draft-ietf-jose-json-web-algorithms-05.txt   draft-ietf-jose-json-web-algorithms-06.txt 
JOSE Working Group M. Jones JOSE Working Group M. Jones
Internet-Draft Microsoft Internet-Draft Microsoft
Intended status: Standards Track July 30, 2012 Intended status: Standards Track October 15, 2012
Expires: January 31, 2013 Expires: April 18, 2013
JSON Web Algorithms (JWA) JSON Web Algorithms (JWA)
draft-ietf-jose-json-web-algorithms-05 draft-ietf-jose-json-web-algorithms-06
Abstract Abstract
The JSON Web Algorithms (JWA) specification enumerates cryptographic The JSON Web Algorithms (JWA) specification enumerates cryptographic
algorithms and identifiers to be used with the JSON Web Signature algorithms and identifiers to be used with the JSON Web Signature
(JWS), JSON Web Encryption (JWE), and JSON Web Key (JWK) (JWS), JSON Web Encryption (JWE), and JSON Web Key (JWK)
specifications. specifications.
Status of this Memo Status of this Memo
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 31, 2013. This Internet-Draft will expire on April 18, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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2.2. Terms Incorporated from the JWE Specification . . . . . . 5 2.2. Terms Incorporated from the JWE Specification . . . . . . 5
2.3. Terms Incorporated from the JWK Specification . . . . . . 6 2.3. Terms Incorporated from the JWK Specification . . . . . . 6
2.4. Defined Terms . . . . . . . . . . . . . . . . . . . . . . 7 2.4. Defined Terms . . . . . . . . . . . . . . . . . . . . . . 7
3. Cryptographic Algorithms for JWS . . . . . . . . . . . . . . . 7 3. Cryptographic Algorithms for JWS . . . . . . . . . . . . . . . 7
3.1. "alg" (Algorithm) Header Parameter Values for JWS . . . . 7 3.1. "alg" (Algorithm) Header Parameter Values for JWS . . . . 7
3.2. MAC with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512 . . . 8 3.2. MAC with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512 . . . 8
3.3. Digital Signature with RSA SHA-256, RSA SHA-384, or 3.3. Digital Signature with RSA SHA-256, RSA SHA-384, or
RSA SHA-512 . . . . . . . . . . . . . . . . . . . . . . . 9 RSA SHA-512 . . . . . . . . . . . . . . . . . . . . . . . 9
3.4. Digital Signature with ECDSA P-256 SHA-256, ECDSA 3.4. Digital Signature with ECDSA P-256 SHA-256, ECDSA
P-384 SHA-384, or ECDSA P-521 SHA-512 . . . . . . . . . . 10 P-384 SHA-384, or ECDSA P-521 SHA-512 . . . . . . . . . . 10
3.5. Using the Algorithm "none" . . . . . . . . . . . . . . . . 11 3.5. Using the Algorithm "none" . . . . . . . . . . . . . . . . 12
3.6. Additional Digital Signature/MAC Algorithms and 3.6. Additional Digital Signature/MAC Algorithms and
Parameters . . . . . . . . . . . . . . . . . . . . . . . . 12 Parameters . . . . . . . . . . . . . . . . . . . . . . . . 12
4. Cryptographic Algorithms for JWE . . . . . . . . . . . . . . . 12 4. Cryptographic Algorithms for JWE . . . . . . . . . . . . . . . 12
4.1. "alg" (Algorithm) Header Parameter Values for JWE . . . . 12 4.1. "alg" (Algorithm) Header Parameter Values for JWE . . . . 12
4.2. "enc" (Encryption Method) Header Parameter Values for 4.2. "enc" (Encryption Method) Header Parameter Values for
JWE . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 JWE . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3. "int" (Integrity Algorithm) Header Parameter Values 4.3. Key Encryption with RSAES-PKCS1-V1_5 . . . . . . . . . . . 15
for JWE . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.4. Key Encryption with RSAES OAEP . . . . . . . . . . . . . . 15
4.4. "kdf" (Key Derivation Function) Header Parameter 4.5. Key Encryption with AES Key Wrap . . . . . . . . . . . . . 15
Values for JWE . . . . . . . . . . . . . . . . . . . . . . 15 4.6. Direct Encryption with a Shared Symmetric Key . . . . . . 15
4.5. Key Encryption with RSAES-PKCS1-V1_5 . . . . . . . . . . . 15 4.7. Key Agreement with Elliptic Curve Diffie-Hellman
4.6. Key Encryption with RSAES OAEP . . . . . . . . . . . . . . 16 Ephemeral Static (ECDH-ES) . . . . . . . . . . . . . . . . 15
4.7. Key Encryption with AES Key Wrap . . . . . . . . . . . . . 16 4.7.1. Key Derivation for "ECDH-ES" . . . . . . . . . . . . . 16
4.8. Direct Encryption with a Shared Symmetric Key . . . . . . 16 4.8. Composite Plaintext Encryption Algorithms
4.9. Key Agreement with Elliptic Curve Diffie-Hellman "A128CBC+HS256" and "A256CBC+HS512" . . . . . . . . . . . 17
Ephemeral Static (ECDH-ES) . . . . . . . . . . . . . . . . 16 4.8.1. Key Derivation for "A128CBC+HS256" and
4.10. Plaintext Encryption with AES CBC Mode . . . . . . . . . . 17 "A256CBC+HS512" . . . . . . . . . . . . . . . . . . . 17
4.11. Plaintext Encryption with AES GCM . . . . . . . . . . . . 17 4.8.2. Encryption Calculation for "A128CBC+HS256" and
4.12. Integrity Calculation with HMAC SHA-256, HMAC SHA-384, "A256CBC+HS512" . . . . . . . . . . . . . . . . . . . 18
or HMAC SHA-512 . . . . . . . . . . . . . . . . . . . . . 17 4.8.3. Integrity Calculation for "A128CBC+HS256" and
4.13. Key Derivation with Concat KDF and SHA-256, SHA-384, "A256CBC+HS512" . . . . . . . . . . . . . . . . . . . 18
or SHA-512 . . . . . . . . . . . . . . . . . . . . . . . . 18 4.9. Plaintext Encryption with AES GCM . . . . . . . . . . . . 19
4.14. Additional Encryption Algorithms and Parameters . . . . . 18 4.10. Additional Encryption Algorithms and Parameters . . . . . 19
5. Cryptographic Algorithms for JWK . . . . . . . . . . . . . . . 19 5. Cryptographic Algorithms for JWK . . . . . . . . . . . . . . . 20
5.1. "alg" (Algorithm Family) Parameter Values for JWK . . . . 19 5.1. "alg" (Algorithm Family) Parameter Values for JWK . . . . 20
5.2. JWK Parameters for Elliptic Curve Keys . . . . . . . . . . 19 5.2. JWK Parameters for Elliptic Curve Keys . . . . . . . . . . 21
5.2.1. "crv" (Curve) Parameter . . . . . . . . . . . . . . . 20 5.2.1. "crv" (Curve) Parameter . . . . . . . . . . . . . . . 21
5.2.2. "x" (X Coordinate) Parameter . . . . . . . . . . . . . 20 5.2.2. "x" (X Coordinate) Parameter . . . . . . . . . . . . . 21
5.2.3. "y" (Y Coordinate) Parameter . . . . . . . . . . . . . 20 5.2.3. "y" (Y Coordinate) Parameter . . . . . . . . . . . . . 21
5.3. JWK Parameters for RSA Keys . . . . . . . . . . . . . . . 20 5.3. JWK Parameters for RSA Keys . . . . . . . . . . . . . . . 22
5.3.1. "mod" (Modulus) Parameter . . . . . . . . . . . . . . 20 5.3.1. "mod" (Modulus) Parameter . . . . . . . . . . . . . . 22
5.3.2. "exp" (Exponent) Parameter . . . . . . . . . . . . . . 21 5.3.2. "xpo" (Exponent) Parameter . . . . . . . . . . . . . . 22
5.4. Additional Key Algorithm Families and Parameters . . . . . 21 5.4. Additional Key Algorithm Families and Parameters . . . . . 22
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
6.1. JSON Web Signature and Encryption Algorithms Registry . . 22 6.1. JSON Web Signature and Encryption Algorithms Registry . . 23
6.1.1. Registration Template . . . . . . . . . . . . . . . . 22 6.1.1. Registration Template . . . . . . . . . . . . . . . . 23
6.1.2. Initial Registry Contents . . . . . . . . . . . . . . 23 6.1.2. Initial Registry Contents . . . . . . . . . . . . . . 24
6.2. JSON Web Key Algorithm Families Registry . . . . . . . . . 28 6.2. JSON Web Key Algorithm Families Registry . . . . . . . . . 27
6.2.1. Registration Template . . . . . . . . . . . . . . . . 28 6.2.1. Registration Template . . . . . . . . . . . . . . . . 27
6.2.2. Initial Registry Contents . . . . . . . . . . . . . . 29 6.2.2. Initial Registry Contents . . . . . . . . . . . . . . 28
6.3. JSON Web Key Parameters Registration . . . . . . . . . . . 29 6.3. JSON Web Key Parameters Registration . . . . . . . . . . . 28
6.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 29 6.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 28
7. Security Considerations . . . . . . . . . . . . . . . . . . . 30 7. Security Considerations . . . . . . . . . . . . . . . . . . . 29
8. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 31 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 30
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 33 8.1. Normative References . . . . . . . . . . . . . . . . . . . 30
9.1. Normative References . . . . . . . . . . . . . . . . . . . 33 8.2. Informative References . . . . . . . . . . . . . . . . . . 31
9.2. Informative References . . . . . . . . . . . . . . . . . . 34
Appendix A. Digital Signature/MAC Algorithm Identifier Appendix A. Digital Signature/MAC Algorithm Identifier
Cross-Reference . . . . . . . . . . . . . . . . . . . 35 Cross-Reference . . . . . . . . . . . . . . . . . . . 32
Appendix B. Encryption Algorithm Identifier Cross-Reference . . . 37 Appendix B. Encryption Algorithm Identifier Cross-Reference . . . 34
Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 39 Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 36
Appendix D. Document History . . . . . . . . . . . . . . . . . . 40 Appendix D. Open Issues . . . . . . . . . . . . . . . . . . . . . 37
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 43 Appendix E. Document History . . . . . . . . . . . . . . . . . . 37
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 40
1. Introduction 1. Introduction
The JSON Web Algorithms (JWA) specification enumerates cryptographic The JSON Web Algorithms (JWA) specification enumerates cryptographic
algorithms and identifiers to be used with the JSON Web Signature algorithms and identifiers to be used with the JSON Web Signature
(JWS) [JWS], JSON Web Encryption (JWE) [JWE], and JSON Web Key (JWK) (JWS) [JWS], JSON Web Encryption (JWE) [JWE], and JSON Web Key (JWK)
[JWK] specifications. All these specifications utilize JavaScript [JWK] specifications. All these specifications utilize JavaScript
Object Notation (JSON) [RFC4627] based data structures. This Object Notation (JSON) [RFC4627] based data structures. This
specification also describes the semantics and operations that are specification also describes the semantics and operations that are
specific to these algorithms and algorithm families. specific to these algorithms and algorithm families.
