wdiff draft-ietf-mile-rolie-03.txt draft-ietf-mile-rolie-04.txt

MILE Working Group J. Field
Internet-Draft Pivotal
Intended status: Informational S. Banghart
Expires: January 9, April 27, 2017 D. Waltermire
NIST
July 8,
October 24, 2016

Resource-Oriented Lightweight Information Exchange
draft-ietf-mile-rolie-03
draft-ietf-mile-rolie-04

Abstract

This document defines a resource-oriented approach for security
automation information publication, discovery, and sharing. Using
this approach, producers may publish, share share, and exchange
representations of security incidents, attack indicators, software
vulnerabilities, configuration checklists, and other security
automation information as Web-addressable resources. Furthermore,
consumers and other stakeholders may access and search this security
information as needed, establishing a rapid and on-demand information
exchange network for restricted internal use or public access
repositories. This specification extends the Atom Publishing
Protocol and Atom Syndication Format to transport and share security
automation resource representations.

Contributing to this document

The source for this draft is being maintained in on GitHub. Suggested
changes should be submitted as pull requests at
<https://github.com/CISecurity/ROLIE>. Instructions are on that page
as well. Editorial changes can be managed in GitHub, but any
substantial issues need to be discussed on the MILE mailing list.

Status of This Memo

This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 9, April 27, 2017.

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
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described in the Simplified BSD License.

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. XML-related Conventions . . . . . . . . . . . . . . . . . . . 4
3.1. XML Namespaces . . . . . . . . . . . . . . . . . . . . . 4
3.2. RELAX NG Compact Schema . . . . . . . . . . . . . . . . . . . . . 5
4. Background and Motivation . . . . . . . . . . . . . . . . . . 5
4.1. Message-oriented versus Resource-oriented Architecture Proactive Sharing . 6
4.1.1. Message-oriented Architecture . . . . . . . . . . . . 6
4.1.2. Resource-Oriented Architecture . . . . . . . 5
4.2. Knowledge Aggregation . . . . 7
4.2. Use of the Atom Publishing Protocol . . . . . . . . . . . 8 . . . 6
4.3. Resource-oriented Architecture . . . . . . . . . . . . . 6
5. ROLIE Requirements for the Atom Publishing Protocol . . . . . 9 7
5.1. AtomPub Service Documents . . . . . . . . . . . . . . . . 9 7
5.1.1. Use of the "app:workspace" Element . . . . . . . . . 9 8
5.1.2. Use of the "app:collection" Element . . . . . . . . . 10 8
5.2. Service Discovery . . . . . . . . . . . . . . . . . . . . 11 9
5.3. Transport Layer Security . . . . . . . . . . . . . . . . 11 10
5.4. User Authentication . . . . . . . . . and Authorization . . . . . . . . . . 11
5.5. User Authorization . . . . . . . . . . . . . . . . . . . 12
5.6. / (forward slash) Resource URL . . . . . . . . . . . . . 12
5.7. 11
5.6. HTTP methods . . . . . . . . . . . . . . . . . . . . . . 12 11
6. ROLIE Requirements for the Atom Syndication Format . . . . . 12
6.1. Use of the "atom:feed" element . . . . . . . . . . . . . 13 12
6.1.1. Use of the "atom:category" Element . . . . . . . . . 13
6.1.2. Use of the "atom:link" Element . . . . . . . . . . . 14
6.1.3. Use of the "atom:updated" Element . . . . . . . . . . 16 15
6.2. Use of the "atom:entry" Element . . . . . . . . . . . . 16 15
6.2.1. Use of the "atom:content" Element . . . . . . . . . . 16
6.2.2. Use of the "atom:link" Element . . . . . . . . . . . 17 16
6.2.3. Use of the "rolie:format" Element . . . . . . . . . . 17

