IDENTIFIER

-- Minimum key length in bits
	other 		SignPolExtensions OPTIONAL
		 }

An Attribute Authority (AA)is authority which assigns privileges by
issuing attribute certificates

5.11	Signature Policy Extensions

Additional signature policy rules may be added to:

     * the overall signature policy structure, as defined in
       clause 5.1;
     * the signature validation policy structure, as defined in
       clause 5.2;
     * the common rules, as defined in clause 5.3;
     * the commitment rules, as defined in clause 5.4;
     * the signer rules, as defined in clause 5.5.1;
     * the verifier rules, as defined in clause 5.5.2;
     * the revocation requirements in clause 5.6.2;
     * the algorithm constraints in clause 5.10.

These extensions to the signature policy rules must be defined using
an ASN.1 syntax with an associated object identifier carried in the
SignPolExtn as defined below:

SignPolExtensions Certificate Values

id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

CertificateValues ::=  SEQUENCE OF SignPolExtn

SignPolExtn Certificate

-- Certificate Revocation Values

id-aa-ets-revocationValues OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 24}

RevocationValues ::=  SEQUENCE {
                extnID      OBJECT IDENTIFIER,
		extnValue   OCTET STRING
   crlVals          [0] SEQUENCE OF CertificateList     OPTIONAL,
   ocspVals         [1] SEQUENCE OF BasicOCSPResponse   OPTIONAL,
   otherRevVals     [2] OtherRevVals
}

The extnID field must contain the object identifier for the extension.
The extnValue field must contain the DER (see ITU-T Recommendation
X.690 [4]) encoded value of the extension.  The definition of an
extension, as identified by extnID must include a definition of the
syntax

OtherRevVals ::= SEQUENCE {
   otherRevValType  OtherRevValType,
  otherRevVals      ANY DEFINED BY otherRevValType
}

OtherRevValType ::= OBJECT IDENTIFIER

-- ES-C Timestamp

id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 25}

ESCTimeStampToken ::= TimeStampToken

-- Time-Stamped Certificates and semantics of the extension.

6.	Security considerations

6.1	Protection of Private Key

The security of the electronic signature mechanism defined in this
document depends on the privacy of the signer's private key.
Implementations must take steps to ensure that private keys cannot be
compromised. CRLs

id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 26}

TimestampedCertsCRLs ::= TimeStampToken

Internet Draft                             Electronic Signature Formats

6.2	Choice of Algorithms

Implementers should be aware that cryptographic algorithms become
weaker with time. As new cryptoanalysis techniques are developed and
computing performance improves, the work factor to break a particular
cryptographic algorithm will reduce. Therefore, cryptographic algorithm
implementations should be modular allowing new algorithms to be readily
inserted. That is, implementers should be prepared for the set of
mandatory to implement algorithms to change over time.

7.	Conformance Requirements

This document only defines conformance requirements up to a ES with
Complete validation data (ES-C). This means that none of the extended
and archive forms of

-- Archive Timestamp

id-aa-ets-archiveTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16)
    id-aa(2) 27}

ArchiveTimeStampToken ::= TimeStampToken

END -- ETS-ElectronicSignatureFormats-88syntax --

Internet Draft                             Electronic Signature (ES-X, ES-A) need to be
implemented to get conformance to this standard.

This document mandates support for elements of the signature policy.

7.1	Signer

A system supporting signers according to this document must, at a
minimum, support generation of an electronic signature consisting of
the following components:

      * Formats

A.2  Definitions Using X.680 1997 ASN.1 Syntax

NOTE:  The general CMS syntax and content type as ASN.1 module defined in RFC 2630
        (see clauses 4.1 and 4.2).

      * CMS SignedData as clause A.1 has precedence over that
defined in RFC 2630 with version set to 3
        and at least one SignerInfo must be present
        (see clauses 4.3, 4.4, 4.5, 4.6).

      * The following CMS Attributes as defined clause A.2 in the case of any conflict.

    ETS-ElectronicSignatureFormats-97Syntax { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-mod(0) 6}

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

-- EXPORTS All -

IMPORTS

-- Cryptographic Message Syntax (CMS): RFC 2630 :
             - ContentType; This must always be present
               (see clause 3.7.1);

             - MessageDigest; This must always be present
               (see clause 3.7.2);

             - SigningTime; This must always be present
               (see clause 3.7.3).

      * The following

  ContentInfo, ContentType, id-data, id-signedData, SignedData,
  EncapsulatedContentInfo, SignerInfo, id-contentType,
  id-messageDigest, MessageDigest, id-signingTime,
  SigningTime, id-countersignature, Countersignature

   FROM CryptographicMessageSyntax
    { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
    smime(16) modules(0) cms(1) }

-- ESS Attributes as defined in Defined attributes: RFC 2634 :
              - SigningCertificate: This must be set as defined
                in clauses 3.8.1 and 3.8.2.

      * The following Attributes as defined in clause 3.9:
             - SignaturePolicyIdentifier; This must always be present.

      * (Enhanced Security Services
-- for S/MIME)

   id-aa-signingCertificate, SigningCertificate, IssuerSerial,
   id-aa-contentReference, ContentReference,
   id-aa-contentIdentifier, ContentIdentifier

  FROM ExtendedSecurityServices
    { iso(1) member-body(2) us(840) rsadsi(113549)
       pkcs(1) pkcs-9(9) smime(16) modules(0) ess(2) }

-- Internet X.509 Public Key Certificates as defined in ITU-T Recommendation
        X.509 [1] Infrastructure
- - Certificate and profiled in RFC CRL Profile:RFC 2459 [7] (see clause 9.1).

   Certificate, AlgorithmIdentifier, CertificateList, Name,
   GeneralNames, GeneralName, DirectoryString, Attribute,
   AttributeTypeAndValue, AttributeType, AttributeValue,
   PolicyInformation.

  FROM PKIX1Explicit93
    {iso(1) identified-organization(3) dod(6) internet(1)
     security(5) mechanisms(5) pkix(7) id-mod(0)
     id-pkix1-explicit-88(1)}

Internet Draft                             Electronic Signature Formats

7.2	Verifier

A system supporting verifiers according to this document must, at a
minimum, support:

       * Verification of the mandated components of an electronic
          signature, as defined in clause 14.1.

       * Signature Timestamp attribute, as defined in clause 5.1.1.

       * Complete Certificate Refs attribute, as defined in
         clause 5.2.1.

       * Complete Revocation Refs Attribute, as defined in
         clause  5.2.2.

       * Public Key Certificates, as defined in ITU-T
         Recommendation X.509 and profiled in RFC 2459
         (see clause 10.1)

       * Either of:
             - Certificate Revocation Lists. as defined in ITU-T
               Recommendation

-- X.509 [1] and profiled '97 Authentication Framework

        AttributeCertificate

        FROM AuthenticationFramework
        {joint-iso-ccitt ds(5) module(1) authenticationFramework(7) 3}

-- OCSP 2560

      BasicOCSPResponse, ResponderID

  FROM OCSP

--  { OID not assigned }

-- Time Stamp Protocol Internet Draft TimeStampToken

  FROM PKIXTSP
  {iso(1) identified-organization(3) dod(6) internet(1)
   security(5) mechanisms(5) pkix(7) id-mod(0) id-mod-tsp(13)}

-- S/MIME Object Identifier arcs used in RFC 2459 [7]
               (see clause 10.2); Or
             - On-line Certificate Status Protocol, as defined this document
-- ===================================================

-- S/MIME  OID arc used in
               RFC 2560 (see clause 10.3).

7.3	Signature Policy

Both signer and verifier systems must be able to process an electronic this document
-- id-smime OBJECT IDENTIFIER ::= { iso(1) member-body(2)
--             us(840) rsadsi(113549) pkcs(1) pkcs-9(9) 16 }

-- S/MIME Arcs
-- id-mod  OBJECT IDENTIFIER ::= { id-smime 0 }
-- modules
-- id-ct   OBJECT IDENTIFIER ::= { id-smime 1 }
-- content types
-- id-aa   OBJECT IDENTIFIER ::= { id-smime 2 }
-- attributes
-- id-spq  OBJECT IDENTIFIER ::= { id-smime 5 }
-- signature policy qualifier
-- id-cti  OBJECT IDENTIFIER ::= { id-smime 6 }
-- commitment type identifier

-- Definitions of Object Identifier arcs used in accordance this document
-- ===========================================================

-- The allocation of OIDs to specific objects are given below with the specification of at least one
-- associated ASN.1 syntax definition

-- OID used referencing electronic signature policy, as identified by mechanisms based on this
-- standard for use with the signature policy attribute IDUP API (see clause 4.9.1).

8. References

[RFC2510] C. Adams, S. Farrell, "Internet X.509 Public Key
Infrastructure, Certificate Management Protocols," RFC 2510, March 1999.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2246] T. Dierks, C. Allen, "The TLS Protocol, Version 1.0," RFC
2246, January 1999.

[RFC 2634] P. Hoffman, "Enhanced Security Services for S/MIME",

[RFC 2630] R. Housley, "Cryptographic Message Syntax", RFC 2630, June
1999. annex D)

Internet Draft                             Electronic Signature Formats

[RFC2459] R. Housley, W. Ford, W. Polk, D. Solo, "Internet X.509 Public
Key Infrastructure, Certificate and CRL Profile," RFC 2459, January
1999.

[PKCS9] RSA Laboratories, "The Public-Key Cryptography Standards
(PKCS)", RSA Data Security Inc., Redwood City, California, November
1993 Release.

[ISONR] ISO/IEC 10181-5:  Security Frameworks in Open Systems.
Non-Repudiation Framework. April 1997.

9. Authors' Addresses

This Informational RFC has been produced

id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::=
  { itu-t(0) identified-organization(4) etsi(0)
   electronic-signature-standard (1733) part1 (1)
   idupMechanism (4)etsiESv1(1) }

-- CMS Attributes Defined in ETSI TC-SEC.

ETSI
F-06921 Sophia Antipolis, Cedex - FRANCE
650 Route des Lucioles - Sophia Antipolis
Valbonne - France
Tel: +33 4 92 94 42 00	Fax: +33 4 93 65 47 16
secretariat@etsi.fr
http://www.etsi.org

ETSI Contact Point

Harri Rasilainen
ETSI
F-06921 Sophie Antipolis
650 Route des Lucioles
Sophia Antipolis, Valbonne
FRANCE
harri.rasilainen@etsi.fr

Additional Contact Points

John Ross
Security & Standards
192 Moulsham Street
Chelmsford, Essex
CM2 0LG
United Kingdom
ross@secstan.com

Denis Pinkas                          Nick Pope
Bull S.A.                             Security & Standards
12, rue de Paris                      192 Moulsham Street
B.P. 59                               Chelmsford, Essex
78231 Le Pecq                         CM2 0LG
FRANCE                                United Kingdom
pinkas.denis@bull.net                 pope@secstan.com

Internet Draft this document
-- =======================================

-- Mandatory Electronic Signature Formats

10. Full Copyright Statement

Copyright (C) The Internet Society (2000). All Rights Reserved.
This document and translations of it may be copied and furnished to others,
and derivative works that comment on or otherwise explain it or assist in
its implementation may be prepared, copied, published and distributed, in
whole or in part, without restriction of any kind, provided that the above
copyright notice and this paragraph are included on all such copies and
derivative works. However, this document itself may not be modified in any
way, such as by removing the copyright notice or references to the Internet
Society or other Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for copyrights
defined in the Internet Standards process must be followed, or as required to
translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked
by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO ANY WARRANTY THAT THE USE Attributes
-- OtherSigningCertificate

id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 19 }

OtherSigningCertificate ::=  SEQUENCE {
    certs        SEQUENCE OF THE INFORMATION HEREIN WILL
NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OtherCertID,
    policies     SEQUENCE OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE.

11.Temportary Issues
It might be interesting to split this document into two RFCs, one RFC
dealing only with ES formats, the other one only with Signature
Policies. In such a case, the basis of this split will be, sections 6
and annex C will be removed from this document and placed in the another
RFC dealing with Signature policies.  The signature policy ASN.1 will be
removed the current ASN.1 modules in annex A and placed in a new ASN.1
module in the other RFC dealing with Signature Policies. Opinions are
requested on this issue.

Internet Draft                                   Electronic Signature Formats

Note: If there is a request to split this document into two RFCs, one
RFC dealing with ES formats, the other with Signature policies, then the
signature policy ASN.1 will be removed the current ASN.1 modules in
annex A and placed in a new ASN.1 module in the other RFC dealing with
Signature policies.

Annex A (normative):

ASN.1 Definitions

This annex provides a summary of all the ASN.1 syntax definitions for
new syntax defined in this document.

A.1	Definitions Using X.208 (1988) ASN.1 Syntax

NOTE:	The ASN.1 module defined in clause A.1 has precedence over that
defined in Annex A-2 in the case of any conflict.

ETS-ElectronicSignature-88syntax PolicyInformation OPTIONAL
                 -- NOT USED IN THIS DOCUMENT
}

OtherCertID ::= SEQUENCE { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-mod(0) 5}

DEFINITIONS EXPLICIT TAGS
     otherCertHash            OtherHash,
     issuerSerial             IssuerSerial OPTIONAL
}

OtherHash ::=
BEGIN CHOICE {
    sha1Hash OtherHashValue,  -- EXPORTS All -

IMPORTS This contains a SHA-1 hash
    otherHash OtherHashAlgAndValue
}

OtherHashValue ::= OCTET STRING

OtherHashAlgAndValue ::= SEQUENCE {
  hashAlgorithm  AlgorithmIdentifier,
  hashValue    OtherHashValue
}

-- Crypographic Message Syntax (CMS): RFC 2630
	ContentInfo, ContentType, id-data, id-signedData, SignedData,
        EncapsulatedContentInfo,
	SignerInfo, id-contentType, id-messageDigest, MessageDigest,
        id-signingTime, SigningTime,
	id-countersignature, Countersignature
	FROM CryptographicMessageSyntax Signature Policy Identifier

id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9) pkcs9(9)
    smime(16) modules(0) cms(1) id-aa(2) 15 }

-- ESS Defined attributes: RFC 2634
-- (Enhanced Security Services for S/MIME)
   id-aa-signingCertificate, SigningCertificate, IssuerSerial,
	id-aa-contentReference, ContentReference,
        id-aa-contentIdentifier, ContentIdentifier
	FROM ExtendedSecurityServices

SignaturePolicyIdentifier ::= SEQUENCE { iso(1) member-body(2) us(840) rsadsi(113549)
       pkcs(1) pkcs-9(9) smime(16) modules(0) ess(2)
        sigPolicyIdentifier   SigPolicyId,
        sigPolicyHash         SigPolicyHash,
        sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                SigPolicyQualifierInfo OPTIONAL
}

SigPolicyId ::= OBJECT IDENTIFIER

Internet Draft                             Electronic Signature Formats

-- Internet X.509 Public Key Infrastructure
- - Certificate and CRL Profile: RFC 2459

	Certificate, AlgorithmIdentifier, CertificateList, Name,
        GeneralNames, GeneralName,
	DirectoryString,Attribute, AttributeTypeAndValue, AttributeType,
        AttributeValue,
	PolicyInformation, BMPString, UTF8String
  FROM PKIX1Explicit88
	{iso(1) identified-organization(3) dod(6) internet(1)
  	security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-explicit-
        88(1)}

-- X.509 '97 Authentication Framework
AttributeCertificate
	FROM AuthenticationFramework
	{joint-iso-ccitt ds(5) module(1) authenticationFramework(7) 3}
-- The imported AttributeCertificate is defined using the X.680 1997
-- ASN.1 Syntax,
-- an equivalent using the 88 ASN.1 syntax may be used.