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These terms defined by the JSON Web Signature (JWS) [JWS] These terms defined by the JSON Web Signature (JWS) [JWS]
specification are incorporated into this specification: specification are incorporated into this specification:
JSON Web Signature (JWS) A data structure cryptographically securing JSON Web Signature (JWS) A data structure cryptographically securing
a JWS Header and a JWS Payload with a JWS Signature value. a JWS Header and a JWS Payload with a JWS Signature value.
JWS Header A string representing a JavaScript Object Notation (JSON) JWS Header A string representing a JavaScript Object Notation (JSON)
[RFC4627] object that describes the digital signature or MAC [RFC4627] object that describes the digital signature or MAC
operation applied to create the JWS Signature value. operation applied to create the JWS Signature value.
JWS Payload The bytes to be secured - a.k.a., the message. The JWS Payload The bytes to be secured -- a.k.a., the message. The
payload can contain an arbitrary sequence of bytes. payload can contain an arbitrary sequence of bytes.
JWS Signature A byte array containing the cryptographic material JWS Signature A byte array containing the cryptographic material
that secures the contents of the JWS Header and the JWS Payload. that secures the contents of the JWS Header and the JWS Payload.
Base64url Encoding The URL- and filename-safe Base64 encoding Base64url Encoding The URL- and filename-safe Base64 encoding
described in RFC 4648 [RFC4648], Section 5, with the (non URL- described in RFC 4648 [RFC4648], Section 5, with the (non URL-
safe) '=' padding characters omitted, as permitted by Section 3.2. safe) '=' padding characters omitted, as permitted by Section 3.2.
(See Appendix C of [JWS] for notes on implementing base64url (See Appendix C of [JWS] for notes on implementing base64url
encoding without padding.) encoding without padding.)
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2.2. Terms Incorporated from the JWE Specification 2.2. Terms Incorporated from the JWE Specification
These terms defined by the JSON Web Encryption (JWE) [JWE] These terms defined by the JSON Web Encryption (JWE) [JWE]
specification are incorporated into this specification: specification are incorporated into this specification:
JSON Web Encryption (JWE) A data structure representing an encrypted JSON Web Encryption (JWE) A data structure representing an encrypted
version of a Plaintext. The structure consists of four parts: the version of a Plaintext. The structure consists of four parts: the
JWE Header, the JWE Encrypted Key, the JWE Ciphertext, and the JWE JWE Header, the JWE Encrypted Key, the JWE Ciphertext, and the JWE
Integrity Value. Integrity Value.
Plaintext The bytes to be encrypted - a.k.a., the message. The Plaintext The bytes to be encrypted -- a.k.a., the message. The
plaintext can contain an arbitrary sequence of bytes. plaintext can contain an arbitrary sequence of bytes.
Ciphertext The encrypted version of the Plaintext. Ciphertext The encrypted version of the Plaintext.
Content Encryption Key (CEK) A symmetric key used to encrypt the Content Encryption Key (CEK) A symmetric key used to encrypt the
Plaintext for the recipient to produce the Ciphertext. Plaintext for the recipient to produce the Ciphertext.
Content Integrity Key (CIK) A key used with a MAC function to ensure Content Integrity Key (CIK) A key used with a MAC function to ensure
the integrity of the Ciphertext and the parameters used to create the integrity of the Ciphertext and the parameters used to create
it. it.
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comparing the unencoded values. In either case, if the values match, comparing the unencoded values. In either case, if the values match,
the HMAC has been validated. If the validation fails, the JWS MUST the HMAC has been validated. If the validation fails, the JWS MUST
be rejected. be rejected.
Securing content with the HMAC SHA-384 and HMAC SHA-512 algorithms is Securing content with the HMAC SHA-384 and HMAC SHA-512 algorithms is
performed identically to the procedure for HMAC SHA-256 - just using performed identically to the procedure for HMAC SHA-256 - just using
the corresponding hash algorithm with correspondingly larger minimum the corresponding hash algorithm with correspondingly larger minimum
key sizes and result values: 384 bits each for HMAC SHA-384 and 512 key sizes and result values: 384 bits each for HMAC SHA-384 and 512
bits each for HMAC SHA-512. bits each for HMAC SHA-512.
An example using this algorithm is shown in Appendix A.1 of [JWS].
3.3. Digital Signature with RSA SHA-256, RSA SHA-384, or RSA SHA-512 3.3. Digital Signature with RSA SHA-256, RSA SHA-384, or RSA SHA-512
This section defines the use of the RSASSA-PKCS1-V1_5 digital This section defines the use of the RSASSA-PKCS1-V1_5 digital
signature algorithm as defined in Section 8.2 of RFC 3447 [RFC3447], signature algorithm as defined in Section 8.2 of RFC 3447 [RFC3447],
(commonly known as PKCS #1), using SHA-256, SHA-384, or SHA-512 [SHS] (commonly known as PKCS #1), using SHA-256, SHA-384, or SHA-512 [SHS]
as the hash functions. The "alg" (algorithm) header parameter values as the hash functions. The "alg" (algorithm) header parameter values
"RS256", "RS384", and "RS512" are used in the JWS Header to indicate "RS256", "RS384", and "RS512" are used in the JWS Header to indicate
that the Encoded JWS Signature contains a base64url encoded RSA that the Encoded JWS Signature contains a base64url encoded RSA
digital signature using the respective hash function. digital signature using the respective hash function.
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the signer to the RSASSA-PKCS1-V1_5-VERIFY algorithm using SHA- the signer to the RSASSA-PKCS1-V1_5-VERIFY algorithm using SHA-
256 as the hash function. 256 as the hash function.
3. If the validation fails, the JWS MUST be rejected. 3. If the validation fails, the JWS MUST be rejected.
Signing with the RSA SHA-384 and RSA SHA-512 algorithms is performed Signing with the RSA SHA-384 and RSA SHA-512 algorithms is performed
identically to the procedure for RSA SHA-256 - just using the identically to the procedure for RSA SHA-256 - just using the
corresponding hash algorithm with correspondingly larger result corresponding hash algorithm with correspondingly larger result
values: 384 bits for RSA SHA-384 and 512 bits for RSA SHA-512. values: 384 bits for RSA SHA-384 and 512 bits for RSA SHA-512.
An example using this algorithm is shown in Appendix A.2 of [JWS].
3.4. Digital Signature with ECDSA P-256 SHA-256, ECDSA P-384 SHA-384, 3.4. Digital Signature with ECDSA P-256 SHA-256, ECDSA P-384 SHA-384,
or ECDSA P-521 SHA-512 or ECDSA P-521 SHA-512
The Elliptic Curve Digital Signature Algorithm (ECDSA) [DSS] provides The Elliptic Curve Digital Signature Algorithm (ECDSA) [DSS] provides
for the use of Elliptic Curve cryptography, which is able to provide for the use of Elliptic Curve cryptography, which is able to provide
equivalent security to RSA cryptography but using shorter key sizes equivalent security to RSA cryptography but using shorter key sizes
and with greater processing speed. This means that ECDSA digital and with greater processing speed. This means that ECDSA digital
signatures will be substantially smaller in terms of length than signatures will be substantially smaller in terms of length than
equivalently strong RSA digital signatures. equivalently strong RSA digital signatures.
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signature and comparing the results. signature and comparing the results.
Signing with the ECDSA P-384 SHA-384 and ECDSA P-521 SHA-512 Signing with the ECDSA P-384 SHA-384 and ECDSA P-521 SHA-512
algorithms is performed identically to the procedure for ECDSA P-256 algorithms is performed identically to the procedure for ECDSA P-256
SHA-256 - just using the corresponding hash algorithm with SHA-256 - just using the corresponding hash algorithm with
correspondingly larger result values. For ECDSA P-384 SHA-384, R and correspondingly larger result values. For ECDSA P-384 SHA-384, R and
S will be 384 bits each, resulting in a 96 byte array. For ECDSA S will be 384 bits each, resulting in a 96 byte array. For ECDSA
P-521 SHA-512, R and S will be 521 bits each, resulting in a 132 byte P-521 SHA-512, R and S will be 521 bits each, resulting in a 132 byte
array. array.
Examples using these algorithms are shown in Appendices A.3 and A.4
of [JWS].
3.5. Using the Algorithm "none" 3.5. Using the Algorithm "none"
JWSs MAY also be created that do not provide integrity protection. JWSs MAY also be created that do not provide integrity protection.
Such a JWS is called a "Plaintext JWS". Plaintext JWSs MUST use the Such a JWS is called a "Plaintext JWS". Plaintext JWSs MUST use the
"alg" value "none", and are formatted identically to other JWSs, but "alg" value "none", and are formatted identically to other JWSs, but
with an empty JWS Signature value. with an empty JWS Signature value.