6.3. Link Relations
6.2.4. Requirements for a Standalone Entry . . . . . . . . . 18
7. Available Extension Points Provided by ROLIE . . . . . . . . 18
7.1. The Category Extension Point . . . . 17
7. . . . . . . . . . . 18
7.1.1. General Use of OpenSearch the "atom:category" Element . . . . . 19
7.1.2. Identification of Security Automation Information
Types . . . . . . . . . . . . . . . . . 17
8. Characterizing ROLIE Collections and Resources . . . . . . . 18
8.1. Identification of Security Automation Information Types 19
7.2. The "rolie:format" Extension Point . 18
8.2. General Use of the "atom:category" Element . . . . . . . 19
8.3. Identification of Security Automation Information Formats 20
9. Formal Syntax for the ROLIE Schema . . . 21
7.3. The Link Relation Extension Point . . . . . . . . . . . . 20
10. 21
8. IANA Considerations TODO . . . . . . . . . . . . . . . . . . 20
10.1. . . . 21
8.1. XML Namespaces and Schema URNs . . . . . . . . . . . . . 20
10.2. 21
8.2. ROLIE Parameters URN Sub-namespace . . . . . . . . . . . . . . . . . 22
8.3. ROLIE URN Parameters . . . . . 21
10.3. . . . . . . . . . . . . . 22
8.4. ROLIE Security Resource Information Type Registry . Sub-Registry . . 23
9. Security Considerations . . . 21
11. Security Considerations TODO . . . . . . . . . . . . . . . . 22
12. 24
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24
13. 26
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 24
13.1. 26
11.1. Normative References . . . . . . . . . . . . . . . . . . 25
13.2. 26
11.2. Informative References . . . . . . . . . . . . . . . . . 26
13.3. 28
11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 27 29
Appendix A. Use Case Examples Relax NG Compact Schema for ROLIE . . . . . . . . . . . . . . . . . 27
A.1. Service Discovery . . . 29
Appendix B. Examples of Use . . . . . . . . . . . . . . . . . 27
A.2. Feed Retrieval . 30
B.1. Service Discovery . . . . . . . . . . . . . . . . . . . . 30
A.3. Entry
B.2. Feed Retrieval . . . . . . . . . . . . . . . . . . . . . 32
A.4. Use Case: Search . . . . . . . . . . . . . . . . . . 33
B.3. Entry Retrieval . . 34
Appendix B. XACML Guidance . . . . . . . . . . . . . . . . . . . 36 35
Appendix C. Relax NG Schema for ROLIE Extensions . . . . . . . . 38
Appendix D. Change Tracking History . . . . . . . . . . . . . . . . . . 38 . 36
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 37

1. Introduction

This document defines a resource-oriented approach to security
automation information sharing that follows the REST (Architectural S
tyles and the Design of Network-based Software Architectures)
architectural style. In this approach, computer security resources
are maintained in web-accessible repositories structured as Atom
Syndication Format [RFC4287] feeds. Feeds. Representations of specific
types of security automation information are categorized and
organized into indexed collections, Collections which may be requested by the
consumer. As the set of resource collections Collections are forward facing, the
consumer may search all available content for which they are
authorized to view, and request the information resources which are
desired. Through use of granular authentication and access controls,
only authorized consumers may be permitted the ability to read or
write to a given feed. Feed. This approach is in contrast to, and meant to
improve on, the traditional point-to-point messaging system, in which
consumers must request individual pieces of information from a server
following a triggering event. The point-to-point approach creates a
closed system of information sharing that encourages duplication of
effort and hinders automated security systems.

The goal of this document is to define a RESTful approach to security
information communication with two primary intents: 1) increasing
communication and sharing of incident reports, vulnerability
assessments, configuration checklists, and other security automation
information between providers and consumers; and 2) establishing a
standardized communication system to support automated computer
security systems.

In order to deal with the great variety in security automation
information types and associated resource representations, this
specification defines extension points that can be used to add
support for new information types and associated resource
representations by means of additional supplementary specification
documents. This primary document is resource representation
agnostic, and defines the core requirements of all implementations.
Those
An overview of the extension system is provided in Section 7.Those
seeking to provide support for specific security automation
information types should refer to the specification for that format domain
described by the IANA registry found in section 10.3. 8.4.

2. Terminology

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

Definitions for some of the common computer security-related
terminology used in this document can be found in Section 2 of
[RFC5070].

3. XML-related Conventions

3.1. XML Namespaces

This specification uses XML Namespaces [W3C.REC-xml-names-20091208]
to uniquely identify XML element names. It uses the following
namespace prefix mappings for the indicated namespace URI:

"app" is used for the "http://www.w3.org/2007/app" namespace
defined in [RFC5023].