-- OCSP 2560
BasicOCSPResponse, ResponderID
	FROM OCSP {-- OID not assigned -- }

-- Time Stamp Protocol Internet Draft
-- TimeStampToken
	FROM TSP {-- OID not assigned -- };

-- S/MIME Object Identifier arcs used in this document
-- ==================================================================

-- S/MIME  OID arc used in this document
-- id-smime OBJECT IDENTIFIER

SigPolicyHash ::= ETSIHashAlgAndValue

SigPolicyQualifierInfo ::= SEQUENCE { iso(1) member-body(2)
--             us(840) rsadsi(113549) pkcs(1) pkcs-9(9) 16
        sigPolicyQualifierId    SIG-POLICY-QUALIFIER.&id
                                 ({SupportedSigPolicyQualifiers}),
        qualifier               SIG-POLICY-QUALIFIER.&Qualifier
                                ({SupportedSigPolicyQualifiers}
                                 {@sigPolicyQualifierId})OPTIONAL }

-- S/MIME Arcs
-- id-mod  OBJECT IDENTIFIER

SupportedSigPolicyQualifiers SIG-POLICY-QUALIFIER ::=
                           { id-smime 0 noticeToUser | pointerToSigPolSpec }
-- modules
-- id-ct

SIG-POLICY-QUALIFIER ::= CLASS {
        &id             OBJECT IDENTIFIER UNIQUE,
        &Qualifier      OPTIONAL }

WITH SYNTAX {
        SIG-POLICY-QUALIFIER-ID     &id
        [SIG-QUALIFIER-TYPE &Qualifier] }

noticeToUser SIG-POLICY-QUALIFIER ::= { id-smime 1
      SIG-POLICY-QUALIFIER-ID id-sqt-unotice SIG-QUALIFIER-TYPE
                                            SPUserNotice
                                                        }
-- content types
-- id-aa   OBJECT IDENTIFIER

pointerToSigPolSpec SIG-POLICY-QUALIFIER ::= { id-smime 2
      SIG-POLICY-QUALIFIER-ID id-sqt-uri SIG-QUALIFIER-TYPE SPuri }
-- attributes
-- id-spq  OBJECT IDENTIFIER ::= { id-smime 5 }
-- signature policy qualifier
-- id-cti  OBJECT IDENTIFIER ::= { id-smime 6 }
-- commitment type identifier

Internet Draft                                   Electronic Signature Formats

-- Definitions of Object Identifier arcs used in this document
-- ==================================================================

-- The allocation of OIDs to specific objects are given below with the
-- associated ASN.1 syntax definition

-- OID used referencing electronic signature mechanisms based on this
-- standard for use with the IDUP API (see annex D)

id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::=
	{ itu-t(0) identified-organization(4) etsi(0)
	   electronic-signature-standard (1733) part1 (1)
         idupMechanism (4)etsiESv1(1) }

-- CMS Attributes Defined in this document
-- ==============================================

-- Mandatory Electronic Signature Attributes

-- OtherSigningCertificate

id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 19 }

OtherSigningCertificate ::=  SEQUENCE {
    certs        SEQUENCE OF OtherCertID,
    policies     SEQUENCE OF PolicyInformation OPTIONAL
                 -- NOT USED IN THIS DOCUMENT
                                            }

OtherCertID ::= SEQUENCE {
     otherCertHash            OtherHash,
     issuerSerial             IssuerSerial OPTIONAL }

OtherHash ::= CHOICE {
    sha1Hash OtherHashValue,  -- This contains a SHA-1 hash
    otherHash OtherHashAlgAndValue}

OtherHashValue ::= OCTET STRING

OtherHashAlgAndValue ::= SEQUENCE {
	hashAlgorithm	AlgorithmIdentifier,
	hashValue		OtherHashValue }

-- Signature Policy Identifier

id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 15 }

Internet Draft                                   Electronic Signature Formats

SignaturePolicyIdentifier ::= SEQUENCE {
        sigPolicyIdentifier   SigPolicyId,
		sigPolicyHash         SigPolicyHash,
        sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                SigPolicyQualifierInfo OPTIONAL}

SigPolicyId ::= OBJECT IDENTIFIER

SigPolicyHash ::= ETSIHashAlgAndValue

SigPolicyQualifierInfo ::= SEQUENCE {
        sigPolicyQualifierId  SigPolicyQualifierId,
        sigQualifier          ANY DEFINED BY sigPolicyQualifierId }

SigPolicyQualifierId ::=
        OBJECT IDENTIFIER

	id-spq-ets-uri

    id-spq-ets-uri OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 1 }

   SPuri ::= IA5String

  id-spq-ets-unotice OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 2 }

   SPUserNotice ::= SEQUENCE {
        noticeRef        NoticeReference OPTIONAL,
        explicitText     DisplayText OPTIONAL} OPTIONAL
}

   NoticeReference ::= SEQUENCE {
        organization     DisplayText,
        noticeNumbers    SEQUENCE OF INTEGER
}

   DisplayText ::= CHOICE {
        visibleString    VisibleString  (SIZE (1..200)),
        bmpString        BMPString      (SIZE (1..200)),
        utf8String       UTF8String     (SIZE (1..200))
}

Internet Draft                             Electronic Signature Formats

-- Optional Electronic Signature Attributes

-- Commitment Type

id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

CommitmentTypeIndication ::= SEQUENCE {
  commitmentTypeId CommitmentTypeIdentifier,
  commitmentTypeQualifier SEQUENCE SIZE (1..MAX) OF
                                           CommitmentTypeQualifier
                                           OPTIONAL}

CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

CommitmentTypeQualifier ::= SEQUENCE {
		commitmentTypeIdentifier CommitmentTypeIdentifier,
        commitmentQualifierId       COMMITMENT-QUALIFIER.&id,
        qualifier	ANY DEFINED BY commitmentTypeIdentifier                   COMMITMENT-QUALIFIER.&Qualifier
                                                  OPTIONAL }

	id-cti-ets-proofOfOrigin OBJECT

COMMITMENT-QUALIFIER ::= CLASS {
                    &id             OBJECT IDENTIFIER UNIQUE,
                    &Qualifier      OPTIONAL }
WITH SYNTAX {
         COMMITMENT-QUALIFIER-ID     &id
                        [COMMITMENT-TYPE &Qualifier] }

  id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= { iso(1) member-
       body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 1}

  id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1) member-
      body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 2}

  id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::= { iso(1) member-
      body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 3}

  id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1) member-
      body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 4}

  id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::= { iso(1) member-
      body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 5}

  id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::= { iso(1) member-
      body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 6}

Internet Draft                             Electronic Signature Formats

-- Signer Location

id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 17}

SignerLocation ::= SEQUENCE {
                       -- At at least one of the following must be present
      countryName [0] DirectoryString OPTIONAL,
        -- As used to name a Country in X.500
      localityName [1] DirectoryString OPTIONAL,
         -- As used to name a locality in X.500
      postalAdddress [2] PostalAddress OPTIONAL }

  PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString

-- Signer Attributes

id-aa-ets-signerAttr OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}

SignerAttribute ::= SEQUENCE OF CHOICE {
      claimedAttributes  [0] ClaimedAttributes,
      certifiedAttributes [1] CertifiedAttributes }

ClaimedAttributes ::= SEQUENCE OF Attribute

CertifiedAttributes ::= AttributeCertificate
-- As defined in X.509 : see section 10.3

-- Content Timestamp

id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) id-aa(2) 20}

ContentTimestamp::= TimeStampToken

-- Validation Data

-- Signature Timestamp

id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::= { iso(1) member-
    body(2)
     member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 14}

SignatureTimeStampToken ::= TimeStampToken

Internet Draft                             Electronic Signature Formats

-- Complete Certificate Refs.

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

CompleteCertificateRefs ::=  SEQUENCE OF ETSICertID OTHERCertID

-- Complete Revocation Refs

id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 22}

CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

CrlOcspRef ::= SEQUENCE {
    crlids           [0] CRLListID   OPTIONAL,
    ocspids          [1] OcspListID  OPTIONAL,
  otherRev     [2] OtherRevRefs OPTIONAL
                                          }

CRLListID ::=  SEQUENCE {
    crls        SEQUENCE OF CrlValidatedID}

CrlValidatedID ::=  SEQUENCE {
     crlHash                   ETSIHash,
     crlIdentifier             CrlIdentifier OPTIONAL}

CrlIdentifier ::= SEQUENCE {
    crlissuer                 Name,
    crlIssuedTime             UTCTime,
    crlNumber                 INTEGER OPTIONAL
                                            }

OcspListID ::=  SEQUENCE {
    ocspResponses        SEQUENCE OF OcspResponsesID}

OcspResponsesID ::=  SEQUENCE {
    ocspIdentifier              OcspIdentifier,
    ocspRepHash                 ETSIHash    OPTIONAL
                                            }

OcspIdentifier ::= SEQUENCE {
  ocspResponderID    ResponderID,
                        -- As in OCSP response data
  producedAt      GeneralizedTime
                        -- As in OCSP response data
                                             }

Internet Draft                             Electronic Signature Formats

OtherRevRefs ::= SEQUENCE {
   otherRevRefType	OtherRevRefType,  OTHER-REVOCATION-REF.&id,
  otherRevRefs	ANY DEFINED BY otherRevRefType  OTHER-REVOCATION-REF.&Type
                                              }

OtherRevRefType

OTHER-REVOCATION-REF ::= CLASS {
    &Type,
    &id  OBJECT IDENTIFIER UNIQUE }
  WITH SYNTAX {
    &Type ID &id }

-- Certificate Values

id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

CertificateValues ::=  SEQUENCE OF Certificate

-- Certificate Revocation Values

id-aa-ets-revocationValues OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840)
     member-body(2)us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 24}

RevocationValues ::=  SEQUENCE {
   crlVals          [0] SEQUENCE OF CertificateList OPTIONAL,
   ocspVals         [1] SEQUENCE OF BasicOCSPResponse OPTIONAL,
   otherRevVals      [2] OtherRevVals }

OtherRevVals ::= SEQUENCE {
   otherRevValType	OtherRevValType,  OTHER-REVOCATION-VAL.&id,
  otherRevVals	ANY DEFINED BY otherRevValType  OTHER-REVOCATION-VAL.&Type
                                               }

OtherRevValType

OTHER-REVOCATION-VAL ::= CLASS {
    &Type,
    &id  OBJECT IDENTIFIER UNIQUE }
  WITH SYNTAX {
    &Type ID &id }

-- ES-C Timestamp

id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1)
     member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 25}

ESCTimeStampToken ::= TimeStampToken

Internet Draft                             Electronic Signature Formats

-- Time-Stamped Certificates and CRLs

id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
    smime(16) id-aa(2) 26}

TimestampedCertsCRLs ::= TimeStampToken

Internet Draft                                   Electronic Signature Formats

-- Archive Timestamp

id-aa-ets-archiveTimestamp OBJECT IDENTIFIER ::= { iso(1) member-
    body(2) us(840)
   member-body(2)us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 27}

ArchiveTimeStampToken ::= TimeStampToken

END                -- Signature Policy Specification
-- ==============================

SignaturePolicy ::= SEQUENCE {
	signPolicyHashAlg      AlgorithmIdentifier,
	signPolicyInfo         SignPolicyInfo,
	signPolicyHash         SignPolicyHash     OPTIONAL }

SignPolicyHash ::= OCTET STRING

SignPolicyInfo ::= SEQUENCE {
	signPolicyIdentifier            SignPolicyId,
	dateOfIssue                     GeneralizedTime,
	policyIssuerName                PolicyIssuerName,
	fieldOfApplication              FieldOfApplication,
	signatureValidationPolicy 	SignatureValidationPolicy,
	signPolExtensions		SignPolExtensions
	                                      OPTIONAL
	                                              }

SignPolicyId ::= OBJECT IDENTIFIER

PolicyIssuerName ::= GeneralNames

FieldOfApplication ::= DirectoryString

SignatureValidationPolicy ::= SEQUENCE {
	signingPeriod          SigningPeriod,
	commonRules            CommonRules,
	commitmentRules        CommitmentRules,
	signPolExtensions	SignPolExtensions
                             		OPTIONAL
                                                }

SigningPeriod ::= SEQUENCE {
	notBefore	GeneralizedTime,
	notAfter	GeneralizedTime OPTIONAL }

Internet Draft                                   Electronic Signature Formats

CommonRules  ::= SEQUENCE {
   	signerAndVeriferRules          [0]  SignerAndVerifierRules
                                                          OPTIONAL,
	signingCertTrustCondition      [1]  SigningCertTrustCondition
                                                          OPTIONAL,
	timeStampTrustCondition        [2]  TimestampTrustCondition
                                                        OPTIONAL,
	attributeTrustCondition        [3]  AttributeTrustCondition
                                                        OPTIONAL,
	algorithmConstraintSet         [4]  AlgorithmConstraintSet
                                                         OPTIONAL,
     	signPolExtensions	       [5]  SignPolExtensions
                                                         OPTIONAL
                                                                 }

CommitmentRules ::= SEQUENCE OF CommitmentRule

CommitmentRule  ::= SEQUENCE {
	selCommitmentTypes                  SelectedCommitmentTypes,
	signerAndVeriferRules          [0]  SignerAndVerifierRules
                                                           OPTIONAL,
	signingCertTrustCondition      [1]  SigningCertTrustCondition
                                                           OPTIONAL,
	timeStampTrustCondition        [2]  TimestampTrustCondition
                                                           OPTIONAL,
	attributeTrustCondition        [3]  AttributeTrustCondition
                                                           OPTIONAL,
	algorithmConstraintSet         [4]  AlgorithmConstraintSet
                                                           OPTIONAL,
	signPolExtensions	       [5]  SignPolExtensions
                                                            OPTIONAL
                                                                  }

SelectedCommitmentTypes ::= SEQUENCE OF CHOICE {
	empty                        NULL,
	recognizedCommitmentType     CommitmentType }

CommitmentType ::= SEQUENCE {
	identifier			CommitmentTypeIdentifier,
	fieldOfApplication	[0] FieldOfApplication OPTIONAL,
	semantics			[1] DirectoryString OPTIONAL }

SignerAndVerifierRules ::= SEQUENCE {
	signerRules      SignerRules,
	verifierRules    VerifierRules } ETS-ElectronicSignatureFormats-97Syntax

Internet Draft                             Electronic Signature Formats

SignerRules ::= SEQUENCE {
	externalSignedData         BOOLEAN	OPTIONAL,
		      -- True if signed data is external to CMS structure
		      -- False if signed data part of CMS structure
		      -- not present if either allowed
	mandatedSignedAttr         CMSAttrs,
                      -- Mandated CMS signed attributes
	mandatedUnsignedAttr       CMSAttrs,
                      -- Mandated CMS unsigned attributed
	mandatedCertificateRef     [0] CertRefReq DEFAULT signerOnly,
		      -- Mandated Certificate Reference
	mandatedCertificateInfo    [1] CertInfoReq DEFAULT none,
		      -- Mandated Certificate Info
	signPolExtensions		 [2] SignPolExtensions
                                                OPTIONAL}

CMSAttrs ::= SEQUENCE OF OBJECT IDENTIFIER

CertRefReq ::= ENUMERATED {
				signerOnly (1),
-- Only reference to signer cert mandated
				fullPath (2)
-- References for full cert path up to a trust point required

					          }

CertInfoReq ::= ENUMERATED {
				none (0),
-- No mandatory requirements
				signerOnly (1),
-- Only reference to signer cert mandated
				fullPath (2)
-- References for full cert path up to a trust point mandated
                                                  }

VerifierRules ::= SEQUENCE {
		mandatedUnsignedAttr	MandatedUnsignedAttr,
		signPolExtensions	SignPolExtensions   OPTIONAL
		                                  }