3.6. Additional Digital Signature/MAC Algorithms and Parameters 3.6. Additional Digital Signature/MAC Algorithms and Parameters
Additional algorithms MAY be used to protect JWSs with corresponding Additional algorithms MAY be used to protect JWSs with corresponding
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| dir | Direct use of a shared | RECOMMENDED | | dir | Direct use of a shared | RECOMMENDED |
| | symmetric key as the Content | | | | symmetric key as the Content | |
| | Master Key (CMK) for the block | | | | Master Key (CMK) for the block | |
| | encryption step (rather than | | | | encryption step (rather than | |
| | using the symmetric key to wrap | | | | using the symmetric key to wrap | |
| | the CMK) | | | | the CMK) | |
| ECDH-ES | Elliptic Curve Diffie-Hellman | RECOMMENDED+ | | ECDH-ES | Elliptic Curve Diffie-Hellman | RECOMMENDED+ |
| | Ephemeral Static [RFC6090] key | | | | Ephemeral Static [RFC6090] key | |
| | agreement using the Concat KDF, | | | | agreement using the Concat KDF, | |
| | as defined in Section 5.8.1 of | | | | as defined in Section 5.8.1 of | |
| | [NIST.800-56A], where the | | | | [NIST.800-56A], with the | |
| | Digest Method is SHA-256 and | |
| | all OtherInfo parameters are | |
| | the empty bit string, with the | |
| | agreed-upon key being used | | | | agreed-upon key being used | |
| | directly as the Content Master | | | | directly as the Content Master | |
| | Key (CMK) (rather than being | | | | Key (CMK) (rather than being | |
| | used to wrap the CMK) | | | | used to wrap the CMK), as | |
| | specified in Section 4.7 | |
| ECDH-ES+A128KW | Elliptic Curve Diffie-Hellman | RECOMMENDED | | ECDH-ES+A128KW | Elliptic Curve Diffie-Hellman | RECOMMENDED |
| | Ephemeral Static key agreement | | | | Ephemeral Static key agreement | |
| | per "ECDH-ES", but where the | | | | per "ECDH-ES" and Section 4.7, | |
| | agreed-upon key is used to wrap | | | | but where the agreed-upon key | |
| | the Content Master Key (CMK) | | | | is used to wrap the Content | |
| | with the "A128KW" function | | | | Master Key (CMK) with the | |
| | (rather than being used | | | | "A128KW" function (rather than | |
| | directly as the CMK) | | | | being used directly as the CMK) | |
| ECDH-ES+A256KW | Elliptic Curve Diffie-Hellman | RECOMMENDED | | ECDH-ES+A256KW | Elliptic Curve Diffie-Hellman | RECOMMENDED |
| | Ephemeral Static key agreement | | | | Ephemeral Static key agreement | |
| | per "ECDH-ES", but where the | | | | per "ECDH-ES" and Section 4.7, | |
| | agreed-upon key is used to wrap | | | | but where the agreed-upon key | |
| | the Content Master Key (CMK) | | | | is used to wrap the Content | |
| | with the "A256KW" function | | | | Master Key (CMK) with the | |
| | (rather than being used | | | | "A256KW" function (rather than | |
| | directly as the CMK) | | | | being used directly as the CMK) | |
+----------------+---------------------------------+----------------+ +----------------+---------------------------------+----------------+
The use of "+" in the Implementation Requirements indicates that the The use of "+" in the Implementation Requirements indicates that the
requirement strength is likely to be increased in a future version of requirement strength is likely to be increased in a future version of
the specification. the specification.
4.2. "enc" (Encryption Method) Header Parameter Values for JWE 4.2. "enc" (Encryption Method) Header Parameter Values for JWE
The table below is the set of "enc" (encryption method) header The table below is the set of "enc" (encryption method) header
parameter values that are defined by this specification for use with parameter values that are defined by this specification for use with
JWE. These algorithms are used to encrypt the Plaintext, which JWE. These algorithms are used to encrypt the Plaintext, which
produces the Ciphertext. produces the Ciphertext.
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requirement strength is likely to be increased in a future version of requirement strength is likely to be increased in a future version of
the specification. the specification.
4.2. "enc" (Encryption Method) Header Parameter Values for JWE 4.2. "enc" (Encryption Method) Header Parameter Values for JWE
The table below is the set of "enc" (encryption method) header The table below is the set of "enc" (encryption method) header
parameter values that are defined by this specification for use with parameter values that are defined by this specification for use with
JWE. These algorithms are used to encrypt the Plaintext, which JWE. These algorithms are used to encrypt the Plaintext, which
produces the Ciphertext. produces the Ciphertext.
+-----------+--------------------------------------+----------------+ +---------------+----------------------------------+----------------+
| enc | Block Encryption Algorithm | Implementation | | enc Parameter | Block Encryption Algorithm | Implementation |
| Parameter | | Requirements | | Value | | Requirements |
| Value | | | +---------------+----------------------------------+----------------+
+-----------+--------------------------------------+----------------+ | A128CBC+HS256 | Composite AEAD algorithm using | REQUIRED |
| A128CBC | Advanced Encryption Standard (AES) | REQUIRED | | | Advanced Encryption Standard | |
| | in Cipher Block Chaining (CBC) mode | | | | (AES) in Cipher Block Chaining | |
| | with PKCS #5 padding [AES] | | | | (CBC) mode with PKCS #5 padding | |
| | [NIST.800-38A] using 128 bit keys | | | | [AES] [NIST.800-38A] with an | |
| A256CBC | AES in CBC mode with PKCS #5 padding | REQUIRED | | | integrity calculation using HMAC | |
| | using 256 bit keys | | | | SHA-256, using a 256 bit CMK | |
| A128GCM | AES in Galois/Counter Mode (GCM) | RECOMMENDED | | | (and 128 bit CEK) as specified | |
| | [AES] [NIST.800-38D] using 128 bit | | | | in Section 4.8 | |
| | keys | | | A256CBC+HS512 | Composite AEAD algorithm using | REQUIRED |
| A256GCM | AES GCM using 256 bit keys | RECOMMENDED | | | AES in CBC mode with PKCS #5 | |
+-----------+--------------------------------------+----------------+ | | padding with an integrity | |
| | calculation using HMAC SHA-512, | |
| | using a 512 bit CMK (and 256 bit | |
| | CEK) as specified in Section 4.8 | |
| A128GCM | AES in Galois/Counter Mode (GCM) | RECOMMENDED |
| | [AES] [NIST.800-38D] using 128 | |
| | bit keys | |
| A256GCM | AES GCM using 256 bit keys | RECOMMENDED |
+---------------+----------------------------------+----------------+
All the names are short because a core goal of JWE is for the All the names are short because a core goal of JWE is for the
representations to be compact. However, there is no a priori length representations to be compact. However, there is no a priori length
restriction on "alg" values. restriction on "alg" values.
See Appendix B for a table cross-referencing the encryption "alg" See Appendix B for a table cross-referencing the encryption "alg"
(algorithm) and "enc" (encryption method) values used in this (algorithm) and "enc" (encryption method) values used in this
specification with the equivalent identifiers used by other standards specification with the equivalent identifiers used by other standards
and software packages. and software packages.
4.3. "int" (Integrity Algorithm) Header Parameter Values for JWE 4.3. Key Encryption with RSAES-PKCS1-V1_5
The table below is the set of "int" (integrity algorithm) header
parameter values defined by this specification for use with JWE.
Note that these are the HMAC SHA subset of the "alg" (algorithm)
header parameter values defined for use with JWS Section 3.1.
+-----------------+-------------------------+-----------------------+
| int Parameter | Algorithm | Implementation |
| Value | | Requirements |
+-----------------+-------------------------+-----------------------+
| HS256 | HMAC using SHA-256 hash | REQUIRED |
| | algorithm | |
| HS384 | HMAC using SHA-384 hash | OPTIONAL |
| | algorithm | |
| HS512 | HMAC using SHA-512 hash | OPTIONAL |
| | algorithm | |
+-----------------+-------------------------+-----------------------+
4.4. "kdf" (Key Derivation Function) Header Parameter Values for JWE
The table below is the set of "kdf" (key derivation function) header
parameter values defined by this specification for use with JWE.
+-----------+--------------------------------------+----------------+
| kdf | Algorithm | Implementation |
| Parameter | | Requirements |
| Value | | |
+-----------+--------------------------------------+----------------+
| CS256 | Concat KDF, as defined in Section | REQUIRED |
| | 5.8.1 of [NIST.800-56A], with | |
| | parameters per Section 4.13, using | |
| | SHA-256 as the digest method | |
| CS384 | Concat KDF with parameters per | OPTIONAL |
| | Section 4.13, using SHA-384 as the | |
| | digest method | |
| CS512 | Concat KDF with parameters per | OPTIONAL |
| | Section 4.13, using SHA-512 as the | |
| | digest method | |
+-----------+--------------------------------------+----------------+
4.5. Key Encryption with RSAES-PKCS1-V1_5
This section defines the specifics of encrypting a JWE CMK with This section defines the specifics of encrypting a JWE CMK with
RSAES-PKCS1-V1_5 [RFC3447]. The "alg" header parameter value RSAES-PKCS1-V1_5 [RFC3447]. The "alg" header parameter value
"RSA1_5" is used in this case. "RSA1_5" is used in this case.
A key of size 2048 bits or larger MUST be used with this algorithm. A key of size 2048 bits or larger MUST be used with this algorithm.
4.6. Key Encryption with RSAES OAEP An example using this algorithm is shown in Appendix A.2 of [JWE].
4.4. Key Encryption with RSAES OAEP
This section defines the specifics of encrypting a JWE CMK with RSAES This section defines the specifics of encrypting a JWE CMK with RSAES
using Optimal Asymmetric Encryption Padding (OAEP) [RFC3447], with using Optimal Asymmetric Encryption Padding (OAEP) [RFC3447], with
the default parameters specified by RFC 3447 in Section A.2.1. The the default parameters specified by RFC 3447 in Section A.2.1. The
"alg" header parameter value "RSA-OAEP" is used in this case. "alg" header parameter value "RSA-OAEP" is used in this case.
A key of size 2048 bits or larger MUST be used with this algorithm. A key of size 2048 bits or larger MUST be used with this algorithm.
4.7. Key Encryption with AES Key Wrap An example using this algorithm is shown in Appendix A.1 of [JWE].
4.5. Key Encryption with AES Key Wrap
This section defines the specifics of encrypting a JWE CMK with the This section defines the specifics of encrypting a JWE CMK with the
Advanced Encryption Standard (AES) Key Wrap Algorithm [RFC3394] using Advanced Encryption Standard (AES) Key Wrap Algorithm [RFC3394] using
128 or 256 bit keys. The "alg" header parameter values "A128KW" or 128 or 256 bit keys. The "alg" header parameter values "A128KW" or
"A256KW" are used in this case. "A256KW" are used in this case.
4.8. Direct Encryption with a Shared Symmetric Key An example using this algorithm is shown in Appendix A.3 of [JWE].
4.6. Direct Encryption with a Shared Symmetric Key
This section defines the specifics of directly performing symmetric This section defines the specifics of directly performing symmetric
key encryption without performing a key wrapping step. In this case, key encryption without performing a key wrapping step. In this case,
the shared symmetric key is used directly as the Content Master Key the shared symmetric key is used directly as the Content Master Key
(CMK) value for the "enc" algorithm. An empty byte array is used as (CMK) value for the "enc" algorithm. An empty byte array is used as
the JWE Encrypted Key value. The "alg" header parameter value "dir" the JWE Encrypted Key value. The "alg" header parameter value "dir"
is used in this case. is used in this case.