"atom" is used for the "http://www.w3.org/2005/Atom" namespace
defined in [RFC4287].

"rolie" is used for the "urn:ietf:params:xml:ns:rolie:1.0"
namespace defined in section 10.1 8.1 of this specification.

3.2. RELAX NG Compact Schema

Some sections of this specification are illustrated with fragments of
a non-normative RELAX NG Compact schema [relax-NG]. However, the
text of this specification provides the definition of conformance.
Complete schemas appear for the "urn:ietf:params:xml:ns:rolie-1.0"
namespace in appendix C.
Schema for the "http://www.w3.org/2007/app" and
"http://www.w3.org/2005/Atom" namespaces appear in RFC5023 appendix B
[RFC5023] and RFC4287 appendix B [RFC4287] respectively.

4. Background and Motivation

Information sharing is well known thatthreats to computer security are evolving ever
more rapidly as time goes on. As software increases in complexity, one of the number core components of vulnerabilities in systems automating
security processes. Vulnerabilities, configurations, software
identification, security incidents, and networks can increase
exponentially. Threat actors looking to exploit these
vulnerabilities patching data are making more frequent and more widely distributed
attacks across a large variety of systems. The adoption of liberal
information sharing amongst attackers creates a window of as little
as just a few hours between
of the discovery classes of a vulnerability and attacks information that are shared today to enable
effective security on a vulnerable system. As wide scale. However, as the skills and knowledge required to
identify and combat these attacks become more and more specialized,
even a well established and secure system may find itself unable to
quickly respond to an incident. Effective identification scale of and
response defense
broadens to a sophisticated attack requires open cooperation and
collaboration between defending operators, software vendors, sometimes global networks, and end-
users. To improve the timeliness inherent scaling
issues of responses, human-in-the-loop sharing become apparent, the need for
automation must be
used to acquire, contextualize, and put to use shared computer
security information. machine-to-machine communication becomes apparent.

4.1. Proactive Sharing

Existing approaches to computer security information sharing often
use message exchange patterns that are point-to-point, and event-
driven. point-to-point. Sometimes,
information that may be useful to share with multiple peers is only
made available to peers after they have specifically requested it.
Unfortunately, a sharing peer may not know, a priori, what
information to request from another peer. Some
exsisting existing systems
provide a mechanism for unsolicited information requests, however however,
these reports are again sent point-to-point, and must be reviewed for
relevance and then prioritized for action by the recipient,
introducing additional latency.

In order to adequately combat evolving threats, computer security
information resource providers should be enabled able to share selected
information proactively as appropriate. proactively. Proactive sharing greatly aids knowledge
dissemination, and improves response times and
usability. usability by allowing
the consumer to choose which information is relevant to its needs.

For example, a security analyst can benefit by having the ability to
search a comprehensive collection of attack indicators that have been
published by a government agency, or by another member of a sharing
consortium. The representation of each indicator may include links
to the related resources, enabling an appropriately authenticated and
authorized analyst to freely navigate the information space of
indicators, incidents, vulnerabilities, and other computer security
domain concepts as needed. In this way, an analyst can more
effectively utilize the super set of information made publicly
available.

Consider also the case

4.2. Knowledge Aggregation

Additionally, there is value in maintaining a repository of knowledge
that can be queried by a new consumer, allowing this consumer to
identify and retrieve any information that is relevant to its needs.
In this way, the consumer can gain access to meaningful current and
historic information, catching up to the knowledge level of its
peers.

Consider the case of an automated endpoint management system
attempting to proactively prevent software flaws and mis-configured
software from compromising the security of the affected systems.
During its full network sweep, the endpoint monitoring system would
check each endpoint for outdated
or vulnerable outdated, vulnerable, and mis-configured
software. This system would benefit from having access to not only
the software vendor's list of vulnerabilities, vulnerabilities and configuration
baselines, but also
vulnerabilities similar information discovered by other vulnerability security
researchers. An advanced system could even give back to this sharing
consortium by sharing any vulnerabilities that it discovers. The natural
conclusion of such a sharing network is an automated security
solution that can dynamically find and collect relevant information from discovered.

These capabilities support a
globally distributed web federated collection of information repositories.