MandatedUnsignedAttr ::=  CMSAttrs
-- Mandated CMS unsigned attributed

Internet Draft                                   Electronic Signature Formats

CertificateTrustTrees ::=   SEQUENCE OF CertificateTrustPoint

CertificateTrustPoint ::= SEQUENCE {
	trustpoint				Certificate,
                            -- self-signed certificate
	pathLenConstraint	[0] PathLenConstraint   OPTIONAL,
	acceptablePolicySet	[1] AcceptablePolicySet OPTIONAL,
                            -- If not present "any policy"
	nameConstraints		[2] NameConstraints     OPTIONAL,
	policyConstraints	[3] PolicyConstraints   OPTIONAL }

PathLenConstraint    ::=   INTEGER (0..MAX)

AcceptablePolicySet ::= SEQUENCE OF CertPolicyId

CertPolicyId ::= OBJECT IDENTIFIER

NameConstraints ::= SEQUENCE {
           permittedSubtrees       [0]     GeneralSubtrees OPTIONAL,
           excludedSubtrees        [1]     GeneralSubtrees OPTIONAL }

      GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree

      GeneralSubtree ::= SEQUENCE {
           base                    GeneralName,
           minimum         [0]     BaseDistance DEFAULT 0,
           maximum         [1]     BaseDistance OPTIONAL }

      BaseDistance ::= INTEGER (0..MAX)

PolicyConstraints ::= SEQUENCE {
        requireExplicitPolicy           [0] SkipCerts OPTIONAL,
        inhibitPolicyMapping            [1] SkipCerts OPTIONAL }

SkipCerts ::= INTEGER (0..MAX)

CertRevReq ::= SEQUENCE {
	endCertRevReq	RevReq,
	caCerts	  [0] RevReq
                             }

RevReq ::= SEQUENCE  {
    enuRevReq  EnuRevReq,
    exRevReq    SignPolExtensions OPTIONAL}

Internet Draft                                   Electronic Signature Formats

EnuRevReq  ::= ENUMERATED {
	clrCheck	(0), --Checks must be made against current CRLs
	-- (or authority revocation lists)
	ocspCheck	(1), -- The revocation status must be checked
	-- using the Online Certificate Status Protocol (RFC 2450)
	bothCheck	(2),
      -- Both CRL and OCSP checks must be carried out
	eitherCheck	(3),
      -- At least one of CRL or OCSP checks must be carried out
	noCheck		(4),
      -- no check is mandated
	other		(5)
      -- Other mechanism as defined by signature policy extension
	                                        }

SigningCertTrustCondition ::=   SEQUENCE {
     signerTrustTrees              CertificateTrustTrees,
     signerRevReq                  CertRevReq
                                               }

TimestampTrustCondition ::= SEQUENCE {
    ttsCertificateTrustTrees	[0]		CertificateTrustTrees
                                                        OPTIONAL,
    ttsRevReq			[1]		CertRevReq
                                                        OPTIONAL,
    ttsNameConstraints  	[2]		NameConstraints
                                                        OPTIONAL,
    cautionPeriod		[3]		DeltaTime
                                                        OPTIONAL,
    signatureTimestampDelay	[4]		DeltaTime
                                                       OPTIONAL }

DeltaTime ::= SEQUENCE {
	deltaSeconds	INTEGER,
	deltaMinutes	INTEGER,
	deltaHours	INTEGER,
	deltaDays	INTEGER }

AttributeTrustCondition ::= SEQUENCE {
	attributeMandated            BOOLEAN,
                                -- Attribute must be present
	howCertAttribute             HowCertAttribute,
	attrCertificateTrustTrees   [0] CertificateTrustTrees  OPTIONAL,
	attrRevReq                  [1] CertRevReq             OPTIONAL,
	attributeConstraints        [2] AttributeConstraints   OPTIONAL }

HowCertAttribute ::= ENUMERATED {
	claimedAttribute    (0),
	certifiedAttribtes  (1),
	either		    (2) }

Internet Draft                                   Electronic Signature Formats

AttributeConstraints ::= SEQUENCE {
	attributeTypeConstarints	[0] AttributeTypeConstraints
                                                        OPTIONAL,
	attributeValueConstarints	[1] AttributeValueConstraints
                                                       OPTIONAL }

AttributeTypeConstraints ::= SEQUENCE OF AttributeType

AttributeValueConstraints ::= SEQUENCE OF AttributeTypeAndValue

AlgorithmConstraintSet ::= SEQUENCE {   -- Algorithm constrains on:
signerAlgorithmConstraints	[0] 	AlgorithmConstraints OPTIONAL,
                                 -- signer
eeCertAlgorithmConstraints	[1] 	AlgorithmConstraints OPTIONAL,
                                 -- issuer of end entity certs.
caCertAlgorithmConstraints	[2] 	AlgorithmConstraints OPTIONAL,
                                 -- issuer of CA certificates
aaCertAlgorithmConstraints	[3] 	AlgorithmConstraints OPTIONAL,
                                 -- Attribute Authority
tsaCertAlgorithmConstraints	[4] 	AlgorithmConstraints OPTIONAL
                                 -- TimeStamping Authority
			                            }

AlgorithmConstraints ::= SEQUENCE OF AlgAndLength

AlgAndLength ::= SEQUENCE {
	algID			OBJECT IDENTIFIER,
	minKeyLength	INTEGER 	OPTIONAL,
                             -- Minimum key length in bits other
 		SignPolExtensions OPTIONAL
		 }

SignPolExtensions ::= SEQUENCE OF SignPolExtn

SignPolExtn ::= SEQUENCE {
        extnID      OBJECT IDENTIFIER,
		extnValue   OCTET STRING  }

END -- ETS-ElectronicSignature-88syntax --

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A.2	Definitions Using X.680 1997 ASN.1 Syntax

NOTE:	The ASN.1 module defined in clause A.1 has precedence over that
defined in clause A.2 in the case of any conflict.

ETS-ElectronicSignature-97Syntax { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-mod(0) 6}

DEFINITIONS EXPLICIT TAGS ::=
BEGIN
-- EXPORTS All -

IMPORTS

-- Crypographic Message Syntax (CMS): RFC 2630
	ContentInfo, ContentType, id-data, id-signedData, SignedData,
	EncapsulatedContentInfo, SignerInfo,
	id-contentType, id-messageDigest, MessageDigest, id-signingTime,
      SigningTime, id-countersignature, Countersignature

   FROM CryptographicMessageSyntax
    { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
    smime(16) modules(0) cms(1) }

-- ESS Defined attributes: RFC 2634 (Enhanced Security Services
-- for S/MIME)
   id-aa-signingCertificate, SigningCertificate, IssuerSerial,
   id-aa-contentReference, ContentReference,
   id-aa-contentIdentifier, ContentIdentifier
	FROM ExtendedSecurityServices
    { iso(1) member-body(2) us(840) rsadsi(113549)
       pkcs(1) pkcs-9(9) smime(16) modules(0) ess(2) }

-- Internet X.509 Public Key Infrastructure
- - Certificate and CRL Profile:RFC 2459
      Certificate, AlgorithmIdentifier, CertificateList, Name,
      GeneralNames, GeneralName, DirectoryString, Attribute,
      AttributeTypeAndValue, AttributeType, AttributeValue,
	PolicyInformation.

  FROM PKIX1Explicit93
  	{iso(1) identified-organization(3) dod(6) internet(1)
   	security(5) mechanisms(5) pkix(7) id-mod(0)
        id-pkix1-explicit-88(1)}

-- X.509 '97 Authentication Framework
        AttributeCertificate
        FROM AuthenticationFramework
        {joint-iso-ccitt ds(5) module(1) authenticationFramework(7) 3}

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-- OCSP 2560
      BasicOCSPResponse, ResponderID
	FROM OCSP
--  { OID not assigned }

-- Time Stamp Protocol Internet Draft TimeStampToken
	FROM TSP
-- { OID not assigned };

-- S/MIME Object Identifier arcs used in this document
-- ==================================================================

-- S/MIME  OID arc used in this document
-- id-smime OBJECT IDENTIFIER ::= { iso(1) member-body(2)
--             us(840) rsadsi(113549) pkcs(1) pkcs-9(9) 16 }

-- S/MIME Arcs
-- id-mod  OBJECT IDENTIFIER ::= { id-smime 0 }
-- modules
-- id-ct   OBJECT IDENTIFIER ::= { id-smime 1 }
-- content types
-- id-aa   OBJECT IDENTIFIER ::= { id-smime 2 }
-- attributes
-- id-spq  OBJECT IDENTIFIER ::= { id-smime 5 }
-- signature policy qualifier
-- id-cti  OBJECT IDENTIFIER ::= { id-smime 6 }
-- commitment type identifier

-- Definitions of Object Identifier arcs used in this document
-- ==================================================================

-- The allocation of OIDs to specific objects are given below with the
-- associated ASN.1 syntax definition

-- OID used referencing electronic signature mechanisms based on this
-- standard for use with the IDUP API (see annex D)

id-etsi-es-IDUP-Mechanism-v1 OBJECT IDENTIFIER ::=
	{ itu-t(0) identified-organization(4) etsi(0)
	   electronic-signature-standard (1733) part1 (1)
         idupMechanism (4)etsiESv1(1) }

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-- CMS Attributes Defined in this document
-- ==============================================

-- Mandatory Electronic Signature Attributes
-- OtherSigningCertificate

id-aa-ets-otherSigCert OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 19 }

OtherSigningCertificate ::=  SEQUENCE {
    certs        SEQUENCE OF OtherCertID,
    policies     SEQUENCE OF PolicyInformation OPTIONAL
                 -- NOT USED IN THIS DOCUMENT
    }

OtherCertID ::= SEQUENCE {
     otherCertHash            OtherHash,
     issuerSerial             IssuerSerial OPTIONAL }

OtherHash ::= CHOICE {
    sha1Hash OtherHashValue,  -- This contains a SHA-1 hash
    otherHash OtherHashAlgAndValue}

OtherHashValue ::= OCTET STRING

OtherHashAlgAndValue ::= SEQUENCE {
	hashAlgorithm	AlgorithmIdentifier,
	hashValue		OtherHashValue }

-- Signature Policy Identifier

id-aa-ets-sigPolicyId OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-aa(2) 15 }

SignaturePolicyIdentifier ::= SEQUENCE {
        sigPolicyIdentifier   SigPolicyId,
		sigPolicyHash         SigPolicyHash,
        sigPolicyQualifiers   SEQUENCE SIZE (1..MAX) OF
                                SigPolicyQualifierInfo OPTIONAL}

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SigPolicyId ::= OBJECT IDENTIFIER

SigPolicyHash ::= ETSIHashAlgAndValue

SigPolicyQualifierInfo ::= SEQUENCE {
        sigPolicyQualifierId       SIG-POLICY-QUALIFIER.&id
                                 ({SupportedSigPolicyQualifiers}),
        qualifier               SIG-POLICY-QUALIFIER.&Qualifier
                                ({SupportedSigPolicyQualifiers}
                                 {@sigPolicyQualifierId})OPTIONAL }

SupportedSigPolicyQualifiers SIG-POLICY-QUALIFIER ::=
                           { noticeToUser | pointerToSigPolSpec }

SIG-POLICY-QUALIFIER ::= CLASS {
        &id             OBJECT IDENTIFIER UNIQUE,
        &Qualifier      OPTIONAL }

WITH SYNTAX {
        SIG-POLICY-QUALIFIER-ID     &id
        [SIG-QUALIFIER-TYPE &Qualifier] }

noticeToUser SIG-POLICY-QUALIFIER ::= {
      SIG-POLICY-QUALIFIER-ID id-sqt-unotice SIG-QUALIFIER-TYPE
                   SPUserNotice
                                  }

pointerToSigPolSpec SIG-POLICY-QUALIFIER ::= {
      SIG-POLICY-QUALIFIER-ID id-sqt-uri SIG-QUALIFIER-TYPE SPuri }

    id-spq-ets-uri OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 1 }

   SPuri ::= IA5String

	id-spq-ets-unotice OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
    smime(16) id-spq(5) 2 }

   SPUserNotice ::= SEQUENCE {
        noticeRef        NoticeReference OPTIONAL,
        explicitText     DisplayText OPTIONAL}

   NoticeReference ::= SEQUENCE {
        organization     DisplayText,
        noticeNumbers    SEQUENCE OF INTEGER }

   DisplayText ::= CHOICE {
        visibleString    VisibleString  (SIZE (1..200)),
        bmpString        BMPString      (SIZE (1..200)),
        utf8String       UTF8String     (SIZE (1..200)) }

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-- Optional Electronic Signature Attributes

-- Commitment Type

id-aa-ets-commitmentType OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 16}

CommitmentTypeIndication ::= SEQUENCE {
  commitmentTypeId CommitmentTypeIdentifier,
  commitmentTypeQualifier SEQUENCE SIZE (1..MAX) OF
                                           CommitmentTypeQualifier
                                           OPTIONAL}

CommitmentTypeIdentifier ::= OBJECT IDENTIFIER

CommitmentTypeQualifier ::= SEQUENCE {
        commitmentQualifierId       COMMITMENT-QUALIFIER.&id,
        qualifier                   COMMITMENT-QUALIFIER.&Qualifier
                                                  OPTIONAL }

COMMITMENT-QUALIFIER ::= CLASS {
                    &id             OBJECT IDENTIFIER UNIQUE,
                    &Qualifier      OPTIONAL }
WITH SYNTAX {
         COMMITMENT-QUALIFIER-ID     &id
                        [COMMITMENT-TYPE &Qualifier] }

	id-cti-ets-proofOfOrigin OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 1}

	id-cti-ets-proofOfReceipt OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 2}

	id-cti-ets-proofOfDelivery OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 3}

	id-cti-ets-proofOfSender OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 4}

	id-cti-ets-proofOfApproval OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 5}

	id-cti-ets-proofOfCreation OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) cti(6) 6}

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-- Signer Location

id-aa-ets-signerLocation OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 17}

SignerLocation ::= SEQUENCE {
                       -- at least one of the following must be present
			countryName [0] DirectoryString OPTIONAL,
				-- As used to name a Country in X.500
		localityName [1] DirectoryString OPTIONAL,
 				-- As used to name a locality in X.500
			postalAdddress [2] PostalAddress OPTIONAL }

	PostalAddress ::= SEQUENCE SIZE(1..6) OF DirectoryString

-- Signer Attributes

id-aa-ets-signerAttr OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 18}

SignerAttribute ::= SEQUENCE OF CHOICE {
			claimedAttributes	[0] ClaimedAttributes,
			certifiedAttributes [1] CertifiedAttributes }

ClaimedAttributes ::= SEQUENCE OF Attribute

CertifiedAttributes ::= AttributeCertificate
-- As defined in X.509 : see section 10.3

-- Content Timestamp

id-aa-ets-contentTimestamp OBJECT IDENTIFIER ::= { iso(1)
      member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
      smime(16) id-aa(2) 20}

ContentTimestamp::= TimeStampToken

-- Validation Data

-- Signature Timestamp

id-aa-signatureTimeStampToken OBJECT IDENTIFIER ::= { iso(1)
     member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 14}

SignatureTimeStampToken ::= TimeStampToken

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-- Complete Certificate Refs.

id-aa-ets-certificateRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 21}

CompleteCertificateRefs ::=  SEQUENCE OF ETSICertID

-- Complete Revocation Refs

id-aa-ets-revocationRefs OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 22}

CompleteRevocationRefs ::=  SEQUENCE OF CrlOcspRef

CrlOcspRef ::= SEQUENCE {
    crlids           [0] CRLListID   OPTIONAL,
    ocspids          [1] OcspListID  OPTIONAL,
	otherRev	   [2] OtherRevRefs OPTIONAL
                                          }