4.9. Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral Static 4.7. Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral Static
(ECDH-ES) (ECDH-ES)
This section defines the specifics of key agreement with Elliptic This section defines the specifics of key agreement with Elliptic
Curve Diffie-Hellman Ephemeral Static [RFC6090], and using the Concat Curve Diffie-Hellman Ephemeral Static [RFC6090], and using the Concat
KDF, as defined in Section 5.8.1 of [NIST.800-56A], where the Digest KDF, as defined in Section 5.8.1 of [NIST.800-56A]. The key
Method is SHA-256 and all OtherInfo parameters are the empty bit agreement result can be used in one of two ways: (1) directly as the
string. The key agreement result can be used in one of two ways: (1) Content Master Key (CMK) for the "enc" algorithm, or (2) as a
directly as the Content Master Key (CMK) for the "enc" algorithm, or symmetric key used to wrap the CMK with either the "A128KW" or
(2) as a symmetric key used to wrap the CMK with either the "A128KW" "A256KW" algorithms. The "alg" header parameter values "ECDH-ES",
or "A256KW" algorithms. The "alg" header parameter values "ECDH-ES",
"ECDH-ES+A128KW", and "ECDH-ES+A256KW" are respectively used in this "ECDH-ES+A128KW", and "ECDH-ES+A256KW" are respectively used in this
case. case.
In the direct case, the output of the Concat KDF MUST be a key of the In the direct case, the output of the Concat KDF MUST be a key of the
same length as that used by the "enc" algorithm; in this case, the same length as that used by the "enc" algorithm; in this case, the
empty byte array is used as the JWE Encrypted Key value. In the key empty byte array is used as the JWE Encrypted Key value. In the key
wrap case, the output of the Concat KDF MUST be a key of the length wrap case, the output of the Concat KDF MUST be a key of the length
needed for the specified key wrap algorithm, either 128 or 256 bits needed for the specified key wrap algorithm, either 128 or 256 bits
respectively. respectively.
A new "epk" (ephemeral public key) value MUST be generated for each A new "epk" (ephemeral public key) value MUST be generated for each
key agreement transaction. key agreement transaction.
4.10. Plaintext Encryption with AES CBC Mode 4.7.1. Key Derivation for "ECDH-ES"
The key derivation process derives the agreed upon key from the
shared secret Z established through the ECDH algorithm, per Section
6.2.2.2 of [NIST.800-56A].
Key derivation is performed using the Concat KDF, as defined in
Section 5.8.1 of [NIST.800-56A], where the Digest Method is SHA-256.
The Concat KDF parameters are set as follows:
Z This is set to the representation of the shared secret Z as a byte
array.
keydatalen This is set to the number of bits in the desired output
key. For "ECDH-ES", this is length of the key used by the "enc"
algorithm. For "ECDH-ES+A128KW", and "ECDH-ES+A256KW", this is
128 and 256, respectively.
AlgorithmID This is set to the concatenation of keydatalen
represented as a 32 bit big endian integer and the bytes of the
UTF-8 representation of the "alg" header parameter value.
PartyUInfo If an "apu" (agreement PartyUInfo) header parameter is
present, this is set to the result of base64url decoding the "apu"
value; otherwise, it is set to the empty byte string.
PartyVInfo If an "apv" (agreement PartyVInfo) header parameter is
present, this is set to the result of base64url decoding the "apv"
value; otherwise, it is set to the empty byte string.
SuppPubInfo This is set to the empty byte string.
SuppPrivInfo This is set to the empty byte string.
For all three "alg" values, the digest function used is SHA-256.
4.8. Composite Plaintext Encryption Algorithms "A128CBC+HS256" and
"A256CBC+HS512"
This section defines two composite "enc" algorithms that perform
plaintext encryption using non-AEAD algorithms and add an integrity
check calculation, so that the resulting composite algorithms are
AEAD. These composite algorithms derive a Content Encryption Key
(CEK) and a Content Integrity Key (CIK) from a Content Master Key,
per Section 4.8.1. They perform block encryption with AES CBC, per
Section 4.8.2. Finally, they add an integrity check using HMAC SHA-2
algorithms of matching strength, per Section 4.8.3.
A 256 bit Content Master Key (CMK) value is used with the
"A128CBC+HS256" algorithm. A 512 bit Content Master Key (CMK) value
is used with the "A256CBC+HS512" algorithm.
An example using this algorithm is shown in Appendix A.2 of [JWE].
4.8.1. Key Derivation for "A128CBC+HS256" and "A256CBC+HS512"
The key derivation process derives CEK and CIK values from the CMK.
This section defines the specifics of deriving keys for the "enc"
algorithms "A128CBC+HS256" and "A256CBC+HS512".
Key derivation is performed using the Concat KDF, as defined in
Section 5.8.1 of [NIST.800-56A], where the Digest Method is SHA-256
or SHA-512, respectively. The Concat KDF parameters are set as
follows:
Z This is set to the Content Master Key (CMK).
keydatalen This is set to the number of bits in the desired output
key.
AlgorithmID This is set to the concatenation of keydatalen
represented as a 32 bit big endian integer and the bytes of the
UTF-8 representation of the "enc" header parameter value.
PartyUInfo If an "epu" (encryption PartyUInfo) header parameter is
present, this is set to the result of base64url decoding the "epu"
value; otherwise, it is set to the empty byte string.
PartyVInfo If an "epv" (encryption PartyVInfo) header parameter is
present, this is set to the result of base64url decoding the "epv"
value; otherwise, it is set to the empty byte string.
SuppPubInfo This is set to the bytes of one of the ASCII strings
"Encryption" ([69, 110, 99, 114, 121, 112, 116, 105, 111, 110]) or
"Integrity" ([73, 110, 116, 101, 103, 114, 105, 116, 121])
respectively, depending upon whether the CEK or CIK is being
generated.
SuppPrivInfo This is set to the empty byte string.
To compute the CEK from the CMK, the ASCII label "Encryption" is used
for the SuppPubInfo value. For "A128CBC+HS256", the keydatalen is
128 and the digest function used is SHA-256. For "A256CBC+HS512",
the keydatalen is 256 and the digest function used is SHA-512.
To compute the CIK from the CMK, the ASCII label "Integrity" is used
for the SuppPubInfo value. For "A128CBC+HS256", the keydatalen is
256 and the digest function used is SHA-256. For "A256CBC+HS512",
the keydatalen is 512 and the digest function used is SHA-512.
Example derivation computations are shown in Appendices A.4 and A.5
of [JWE].
4.8.2. Encryption Calculation for "A128CBC+HS256" and "A256CBC+HS512"
This section defines the specifics of encrypting the JWE Plaintext This section defines the specifics of encrypting the JWE Plaintext
with Advanced Encryption Standard (AES) in Cipher Block Chaining with Advanced Encryption Standard (AES) in Cipher Block Chaining
(CBC) mode with PKCS #5 padding [AES] [NIST.800-38A] using 128 or 256 (CBC) mode with PKCS #5 padding [AES] [NIST.800-38A] using 128 or 256
bit keys. The "enc" header parameter values "A128CBC" or "A256CBC" bit keys. The "enc" header parameter values "A128CBC+HS256" or
are used in this case. "A256CBC+HS512" are respectively used in this case.
The CEK is used as the encryption key.
Use of an initialization vector of size 128 bits is REQUIRED with Use of an initialization vector of size 128 bits is REQUIRED with
this algorithm. these algorithms.
4.11. Plaintext Encryption with AES GCM 4.8.3. Integrity Calculation for "A128CBC+HS256" and "A256CBC+HS512"
This section defines the specifics of computing the JWE Integrity
Value for the "enc" algorithms "A128CBC+HS256" and "A256CBC+HS512".
This value is computed as a MAC of the JWE parameters to be secured.
The MAC input value is the bytes of the ASCII representation of the
concatenation of the Encoded JWE Header, a period ('.') character,
the Encoded JWE Encrypted Key, a second period character ('.'), the
Encoded JWE Initialization Vector, a third period ('.') character,
and the Encoded JWE Ciphertext.
The CIK is used as the MAC key.
For "A128CBC+HS256", HMAC SHA-256 is used as the MAC algorithm. For
"A256CBC+HS512", HMAC SHA-512 is used as the MAC algorithm.
The resulting MAC value is used as the JWE Integrity Value. The same
integrity calculation is performed during decryption. During
decryption, the computed integrity value must match the received JWE
Integrity Value.
4.9. Plaintext Encryption with AES GCM
This section defines the specifics of encrypting the JWE Plaintext This section defines the specifics of encrypting the JWE Plaintext
with Advanced Encryption Standard (AES) in Galois/Counter Mode (GCM) with Advanced Encryption Standard (AES) in Galois/Counter Mode (GCM)
[AES] [NIST.800-38D] using 128 or 256 bit keys. The "enc" header [AES] [NIST.800-38D] using 128 or 256 bit keys. The "enc" header
parameter values "A128GCM" or "A256GCM" are used in this case. parameter values "A128GCM" or "A256GCM" are used in this case.
The CMK is used as the encryption key.
Use of an initialization vector of size 96 bits is REQUIRED with this Use of an initialization vector of size 96 bits is REQUIRED with this
algorithm. algorithm.
The "additional authenticated data" parameter is used to secure the The "additional authenticated data" parameter is used to secure the
header and key values, as specified for AEAD algorithms in Section 5 header and key values. The "additional authenticated data" value
of [JWE]. used is the bytes of the ASCII representation of the concatenation of
the Encoded JWE Header, a period ('.') character, the Encoded JWE
Encrypted Key, a second period character ('.'), and the Encoded JWE
Initialization Vector. This same "additional authenticated data"
value is used when decrypting as well.
The requested size of the "authentication tag" output MUST be 128 The requested size of the "authentication tag" output MUST be 128
bits, regardless of the key size. bits, regardless of the key size.
As GCM is an AEAD algorithm, the JWE Integrity Value is set to be the As GCM is an AEAD algorithm, the JWE Integrity Value is set to be the
"authentication tag" value produced by the encryption. "authentication tag" value produced by the encryption. During
decryption, the received JWE Integrity Value is used as the
4.12. Integrity Calculation with HMAC SHA-256, HMAC SHA-384, or HMAC "authentication tag" value.
SHA-512
This section defines the specifics of computing a JWE Integrity Value
with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512 [SHS]. Other than
as stated below, these computations are performed identically to
those specified in Section 3.2.