The following section discusses additional specific technical issues
repositories that motivated the development of this alternative approach.

4.1. Message-oriented versus can be queried and contributed to by an
organization, further supporting automated security solutions.

4.3. Resource-oriented Architecture

The existing approaches

Applying the REST architectural style to computer the problem domain of
security information sharing are
based upon message-oriented interactions. The following paragraphs
explore some involves exposing information of the architectural constraints associated any
relevant type as simple Web-addressable resources. Each provider
maintains their own repository of data, with
message-oriented interactions public and consider the relative merits of private
sections as needed. Any producer or consumer can then discover these
repositories, search for relevant Feeds, and pull information from
them. By using this approach, an
alternative model based on organization can more quickly and
easily share relevant data representations with a resource-oriented architecture for use much larger and
potentially more diverse constituency. A consumer may leverage
virtually any available HTTP user agent in some use case scenarios.

ROLIE specifies a resource-oriented architecture that attempts order to
address the issues present in a message-oriented architecture.

4.1.1. Message-oriented Architecture

In general, message-based integration architectures may be based upon
either an RPC-style or a document-style binding. The message types
defined by Real-time Inter-network Defense (RID) [RFC6545] represents
an example of an RPC-style request. This approach imposes implied
requirements for conversational state management on both of the
communicating RID endpoint(s). Experience has shown that this state
management frequently becomes the limiting factor with respect to the
runtime scalability of an RPC-style architecture.

In addition, the practical scalability of a peer-to-peer message-
based approach will be limited by the administrative procedures
required to manage O(N^2) trust relationships and at least O(N)
policy groups.

As long as the number of participating entities in an information
sharing consortium is limited to a relatively small number of nodes
(i.e., O(2^N), where N < 5), these scalability constraints may not
represent a critical concern. However, when there is a requirement
to support a significantly larger number of participating peers, a
different architectural approach will be required. Towards the goal
to create a large-scale network of entities sharing information, this
traditional architecture only creates small and isolated groupings of
sharing, encouraging effort duplication between these sharing
islands. One alternative to the message-based approach that has
demonstrated scalability and a high degree of connectedness is the
REST [REST] architectural style.

4.1.2. Resource-Oriented Architecture

Applying the REST architectural style to the problem domain of
security information sharing involves exposing information in any
relevant type as simple Web-addressable resources. Each provider
maintains their own repository of data, with public and private
sections as needed. Any producer or consumer can then discover these
repositories, search for relevant feeds, and pull information from
them. By using this approach, an organization can more quickly and
easily share relevant data representations with a much larger and
potentially more diverse constituency. A consumer may leverage
virtually any available HTTP user agent in order to make requests of make requests of
the service provider. This improved ease of use enables more rapid
adoption and broader participation, thereby improving security for
everyone.

A key aspect of any RESTful Web service is the ability to provide
multiple resource representations. For example, clients may request
that a given resource representation be returned as XML, JSON, or in
some other format. In order to enable backwards-compatibility and
interoperability with existing implementations, the RESTful approach
allows the provider to make differing formats available proactively,
allowing the consumer to simply select the version that best suits
them.

Finally, an important principle of the REST architectural style is
the focus on hypermedia as the engine of application state (HATEOAS).
Rather than the server maintaining conversational state for each
client, the server will instead include a suitable set of hyperlinks
in the resource representation that is returned to the client. The
included hyperlinks provide the client with a specific set of
permitted state transitions. Using these links the client may
perform an operation, such as updating or deleting the resource
representation. The client may also be provided with hypertext links
that can be used to navigate to any related resource. For example,
the resource representation for an incident object may contain links to the
related indicator resource(s). In this way, the server remains stateless with
respect to a series of client requests.

4.1.2.1. A Resource-Oriented Use Case: "Mashup"

In this section we consider an example scenario

5. ROLIE Requirements for creating a
computer security "mashup".

A producer creates and maintains a feed of information on threat
actors, whilst another creates and maintains a feed of attack
indicators. Each has authorized a large consortium of security
analysts to access these feeds as they see fit. Any one of these
analysts can then make HTTP(s) requests to the servers to collect
sets of information from each provider. The resulting correlations
may yield new insights that enable a more timely and effective
defensive response. Of course, this report may, in turn, be made
available to others as a new Web-addressable resource, reachable via
another URL. By exposing information using the RESTful approach in
this way, the effectiveness of the collaboration amongst a consortium
of cyber security stakeholders can be greatly improved.