CRLListID ::=  SEQUENCE {
    crls        SEQUENCE OF CrlValidatedID}

CrlValidatedID ::=  SEQUENCE {
     crlHash                   ETSIHash,
     crlIdentifier             CrlIdentifier OPTIONAL}

CrlIdentifier ::= SEQUENCE {
    crlissuer                 Name,
    crlIssuedTime             UTCTime,
    crlNumber                 INTEGER OPTIONAL
                                            }

OcspListID ::=  SEQUENCE {
    ocspResponses        SEQUENCE OF OcspResponsesID}

OcspResponsesID ::=  SEQUENCE {
    ocspIdentifier              OcspIdentifier,
    ocspRepHash                 ETSIHash    OPTIONAL
                                            }

OcspIdentifier ::= SEQUENCE {
	ocspResponderID		ResponderID,
                        -- As in OCSP response data
	producedAt			GeneralizedTime
                        -- As in OCSP response data
                                             }

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OtherRevRefs ::= SEQUENCE {
 	otherRevRefType	OTHER-REVOCATION-REF.&id,
	otherRevRefs	OTHER-REVOCATION-REF.&Type
                                              }

OTHER-REVOCATION-REF ::= CLASS {
		&Type,
		&id	OBJECT IDENTIFIER UNIQUE }
	WITH SYNTAX {
		&Type ID &id }

-- Certificate Values

id-aa-ets-certValues OBJECT IDENTIFIER ::= { iso(1) member-body(2)
    us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) id-aa(2) 23}

CertificateValues ::=  SEQUENCE OF Certificate

-- Certificate Revocation Values

id-aa-ets-revocationValues OBJECT IDENTIFIER ::= { iso(1)
     member-body(2)us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 24}

RevocationValues ::=  SEQUENCE {
   crlVals          [0] SEQUENCE OF CertificateList OPTIONAL,
   ocspVals         [1] SEQUENCE OF BasicOCSPResponse OPTIONAL,
   otherRevVals	    [2] OtherRevVals }

OtherRevVals ::= SEQUENCE {
 	otherRevValType	OTHER-REVOCATION-VAL.&id,
	otherRevVals	OTHER-REVOCATION-VAL.&Type
                                               }

OTHER-REVOCATION-VAL ::= CLASS {
		&Type,
		&id	OBJECT IDENTIFIER UNIQUE }
	WITH SYNTAX {
		&Type ID &id }

-- ES-C Timestamp

id-aa-ets-escTimeStamp OBJECT IDENTIFIER ::= { iso(1)
     member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
     smime(16) id-aa(2) 25}

ESCTimeStampToken ::= TimeStampToken

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-- Time-Stamped Certificates and CRLs

id-aa-ets-certCRLTimestamp OBJECT IDENTIFIER ::= { iso(1)
    member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
    smime(16) id-aa(2) 26}

TimestampedCertsCRLs ::= TimeStampToken

-- Archive Timestamp

id-aa-ets-archiveTimestamp OBJECT IDENTIFIER ::= { iso(1)
   member-body(2)us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
   smime(16) id-aa(2) 27}

ArchiveTimeStampToken ::= TimeStampToken

-- Signature Policy Specification
-- ==============================

SignaturePolicy ::= SEQUENCE {
	signPolicyHashAlg      AlgorithmIdentifier,
	signPolicyInfo         SignPolicyInfo,
	signPolicyHash         SignPolicyHash     OPTIONAL }

SignPolicyHash ::= OCTET STRING

SignPolicyInfo ::= SEQUENCE {
	signPolicyIdentifier            SignPolicyId,
	dateOfIssue                     GeneralizedTime,
	policyIssuerName                PolicyIssuerName,
	fieldOfApplication              FieldOfApplication,
	signatureValidationPolicy 	SignatureValidationPolicy,
	signPolExtensions		SignPolExtensions
	                                                OPTIONAL
	                                                       }

SignPolicyId ::= OBJECT IDENTIFIER

PolicyIssuerName ::= GeneralNames

FieldOfApplication ::= DirectoryString

SignatureValidationPolicy ::= SEQUENCE {
	signingPeriod          SigningPeriod,
	commonRules            CommonRules,
	commitmentRules        CommitmentRules,
	signPolExtensions      SignPolExtensions   OPTIONAL
                                                       }

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SigningPeriod ::= SEQUENCE {
	notBefore	GeneralizedTime,
	notAfter	GeneralizedTime OPTIONAL }

CommonRules  ::= SEQUENCE {
	signerAndVeriferRules          [0]  SignerAndVerifierRules
                                                         OPTIONAL,
	signingCertTrustCondition      [1]  SigningCertTrustCondition
                                                         OPTIONAL,
	timeStampTrustCondition        [2]  TimestampTrustCondition
                                                         OPTIONAL,
	attributeTrustCondition        [3]  AttributeTrustCondition
                                                         OPTIONAL,
	algorithmConstraintSet         [4]  AlgorithmConstraintSet
                                                         OPTIONAL,
	signPolExtensions	       [5]  SignPolExtensions
                                                         OPTIONAL
                                                        }

CommitmentRules ::= SEQUENCE OF CommitmentRule

CommitmentRule  ::= SEQUENCE {
	selCommitmentTypes                  SelectedCommitmentTypes,
	signerAndVeriferRules          [0]  SignerAndVerifierRules
                                                         OPTIONAL,
	signingCertTrustCondition      [1]  SigningCertTrustCondition
                                                         OPTIONAL,
	timeStampTrustCondition        [2]  TimestampTrustCondition
                                                         OPTIONAL,
	attributeTrustCondition        [3]  AttributeTrustCondition
                                                         OPTIONAL,
	algorithmConstraintSet         [4]  AlgorithmConstraintSet
                                                         OPTIONAL,
	signPolExtensions	       [5]  SignPolExtensions
                                                         OPTIONAL
                                                              }

SelectedCommitmentTypes ::= SEQUENCE OF CHOICE {
	empty                        NULL,
	recognizedCommitmentType     CommitmentType }

CommitmentType ::= SEQUENCE {
	identifier			CommitmentTypeIdentifier,
	fieldOfApplication	[0] FieldOfApplication OPTIONAL,
	semantics		[1] DirectoryString OPTIONAL }

SignerAndVerifierRules ::= SEQUENCE {
	signerRules      SignerRules,
	verifierRules    VerifierRules }

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SignerRules ::= SEQUENCE {
	externalSignedData         BOOLEAN	OPTIONAL,
		      -- True if signed data is external to CMS structure
			-- False if signed data part of CMS structure
			-- not present if either allowed
	mandatedSignedAttr         CMSAttrs,
                  -- Mandated CMS signed attributes
	mandatedUnsignedAttr       CMSAttrs,
                  -- Mandated CMS unsigned attributed
	mandatedCertificateRef     [0] CertRefReq DEFAULT signerOnly,
			-- Mandated Certificate Reference
	mandatedCertificateInfo    [1] CertInfoReq DEFAULT none,
			-- Mandated Certificate Info
	signPolExtensions		 [2] SignPolExtensions	OPTIONAL
                                                      }

CMSAttrs ::= SEQUENCE OF OBJECT IDENTIFIER

CertRefReq ::= ENUMERATED {
				signerOnly (1),
                   -- Only reference to signer cert mandated
				fullPath (2)
                   -- References for full cert path up to a trust
                   -- point required
									}

CertInfoReq ::= ENUMERATED {
				none (0)	,
                   -- No mandatory requirements
				signerOnly (1)	,
                   -- Only reference to signer cert mandated
				fullPath (2)
			 -- References for full cert path up to a
                   -- trust point mandated
		                                          }

VerifierRules ::= SEQUENCE {
		mandatedUnsignedAttr	MandatedUnsignedAttr,
		signPolExtensions		SignPolExtensions		OPTIONAL
		}

MandatedUnsignedAttr ::=  CMSAttrs
                          -- Mandated CMS unsigned attributed

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CertificateTrustTrees ::=   SEQUENCE OF CertificateTrustPoint

CertificateTrustPoint ::= SEQUENCE {
	trustpoint				Certificate,
                          -- self-signed certificate
	pathLenConstraint	[0] PathLenConstraint   OPTIONAL,
	acceptablePolicySet	[1] AcceptablePolicySet OPTIONAL,
                          -- If not present "any policy"
	nameConstraints		[2] NameConstraints     OPTIONAL,
	policyConstraints	[3] PolicyConstraints   OPTIONAL }

PathLenConstraint    ::=   INTEGER (0..MAX)

AcceptablePolicySet ::= SEQUENCE OF CertPolicyId

CertPolicyId ::= OBJECT IDENTIFIER

NameConstraints ::= SEQUENCE {
           permittedSubtrees       [0]     GeneralSubtrees OPTIONAL,
           excludedSubtrees        [1]     GeneralSubtrees OPTIONAL }

      GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree

      GeneralSubtree ::= SEQUENCE {
           base                    GeneralName,
           minimum         [0]     BaseDistance DEFAULT 0,
           maximum         [1]     BaseDistance OPTIONAL }

      BaseDistance ::= INTEGER (0..MAX)

PolicyConstraints ::= SEQUENCE {
        requireExplicitPolicy           [0] SkipCerts OPTIONAL,
        inhibitPolicyMapping            [1] SkipCerts OPTIONAL }

SkipCerts ::= INTEGER (0..MAX)

CertRevReq ::= SEQUENCE {
	endCertRevReq	RevReq,
	caCerts	     [0] RevReq
                                          }

RevReq ::= SEQUENCE  {
    enuRevReq  EnuRevReq,
    exRevReq    SignPolExtensions OPTIONAL}

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EnuRevReq  ::= ENUMERATED {
	clrCheck	(0),
                   -- Checks must be made against current CRLs
                   -- (or authority revocation lists)
	ocspCheck	(1),
                   -- The revocation status must be checked using
                   -- the Online Certificate Status Protocol (RFC 2450)
	bothCheck	(2),
                   -- Both CRL and OCSP checks must be carried out
	eitherCheck	(3),
                   -- At least one of CRL or OCSP checks must be carried out
	noCheck		(4),
                   -- no check is mandated
	other		(5)
                   -- Other mechanism as defined by signature poilicy
                   -- extension
	                                      }

SigningCertTrustCondition ::=   SEQUENCE {
     signerTrustTrees              CertificateTrustTrees,
     signerRevReq                  CertRevReq
                                              }

TimestampTrustCondition ::= SEQUENCE {
    ttsCertificateTrustTrees	[0]		CertificateTrustTrees
                                                       OPTIONAL,
    ttsRevReq			[1]		CertRevReq
                                                       OPTIONAL,
    ttsNameConstraints  	[2]		NameConstraints
                                                       OPTIONAL,
    cautionPeriod		[3]		DeltaTime
                                                       OPTIONAL,
    signatureTimestampDelay	[4]		DeltaTime
                                                      OPTIONAL }

DeltaTime ::= SEQUENCE {
	deltaSeconds	INTEGER,
	deltaMinutes	INTEGER,
	deltaHours	INTEGER,
	deltaDays	INTEGER }

AttributeTrustCondition ::= SEQUENCE {
	attributeMandated            BOOLEAN,
                               -- Attribute must be present
	howCertAttribute             HowCertAttribute,
	attrCertificateTrustTrees   [0] CertificateTrustTrees  OPTIONAL,
	attrRevReq                  [1] CertRevReq             OPTIONAL,
	attributeConstraints        [2] AttributeConstraints   OPTIONAL }

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HowCertAttribute ::= ENUMERATED {
	claimedAttribute	(0),
	certifiedAttribtes	(1),
	either			(2) }

AttributeConstraints ::= SEQUENCE {
	attributeTypeConstarints	[0] AttributeTypeConstraints
                                                       OPTIONAL,
	attributeValueConstarints	[1] AttributeValueConstraints
                                                       OPTIONAL }

AttributeTypeConstraints ::= SEQUENCE OF AttributeType

AttributeValueConstraints ::= SEQUENCE OF AttributeTypeAndValue

AlgorithmConstraintSet ::= SEQUENCE {
                               -- Algorithm constrains on:
signerAlgorithmConstraints	[0] 	AlgorithmConstraints OPTIONAL,
                                -- signer
eeCertAlgorithmConstraints	[1] 	AlgorithmConstraints OPTIONAL,
                                -- issuer of end entity certs.
caCertAlgorithmConstraints	[2] 	AlgorithmConstraints OPTIONAL,
                                -- issuer of CA certificates
aaCertAlgorithmConstraints	[3] 	AlgorithmConstraints OPTIONAL,
                                -- Attribute Authority
tsaCertAlgorithmConstraints	[4] 	AlgorithmConstraints OPTIONAL
                                -- TimeStamping Authority
	                                     		 }

AlgorithmConstraints ::= SEQUENCE OF AlgAndLength

AlgAndLength ::= SEQUENCE {
	algID		OBJECT IDENTIFIER,
	minKeyLength	INTEGER 	OPTIONAL,
                               -- Minimum key length in bits
	other 		SignPolExtensions OPTIONAL
                                        		 }

SignPolExtensions ::= SEQUENCE OF SignPolExtn

SignPolExtn ::= SEQUENCE {
        extnID      OBJECT IDENTIFIER,
	extnValue   OCTET STRING  }

END                           -- ETS-ElectronicSignature-97Syntax

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Annex B (informative):

General Description

This annex captures the concepts that apply to this document and the
rational for the elements of the specification defined using ASN.1 in
the main text of this document.

The specification below includes a description why the component is
needed, with a brief description of the vulnerabilities and threats and
the manner by which they are countered.

B.1	The Signature Policy

The signature policy is a set of rules for the creation and validation
of an electronic signature, under which the signature can be determined
to be valid. A given legal/contractual context may recognize a
particular signature policy as meeting its requirements. A signature
policy may be issued, for example, by a party relying on the electronic
signatures and selected by the signer for use with that relying party.
Alternatively, a signature policy may be established through an
electronic trading association for use amongst its members. Both the
signer and verifier use the same signature policy.

A signature policy has a globally unique reference, which is bound to
an electronic signature by the signer as part of the signature
calculation.

The signature policy needs to be available in human readable form so
that it can be assessed to meet the requirements of the legal and
contractual context in which it is being applied. To facilitate the
automatic processing of an electronic signature the parts of the
signature policy which specify the electronic rules for the creation
and validation of the electronic signature also needs to be in a
computer processable form.

The signature policy thus includes the following:

     * Rules, which apply to functionality, covered by this document
       (referred to as the Signature Validation Policy).
     * Rules which may be implied through adoption of Certificate
       Policies that apply to the electronic signature (e.g. rules for
       ensuring the secrecy of the private signing key).
     * Rules, which relate to the environment used by the signer,
       e.g. the use of an agreed CAD (Card Accepting Device) used
       in conjunction with a smart card.

The Signature Validation Policy may be structured so that it can be
computer processable. The current document includes, as an option, a
formal structure for the signature validation policy based on the used
of Abstract Syntax Notation 1 (ASN.1). Other formats of the signature
validation policy are allowed by this document. However, for a given
signature policy there must be one definitive form that has a unique
binary encoded value.

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The Signature Validation Policy includes rules regarding use of TSPs
(CA, Attribute Authorities, Time Stamping Authorities) as well as rules
defining the components of the electronic signature that must be
provided by the signer with data required by the verifier to provide
long term proof.

B.2	Signed Information

The information being signed may be defined as a MIME-encapsulated
message which can be used to signal the format of the content in order
to select the right display or application. It can be composed of
formatted text (e.g. EDIFACT), free text or of fields from an
electronic form (e-form). For example, the Adobe(tm) format "pdf" may
be used or the eXtensible Mark up Language (XML).