A key of the same size as the hash output (for instance, 256 bits for
"HS256") MUST be used with this algorithm.
Per Section 9 of [JWE], the JWS Secured Input value used contains the
header, encrypted key, and ciphertext.
4.13. Key Derivation with Concat KDF and SHA-256, SHA-384, or SHA-512
The key derivation process derives CEK and CIK values from the CMK.
It uses as a primitive a Key Derivation Function (KDF) which
notionally takes three arguments:
MasterKey: The master key used to compute the individual use keys
Label: The use key label, used to differentiate individual use keys
Length: The desired length of the use key
This section defines the specifics of using the Concat KDF, as
defined in Section 5.8.1 of [NIST.800-56A], where the Digest Method
is one of SHA-256, SHA-384, or SHA-512, the SuppPubInfo parameter is
the Label, and the remaining OtherInfo parameters are the empty bit
string.
The "kdf" (key derivation function) header parameter values "CS256",
"CS384", and "CS512" are respectively used in the JWE Header to
indicate the use of the Concat KDF as above with the respective
digest methods. If the "kdf" header parameter is omitted when an
AEAD "enc" algorithm is not used, this is equivalent to specifying
use of the "CS256" key derivation function.
To compute the CEK from the CMK, the ASCII label "Encryption" ([69,
110, 99, 114, 121, 112, 116, 105, 111, 110]) is used. Use the key
size for the "enc" algorithm as the CEK desired key length.
To compute the CIK from the CMK, the ASCII label "Integrity" ([73, Examples using this algorithm are shown in Appendices A.1 and A.3 of
110, 116, 101, 103, 114, 105, 116, 121]) is used. Use the minimum [JWE].
key size for the "int" algorithm (for instance, 256 bits for "HS256")
as the CIK desired key length.
4.14. Additional Encryption Algorithms and Parameters 4.10. Additional Encryption Algorithms and Parameters
Additional algorithms MAY be used to protect JWEs with corresponding Additional algorithms MAY be used to protect JWEs with corresponding
"alg" (algorithm), "enc" (encryption method), and "int" (integrity "alg" (algorithm) and "enc" (encryption method) header parameter
algorithm) header parameter values being defined to refer to them. values being defined to refer to them. New "alg" and "enc" header
New "alg", "enc", and "int" header parameter values SHOULD either be parameter values SHOULD either be registered in the IANA JSON Web
registered in the IANA JSON Web Signature and Encryption Algorithms Signature and Encryption Algorithms registry Section 6.1 or be a URI
registry Section 6.1 or be a URI that contains a Collision Resistant that contains a Collision Resistant Namespace. In particular, it is
Namespace. In particular, it is permissible to use the algorithm permissible to use the algorithm identifiers defined in XML
identifiers defined in XML Encryption [W3C.REC-xmlenc-core-20021210], Encryption [W3C.REC-xmlenc-core-20021210], XML Encryption 1.1
XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313], and related [W3C.CR-xmlenc-core1-20120313], and related specifications as "alg"
specifications as "alg", "enc", and "int" values. and "enc" values.
As indicated by the common registry, JWSs and JWEs share a common As indicated by the common registry, JWSs and JWEs share a common
"alg" value space. The values used by the two specifications MUST be "alg" value space. The values used by the two specifications MUST be
distinct, as the "alg" value MAY be used to determine whether the distinct, as the "alg" value MAY be used to determine whether the
object is a JWS or JWE. object is a JWS or JWE.
Likewise, additional reserved header parameter names MAY be defined Likewise, additional reserved header parameter names MAY be defined
via the IANA JSON Web Signature and Encryption Header Parameters via the IANA JSON Web Signature and Encryption Header Parameters
registry [JWS]. As indicated by the common registry, JWSs and JWEs registry [JWS]. As indicated by the common registry, JWSs and JWEs
share a common header parameter space; when a parameter is used by share a common header parameter space; when a parameter is used by
skipping to change at page 21, line 9 skipping to change at page 22, line 21
5.3.1. "mod" (Modulus) Parameter 5.3.1. "mod" (Modulus) Parameter
The "mod" (modulus) member contains the modulus value for the RSA The "mod" (modulus) member contains the modulus value for the RSA
public key. It is represented as the base64url encoding of the public key. It is represented as the base64url encoding of the
value's unsigned big endian representation as a byte array. The value's unsigned big endian representation as a byte array. The
array representation MUST not be shortened to omit any leading zero array representation MUST not be shortened to omit any leading zero
bytes. For instance, when representing 2048 bit integers, the byte bytes. For instance, when representing 2048 bit integers, the byte
array to be base64url encoded MUST contain 256 bytes, including any array to be base64url encoded MUST contain 256 bytes, including any
leading zero bytes. leading zero bytes.
5.3.2. "exp" (Exponent) Parameter 5.3.2. "xpo" (Exponent) Parameter
The "exp" (exponent) member contains the exponent value for the RSA The "xpo" (exponent) member contains the exponent value for the RSA
public key. It is represented as the base64url encoding of the public key. It is represented as the base64url encoding of the
value's unsigned big endian representation as a byte array. The value's unsigned big endian representation as a byte array. The
array representation MUST utilize the minimum number of bytes to array representation MUST utilize the minimum number of bytes to
represent the value. For instance, when representing the value represent the value. For instance, when representing the value
65537, the byte array to be base64url encoded MUST consist of the 65537, the byte array to be base64url encoded MUST consist of the
three bytes [1, 0, 1]. three bytes [1, 0, 1].
5.4. Additional Key Algorithm Families and Parameters 5.4. Additional Key Algorithm Families and Parameters
Public keys using additional algorithm families MAY be represented Public keys using additional algorithm families MAY be represented
skipping to change at page 21, line 39 skipping to change at page 22, line 51
families or additional key properties SHOULD either be registered in families or additional key properties SHOULD either be registered in
the IANA JSON Web Key Parameters registry [JWK] or be a URI that the IANA JSON Web Key Parameters registry [JWK] or be a URI that
contains a Collision Resistant Namespace. contains a Collision Resistant Namespace.
6. IANA Considerations 6. IANA Considerations
The following registration procedure is used for all the registries The following registration procedure is used for all the registries
established by this specification. established by this specification.
Values are registered with a Specification Required [RFC5226] after a Values are registered with a Specification Required [RFC5226] after a
two week review period on the [TBD]@ietf.org mailing list, on the two-week review period on the [TBD]@ietf.org mailing list, on the
advice of one or more Designated Experts. However, to allow for the advice of one or more Designated Experts. However, to allow for the
allocation of values prior to publication, the Designated Expert(s) allocation of values prior to publication, the Designated Expert(s)
may approve registration once they are satisfied that such a may approve registration once they are satisfied that such a
specification will be published. specification will be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list Registration requests must be sent to the [TBD]@ietf.org mailing list
for review and comment, with an appropriate subject (e.g., "Request for review and comment, with an appropriate subject (e.g., "Request
for access token type: example"). [[ Note to RFC-EDITOR: The name of for access token type: example"). [[ Note to RFC-EDITOR: The name of
the mailing list should be determined in consultation with the IESG the mailing list should be determined in consultation with the IESG
and IANA. Suggested name: jose-reg-review. ]] and IANA. Suggested name: jose-reg-review. ]]
skipping to change at page 22, line 4 skipping to change at page 23, line 14
advice of one or more Designated Experts. However, to allow for the advice of one or more Designated Experts. However, to allow for the
allocation of values prior to publication, the Designated Expert(s) allocation of values prior to publication, the Designated Expert(s)
may approve registration once they are satisfied that such a may approve registration once they are satisfied that such a
specification will be published. specification will be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list Registration requests must be sent to the [TBD]@ietf.org mailing list
for review and comment, with an appropriate subject (e.g., "Request for review and comment, with an appropriate subject (e.g., "Request
for access token type: example"). [[ Note to RFC-EDITOR: The name of for access token type: example"). [[ Note to RFC-EDITOR: The name of
the mailing list should be determined in consultation with the IESG the mailing list should be determined in consultation with the IESG
and IANA. Suggested name: jose-reg-review. ]] and IANA. Suggested name: jose-reg-review. ]]
Within the review period, the Designated Expert(s) will either Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request and, if applicable, suggestions as to how to make the request
successful. successful.
IANA must only accept registry updates from the Designated Expert(s), IANA must only accept registry updates from the Designated Expert(s)
and should direct all requests for registration to the review mailing and should direct all requests for registration to the review mailing
list. list.
6.1. JSON Web Signature and Encryption Algorithms Registry 6.1. JSON Web Signature and Encryption Algorithms Registry
This specification establishes the IANA JSON Web Signature and This specification establishes the IANA JSON Web Signature and
Encryption Algorithms registry for values of the JWS and JWE "alg" Encryption Algorithms registry for values of the JWS and JWE "alg"
(algorithm), "enc" (encryption method), and "int" (integrity (algorithm) and "enc" (encryption method) header parameters. The
algorithm) header parameters. The registry records the algorithm registry records the algorithm name, the algorithm usage locations
name, the algorithm usage locations from the set "alg", "enc", and from the set "alg" and "enc", implementation requirements, and a
"int", implementation requirements, and a reference to the reference to the specification that defines it. The same algorithm
specification that defines it. The same algorithm name may be name may be registered multiple times, provided that the sets of
registered multiple times, provided that the sets of usage locations usage locations are disjoint. The implementation requirements of an
are disjoint. The implementation requirements of an algorithm may be algorithm may be changed over time by the Designated Experts(s) as
changed over time by the Designated Experts(s) as the cryptographic the cryptographic landscape evolves, for instance, to change the
landscape evolves, for instance, to change the status of an algorithm status of an algorithm to DEPRECATED, or to change the status of an
to DEPRECATED, or to change the status of an algorithm from OPTIONAL algorithm from OPTIONAL to RECOMMENDED or REQUIRED.
to RECOMMENDED or REQUIRED.
6.1.1. Registration Template 6.1.1. Registration Template
Algorithm Name: Algorithm Name:
The name requested (e.g., "example"). This name is case The name requested (e.g., "example"). This name is case
sensitive. Names that match other registered names in a case sensitive. Names that match other registered names in a case
insensitive manner SHOULD NOT be accepted. insensitive manner SHOULD NOT be accepted.
Algorithm Usage Location(s): Algorithm Usage Location(s):
The algorithm usage, which must be one or more of the values The algorithm usage, which must be one or more of the values "alg"
"alg", "enc", "int", or "kdf". or "enc".