4.2. Use of the Atom Publishing Protocol

This specification defines a profile of the Atom Publishing Protocol
(AtomPub) [RFC5023] and Atom Syndication Format [RFC4287] providing
implementation requirements for a security information sharing
solution as a RESTful Web service.

This document assumes that the reader has an understanding of both
the AtomPub and Atom Syndication Format specifications.

The following two sections of this document provide requirements for
using the Atom Syndication Format and AtomPub as a RESTful binding
for security automation information sharing.

5. ROLIE Requirements for the Atom Publishing Protocol

This section describes the Atom Publishing Protocol

This section describes a number of restrictions of and extensions to
the Atom Publishing Protocol (AtomPub) [RFC5023] that define the use
of that protocol in the context of a ROLIE-based solution.

This document assumes that the reader has an understanding of the
Atom Publishing Protocol specification.

5.1. AtomPub Service Documents

As described in RFC5023 section 8 [RFC5023], a Service Document is an
XML-based document format that allows a client to dynamically
discover the collections Collections provided by a publisher. A Service Document
consists of one or more app:workspace elements that may each contain
a number of app:collection elements.

The general structure of a service document is as follows (from
RFC5023 section 4.2 [RFC5023]):

5.1.1. Use of the "app:workspace" Element

In AtomPub, a Workspace, represented by the "app:workspace" element,
describes a group of one or more Collections. Building on the
AtomPub concept of a Workspace, in ROLIE a Workspace represents an
aggregation of Collections pertaining to security automation
information resources. This specification does not impose any
restrictions on the number of Workspaces that may be in a Service
Document or the specific Collections to be provided within a given
Workspace.

The following restrictions are imposed on the use of the
app:workspace element in ROLIE:

o A ROLE ROLIE repository can host Collections containing both public and
private information entries. It is RECOMMENDED that public and
private collections Collections be segregated into different Workspaces. By
doing this, Workspaces that contain private information can be
ignored by clients. clients or can be omitted from the Service Document
provided to a client that lacks the appropriate privilege to
access the set of Collections associated with the Workspace.

o Appropriate descriptions and naming conventions SHOULD be used to
indicate the intended audience of each workspace. This helps to
facilitate the selection of appropriate Workspaces by clients.

o An implementation can provide any number users.

5.1.2. Use of Collections within the "app:collection" Element

In AtomPub, a
given Workspace. It is RECOMMENDED that each collection appear in
only a single Workspace. This helps to reduce the number of
duplicate collections that need to be examined to discover
information that is relevant to a given client.

5.1.2. Use of the "app:collection" Element

In AtomPub, a Collection Collection in a Service Document, represented by the
"app:collection" element, provides metadata that can be used to point
to a specific Atom Feed that contains information Entries that may be
of interest to a client. The association between a Collection and a
Feed is provided by the "href" attribute of the app:collection
element. Building on the AtomPub concept of a Collection, in ROLIE a
Collection represents a pointer to a group of security automation
information resources pertaining to a given type of security
automation information. Collections are represented as Atom feeds Feeds as
per RFC 5023. Feed specific requirements are defined in section 6.1.

The following restrictions are imposed on the use of the
app:collection element for ROLIE:

o The atom:category elements contained in the app:categories element
MUST be the same set of atom:categories used in the Atom Feed
resource indicated by the app:collection "href" attribute value.
This ensures that the category metadata associated with the Feed
Collection is discoverable in both the Feed and the corresponding
Collection in the Service Document.

o An app:collection pertaining to a security automation information
resource Feed MUST contain an app:categories element that
minimally contains a single atom:category element with the
"scheme" attribute value of "urn:ietf:params:rolie:information-
type".
"urn:ietf:params:rolie:category:information-type". This category
MUST have an appropriate "term" attribute value as defined in
section 8.2. 7.1.1. This ensures that a given Collection corresponds
to a specific type of security automation information.

o Any app:collection element that does not contain a descendant
atom:category element with the "scheme" attribute value of
"urn:ietf:params:rolie:information-type"
"urn:ietf:params:rolie:category:information-type" MUST be
considered a non-
ROLIE non-ROLIE Collection. This allows Collections
pertaining to security automation information to co-exist
alongside Collections of other non-ROLIE information within the
same AtomPub instance.

o The app:categories element in an app:collection may MAY include
additional atom:category elements using a scheme other than
"urn:ietf:params:rolie:information-type".
"urn:ietf:params:rolie:category:information-type". This allows
other category metadata to be included.