B.3	Components of an Electronic Signature

B.3.1	Reference to the Signature Policy

The definition of electronic signature includes: "a commitment has been
explicitly endorsed under a "Signature policy", at a given time, by a
signer under an identifier, e.g. a name or a pseudonym, and optionally
a role".

When two independent parties want to evaluate an electronic signature,
it is fundamental that they get the same result. To meet this
requirement the technical components and technical aspects used in
creating the signature must be referenced, this is provided by a
reference to the "Signature Validation Policy". The "Signature
Validation Policy" defines:

    * the components of an electronic signature to be provided by the
       signer;
    * any additional components (i.e. verifier components) used to
      validate an electronic signature at the time of receipt by a
      verifier and later by an arbitrator, auditor or other
      independent parties.

By signing over the signature policy identifier, the algorithm
identifier and the hash of the signature policy, the signer explicitly
indicates that he or she has applied the signature policy in creating
the signature. Thus, undertakes any commitments implied by the
signature policy, any indication of commitment type included in the
electronic signature, and the user data that is signed.

The hash algorithm identifier and value is included to ensure that both
the signer and verifier use exactly the same signature policy. This
unambiguously binds the signer and verifier to same definitive form of
the signature policy has a unique binary encoding.

Internet Draft                                   Electronic Signature Formats

In order to identify unambiguously the "Signature Validation Policy" to
be used to verify the signature an identifier and hash of the
"Signature policy" must be part of the signed data. Additional
information about the policy (e.g. web reference to the document) may
be carried as "qualifiers" to the signature policy identifier

B.3.2	Commitment Type Indication

The definition of electronic signature includes: "a commitment has been
explicitly endorsed under a signature policy, at a given time, by a
signer under an identifier, e.g. a name or a pseudonym, and optionally a
role".

The commitment type can be indicated in the electronic signature
either:

      * explicitly using a "commitment type indication" in the
        electronic signature;

      * implicitly or explicitly from the semantics of the signed data.

If the indicated commitment type is explicit using a "commitment type
indication" in the electronic signature , acceptance of a verified
signature implies acceptance of the semantics of that commitment type.
The semantics of explicit commitment types indications must be
specified either as part of the signature policy or may be registered
for generic use across multiple policies.

If a signature includes a commitment type indication other than one of
those recognized under the signature policy the signature must be
treated as invalid.

How commitment is indicated using the semantics of the data being
signed is outside the scope of this document.

NOTE:	Examples of commitment indicated through the semantics of the
data being signed, are:

     * An explicit commitment made by the signer indicated by the type
       of data being signed over.  Thus, the data structure being
       signed can have an explicit commitment within the context of the
       application (e.g. EDIFACT purchase order).

     * An implicit commitment which is a commitment made by the signer
       because the data being signed over has specific semantics
      (meaning) which is only interpretable by humans,
      (i.e. free text).

Internet Draft                                   Electronic Signature Formats

B.3.4	Certificate Identifier from the Signer

The definition of the ETSI electronic signature includes: "a commitment
has been explicitly endorsed under a signature policy, at a given time,
by a signer under an identifier, e.g. a name or a pseudonym, and
optionally a role."

In many real life environments users will be able to get from different
CAs or even from the same CA, different certificates containing the
same public key for different names. The prime advantage is that a user
can use the same private key for different purposes. Multiple use of
the private key is an advantage when a smart card is used to protect
the private key, since the storage of a smart card is always limited.
When several CAs are involved, each different certificate may contain a
different identity, e.g. as a national or as an employee from a
company. Thus when a private key is used for various purposes, the
certificate is needed to clarify the context in which the private key
was used when generating the signature. Where there is the possibility
of multiple use of private keys it is necessary for the
signer to indicate to the verifier the precise certificate to be used.

Many current schemes simply add the certificate after the signed data
and thus are subject to various substitution attacks. An example of a
substitution attack is a "bad" CA that would issue a certificate to
someone with the public key of someone else. If the certificate from
the signer was simply appended to the signature and thus not protected
by the signature, any one could substitute one certificate by another
and the message would appear to be signed by some one else.

In order to counter this kind of attack, the identifier of the signer
has to be protected by the digital signature from the signer.

Although it does not provide the same advantages as the previous
technique, another technique to counter that threat has been
identified. It requires all CAs to perform a Proof Of Possession of the
private key at the time of registration. The problem with that
technique is that it does not provide any guarantee at the time of
verification and only some proof "after the event" may be obtained, if
and only if the CA keeps the Proof Of Possession in audit trail.

In order to identify unambiguously the certificate to be used for the
verification of the signature an identifier of the certificate from the
signer must be part of the signed data.

B.3.5	Role Attributes

The definition of electronic signature includes: "a commitment has been
explicitly endorsed under a non repudiation security policy, at a given
time, by a signer under an identifier, e.g. a name or a pseudonym, and
optionally a role. "

Internet Draft                                   Electronic Signature Formats

While the name of the signer is important, the position of the signer
within a company or an organization can be even more important. Some
contracts may only be valid if signed by a user in a particular role,
e.g. a Sales Director. In many cases whom the sales Director really is,
is not that important but being sure that the signer is empowered by
his company to be the Sales Director is fundamental.

This document defines two different ways for providing this feature:

      * by placing a claimed role name in the CMS signed
        attributes field;
     * by placing a attribute certificate containing a certified
       role name in the CMS signed attributes field.

NOTE:	Another possible approach would have been to use additional
attributes containing the roles name(s) in the signer's certificate.
However, it was decided not to follow this approach as it breaks the
basic philosophy of the certificate being issued for one primary
purpose. Also, by using separate certificates for management of the
signer's identity certificate and management of additional roles can
simplify the management, as new identity keys need not be issued if a
use of role is to be changed.

B.3.5.1	Claimed Role

The signer may be trusted to state his own role without any certificate
to corroborate this claim. In which case the claimed role can be added
to the signature as a signed attribute.

B.3.5.2	Certified Role

Unlike public key certificates that bind an identifier to a public key,
Attribute Certificates bind the identifier of a certificate to some
attributes, like a role. An Attribute Certificate is NOT issued by a CA
but by an Attribute Authority (AA). The Attribute Authority will be
most of the time under the control of an organization or a company that
is best placed to know which attributes are relevant for which
individual. The Attribute Authority may use or point to public key
certificates issued by any CA, provided that the appropriate trust may
be placed in that CA. Attribute Certificates may have various periods
of validity. That period may be quite short, e.g. one day. While this
requires that a new Attribute Certificate is obtained every day, valid
for that day, this can be advantageous since revocation of such
certificates may not be needed. When signing, the signer will have to
specify which Attribute Certificate it selects. In order to do
so, the Attribute Certificate will have to be included in the signed
data in order to be protected by the digital signature from the signer.

Internet Draft                                   Electronic Signature Formats

In order to identify unambiguously the attribute certificate(s) to be
used for the verification of the signature an identifier of the
attribute certificate(s) from the signer must be part of the signed
data.

B.3.6	Signer Location

In some transactions the purported location of the signer at the time
he or she applies his signature may need to be indicated. For this
reason an optional location indicator must be able to be included.

In order to provide indication of the location of the signer at the
time he or she applied his signature a  location attribute may be
included in the signature.

B.3.7	Signing Time

The definition of electronic signature includes: "a commitment has been
explicitly endorsed under a signature policy, at a given time, by a
signer under an identifier, e.g. a name or a pseudonym, and optionally a
role. "

There are several ways to address this problem. The solution adopted in
this document is to sign over a time which the signer claims is the
signing time (i.e. claimed signing time) and to require  a trusted time
stamp to be obtained when building a ES with Timestamp. When a verifier
accepts a signature, the two times must be within acceptable limits.

The solution that is adopted in this document offers the major
advantage that electronic signatures can be generated without any on-
line connection to a trusted time source (i.e. they may be generated
off-line).

Thus two dates and two signatures are required:
     * a signing time indicated by the signer and which is part of
       the data signed by the signer (i.e. part of the basic electronic
       signature);
     * a time indicated by a TimeStamping Authority (TSA) which is
       signed over the digital signature value of the basic electronic
       signature. The signer, verifier or both may obtain the TSA
       timestamp.

In order for an electronic signature to be valid under a signature
policy, it must be timestamped by a TSA where the signing time as
indicated by the signer and the time of time stamping as indicated by a
TSA must be "close enough" to meet the requirements of the signature
validation policy.

"Close enough" means a few minutes, hours or even days according to the
"Signature Validation Policy".

Internet Draft                                   Electronic Signature Formats

NOTE:	The need for Timestamping is further explained in clause B.4.5.
A further optional attribute is defined in this document to timestamp
the content, to provide proof of the existence of the content, at the
time indicated by the timestamp.

Using this optional attribute a trusted secure time may be obtained
before the document is signed and included under the digital signature.
This solution requires an on-line connection to a trusted timestamping
service before generating the signature and may not represent the
precise signing time, since it can be obtained in advance.  However,
this optional attribute may be used by the signer to prove that the
signed object existed before the  date included in the timestamp (see
4.12.3, Content Timestamp).

Also, the signing time should be between the time indicated by this
timestamp and time indicated by the ES-T timestamp.

B.4	Components of Validation Data

B.4.1	Revocation Status Information

A verifier will have to prove that the certificate of the signer was
valid at the time of the signature. This can be done by either:
     * using Certificate Revocation Lists (CRLs);
     * using responses from an on-line certificate status server
       (for example; obtained through the OCSP protocol).

B.4.2	CRL Information

When using CRLs to get revocation information, a verifier will have to
make sure that he or she gets at the time of the first verification the
appropriate certificate revocation information from the signer's CA.
This should be done as soon as possible to minimize the time delay
between the generation and verification of the signature. This involves
checking that the signer certificate serial number is not included in
the CRL. The signer, the verifier or any other third party may obtain
either this CRL. If obtained by the signer, then it must be conveyed
to the verifier. It may be convenient to archive the CRL for ease of
subsequent verification or arbitration.

Alternatively, provided the CRL is archived elsewhere which is
accessible for the purpose of arbitration, then the serial number of
the CRL used may be archived together with the verified electronic
signature.

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It may happen that the certificate serial number appears in the CRL but
with the status "suspended" (i.e. on hold). In such a case, the
electronic signature is not yet valid, since it is not possible to know
whether the certificate will or will not be revoked at the end of the
suspension period. If a decision has to be taken immediately then the
signature has to be considered as invalid. If a decision can wait until
the end of the suspension period, then two cases are possible:

     * the certificate serial number has disappeared from the list
       and thus the certificate can be considered as valid and that CRL
       must be captured and archived either by the verifier or
       elsewhere and be kept accessible for the purpose of arbitration.

     * the certificate serial number has been maintained on the list
       with the status definitively revoked and thus the electronic
       signature must be considered as invalid and discarded.

At this point the verifier may be convinced that he or she got a valid
signature, but is not yet in a position to prove at a later time that
the signature was verified as valid. Before addressing this point, an
alternative to CRL is to use OCSP responses.

B.4.3	OCSP Information

When using OCSP to get revocation information , a verifier will have to
make sure that he or she gets at the time of the first verification an
OCSP response that contains the status "valid".

Annex B (informative): General Description

This should be done as
soon as possible after the generation of the signature. The signer, the
verifier or any other third party may fetch this OCSP response. Since
OSCP responses are transient and thus are not archived by any TSP
including CA, it is the responsibility of every verifier to make sure
that it is stored in a safe place. The simplest way is to store them
associated with the electronic signature. An alternative would be to
store them in some storage so that they can then be easily retrieved.

In the same way as for the case of the CRL, it may happen that the
certificate is declared as invalid but with the secondary status
"suspended".

In such a case, annex captures the electronic signature is not yet valid, since it is
not possible concepts that apply to know whether this document and the certificate will or will not be
revoked at
rational for the end elements of the suspension period. If a decision has to be
taken immediately then the electronic signature has to be considered as
invalid. If a decision can wait until specification defined using ASN.1 in
the end main text of the suspension period,
then two cases are possible:

     * An OCSP response with a valid status is obtained at this document.

The specification below includes a later date
       and thus description why the certificate can be considered as valid and that
       OCSP response must be captured.

     * An OCSP response with an invalid status component is obtained
needed, with a
       secondary status indicating that brief description of the certificate is definitively
       revoked vulnerabilities and thus the electronic signature must be considered as
       invalid threats
and discarded.

Internet Draft                                   Electronic the manner by which they are countered.

B.1  The Signature Formats

As in Policy

The signature policy is a set of rules for the CRL case, at this point, creation and validation
of an electronic signature, under which the verifier may signature can be convinced that
he or she got a valid signature, but is not yet in a position
determined to prove
at be valid. A given legal/contractual context may
recognize a later time that the particular signature was verified policy as valid.

B.4.4	Certification Path meeting its requirements.
A verifier will have to prove that the certification path was valid, at
the time of the signature, up to signature policy may be issued, for example, by a trust point according to party relying on
the naming
constraints electronic signatures and selected by the certificate signer for use with that
relying party. Alternatively, a signature policy constraints from the "Signature
Validation Policy". It will may be necessary to capture all the
certificates from the certification path, starting with those from established
through an electronic trading association for use amongst its members.
Both the signer and ending up with those of verifier use the self-signed certificate from one
trusted root same signature policy.

A signature policy has a globally unique reference, which is bound to
an electronic signature by the signer as part of the "Signature Validation Policy". In addition, signature
calculation.

The signature policy needs to be available in human readable form so
that it will can be necessary to capture the Authority Revocation Lists (ARLs) assessed to prove
than none of the CAs from the chain was revoked at meet the time requirements of the
signature.

As legal and
contractual context in the OCSP case, at this point, the verifier may be convinced that
he or she got a valid signature, but which it is not yet in a position to prove
at a later time that being applied. To facilitate the signature was verified as valid.

B.4.5	Timestamping for Long Life
automatic processing of Signature

An important property for long standing signatures is that a signature,
having been found once to be valid, must continue to be so months or
years later.

A signer, verifier or both may be required to provide on request, proof
that a digital an electronic signature was created or verified during the validity
period parts of the all
signature policy which specify the certificates that make up electronic rules for the certificate path.
In this case, creation
and validation of the signer, verifier or both will electronic signature also be required needs to
provide proof that all be in a
computer processable form.

The signature policy thus includes the user and CA certificates used were not
revoked when following:

     * Information about the signature was created or verified.

It would policy that can be quite unacceptable, displayed
       to consider a signature as invalid even
if the keys signer or certificates were later compromised. Thus there is a
need the verifiers.
     * Rules, which apply to be able functionality, covered by this document
       (referred to demonstrate as the Signature Validation Policy).
     * Rules which may be implied through adoption of Certificate
       Policies that apply to the electronic signature keys was valid around (e.g. rules for
       ensuring the time that secrecy of the signature was created private signing key).
     * Rules, which relate to provide long term evidence
of the validity environment used by the signer,
       e.g. the use of an agreed CAD (Card Accepting Device) used
       in conjunction with a signature.

It could smart card.

The Signature Validation Policy may be the case structured so that a certificate was valid at the time it can be
computer processable. Any format of the signature but revoked some time later. In validation policy
is allowed by this event, evidence document. However, for a given signature policy
there must be
provided one definitive form that the document was signed before the signing key was
revoked.

Timestamping by has a Time Stamping Authority (TSA) can provide such
evidence. A time stamp is obtained by sending unique binary encoded
value.

Internet Draft                             Electronic Signature Formats

The Signature Validation Policy includes rules regarding use of TSPs
(CA, Attribute Authorities, Time Stamping Authorities) as well as
rules defining the hash value components of the
given electronic signature that must be
provided by the signer with data to required by the TSA. verifier to provide
long term proof.