Implementation Requirements: Implementation Requirements:
The algorithm implementation requirements, which must be one the The algorithm implementation requirements, which must be one the
words REQUIRED, RECOMMENDED, OPTIONAL, or DEPRECATED. Optionally, words REQUIRED, RECOMMENDED, OPTIONAL, or DEPRECATED. Optionally,
the word may be followed by a "+" or "-". The use of "+" the word may be followed by a "+" or "-". The use of "+"
indicates that the requirement strength is likely to be increased indicates that the requirement strength is likely to be increased
in a future version of the specification. The use of "-" in a future version of the specification. The use of "-"
indicates that the requirement strength is likely to be decreased indicates that the requirement strength is likely to be decreased
in a future version of the specification. in a future version of the specification.
Change Controller: Change Controller:
For standards-track RFCs, state "IETF". For others, give the name For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address, of the responsible party. Other details (e.g., postal address,
e-mail address, home page URI) may also be included. email address, home page URI) may also be included.
Specification Document(s): Specification Document(s):
Reference to the document that specifies the parameter, preferably Reference to the document(s) that specify the parameter,
including a URI that can be used to retrieve a copy of the preferably including URI(s) that can be used to retrieve copies of
document. An indication of the relevant sections may also be the document(s). An indication of the relevant sections may also
included, but is not required. be included but is not required.
6.1.2. Initial Registry Contents 6.1.2. Initial Registry Contents
o Algorithm Name: "HS256" o Algorithm Name: "HS256"
o Algorithm Usage Location(s): "alg"
o Algorithm Usage Location(s): "alg", "int"
o Implementation Requirements: REQUIRED o Implementation Requirements: REQUIRED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]]
o Specification Document(s): Section 3.1 and Section 4.3 of [[ this
document ]]
o Algorithm Name: "HS384" o Algorithm Name: "HS384"
o Algorithm Usage Location(s): "alg"
o Algorithm Usage Location(s): "alg", "int"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]]
o Specification Document(s): Section 3.1 and Section 4.3 of [[ this
document ]]
o Algorithm Name: "HS512" o Algorithm Name: "HS512"
o Algorithm Usage Location(s): "alg"
o Algorithm Usage Location(s): "alg", "int"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]]
o Specification Document(s): Section 3.1 and Section 4.3 of [[ this
document ]]
o Algorithm Name: "RS256" o Algorithm Name: "RS256"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "RS384" o Algorithm Name: "RS384"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "RS512" o Algorithm Name: "RS512"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "ES256" o Algorithm Name: "ES256"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED+ o Implementation Requirements: RECOMMENDED+
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "ES384" o Algorithm Name: "ES384"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "ES512" o Algorithm Name: "ES512"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "none" o Algorithm Name: "none"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: REQUIRED o Implementation Requirements: REQUIRED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 3.1 of [[ this document ]] o Specification Document(s): Section 3.1 of [[ this document ]]
o Algorithm Name: "RSA1_5" o Algorithm Name: "RSA1_5"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: REQUIRED o Implementation Requirements: REQUIRED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "RSA-OAEP" o Algorithm Name: "RSA-OAEP"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: OPTIONAL o Implementation Requirements: OPTIONAL
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "A128KW" o Algorithm Name: "A128KW"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "A256KW" o Algorithm Name: "A256KW"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "dir" o Algorithm Name: "dir"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "ECDH-ES" o Algorithm Name: "ECDH-ES"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED+ o Implementation Requirements: RECOMMENDED+
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "ECDH-ES+A128KW" o Algorithm Name: "ECDH-ES+A128KW"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "ECDH-ES+A256KW" o Algorithm Name: "ECDH-ES+A256KW"
o Algorithm Usage Location(s): "alg" o Algorithm Usage Location(s): "alg"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1 of [[ this document ]] o Specification Document(s): Section 4.1 of [[ this document ]]
o Algorithm Name: "A128CBC" o Algorithm Name: "A128CBC+HS256"
o Algorithm Usage Location(s): "enc" o Algorithm Usage Location(s): "enc"
o Implementation Requirements: REQUIRED o Implementation Requirements: REQUIRED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.2 of [[ this document ]] o Specification Document(s): Section 4.2 of [[ this document ]]
o Algorithm Name: "A256CBC" o Algorithm Name: "A256CBC+HS512"
o Algorithm Usage Location(s): "enc" o Algorithm Usage Location(s): "enc"
o Implementation Requirements: REQUIRED o Implementation Requirements: REQUIRED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.2 of [[ this document ]] o Specification Document(s): Section 4.2 of [[ this document ]]
o Algorithm Name: "A128GCM" o Algorithm Name: "A128GCM"
o Algorithm Usage Location(s): "enc" o Algorithm Usage Location(s): "enc"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.2 of [[ this document ]] o Specification Document(s): Section 4.2 of [[ this document ]]
o Algorithm Name: "A256GCM" o Algorithm Name: "A256GCM"
o Algorithm Usage Location(s): "enc" o Algorithm Usage Location(s): "enc"
o Implementation Requirements: RECOMMENDED o Implementation Requirements: RECOMMENDED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.2 of [[ this document ]] o Specification Document(s): Section 4.2 of [[ this document ]]
o Algorithm Name: "CS256"
o Algorithm Usage Location(s): "kdf"
o Implementation Requirements: REQUIRED
o Change Controller: IETF
o Specification Document(s): Section 4.4 of [[ this document ]]
o Algorithm Name: "CS384"
o Algorithm Usage Location(s): "kdf"
o Implementation Requirements: OPTIONAL
o Change Controller: IETF
o Specification Document(s): Section 4.4 of [[ this document ]]
o Algorithm Name: "CS512"
o Algorithm Usage Location(s): "kdf"
o Implementation Requirements: OPTIONAL
o Change Controller: IETF
o Specification Document(s): Section 4.4 of [[ this document ]]
6.2. JSON Web Key Algorithm Families Registry 6.2. JSON Web Key Algorithm Families Registry
This specification establishes the IANA JSON Web Key Algorithm This specification establishes the IANA JSON Web Key Algorithm
Families registry for values of the JWK "alg" (algorithm family) Families registry for values of the JWK "alg" (algorithm family)
parameter. The registry records the "alg" value and a reference to parameter. The registry records the "alg" value and a reference to
the specification that defines it. This specification registers the the specification that defines it. This specification registers the
values defined in Section 5.1. values defined in Section 5.1.
6.2.1. Registration Template 6.2.1. Registration Template
"alg" Parameter Value: "alg" Parameter Value:
The name requested (e.g., "example"). This name is case The name requested (e.g., "example"). This name is case
sensitive. Names that match other registered names in a case sensitive. Names that match other registered names in a case
insensitive manner SHOULD NOT be accepted. insensitive manner SHOULD NOT be accepted.
Change Controller: Change Controller:
For standards-track RFCs, state "IETF". For others, give the name For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address, of the responsible party. Other details (e.g., postal address,
e-mail address, home page URI) may also be included. email address, home page URI) may also be included.
Implementation Requirements: Implementation Requirements:
The algorithm implementation requirements, which must be one the The algorithm implementation requirements, which must be one the
words REQUIRED, RECOMMENDED, OPTIONAL, or DEPRECATED. Optionally, words REQUIRED, RECOMMENDED, OPTIONAL, or DEPRECATED. Optionally,
the word may be followed by a "+" or "-". The use of "+" the word may be followed by a "+" or "-". The use of "+"
indicates that the requirement strength is likely to be increased indicates that the requirement strength is likely to be increased
in a future version of the specification. The use of "-" in a future version of the specification. The use of "-"
indicates that the requirement strength is likely to be decreased indicates that the requirement strength is likely to be decreased
in a future version of the specification. in a future version of the specification.
Specification Document(s): Specification Document(s):
Reference to the document that specifies the parameter, preferably Reference to the document(s) that specify the parameter,
including a URI that can be used to retrieve a copy of the preferably including URI(s) that can be used to retrieve copies of
document. An indication of the relevant sections may also be the document(s). An indication of the relevant sections may also
included, but is not required. be included but is not required.
6.2.2. Initial Registry Contents 6.2.2. Initial Registry Contents
o "alg" Parameter Value: "EC" o "alg" Parameter Value: "EC"
o Implementation Requirements: RECOMMENDED+ o Implementation Requirements: RECOMMENDED+
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.1 of [[ this document ]] o Specification Document(s): Section 5.1 of [[ this document ]]
o "alg" Parameter Value: "RSA" o "alg" Parameter Value: "RSA"
o Implementation Requirements: REQUIRED o Implementation Requirements: REQUIRED
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.1 of [[ this document ]] o Specification Document(s): Section 5.1 of [[ this document ]]
6.3. JSON Web Key Parameters Registration 6.3. JSON Web Key Parameters Registration
This specification registers the parameter names defined in This specification registers the parameter names defined in Sections
Section 5.2 and Section 5.3 in the IANA JSON Web Key Parameters 5.2 and 5.3 in the IANA JSON Web Key Parameters registry [JWK].
registry [JWK].
6.3.1. Registry Contents 6.3.1. Registry Contents
o Parameter Name: "crv"
o Parameter Name: "crv"
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.2.1 of [[ this document ]] o Specification Document(s): Section 5.2.1 of [[ this document ]]
o Parameter Name: "x" o Parameter Name: "x"
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.2.2 of [[ this document ]] o Specification Document(s): Section 5.2.2 of [[ this document ]]
o Parameter Name: "y" o Parameter Name: "y"
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.2.3 of [[ this document ]] o Specification Document(s): Section 5.2.3 of [[ this document ]]
o Parameter Name: "mod" o Parameter Name: "mod"
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.3.1 of [[ this document ]] o Specification Document(s): Section 5.3.1 of [[ this document ]]
o Parameter Name: "exp" o Parameter Name: "xpo"
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 5.3.2 of [[ this document ]] o Specification Document(s): Section 5.3.2 of [[ this document ]]
7. Security Considerations 7. Security Considerations
All of the security issues faced by any cryptographic application All of the security issues faced by any cryptographic application
must be faced by a JWS/JWE/JWK agent. Among these issues are must be faced by a JWS/JWE/JWK agent. Among these issues are
protecting the user's private key, preventing various attacks, and protecting the user's private key, preventing various attacks, and
helping the user avoid mistakes such as inadvertently encrypting a helping the user avoid mistakes such as inadvertently encrypting a
message for the wrong recipient. The entire list of security message for the wrong recipient. The entire list of security
considerations is beyond the scope of this document, but some considerations is beyond the scope of this document, but some
skipping to change at page 31, line 9 skipping to change at page 29, line 27
[RFC3447], [RFC5116], [RFC6090], and [SHS] apply to this [RFC3447], [RFC5116], [RFC6090], and [SHS] apply to this
specification. specification.