5.2. Service Discovery

This specification requires that an implementation MUST publish an
Atom Service Document that describes the set of security information
sharing collections Collections that are provided by the repository.

The service document SHOULD be discoverable via the organization's
Web home page or another well-known public resource. An example of
this can be found in appendix A.1. B.1.

The service document SHOULD (TODO: MUST?) be located at the standardized location
"https://{host:port}/rolie/servicedocument", where {host:port} is the
authority portion of the URI. Dereferencing this URI MAY result in a
redirect based on a HTTP 3xx status code to direct the client to the
actual service document. This allows clients to have a well-known
location to find a ROLIE service document, while giving implmentations
implementations flexibility over how the service is deployed.

When deploying a service document for use by a closed consortium, the
service document MAY also be digitally signed and/or encrypted. For
example, consider XML Signature Syntax and Processing [xmldsig] and
XML Encryption Syntax and Processing [xmlenc]

5.3. Transport Layer Security

Implementations MUST support server-authenticated TLS.

Implementations MAY support mutually authenticated TLS.

Implementations MAY support client authenticated

ROLIE is intended to be handled with TLS.

5.4. User Authentication

Implementations The following requirements
have been derived from [RFC7589].

The most recent published version of TLS MUST be supported, and any
mandatory-to-implement (MTI) cipher suites in that version MUST be
supported as well.

The server MUST support user certificate-based client authentication. User
authentication MAY be enabled for specific feeds.

Implementations The
implementation MAY support more than one use any TLS cipher suite that supports mutual
authentication.

During the TLS negotiation, the client authentication
method.

Servers participating in an information sharing consortium and
supporting interactive user logins MUST carefully examine the
certificate presented by members of the consortium
SHOULD support server to determine if it meets the
client's expectations. Particularly, the client authentication via a federated MUST check its
understanding of the server hostname against the server's identity scheme as per SAML 2.0.

5.5. User Authorization

This document does not mandate
presented in the use server Certificate message, in order to prevent man-
in-the-middle attacks. Matching is performed according to the rules
laid out in the Security Considerations section of any specific user
authorization mechanisms. However, service implementers SHOULD
provide appropriate authorization checking [RFC4642].

If the match fails, the client MUST either ask for all resource accesses,
including individual Atom Entries, Atom Feeds, explicit user
confirmation or terminate the connection and Atom Service
Documents.

Authorization for a resource MAY be adjudicated based on indicate the value(s)
of server's
identity is suspect. Additionally, clients MUST verify the associated Atom <category> element(s).

5.6. binding
between the identity of the servers to which they connect and the
public keys presented by those servers. Clients SHOULD implement the
algorithm in Section 6 of [RFC5280] for general certificate
validation, but MAY supplement that algorithm with other validation
methods that achieve equivalent levels of verification (such as
comparing the server certificate against a local store of already-
verified certificates and identity bindings). If the client has
external information as to the expected identity of the server, the
hostname check MAY be omitted.

The server MUST be capable of verifying the identity of the client
with certificate-based authentication according to local policy to
ensure that the incoming client request is legitimate before any
configuration or state data is sent to or received from the client.

5.4. User Authentication and Authorization

Implementations MUST support user authentication. User
authentication MAY be enabled for specific Feeds.

Servers participating in an information sharing consortium and
supporting interactive user logins by members of the consortium
SHOULD support client authentication via a federated identity scheme
(e.g., SAML 2.0).

This document does not mandate the use of any specific user
authorization mechanisms. However, service implementers SHOULD
provide appropriate authorization checking for all resource accesses,
including individual Atom Entries, Atom Feeds, and Atom Service
Documents.