B.2  Signed Information

The returned "timestamp" is a information being signed document
that contains the hash value, may be defined as a MIME-encapsulated
message which can be used to signal the identity format of the TSA, and content in order
to select the time right display or application. It can be composed of
stamping. This proves that
formatted text (e.g. EDIFACT), free text or of fields from an
electronic form (e-form). For example, the given data existed before Adobe(tm) format "pdf" may
be used or the time of
stamping. Timestamping a digital signature (by sending a hash eXtensible Mark up Language (XML).

B.3  Components of the
signature an Electronic Signature

B.3.1  Reference to the TSA) before the revocation Signature Policy

The definition of the signer's private
key, provides evidence that the electronic signature includes: "a commitment has
been created before the
key was revoked.

Internet Draft                                   Electronic Signature Formats

If explicitly endorsed under a recipient wants to hold "Signature policy", at a valid electronic signature he will have
to ensure that he has obtained given time,
by a valid time stamp for it, before signer under an identifier, e.g. a name or a pseudonym, and
optionally a role".

When two independent parties want to evaluate an electronic signature,
it is fundamental that
key (and any key involved in they get the validation) is revoked. The sooner same result. To meet this
requirement the technical components and technical aspects used in
creating the
timestamp signature must be referenced, this is obtained after provided by a
reference to the signing time, "Signature Validation Policy". The "Signature
Validation Policy" defines:

    * the better.

It is important components of an electronic signature to note that signatures may be generated "off-line" and
time-stamped provided by the
      signer;

    * any additional components (i.e. verifier components) used to
      validate an electronic signature at a later the time of receipt by anyone, for example a
      verifier and later by the signer an arbitrator, auditor or
any recipient interested in other
      independent parties.

By signing over the value signature policy identifier, the algorithm
identifier and the hash of the signature. The time stamp
can thus be provided by signature policy, the signer together with the signed document, explicitly
indicates that he or obtained by the recipient following receipt of she has applied the signed document.

The time stamp is NOT a component of signature policy in creating
the Electronic Signature, but signature. Thus, undertakes any commitments implied by the
essential component
signature policy, any indication of the ES with Timestamp.

It is required commitment type included in this document the
electronic signature, and the user data that signer's digital signature is signed.

The hash algorithm identifier and value is timestamped by a trusted source, known as a TimeStamping Authority.

This document requires included to ensure that
both the signer's digital signer and verifier use exactly the same signature value is
timestamped by a trusted source before policy.
This unambiguously binds the signer and verifier to same definitive
form of the electronic signature can
become policy has a ES with Complete validation data (ES-C). The acceptable TSAs
are specified in the unique binary encoding.

Internet Draft                             Electronic Signature Validation Policy.

Should both Formats

In order to identify unambiguously the signer and verifier "Signature Validation Policy"
to be required used to timestamp verify the signature value to meet an identifier and hash of the requirements
"Signature policy" must be part of the signature policy, signed data. Additional
information about the
signature policy MAY specify a permitted time delay between the two
time stamps.

B.4.6	Timestamping for Long Life of Signature before CA Key Compromises

Timestamped extended electronic signatures are needed when there is a
requirement (e.g. web reference to safeguard against the possibility of a CA key in the
certificate chain ever being compromised. A verifier document) may
be required carried as "qualifiers" to
provide on request, proof that the certification path signature policy identifier.

B.3.2  Commitment Type Indication

The definition of electronic signature includes: "a commitment has
been explicitly endorsed under a signature policy, at a given time,
by a signer under an identifier, e.g. a name or a pseudonym, and the
revocation information used
optionally a role".

The commitment type can be indicated in the time of the electronic signature were valid,
even
either:

      * explicitly using a "commitment type indication" in the case where one of the issuing keys or OCSP responder keys
is later compromised.

The current document defines two ways of using timestamps to protect
against this compromise:
        electronic signature;

      * Timestamp the ES with Complete validation data, when an OCSP
      response is used to get implicitly or explicitly from the status semantics of the certificate from the
      signer.
    * Timestamp only signed data.

If the certification path and revocation information
      references when a CRL indicated commitment type is used to get explicit using a "commitment type
indication" in the status electronic signature, acceptance of a verified
signature implies acceptance of the
      certificate from the signer.

NOTE: semantics of that commitment type.
The semantics of explicit commitment types indications must be
specified either as part of the signer, verifier signature policy or both may obtain be registered
for generic use across multiple policies.

If a signature includes a commitment type indication other than one of
those recognized under the timestamp.

Internet Draft                                   Electronic Signature Formats

B.4.6.1	Timestamping signature policy the ES with Complete validation data

When an OCSP response signature must be
treated as invalid.

How commitment is used, it indicated using the semantics of the data being
signed is necessary to time stamp in
particular that response in outside the case scope of this document.

NOTE:  Examples of commitment indicated through the key from semantics of the responder would
be compromised. Since
data being signed, are:

     * An explicit commitment made by the information contained in signer indicated by the OCSP response is
user specific and time specific, an individual time stamp is needed for
every signature received. Instead type
       of placing data being signed over. Thus, the time stamp only over data structure being
       signed can have an explicit commitment within the certification path references and context of
       the revocation information
references, application (e.g. EDIFACT purchase order).

     * An implicit commitment which include the OCSP response, the time stamp is placed
on the ES-C. Since a commitment made by the certification path and revocation information
references are included in signer
       because the ES with Complete validation data they
are also protected. For the same cryptographic price, this provides an
integrity mechanism being signed over has specific semantics
       (meaning) which is only interpretable by humans, (i.e. free
       text).

Internet Draft                             Electronic Signature Formats

B.3.3  Certificate Identifier from the ES with Complete validation data. Any
modification can be immediately detected. It should be noticed that
other means of protecting/detecting the integrity Signer

The definition of the ES with
Complete Validation Data exist ETSI electronic signature includes: "a
commitment has been explicitly endorsed under a signature policy,
at a given time, by a signer under an identifier, e.g. a name or a
pseudonym, and could optionally a role."

In many real life environments users will be used.

Although able to get from
different CAs or even from the technique requires a time stamp same CA, different certificates
containing the same public key for every signature, it different names. The prime
advantage is
well suited that a user can use the same private key for individual users wishing to have an integrity protected
copy different
purposes. Multiple use of all the validated signatures they have received.

By timestamping private key is an advantage when a smart
card is used to protect the complete electronic signature, including private key, since the
digital signature storage of a smart
card is always limited. When several CAs are involved, each different
certificate may contain a different identity, e.g. as well a national or as the references to the certificates and
revocation status information used to support validation of that
signature, the timestamp ensures that there
an employee from a company. Thus when a private key is no ambiguity in used for
various purposes, the
means of validating that signature.

This technique certificate is referred needed to as ES with eXtended validation data (ES-
X), type 1 Timestamped clarify the context in this document.

NOTE:	Trust
which the private key was used when generating the signature. Where
there is achieved in the references by including a hash possibility of the
data being referenced.

If multiple use of private keys it is desired
necessary for any reason to keep a copy of the additional data
being referenced, the additional data may be attached signer to indicate to the electronic
signature, in which case verifier the electronic signature becomes a ES-X Long
as defined by this document.

A ES-X Long Timestamped  is precise
certificate to be used.

Many current schemes simply add the concatenation of a ES-X
Timestamped  with a copy of certificate after the additional signed data being referenced.

B.4.6.2	Timestamping Certificates
and Revocation Information

References Timestamping each ES with Complete validation data as
defined above may not be efficient, particularly when the same set thus are subject to various substitution attacks. An example of
CA certificates and CRL information a
substitution attack is used to validate many
signatures.

Internet Draft                                   Electronic Signature Formats

Timestamping CA certificates will stop any attacker from issuing bogus a "bad" CA certificates that could be claimed would issue a certificate to existing before
someone with the CA public key was
compromised. Any bogus timestamped CA certificates will show that of someone else. If the certificate was created after from
the legitimate CA key signer was compromised. In
the same way, timestamping CA CRLs, will stop any attacker from issuing
bogus CA CRLs which could be claimed simply appended to existing before the CA key was
compromised.

Timestamping of commonly used certificates signature and thus not protected
by the signature, any one could substitute one certificate by another
and CRLs can the message would appear to be done
centrally, e.g. inside a company or signed by a service provider. This method
reduces some one else.

In order to counter this kind of attack, the amount identifier of data the verifier signer
has to timestamp, for example
it could reduce to just one time stamp per day (i.e. in be protected by the case were
all digital signature from the signers use signer.

Although it does not provide the same CA and the CRL applies for advantages as the whole day).
The information previous
technique, another technique to counter that needs threat has been
identified. It requires all CAs to be perform a Proof Of Possession of
the private key at the time stamped of registration. The problem with that
technique is that it does not provide any guarantee at the actual
certificates time of
verification and CRLs but only some proof "after the unambiguous references event" may be obtained, if
and only if the CA keeps the Proof Of Possession in audit trail.

In order to those
certificates identify unambiguously the certificate to be used for the
verification of the signature an identifier of the certificate from
the signer must be part of the signed data.

B.3.4  Role Attributes

The definition of electronic signature includes: "a commitment has
been explicitly endorsed under a non repudiation security policy,
at a given time, by a signer under an identifier, e.g. a name or a
pseudonym, and CRLs.

To comply with extended validation data, type 2 Timestamped, this
document requires optionally a role. "

Internet Draft                             Electronic Signature Formats

While the name of the following:
     * All signer is important, the CA certificates references and revocation information
       references (i.e. CRLs) used in validating position of the ES-C are covered
       by one or more timestamp.

Thus a ES-C with signer
within a timestamp signature value at time T1, company or an organization can be proved even more important. Some
contracts may only be valid if all the CA and CRL references are timestamped at time T1+.

B.4.7	Timestamping for Long Life of Signature

Advances signed by a user in computing increase a particular role,
e.g. a Sales Director. In many cases whom the probability of sales Director really
is, is not that important but being able to break
algorithms and compromise keys. There sure that the signer is therefore a requirement empowered
by his company to be
able to protect electronic signatures against this probability.

Over a period of time weaknesses may occur in the cryptographic
algorithms used to create an electronic signature (e.g. due to the time
available Sales Director is fundamental.

This document defines two different ways for cryptoanalysis, or improvements in cryptoanalytical
techniques). Before providing this such weaknesses become likely, feature:

      * by placing a verifier
should take extra measures to maintain the validity of the electronic
signature. Several techniques could be used to achieve this goal
depending on the nature of claimed role name in the weakened cryptography. In order to
simplify, CMS signed
        attributes field;

     * by placing a single technique, called Archive validation data, covering
all attribute certificate containing a certified
       role name in the cases is being used CMS signed attributes field.

NOTE:  Another possible approach would have been to use additional
attributes containing the roles name(s) in the signer's certificate.
However, it was decided not to follow this document.

Archive validation data consists approach as it breaks the
basic philosophy of the Complete validation data and certificate being issued for one primary
purpose. Also, by using separate certificates for management of the complete
signer's identity certificate and revocation data, time stamped together
with management of additional roles can
simplify the electronic signature. The Archive validation data  is
necessary management, as new identity keys need not be issued if the hash function and the crypto algorithms that were used a
use of role is to create the signature are no longer secure. Also, if it cannot be
assumed that the hash function used by the Time Stamping Authority is
secure, then nested timestamps of Archived Electronic Signature are
required.

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B.3.5.1  Claimed Role

The potential for Trusted Service Provider (TSP) key compromise should signer may be significantly lower than user keys, because TSP(s) are expected trusted to
use stronger cryptography and better key protection. It state his own role without any
certificate to corroborate this claim. In which case the claimed role
can be expected
that new algorithms (or old ones with greater key lengths) will be
used. In such added to the signature as a case, signed attribute.

B.3.5.2  Certified Role

Unlike public key certificates that bind an identifier to a sequence public
key, Attribute Certificates bind the identifier of timestamps will protect against
forgery. Each timestamp needs a certificate to
some attributes, like a role. An Attribute Certificate is NOT issued
by a CA but by an Attribute Authority (AA). The Attribute Authority
will be affixed before either the
compromise most of the signing key or of time under the cracking control of the algorithms used an organization or a
company that is best placed to know which attributes are relevant for
which individual.

The Attribute Authority may use or point to public key certificates
issued by any CA, provided that the TSA. TSAs (TimeStamping Authorities) should appropriate trust may be placed
in that CA. Attribute Certificates may have long keys (e.g.
which at the time various periods of drafting
validity. That period may be quite short, e.g. one day. While this document was 2048 bits
requires that a new Attribute Certificate is obtained every day, valid
for that day, this can be advantageous since revocation of such
certificates may not be needed. When signing, the
signing RSA algorithm) and/or a "good" or different algorithm.

Nested timestamps signer will also protect the verifier against key compromise
or cracking the algorithm on have to
specify which Attribute Certificate it selects. In order to do
so, the old electronic signatures.

The process Attribute Certificate will need have to be performed and iterated before included in the
cryptographic algorithms signed
data in order to be protected by the digital signature from the signer.

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In order to identify unambiguously the attribute certificate(s) to be
used for generating the previous time stamp
are no longer secure. Archive validation data may thus bear multiple
embedded time stamps.

B.4.8	Reference to Additional Data

Using type 1 or 2 verification of Timestamped extended validation data verifiers
still needs to keep track the signature an identifier of the
attribute certificate(s) from the signer must be part of all the components that were used to
validate signed
data.

B.3.5  Signer Location

In some transactions the signature, in order purported location of the signer at the time
he or she applies his signature may need to be indicated. For this
reason an optional location indicator must be able to retrieve them again
later on. These components be included.

In order to provide indication of the location of the signer at the
time he or she applied his signature a  location attribute may be archived
included in the signature.

B.3.6  Signing Time

The definition of electronic signature includes: "a commitment has
been explicitly endorsed under a signature policy, at a given time,
by a signer under an external source like identifier, e.g. a
trusted service provider, name or a pseudonym, and
optionally a
role. "

There are several ways to address this problem. The solution adopted
in this document is to sign over a time which case referenced information that the signer claims is
provided as part of the
signing time (i.e. claimed signing time) and to require a trusted
time stamp to be obtained when building a ES with Complete validation data (ES-C) is
adequate. Timestamp. When a
verifier accepts a signature, the two times must be within acceptable
limits.

The actual certificates and CRL information reference solution that is adopted in this document offers the
ES-C major
advantage that electronic signatures can be gathered when needed for arbitration.

B.4.9	Timestamping for Mutual Recognition

In some business scenarios both generated without any on-
line connection to a trusted time source (i.e. they may be generated
off-line).

Thus two dates and two signatures are required:

     * a signing time indicated by the signer and the verifier need to
timestamp their own copy which is part of
       the signature value. Ideally the two
timestamps should be as close as possible to each other.

Example: A contract is data signed by two parties A and B representing their
respective organizations, to timestamp the signer and verifier data two
approaches are possible:

      * under the terms (i.e. part of the contract pre-defined common "trusted"
        TSA may be used; basic
       electronic signature);

     * if both organizations run their own timestamping services, A
        and B can have the transaction timestamped a time indicated by these two
        timestamping services.In a TimeStamping Authority (TSA) which is
       signed over the latter case, digital signature value of the basic electronic
       signature. The signer, verifier or both may obtain the TSA
       timestamp.

In order for an electronic signature will only to be considered as valid, if both timestamps
        were obtained in due time (i.e. there should not valid under a signature
policy, it must be timestamped by a long
        delay between obtaining the two timestamps). Thus, neither A
        nor B can repudiate TSA where the signing time as
indicated by their own
        timestamping service.