Eventually the algorithms and/or key sizes currently described in Eventually the algorithms and/or key sizes currently described in
this specification will no longer be considered sufficiently secure this specification will no longer be considered sufficiently secure
and will be removed. Therefore, implementers and deployments must be and will be removed. Therefore, implementers and deployments must be
prepared for this eventuality. prepared for this eventuality.
Algorithms of matching strength should be used together whenever Algorithms of matching strength should be used together whenever
possible. For instance, when AES Key Wrap is used with a given key possible. For instance, when AES Key Wrap is used with a given key
size, using the same key size for AES CBC or GCM is recommended. size, using the same key size is recommended when AES GCM is also
Likewise, when AES CBC is used with a 128 bit key, using HMAC SHA-256 used.
as the integrity algorithm is recommended, whereas when AES CBC is
used with a 256 bit key, using HMAC SHA-512 as the integrity
algorithm is recommended.
While Section 8 of RFC 3447 [RFC3447] explicitly calls for people not While Section 8 of RFC 3447 [RFC3447] explicitly calls for people not
to adopt RSASSA-PKCS1 for new applications and instead requests that to adopt RSASSA-PKCS1 for new applications and instead requests that
people transition to RSASSA-PSS, this specification does include people transition to RSASSA-PSS, this specification does include
RSASSA-PKCS1, for interoperability reasons, because it commonly RSASSA-PKCS1, for interoperability reasons, because it commonly
implemented. implemented.
Keys used with RSAES-PKCS1-v1_5 must follow the constraints in Keys used with RSAES-PKCS1-v1_5 must follow the constraints in
Section 7.2 of RFC 3447 [RFC3447]. In particular, keys with a low Section 7.2 of RFC 3447 [RFC3447]. In particular, keys with a low
public key exponent value must not be used. public key exponent value must not be used.
skipping to change at page 31, line 41 skipping to change at page 30, line 7
encrypt messages need to be cautious of cryptographic processing encrypt messages need to be cautious of cryptographic processing
usage when validating signatures and encrypting messages using keys usage when validating signatures and encrypting messages using keys
larger than those mandated in this specification. An attacker could larger than those mandated in this specification. An attacker could
send certificates with keys that would result in excessive send certificates with keys that would result in excessive
cryptographic processing, for example, keys larger than those cryptographic processing, for example, keys larger than those
mandated in this specification, which could swamp the processing mandated in this specification, which could swamp the processing
element. Agents that use such keys without first validating the element. Agents that use such keys without first validating the
certificate to a trust anchor are advised to have some sort of certificate to a trust anchor are advised to have some sort of
cryptographic resource management system to prevent such attacks. cryptographic resource management system to prevent such attacks.
8. Open Issues 8. References
[[ to be removed by the RFC editor before publication as an RFC ]]
The following items remain to be considered or done in this draft:
o Should we use the "alg" value as the AlgorithmID input to the
Concat KDF when doing key agreement? Or is an AlgorithmID value
unnecessary in the way that we are using Concat for key agreement?
o Similarly, should we use a combination of the "enc" and "int"
values as the AlgorithmID input to the Concat KDF when doing key
derivation? Or is an AlgorithmID value unnecessary in the way
that we are using Concat for key derivation?
o Do we want to add the output key length to the Concat KDF input
parameters?
o Do we need non-empty PartyUInfo and PartyVInfo values when using
the Concat KDF for key agreement? Or given that we already
require the use of a random unique Ephemeral Public Key (EPK), is
this superfluous, as duplicate keys will not be generated unless a
duplicate EPK is used? If we do decide we need PartyUInfo and
PartyVInfo values, how can we dynamically generate them from
information already carried in the header, rather than requiring
that they be explicitly passed as header parameters?
o Similarly, do we need non-empty PartyUInfo and PartyVInfo values
when using the Concat KDF for key derivation? Or given that we
already require the use of a random unique Content Master Key
(CMK), is this superfluous, as duplicate keys will not be
generated unless a duplicate CMK is used? If we do decide we need
PartyUInfo and PartyVInfo values, how can we dynamically generate
them from information already carried in the header, rather than
requiring that they be explicitly passed as header parameters?
o We use the same secret multiple times with the Concat KDF with
different parameters to generate multiple derived keys. Do we
want to continue this practice or instead use the KDF once to
generate a big enough byte array for all derived keys, and use
different parts of the byte array for each key?
o Do we want to add AES ECB as a (non-authenticated) key wrap
algorithm? Is there any problem with doing key wrap without an
integrity check, given that a separate integrity check already
covers the wrapped key?
o Do we want the ability to perform symmetric encryption directly
with a shared key, without using a separate CMK? This would save
space and time in the single recipient case. It would also be
parallel to this option for key agreement, which doesn't use a
separate CMK.
o Do we want the ability to perform symmetric encryption directly
with an agreed upon key, without using a separate CMK? The
arguments for this parallel those for direct encryption using a
shared key.
9. References
9.1. Normative References 8.1. Normative References
[AES] National Institute of Standards and Technology (NIST), [AES] National Institute of Standards and Technology (NIST),
"Advanced Encryption Standard (AES)", FIPS PUB 197, "Advanced Encryption Standard (AES)", FIPS PUB 197,
November 2001. November 2001.
[DSS] National Institute of Standards and Technology, "Digital [DSS] National Institute of Standards and Technology, "Digital
Signature Standard (DSS)", FIPS PUB 186-3, June 2009. Signature Standard (DSS)", FIPS PUB 186-3, June 2009.
[JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web [JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web
Encryption (JWE)", July 2012. Encryption (JWE)", October 2012.
[JWK] Jones, M., "JSON Web Key (JWK)", July 2012. [JWK] Jones, M., "JSON Web Key (JWK)", October 2012.
[JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web [JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", July 2012. Signature (JWS)", October 2012.
[NIST.800-38A] [NIST.800-38A]
National Institute of Standards and Technology (NIST), National Institute of Standards and Technology (NIST),
"Recommendation for Block Cipher Modes of Operation", "Recommendation for Block Cipher Modes of Operation",
NIST PUB 800-38A, December 2001. NIST PUB 800-38A, December 2001.
[NIST.800-38D] [NIST.800-38D]
National Institute of Standards and Technology (NIST), National Institute of Standards and Technology (NIST),
"Recommendation for Block Cipher Modes of Operation: "Recommendation for Block Cipher Modes of Operation:
Galois/Counter Mode (GCM) and GMAC", NIST PUB 800-38D, Galois/Counter Mode (GCM) and GMAC", NIST PUB 800-38D,
skipping to change at page 34, line 32 skipping to change at page 31, line 36
[RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic [RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic
Curve Cryptography Algorithms", RFC 6090, February 2011. Curve Cryptography Algorithms", RFC 6090, February 2011.
[SHS] National Institute of Standards and Technology, "Secure [SHS] National Institute of Standards and Technology, "Secure
Hash Standard (SHS)", FIPS PUB 180-3, October 2008. Hash Standard (SHS)", FIPS PUB 180-3, October 2008.
[USASCII] American National Standards Institute, "Coded Character [USASCII] American National Standards Institute, "Coded Character
Set -- 7-bit American Standard Code for Information Set -- 7-bit American Standard Code for Information
Interchange", ANSI X3.4, 1986. Interchange", ANSI X3.4, 1986.
9.2. Informative References 8.2. Informative References
[CanvasApp] [CanvasApp]
Facebook, "Canvas Applications", 2010. Facebook, "Canvas Applications", 2010.
[I-D.rescorla-jsms] [I-D.rescorla-jsms]
Rescorla, E. and J. Hildebrand, "JavaScript Message Rescorla, E. and J. Hildebrand, "JavaScript Message
Security Format", draft-rescorla-jsms-00 (work in Security Format", draft-rescorla-jsms-00 (work in
progress), March 2011. progress), March 2011.
[JCA] Oracle, "Java Cryptography Architecture", 2011. [JCA] Oracle, "Java Cryptography Architecture", 2011.
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[RFC3275] Eastlake, D., Reagle, J., and D. Solo, "(Extensible Markup [RFC3275] Eastlake, D., Reagle, J., and D. Solo, "(Extensible Markup
Language) XML-Signature Syntax and Processing", RFC 3275, Language) XML-Signature Syntax and Processing", RFC 3275,
March 2002. March 2002.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122, Unique IDentifier (UUID) URN Namespace", RFC 4122,
July 2005. July 2005.
[W3C.CR-xmldsig-core2-20120124] [W3C.CR-xmldsig-core2-20120124]
Solo, D., Datta, P., Hirsch, F., Cantor, S., Reagle, J., Roessler, T., Yiu, K., Solo, D., Reagle, J., Datta, P.,
Roessler, T., Eastlake, D., and K. Yiu, "XML Signature Eastlake, D., Hirsch, F., and S. Cantor, "XML Signature
Syntax and Processing Version 2.0", World Wide Web Syntax and Processing Version 2.0", World Wide Web
Consortium CR CR-xmldsig-core2-20120124, January 2012, Consortium CR CR-xmldsig-core2-20120124, January 2012,
<http://www.w3.org/TR/2012/CR-xmldsig-core2-20120124>. <http://www.w3.org/TR/2012/CR-xmldsig-core2-20120124>.
[W3C.CR-xmlenc-core1-20120313] [W3C.CR-xmlenc-core1-20120313]
Eastlake, D., Reagle, J., Hirsch, F., and T. Roessler, Eastlake, D., Reagle, J., Hirsch, F., and T. Roessler,
"XML Encryption Syntax and Processing Version 1.1", World "XML Encryption Syntax and Processing Version 1.1", World
Wide Web Consortium CR CR-xmlenc-core1-20120313, Wide Web Consortium CR CR-xmlenc-core1-20120313,
March 2012, March 2012,
<http://www.w3.org/TR/2012/CR-xmlenc-core1-20120313>. <http://www.w3.org/TR/2012/CR-xmlenc-core1-20120313>.
skipping to change at page 38, line 10 skipping to change at page 35, line 10
This appendix contains a table cross-referencing the "alg" This appendix contains a table cross-referencing the "alg"
(algorithm) and "enc" (encryption method) values used in this (algorithm) and "enc" (encryption method) values used in this
specification with the equivalent identifiers used by other standards specification with the equivalent identifiers used by other standards
and software packages. See XML Encryption and software packages. See XML Encryption
[W3C.REC-xmlenc-core-20021210], XML Encryption 1.1 [W3C.REC-xmlenc-core-20021210], XML Encryption 1.1
[W3C.CR-xmlenc-core1-20120313], and Java Cryptography Architecture [W3C.CR-xmlenc-core1-20120313], and Java Cryptography Architecture
[JCA] for more information about the names defined by those [JCA] for more information about the names defined by those
documents. documents.