5.5. / (forward slash) Resource URL

The "/" resource MAY be provided for compatibility with existing
deployments that are using Transport of Real-time Inter-network
Defense (RID) Messages over HTTP/TLS [RFC6546]. If the "/" resource
is supported the following behavior MUST be also supported:

o Consistent with RFC6546 errata, a client requesting a GET on "/" MUST
SHOULD receive an HTTP status code 405 Method Not Allowed.

o An implementation MAY provide full support for RFC6546 [RFC6546] such that
a POST to "/" containing a recognized RID message type just works. is handled
correctly as a RID request. Alternatively, a client requesting a
POST to "/" MAY receive an HTTP status code 307 Temporary
Redirect. In this case, the location header in the HTTP response
will provide the URL of the appropriate RID endpoint, and the
client may repeat the POST method at the indicated location.
This resource could also leverage

If the new draft by reschke that
proposes "/" resource is unsupported, then a request for this resource
MUST provide a 404 HTTP status code 308 (cf: draft-reschke-http-status-
308-07.txt). TODO

5.7. code.

5.6. HTTP methods

Clients MUST be capable of recognizing and processing any standard
HTTP status code, as defined in [RFC5023] Section 5 5.

6. ROLIE Requirements for the Atom Syndication Format

This section describes a number of restrictions of and extensions to
the Atom Syndication Format [RFC4287] that define the use of that
format in the context of a ROLIE-based solution.

This document assumes that the reader has an understanding of the
Atom Syndication Format specification.

6.1. Use of the "atom:feed" element

As described in RFC4287 section 4.1.1 [RFC4287], an Atom Feed is an
XML-based document format that describes a list of related
information items, also known as a collection. Collection. Each Feed document,
represented using the atom:feed element, contains a collection Collection of
zero or more related information items individually called a "member
entry"
Entry" or "entry". "Entry".

When applied to the problem domain of security automation information
sharing, an Atom Feed may be used to represent any meaningful
collection
Collection of security automation information resources including a
set of configuration checklists or software vulnerabilities. resources. Each
entry Entry
in an atom:feed represents an individual resource, such as resource (e.g., a specific
checklist or , a software vulnerability record. record). Additional Feeds can
be used to represent collections of other meaningful and
useful Collections of security automation
resources.

This Atom feed Feed definition represents a stricter definition of the
Atom entry element.
atom:feed element defined in RFC 4287 for use in a ROLIE Any element
not specified here inherits its definition and requirements from RFC 4287.
[RFC4287].

atomFeed =
element atom:feed {
atomCommonAttributes,
(atomAuthor*
& atomCategory+
& atomContributor*
& atomGenerator?
& atomIcon?
& atomId
& atomLink* atomLink+
& atomLogo?
& atomRights?
& atomSubtitle?
& atomTitle
& atomUpdated
& extensionElement*),
atomEntry*
}

6.1.1. Use of the "atom:category" Element

An atom:feed may can be categorized and may can contain information from zero
or more categories. In Atom the naming scheme and the semantic
meaning of the terms used to identify an Atom category are
application-defined.

The following restrictions are imposed on the use of the
atom:category element when used in a ROLIE an atom:feed:

o An atom:feed element MUST minimally contain a single atom:category
element with the "scheme" attribute value of
"urn:ietf:params:rolie:information-type".
"urn:ietf:params:rolie:category:information-type". This category
MUST have an appropriate "term" attribute value as defined in
section 8.2. 7.1.1. This ensures that a given Collection corresponds
to a specific type of security automation information. All member
entries in the collection Collection MUST represent security automation
information records of this information type.

o Any atom:feed element that does not contain a child atom:category
element with the "scheme" attribute value of
"urn:ietf:params:rolie:information-type"
"urn:ietf:params:rolie:category:information-type" MUST NOT be
considered a ROLIE Collection. This allows Feeds pertaining to
security automation information to co-exist alongside Feeds of
other non-
ROLIE non-ROLIE information within the same AtomPub instance.

o An atom:feed may include additional atom:category elements using a
scheme other than "urn:ietf:params:rolie:information-type". "urn:ietf:params:rolie:category:information-
type". This allows other category metadata to be included.