Therefore, A the signer and B do not need to agree on the time of time stamping as indicated by
a common "trusted" TSA must be "close enough" to
get a valid transaction. meet the requirements of the signature
validation policy.

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It is important

"Close enough" means a few minutes, hours or even days according to note that signatures may be generated "off-line" and
timestamped
the "Signature Validation Policy".

NOTE:  The need for Timestamping is further explained in clause B.4.5.
A further optional attribute is defined in this document to timestamp
the content, to provide proof of the existence of the content, at a later the
time by anyone, e.g. indicated by the signer or any
recipient interested in validating timestamp.

Using this optional attribute a trusted secure time may be obtained
before the document is signed and included under the digital signature. The timestamp over
This solution requires an on-line connection to a trusted timestamping
service before generating the signature from and may not represent the signer
precise signing time, since it can thus be provided obtained in advance.  However,
this optional attribute may be used by the signer
together with to prove that the
signed document, and /or obtained by object existed before the verifier
following receipt of date included in the signed document.

The business scenarios may thus dictate that one or more of timestamp (see
3.12.3, Content Timestamp).

Also, the long-
term signature timestamping methods describe above signing time should be used. This between the time indicated by this
timestamp and time indicated by the ES-T timestamp.

B.4  Components of Validation Data

B.4.1  Revocation Status Information

A verifier will
need have to be part of a mutually agreed prove that the Signature Validation Policy
with is part certificate of the overall signature policy under which digital
signature may be used to support signer was
valid at the business relationship between time of the
two parties.

B.4.10	TSA Key Compromise

TSA servers should signature. This can be built in such done by either:

     * using Certificate Revocation Lists (CRLs);

     * using responses from an on-line certificate status server
       (for example; obtained through the OCSP protocol).

B.4.2  CRL Information

When using CRLs to get revocation information, a way verifier will have to
make sure that once he or she gets at the private
signature key is installed, that there is minimal likelihood time of
compromise over as long as possible period. Thus the validity period
for first verification the TSA's keys
appropriate certificate revocation information from the signer's CA.
This should be done as long soon as possible.

Both the ES-T and possible to minimize the ES-C contain at least one time stamp over the
signer's signature. In order to protect against delay
between the compromise generation and verification of the
private signature key used to produce signature. This involves
checking that timestamp, the Archive
validation data can be used when a different TimeStamping Authority key signer certificate serial number is involved to produce not included in
the additional timestamp. CRL. The signer, the verifier or any other third party may obtain
either this CRL. If obtained by the signer, then it is believed that must be conveyed
to the TSA key used in providing an earlier timestamp verifier. It may ever be
compromised (e.g. outside its validity period), convenient to archive the CRL for ease of
subsequent verification or arbitration.

Alternatively, provided the CRL is archived elsewhere which is
accessible for the purpose of arbitration, then the ES-A should be
used. For extremely long periods this serial number of
the CRL used may be applied repeatedly using
new TSA keys.

B.5	Multiple Signatures

Some archived together with the verified electronic signatures may only be valid if they bear more than one
signature. This is

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It may happen that the case generally when a contract is signed between
two parties. The ordering of certificate serial number appears in the CRL
but with the status "suspended" (i.e. on hold). In such a case, the signatures may or may
electronic signature is not be
important, i.e. one may or may yet valid, since it is not need possible to be applied before
know whether the other.

Several forms of multiple and counter signatures need to certificate will or will not be supported,
which fall into two basic categories:
     * independent signatures;
     * embedded signatures.
Independent signatures are parallel signatures where revoked at the ordering end
of the signatures is not important. The capability suspension period. If a decision has to have more than one
independent signature over the same data must be provided.

Embedded signatures are applied one after the other and are used where
the order taken immediately
then the signatures are applied is important. The capability signature has to
sign over signed data must be provided.

These forms are described in clause 4.13. All other multiple signature
schemes, e.g. a signed document with considered as invalid. If a countersignature, double
countersignatures or multiple signatures, decision can be reduced to one or more
occurrence
wait until the end of the above suspension period, then two cases.

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Annex C (informative):

C.1	Signature Policy and Signature Validation Policy

The definition of electronic signature mentions: "a commitment cases are
possible:

     * the certificate serial number has been
explicitly endorsed under a "Signature Policy", at a given time, disappeared from the list
       and thus the certificate can be considered as valid and that
       CRL must be captured and archived either by a
signer under an identifier, e.g. a name the verifier or a pseudonym, and optionally
a role. "

Electronic signatures are commonly applied within
       elsewhere and be kept accessible for the context purpose of a
legal or contractual framework. This establishes arbitration.

     * the requirements certificate serial number has been maintained on the list
       with the status definitively revoked and thus the electronic signatures
       signature must be considered as invalid and any special semantics (e.g. agreement,
intent). These requirements discarded.

At this point the verifier may be defined in very general abstract
terms convinced that he or she got a valid
signature, but is not yet in terms of detailed rules. The specific semantics associated
with an electronic a position to prove at a later time that
the signature implied by was verified as valid. Before addressing this point, an
alternative to CRL is to use OCSP responses.

B.4.3  OCSP Information

When using OCSP to get revocation information , a legal verifier will have
to make sure that he or contractual
framework are outside she gets at the scope time of this document.

If the signature policy is recognized, within first verification
an OCSP response that contains the legal/contractual
context, status "valid". This should be done
as providing commitment, then soon as possible after the signer explicitly agrees
with terms and conditions which are implicitly or explicitly part generation of the signed data.

When two independent parties want to evaluate an electronic signature,
it is fundamental that they get the same result. It is therefore
important that signature. The signer,
the conditions agreed verifier or any other third party may fetch this OCSP response.
Since OSCP responses are transient and thus are not archived by any
TSP including CA, it is the signer at the time responsibility of
signing are indicated every verifier to make
sure that it is stored in a safe place. The simplest way is to store
them associated with the verifier and any arbitrator. electronic signature. An aspect
that enables this alternative would be
to store them in some storage so that they can then be known by all parties is easily
retrieved.

In the signature policy.
The technical implications same way as for the case of the signature policy on CRL, it may happen that the electronic
signature
certificate is declared as invalid but with all the validation data are called secondary status
"suspended".

In such a case, the "Signature
Validation Policy". The electronic signature validation policy specifies
the rules used is not yet valid, since it is
not possible to validate know whether the signature.

This document does certificate will or will not mandate the form and encoding of be
revoked at the
specification end of the signature policy. However, for suspension period. If a given signature
policy there must decision has to be one definitive form that
taken immediately then the electronic signature has a unique binary
encoded value.

This document includes, to be considered
as an option, invalid. If a formal structure for signature
validation policy based on the use of Abstract Syntax Notation 1
(ASN.1).

Given decision can wait until the specification end of the signature policy and its hash value an
implementation of suspension
period, then two cases are possible:

     * An OCSP response with a verification process must obey the rules defined
in valid status is obtained at a later
       date and thus the specification.

This document places no restriction on how it should certificate can be implemented.
Provide the implementation conforms to the conformance requirements considered as
define in clause 14.1, 14.2 valid and 14.3 implementation options include:
       that OCSP response must be captured.

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A validation process that supports a specific signature policy as
identified by the signature policy OID. Such

     * An OCSP response with an implementation should
conform to invalid status is obtained with a human readable description provided all
       secondary status indicating that the processing
rules of certificate is
       definitively revoked and thus the electronic signature policy are clearly defined. However, if
additional policies need to be supported, then such an implementation
would need to must be customized for each additional policy. This type of
implementation
       considered as invalid and discarded.

As in the CRL case, at this point, the verifier may be simpler to implement initially, but can be
difficult to enhance to support numerous additional signature policies.

A validation process convinced that is dynamically programmable and able to adapt
its validation rules in accordance with
he or she got a description of the signature
policy provided valid signature, but is not yet in a computer-processable language. This present
document defines such position to prove
at a policy using an ASN.1 structure (see 6.1). This
type of implementation could support multiple signature policies
without being modified every time, provided all later time that the validation rules
specified signature was verified as part of valid.

B.4.4  Certification Path

A verifier will have to prove that the signature policy are known by certification path was valid,
at the
implementation. (i.e. only requires modification if there are
additional rules specified).

The precise content time of a signature policy is not mandated by the
current document. However, a signature policy must be sufficiently
definitive signature, up to avoid any ambiguity as a trust point according to its implementation
requirements. the
naming constraints and the certificate policy constraints from the
"Signature Validation Policy". It must be absolutely clear under which conditions an
electronic signature should will be accepted. For this reason, it should
contain the following information:

     * General information about necessary to capture all the signature policy which includes:
        - a unique identifier of
certificates from the policy;
        - certification path, starting with those from the name
signer and ending up with those of the issuer self-signed certificate from
one trusted root of the policy;
        - "Signature Validation Policy". In addition, it
will be necessary to capture the date Authority Revocation Lists (ARLs) to
prove than none of the policy CAs from the chain was issued;
        - revoked at the field of application time of
the policy.

     * The signature verification policy which includes:
       - signature.

As in the signing period,
       - OCSP case, at this point, the verifier may be convinced that
he or she got a list of recognized commitment types;
       - rules for Use of Certification Authorities;
       - rules for Use of Revocation Status Information;
       - rules valid signature, but is not yet in a position to prove
at a later time that the signature was verified as valid.

B.4.5  Timestamping for Use Long Life of Roles;
       - rules Signature

An important property for use of Timestamping and Timing;
       - signature verification data long standing signatures is that a
signature, having been found once to be provided by the
         signer/collected by verifier;
       - any constraints on signature algorithms and key lengths.
     * Other signature policy rules valid, must continue to be so
months or years later.

A signer, verifier or both may be required to meet provide on request,
proof that a digital signature was created or verified during the objectives
validity period of the signature.

Variations of all the validation policy rules may apply to different
commitment types.

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C.2	Identification of Signature Policy

When data is signed certificates that make up the
certificate path. In this case, the signer indicates signer, verifier or both will
also be required to provide proof that all the user and CA
certificates used were not revoked when the signature policy
applicable was created
or verified.

It would be quite unacceptable, to that electronic consider a signature by including an object
identifier for as invalid
even if the signature policy with keys or certificates were later compromised. Thus there
is a need to be able to demonstrate that the signature. The signer and
verifier must apply signature keys was valid
around the rules specified by time that the identified policy. In
addition signature was created to the identifier provide long term
evidence of the signature policy validity of a signature.

It could be the signer must
include case that a certificate was valid at the hash time of the
signature policy, so it can but revoked some time later. In this event, evidence must be verified
provided that the policy selected by the signer is the identical to the one being
used document was signed before the verifier.

A signature policy may be qualified signing key was
revoked.

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Timestamping by additional information. This a Time Stamping Authority (TSA) can
includes:

     * provide such
evidence. A URL where a copy time stamp is obtained by sending the hash value of the Signature Policy may be obtained;
     * A user notice that should be displayed when
given data to the signature is
       verified;

If no signature policy TSA. The returned "timestamp" is identified then a signed document
that contains the signature may be assumed
to have been generated/verified without any policy constraints, hash value, the identity of the TSA, and
hence may be the time of
stamping. This proves that the given no specific legal or contractual significance
through data existed before the context time of
stamping. Timestamping a digital signature policy.

A "Signature Policy" will be identifiable by an OID (Object Identifier)
and verifiable using (by sending a hash of the
signature policy.

C.3	General Signature Policy Information

General information should be recorded about to the signature policy along
with TSA) before the definition revocation of the rules which form signer's private
key, provides evidence that the signature policy as
described has been created before the
key was revoked.

If a recipient wants to hold a valid electronic signature he will have
to ensure that he has obtained a valid time stamp for it, before that
key (and any key involved in subsequent subclauses. This should include:

     * Policy Object Identifier: the validation) is revoked. The "Signature Policy" will be
       identifiable by an OID (Object Identifier) whose last component
       (i.e. right most) sooner
the timestamp is an integer that obtained after the signing time, the better.

It is specific important to note that signatures may be generated "off-line"
and time-stamped at a particular
        version issued on later time by anyone, for example by the given date.
     * Date signer
or any recipient interested in the value of issue: When the "Signature Policy" was issued.
     * Signature Policy Issuer name: An identifier for signature. The time
stamp can thus be provided by the body
       responsible for issuing signer together with the Signature Policy. signed
document, or obtained by the recipient following receipt of the signed
document.

The time stamp is NOT a component of the Electronic Signature, but the
essential component of the ES with Timestamp.

It is required in this document that signer's digital signature value
is timestamped by a trusted source, known as a TimeStamping Authority.

This may be used document requires that the signer's digital signature value is
timestamped by the signer or verifying in deciding if a policy is to be
       trusted, in which case the signer/verifier must authenticate
       the origin of trusted source before the electronic signature policy as coming from the identified
       issuer.
     * Signing period: The start time and date, optionally can
become a ES with an end
       time and date, for Complete validation data (ES-C). The acceptable TSAs
are specified in the period over which Signature Validation Policy.

Should both the signature policy
       may signer and verifier be used required to generate electronic signatures.
     * Field of application: This defines in general terms the general
       legal/contract/application contexts in which timestamp the
signature
       policy is value to be used and meet the specific purposes for which requirements of the
       electronic signature is to be applied.

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C.4	Recognized Commitment Types

The signature validation policy may recognize one or more types of
commitment as being supported by electronic signatures produced under policy, the security policy.If an electronic
signature does not contain policy MAY specify a
recognized commitment type then the semantics of permitted time delay between the two
time stamps.

B.4.6  Timestamping before CA Key Compromises

Timestamped extended electronic
signature signatures are needed when there is dependent on the data being signed and a
requirement to safeguard against the context in
which it is being used.

Only recognized commitment types are allowed in an electronic
signature.

The definition possibility of a commitment type includes:
     * the object identifier for the commitment;
     * the contractual/legal/application context CA key in which the signature
certificate chain ever being compromised. A verifier may be used (e.g. submission of messages);
     * a description of the support provided within the terms of the
       context (e.g. required
to provide on request, proof that the identified source submitted certification path and the
       message if
revocation information used a the time of the signature were valid,
even in the case where one of the issuing keys or OCSP responder keys
is created when message submission is
       initiated). later compromised.

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The definition current document defines two ways of a commitment type can be registered: using timestamps to protect
against this compromise:

    * as part of Timestamp the ES with Complete validation policy;
     * as part of data, when an OCSP
      response is used to get the application/contract/legal environment;
     * as part of generic register status of definitions.

The legal/contractual context will determine the rules applied to certificate from the
signature, as defined by
      signer.

    * Timestamp only the signature policy certification path and its recognized
commitment types, make it fit for purpose intended.

C.5	Rules for Use of Certification Authorities

The certificate validation process revocation information
      references when a CRL is used to get the status of the verifier, and hence
      certificate from the
certificates that may be used by signer.

NOTE:  the signer for a valid electronic
signature, signer, verifier or both may be constrained by obtain the combination of timestamp.

B.4.6.1  Timestamping the trust point and
certificate path constraints ES with Complete validation data

When an OCSP response is used, it is necessary to time stamp in
particular that response in the signature validation policy.

C.5.1	Trust Points

The signature validation policy defines case the certification authority
trust points that are to key from the responder would
be used compromised. Since the information contained in the OCSP response
is user specific and time specific, an individual time stamp is needed
for every signature verification. Several
trust points may be specified under one signature policy. Specific
trust points may be specified for a particular type received. Instead of commitment
defined under placing the time stamp only
over the signature policy. For a signature to be valid a certification path must exists between references and the Certification Authority
that has granted revocation information
references, which include the certificate selected by OCSP response, the signer (i.e. time stamp is placed
on the used
user-certificate) ES-C. Since the certification path and one revocation information
references are included in the ES with Complete validation data they
are also protected. For the same cryptographic price, this provides an
integrity mechanism over the ES with Complete validation data. Any
modification can be immediately detected. It should be noticed that
other means of protecting/detecting the trust point integrity of the "Signature ES with
Complete Validation Policy".