+----------+------+---------------------------+---------------------+ For the composite algorithms "A128CBC+HS256" and "A256CBC+HS512", the
| Algorith | JWE | XML ENC | JCA | corresponding AES CBC algorithm identifiers are listed.
| m | | | |
+----------+------+---------------------------+---------------------+ +----------+--------+--------------------------+--------------------+
| RSAES-PK | RSA1 | http://www.w3.org/2001/04 | RSA/ECB/PKCS1Paddin | | Algorith | JWE | XML ENC | JCA |
| CS1-V1_5 | _5 | /xmlenc#rsa-1_5 | g | | m | | | |
| RSAES | RSA- | http://www.w3.org/2001/04 | RSA/ECB/OAEPWithSHA | +----------+--------+--------------------------+--------------------+
| using | OAEP | /xmlenc#rsa-oaep-mgf1p | -1AndMGF1Padding | | RSAES-PK | RSA1_5 | http://www.w3.org/2001/0 | RSA/ECB/PKCS1Paddi |
| Optimal | | | | | CS1-V1_5 | | 4/xmlenc#rsa-1_5 | ng |
| Asymmetr | | | | | RSAES | RSA-OA | http://www.w3.org/2001/0 | RSA/ECB/OAEPWithSH |
| ic | | | | | using | EP | 4/xmlenc#rsa-oaep-mgf1p | A-1AndMGF1Padding |
| Encrypt | | | | | Optimal | | | |
| ion | | | | | Asymmetr | | | |
| Paddin | | | | | ic | | | |
| g (OAEP) | | | | | Encrypt | | | |
| Elliptic | ECDH | http://www.w3.org/2009/xm | | | ion | | | |
| Curve | -ES | lenc11#ECDH-ES | | | Paddin | | | |
| Diffie-H | | | | | g (OAEP) | | | |
| ellman | | | | | Elliptic | ECDH-E | http://www.w3.org/2009/x | |
| Ephemer | | | | | Curve | S | mlenc11#ECDH-ES | |
| alStatic | | | | | Diffie-H | | | |
| Advanced | A128 | http://www.w3.org/2001/04 | | | ellman | | | |
| Encrypti | KW | /xmlenc#kw-aes128 | | | Ephemer | | | |
| on | | | | | alStatic | | | |
| Standar | | | | | Advanced | A128KW | http://www.w3.org/2001/0 | |
| d(AES) | | | | | Encrypti | | 4/xmlenc#kw-aes128 | |
| Key Wra | | | | | on | | | |
| pAlgorit | | | | | Standar | | | |
| hmusing | | | | | d(AES) | | | |
| 128 bi | | | | | Key Wra | | | |
| t keys | | | | | pAlgorit | | | |
| AES Key | A256 | http://www.w3.org/2001/04 | | | hmusing | | | |
| Wrap | KW | /xmlenc#kw-aes256 | | | 128 bi | | | |
| Algorith | | | | | t keys | | | |
| musing | | | | | AES Key | A256KW | http://www.w3.org/2001/0 | |
| 256 bit | | | | | Wrap | | 4/xmlenc#kw-aes256 | |
| keys | | | | | Algorith | | | |
| AES in | A128 | http://www.w3.org/2001/04 | AES/CBC/PKCS5Paddin | | musing | | | |
| Cipher | CBC | /xmlenc#aes128-cbc | g | | 256 bit | | | |
| Block | | | | | keys | | | |
| Chaining | | | | | AES in | A128CB | http://www.w3.org/2001/0 | AES/CBC/PKCS5Paddi |
| (CBC) | | | | | Cipher | C+HS25 | 4/xmlenc#aes128-cbc | ng |
| mode | | | | | Block | 6 | | |
| with | | | | | Chaining | | | |
| PKCS #5 | | | | | (CBC) | | | |
| padding | | | | | mode | | | |
| using | | | | | with | | | |
| 128 bit | | | | | PKCS #5 | | | |
| keys | | | | | padding | | | |
| AES in | A256 | http://www.w3.org/2001/04 | AES/CBC/PKCS5Paddin | | using | | | |
| CBC mode | CBC | /xmlenc#aes256-cbc | g | | 128 bit | | | |
| with | | | | | keys | | | |
| PKCS #5 | | | | | AES in | A256CB | http://www.w3.org/2001/0 | AES/CBC/PKCS5Paddi |
| padding | | | | | CBC mode | C+HS51 | 4/xmlenc#aes256-cbc | ng |
| using | | | | | with | 2 | | |
| 256 bit | | | | | PKCS #5 | | | |
| keys | | | | | padding | | | |
| AES in | A128 | http://www.w3.org/2009/xm | AES/GCM/NoPadding | | using | | | |
| Galois/C | GCM | lenc11#aes128-gcm | | | 256 bit | | | |
| ounter | | | | | keys | | | |
| Mode | | | | | AES in | A128GC | http://www.w3.org/2009/x | AES/GCM/NoPadding |
| (GCM) | | | | | Galois/C | M | mlenc11#aes128-gcm | |
| using | | | | | ounter | | | |
| 128 bit | | | | | Mode | | | |
| keys | | | | | (GCM) | | | |
| AES GCM | A256 | http://www.w3.org/2009/xm | AES/GCM/NoPadding | | using | | | |
| using | GCM | lenc11#aes256-gcm | | | 128 bit | | | |
| 256 bit | | | | | keys | | | |
| keys | | | | | AES GCM | A256GC | http://www.w3.org/2009/x | AES/GCM/NoPadding |
+----------+------+---------------------------+---------------------+ | using | M | mlenc11#aes256-gcm | |
| 256 bit | | | |
| keys | | | |
+----------+--------+--------------------------+--------------------+
Appendix C. Acknowledgements Appendix C. Acknowledgements
Solutions for signing and encrypting JSON content were previously Solutions for signing and encrypting JSON content were previously
explored by Magic Signatures [MagicSignatures], JSON Simple Sign explored by Magic Signatures [MagicSignatures], JSON Simple Sign
[JSS], Canvas Applications [CanvasApp], JSON Simple Encryption [JSE], [JSS], Canvas Applications [CanvasApp], JSON Simple Encryption [JSE],
and JavaScript Message Security Format [I-D.rescorla-jsms], all of and JavaScript Message Security Format [I-D.rescorla-jsms], all of
which influenced this draft. Dirk Balfanz, John Bradley, Yaron Y. which influenced this draft. Dirk Balfanz, John Bradley, Yaron Y.
Goland, John Panzer, Nat Sakimura, and Paul Tarjan all made Goland, John Panzer, Nat Sakimura, and Paul Tarjan all made
significant contributions to the design of this specification and its significant contributions to the design of this specification and its
related specifications. related specifications.
Appendix D. Document History Jim Schaad and Karen O'Donoghue chaired the JOSE working group and
Sean Turner and Stephen Farrell served as Security area directors
during the creation of this specification.
Appendix D. Open Issues
[[ to be removed by the RFC editor before publication as an RFC ]] [[ to be removed by the RFC editor before publication as an RFC ]]
The following items remain to be considered or done in this draft:
o No known open issues.
Appendix E. Document History
[[ to be removed by the RFC editor before publication as an RFC ]]
-06
o Removed the "int" and "kdf" parameters and defined the new
composite AEAD algorithms "A128CBC+HS256" and "A256CBC+HS512" to
replace the former uses of AES CBC, which required the use of
separate integrity and key derivation functions.
o Included additional values in the Concat KDF calculation -- the
desired output size and the algorithm value, and optionally
PartyUInfo and PartyVInfo values. Added the optional header
parameters "apu" (agreement PartyUInfo), "apv" (agreement
PartyVInfo), "epu" (encryption PartyUInfo), and "epv" (encryption
PartyVInfo).
o Changed the name of the JWK RSA exponent parameter from "exp" to
"xpo" so as to allow the potential use of the name "exp" for a
future extension that might define an expiration parameter for
keys. (The "exp" name is already used for this purpose in the JWT
specification.)
o Applied changes made by the RFC Editor to RFC 6749's registry
language to this specification.
-05 -05
o Support both direct encryption using a shared or agreed upon o Support both direct encryption using a shared or agreed upon
symmetric key, and the use of a shared or agreed upon symmetric symmetric key, and the use of a shared or agreed upon symmetric
key to key wrap the CMK. Specifically, added the "alg" values key to key wrap the CMK. Specifically, added the "alg" values
"dir", "ECDH-ES+A128KW", and "ECDH-ES+A256KW" to finish filling in "dir", "ECDH-ES+A128KW", and "ECDH-ES+A256KW" to finish filling in
this set of capabilities. this set of capabilities.
o Updated open issues. o Updated open issues.
skipping to change at page 41, line 45 skipping to change at page 39, line 32
o For AES GCM, use the "additional authenticated data" parameter to o For AES GCM, use the "additional authenticated data" parameter to
provide integrity for the header, encrypted key, and ciphertext provide integrity for the header, encrypted key, and ciphertext
and use the resulting "authentication tag" value as the JWE and use the resulting "authentication tag" value as the JWE
Integrity Value. Integrity Value.
o Defined minimum required key sizes for algorithms without o Defined minimum required key sizes for algorithms without
specified key sizes. specified key sizes.
o Defined KDF output key sizes. o Defined KDF output key sizes.
o Specified the use of PKCS #5 padding with AES-CBC. o Specified the use of PKCS #5 padding with AES CBC.
o Generalized text to allow key agreement to be employed as an o Generalized text to allow key agreement to be employed as an
alternative to key wrapping or key encryption. alternative to key wrapping or key encryption.
o Clarified that ECDH-ES is a key agreement algorithm. o Clarified that ECDH-ES is a key agreement algorithm.
o Required implementation of AES-128-KW and AES-256-KW. o Required implementation of AES-128-KW and AES-256-KW.
o Removed the use of "A128GCM" and "A256GCM" for key wrapping. o Removed the use of "A128GCM" and "A256GCM" for key wrapping.
 End of changes. 160 change blocks. 
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