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C.5.2	Certification Path

There may Data exist and could be constraints on used.

Although the use technique requires a time stamp for every signature, it
is well suited for individual users wishing to have an integrity
protected copy of certificates issued by one or
more CA(s) in all the certificate chain and trust points. The two prime
constraints are certificate policy constraints and naming constraints:

     * Certificate policy constraints limit validated signatures they have received.

By timestamping the certification chain
       between complete electronic signature, including the user certificate and
digital signature as well as the certificate of references to the trusted
       point certificates and
revocation status information used to a given set support validation of certificate policies, or equivalents
       identified through certificate policy mapping.
     * The naming constraints limit that
signature, the forms of names timestamp ensures that there is no ambiguity in the CA
means of validating that signature.

This technique is
       allowed referred to certify.

Name constraints are particularly important when a "Signature policy"
identifies more than one trust point. In as ES with eXtended validation data
(ES-X), type 1 Timestamped in this case, document.

NOTE:  Trust is achieved in the references by including a certificate hash of the
data being referenced.

If it is desired for any reason to keep a
particular trusted point copy of the additional data
being referenced, the additional data may only be used attached to verify signatures from
users with names permitted under the name constraint.

Certificate Authorities may be organized
electronic signature, in which case the electronic signature becomes
a tree structure, ES-X Long as defined by this tree
structure may represent the trust relationship between various CA(s)
and document.

A ES-X Long Timestamped  is simply the users CA. Alternatively, concatenation of a mesh relationship may exist where ES-X
Timestamped  with a
combination copy of tree the additional data being referenced.

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B.4.6.2  Timestamping Certificates and peer cross-certificates Revocation Information

References Timestamping each ES with Complete validation data as
defined above may not be used. The
requirement of the certificate path in this document is that it
provides the trust relationship between all the CAs and efficient, particularly when the signers
user certificate. The starting point from a verification point same set of view,
CA certificates and CRL information is used to validate many
signatures.

Timestamping CA certificates will stop any attacker from issuing bogus
CA certificates that could be claimed to existing before the "trust point". A trust point is usually a CA key
was compromised. Any bogus timestamped CA certificates will show that publishes
self-certified certificates, is
the starting point from which certificate was created after the
verifier verifies legitimate CA key was
compromised. In the certificate chain. Naming constraints may
apply same way, timestamping CA CRLs, will stop any
attacker from the trust point, in issuing bogus CA CRLs which case they apply throughout could be claimed to existing
before the set CA key was compromised.

Timestamping of commonly used certificates that make up the certificate path down to the signer's
user certificate.

Policy constraints and CRLs can be easier to process but to be effective require
the presence of done
centrally, e.g. inside a certificate policy identifier in the certificates
used in company or by a certification path.

Certificate path processing, thus generally starts with one of the
trust point from the signature policy and ends with the user
certificate. The certificate path processing procedures defined in RFC
2459 clause 6 identifies service provider. This method
reduces the following initial parameters that are
selected by amount of data the verifier in certificate path processing:

     * acceptable certificate policies;
     * naming constraints in terms of constrained and excluded naming
       subtree;
     * requirements has to timestamp, for explicit certificate policy indication and
       whether certificate policy mapping are allowed;
     * restrictions on example
it could reduce to just one time stamp per day (i.e. in the certificate path length.

The signature validation policy identifies constraints on these
parameters.

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C.5	Revocation Rules

The signature policy should defines rules specifying requirements for case were
all the signers use of certificate revocation lists (CRLs) and/or on-line
certificate status check service to check the validity of a certificate.
These rules specify same CA and the mandated minimum checks CRL applies for the whole day).
The information that must needs to be carried
out.

It time stamped is expected that in many cases either check may be selected with not the actual
certificates and CRLs checks being carried out for certificate status that are
unavailable from OCSP servers. The verifier may take into account
information in but the unambiguous references to those
certificates and CRLs.

To comply with extended validation data, type 2 Timestamped, this
document requires the certificate in deciding how best to check following:

     * All the CA certificates references and revocation status (e.g. a certificate extension field about authority information access
       references (i.e. CRLs) used in validating the ES-C are covered
       by one or more timestamp.

Thus a CRL distribution point) provided that it does
not conflict ES-C with the a timestamp signature policy revocation rules.

C.6	Rules value at time T1, can be proved
valid if all the CA and CRL references are timestamped at time T1+.

B.4.7  Timestamping for Long Life of Signature

Advances in computing increase the Use probability of Roles

Roles can being able to break
algorithms and compromise keys. There is therefore a requirement to be supported as claimed roles or as certified roles using
Attribute Certificates.

C.6.1	Attribute Values

When signature under
able to protect electronic signatures against this probability.

Over a role is mandated by the signature policy, then
either Attribute Certificates period of time weaknesses may be occur in the cryptographic
algorithms used or to create an electronic signature (e.g. due to the signer may provide a
claimed role attribute. The acceptable attribute types
time available for cryptoanalysis, or values may be
dependent on improvements in cryptoanalytical
techniques). Before this such weaknesses become likely, a verifier
should take extra measures to maintain the type validity of commitment. For example, a user may have
several roles that allow the user electronic
signature. Several techniques could be used to sign data that imply commitments
based achieve this goal
depending on one or more the nature of his roles.

C.6.2	Trust Points for Certified Attributes

When a signature under the weakened cryptography. In order to
simplify, a certified role is mandated by single technique, called Archive validation data, covering
all the signature
policy, Attribute Authorities are cases is being used and need to be validated as part in this document.

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Archive validation data consists of the overall Complete validation of data and
the complete certificate and revocation data, time stamped together
with the electronic signature. The trust points
for Attribute Authorities do not need Archive validation data is
necessary if the hash function and the crypto algorithms that were
used to create the signature are no longer secure. Also, if it cannot
be assumed that the same as hash function used by the trust
points Time Stamping Authority
is secure, then nested timestamps of Archived Electronic Signature are
required.

The potential for Trusted Service Provider (TSP) key compromise should
be significantly lower than user keys, because TSP(s) are expected to evaluate
use stronger cryptography and better key protection. It can be expected
that new algorithms (or old ones with greater key lengths) will be
used. In such a certificate from case, a sequence of timestamps will protect against
forgery. Each timestamp needs to be affixed before either the CA
compromise of the signer. Thus signing key or of the
trust point for verifying roles need not be cracking of the same as trust point algorithms used to validate
by the certificate path TSA. TSAs (TimeStamping Authorities) should have long keys (e.g.
which at the time of drafting this document was 2048 bits for the user's key.

Naming and certification policy constraints may apply to
signing RSA algorithm) and/or a "good" or different algorithm.

Nested timestamps will also protect the AA in
similar circumstance to when they apply to CA. Constraints verifier against key compromise
or cracking the algorithm on the AA
and CA old electronic signatures.

The process will need not to be exactly performed and iterated before the same.

AA(s) may be
cryptographic algorithms used when a signer is creating a signature on behalf of an
organization, they can be particularly useful when for generating the signature
represents an organizational role. AA(s) previous time stamp
are no longer secure. Archive validation data may thus bear multiple
embedded time stamps.

B.4.8  Reference to Additional Data

Using type 1 or may not be the same
authority as CA(s).

Thus, 2 of Timestamped extended validation data verifiers
still needs to keep track of all the Signature Policy identifies trust points components that can be were used for
Attribute Authorities, either by reference to
validate the same trust points as
used for Certification Authorities, or by an independent list.

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C.6.3	Certification Path for Certified Attributes

Attribute Authorities may be organized in a tree structure signature, in similar
way order to CA where the AAs are the leafs of such a tree. Naming and other
constraints be able to retrieve them again
later on. These components may be required on attribute certificate paths in archived by an external source like
a similar
manner to other electronic signature certificate paths.

Thus, the Signature Policy identify constraints on the following
parameters used trusted service provider, in which case referenced information that
is provided as input to part of the certificate path processing:

     * acceptable certificate policies, including requirements for
       explicit certificate policy indication and whether certificate
       policy mapping ES with Complete validation data (ES-C) is allowed;
     * naming constraints in terms of constrained
adequate. The actual certificates and excluded naming
       subtrees;
     * restrictions on the certificate path length.

C.7	Rules for CRL information reference in the Use of Timestamping and Timing

The following rules should
ES-C can be used gathered when specifying, constraints on the
certificate paths needed for arbitration.

B.4.9  Timestamping for timestamping authorities, constraints on Mutual Recognition

In some business scenarios both the
timestamping authority names and general timing constraints.

C.7.1	Trust Points signer and Certificate Paths

Signature keys from timestamping authorities will the verifier need to
timestamp their own copy of the signature value. Ideally the two
timestamps should be supported as close as possible to each other.

Example: A contract is signed by a certification path. The certification path used for timestamping
authorities requires a trustpoint two parties A and possibly path constraints in B representing
their respective organizations, to timestamp the
same way that signer and verifier
data two approaches are possible:

      * under the certificate path for terms of the signer's key.

C.7.2	Timestamping Authority Names

Restrictions contract pre-defined common "trusted"
        TSA may need to be placed used;

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      * if both organizations run their own timestamping services, A
        and B can have the transaction timestamped by these two
        timestamping services. In the validation policy on latter case, the
named entities that may act a timestamping authorities.

C.7.3	Timing Constraints - Caution Period

Before an electronic
        signature may really will only be considered as valid, the verifier has to
be sure that the holder of the private key was really the only one if both timestamps
        were obtained in
possession of key at the due time of signing. However, (i.e. there is an
inevitable should not be a long
        delay between a compromise or loss of key being noted, and a
report of revocation being distributed. To allow greater confidence in obtaining the validity of a signature, two timestamps). Thus, neither A
        nor B can repudiate the signing time indicated by their own
        timestamping service.

Therefore, A and B do not need to agree on a "cautionary period" may be identified
before common "trusted" TSA to
get a signature may be said valid transaction.

It is important to be valid with high confidence. A
verifier note that signatures may revalidate be generated "off-line"
and timestamped at a signature after this cautionary signature, later time by anyone, e.g. by the signer or
wait for this period before any
recipient interested in validating a the signature. The validation policy may specify such a cautionary period.

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C.7.4	Timing Constraints - Timestamp Delay

There will be some delay between timestamp over
the time that a signature is created
and from the time signer can thus be provided by the signer's digital signature is timestamped. However, signer
together with the longer this elapsed period signed document, and /or obtained by the greater verifier
following receipt of the risk signed document.

The business scenarios may thus dictate that one or more of the long-
term signature
being invalidated due timestamping methods describe above be used. This will
need to compromise or deliberate revocation be part of its
private signing key by a mutually agreed the signer. Thus Signature Validation Policy
with is part of the overall signature policy under which digital
signature may be used to support the business relationship between the
two parties.

B.4.10  TSA Key Compromise

TSA servers should
specify be built in such a maximum acceptable delay between way that once the signing time private
signature key is installed, that there is minimal likelihood of
compromise over as claimed
by the signer and the time included within long as possible period. Thus the timestamp.

C.8	Rules validity period
for Verification Data to be followed

By specifying the requirements on the signer and verifier the
responsibilities of the two parties can TSA's keys should be clearly defined to establish
all as long as possible.

Both the necessary information.

These verification data rules should include:
* requirements on ES-T and the signer to provide given signed attributes;
* requirements on ES-C contain at least one time stamp over the verifier
signer's signature. In order to obtain additional certificates, CRLs,
results protect against the compromise of on line certificate status checks and to use timestamps (if
no already provided by the signer).

C.9	Rules for Algorithm Constraints and Key Lengths
The
private signature validation policy may identify a set of signing
algorithms (hashing, public key, combinations) and minimum key lengths used to produce that may be used:

     * by the signer in creating timestamp, the signature;
     * in end entity public Archive
validation data can be used when a different TimeStamping Authority key Certificates;
     * CA Certificates;
     * attribute Certificates;
     * by
is involved to produce the timestamping authority.

C.10	Other Signature Policy Rules

The signature policy may specify additional policy rules, for example
rules timestamp. If it is believed that relate to
the environment TSA key used by the signer. These
additional rules may be defined in computer processable and/or human
readable form.

C.11	Signature Policy Protection

When signer or verifier obtains a copy of the Signature Policy from providing an
issuer, earlier timestamp may ever be
compromised (e.g. outside its validity period), then the source ES-A should be authenticated (for example by
used. For extremely long periods this may be applied repeatedly using
new TSA keys.

B.5  Multiple Signatures

Some electronic signatures). When signatures may only be valid if they bear more than one
signature. This is the signer references case generally when a signature policy
the Object Identifier (OID) contract is signed between
two parties. The ordering of the policy, the hash value and the hash
algorithm OID of that policy must signatures may or may not be included in
important, i.e. one may or may not need to be applied before the Electronic
Signature. other.

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It is a mandatory requirement

Several forms of this present document that the
signature policy value computes to one, multiple and only one hash value using
the specified hash algorithm. This means that there must be a single
binary value of the encoded form of the signature policy for the unique
hash value counter signatures may need to be calculated. For example, there may exist a particular
file type, length and format on which the hash value is calculated
supported, which is fixed and definitive for a particular signature policy.

The hash value may be obtained by: fall into two basic categories:

     * independent signatures;
     * embedded signatures.

Independent signatures are parallel signatures where the signer performing his own computation ordering of
the hash signatures is not important. The capability to have more than one
independent signature over the
      signature policy using his preferred hash algorithm permitted by same data must be provided.

Embedded signatures are applied one after the signature policy, other and are used where
the definitive binary encoded form.

      the signer, having verified the source of the policy, may use
      both the hash algorithm and order the hash value included signatures are applied is important. The capability to
sign over signed data must be provided.

These forms are described in the
      computer processable form clause 3.13. All other multiple signature
schemes, e.g. a signed document with a countersignature, double
countersignatures or multiple signatures, can be reduced to one or more
occurrence of the policy (see section 6.1). above two cases.

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Annex D C (informative):  Identifiers and roles
D.1

C.1  Signer Name Forms

The name used by the signer, held as the subject in the signer's
certificate, must uniquely identify the entity.  The name must be
allocated and verified on registration with the Certification
Authority, either directly or indirectly through a Registration
Authority, before being issued with a Certificate.

This document places no restrictions on the form of the name. The
subject's name may be a distinguished name, as defined in ITU-T
Recommendation X.500 [15], [RFC2459],
held in the subject field of the certificate, or any other name form
held in the X.509 subjectAltName certificate extension field. In the
case that the subject has no distinguished name, the subject name can
be an empty sequence and the subjectAltName extension must be critical.

D.2

C.2  TSP Name Forms

All TSP name forms (Certification Authorities, Attribute Authorities
and TimeStamping Authorities) must be in the form of a distinguished
name held in the subject field of the certificate.

The TSP name form must include identifiers for the organization
providing the service and the legal jurisdiction (e.g. (i.e. country)
under which it operates.

D.3 operates and an identification for the organization
providing the service.

C.3  Roles and Signer Attributes

Where a signer signs as an individual but wishes to also identify
him/herself as acting on behalf of an organization, it may be necessary
to provide two independent forms of identification. The first identity,
with is directly associated with the signing key identifies him/her as
an individual. The second, which is managed independently, identifies
that person acting as part of the organization, possibly with a given
role.

In this case the first identity is carried in the
subject/subjectAltName field of the signer's certificate as described
above.

This document supports the following means of providing a second form
of identification:

     * by placing a secondary name field containing a claimed role in
       the CMS signed attributes field;

     * by placing an attribute certificate containing a certified role
       in the CMS signed attributes field.