6.1.2. Use of the "atom:link" Element

Link relations defined by the atom:link element are used to represent
state transitions using a stateless approach. In Atom a type of link
relationship can be defined using the "rel" attribute. The following
are link relations that provide state transitions related to a

A ROLIE
Atom feed.

o "service" - Indicates that the atom:feed MUST contain one or more atom:link elements with
rel="service" and href attribute whose value of the link identifies is a
resource IRI that can be used points to retrieve
an Atom Service Document associated with the feed. A feed MUST include one or more links atom:feed. When a
client is presented with rel="service" to point to the service document(s) that are
associated a Feed as its initial view into a
repository, a link with the feed. The "service" link service relationship type is
defined in the IANA Link Relations Registry [1].

o "search" - Indicates that the href value of the link identifies provides a
resource IRI that can be used to search through the containing
feed and related resources. A feed MAY include one or more links
with rel="search" means to point TBD.
discover additional security automation information. The "search" "service"
link relationship
type is defined in the IANA Link Relations Registry [2]. [1].

An atom:feed MAY include additional link relationships not specified
in this document. If a client encounters an unknown link
relationship type, the client MUST ignore the unrecognized link and
continue processing the remaining resource representation as if the
unrecognized link element did not appear.

The Feed Paging and Archiving [RFC5005] Atom extension provides
capabilities for paging and archiving of feeds.

A atom:feed can contain an arbitrary number of entries. Entries. In some
cases, a complete feed Feed may consist of a large number of entries. Entries.
Additionally, as new and updated entries Entries are ordered at the beginning
of a feed, Feed, a client may only be interested in retriving retrieving the first X N
entries in a feed Feed to process only the entries Entries that have changed since
the last access to a ROLIE repository feed. As retrieval of the Feed. As a practical matter,
the full result a large set
of Entries will likely need to be divided into more manageable
portions. Based on RFC5005 section 3 [RFC5005], the links link elements SHOULD
be included in all feeds Feeds to support paging using the following link
relation types:

o "first" - Indicates that the href attribute value of the link
identifies a resource IRI for the furthest preceding page of the feed.
Feed.

o "last" - Indicates that the href attribute value of the link
identifies a resource IRI for the furthest following page of the feed.
Feed.

o "previous" - Indicates that the href attribute value of the link
identifies a resource IRI for the immediately preceeding preceding page of
the feed. Feed.

o "next" - Indicates that the href attribute value of the link
identifies a resource IRI for the immediately following page of
the feed. Feed.

For example:

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
<id>b7f65304-b63b-4246-88e2-c104049c5fd7</id>
<title>Paged Feed</title>
<link rel="self" href="http://example.org/feedA?page=5"/>
<link rel="first" href="http://example.org/feedA?page=1"/>
<link rel="prev" href="http://example.org/feedA?page=4"/>
<link rel="next" href="http://example.org/feedA?page=6"/>
<link rel="last" href="http://example.org/feedA?page=10"/>
<updated>2012-05-04T18:13:51.0Z</updated>

</feed>

Example Paged Feed

A reference to a historical feed Feed may need to be stable, and/or a Feed
may need to be divided into some a series of defined epochs.
Implementations SHOULD support the mechanisms described in RFC5005
section 4 [RFC5005] to provide capabilities link-based state transitions for
maintaining archiving of feeds. Feeds.

An atom:feed MAY include additional link relationships not specified
in this document. If a client encounters an unknown link
relationship type, the client MUST ignore the unrecognized link and
continue processing as if the unrecognized link element did not
appear. The definition of new Link relations that provide additional
state transition extensions is discussed in section 7.3.

6.1.3. Use of the "atom:updated" Element

The atom:updated element MUST be populated with the current time at
the instant the feed Feed representation was last updated by adding,
updating, or deleting an entry; Entry; or changing any metadata for the
feed.
Feed.

6.2. Use of the "atom:entry" Element

Each entry Entry in an Atom feed, Feed, represented by the atom:entry element,
describes a single information record, format, and type combination.
The following atom:entry schema definition represents a stricter
representation of the atom:entry element defined in RFC 4287 [RFC4287] for use
in a ROLE-based ROLIE-based Atom Feed.

atomEntry =
element atom:entry {
atomCommonAttributes,
(atomAuthor*
& atomCategory*
& atomContent
& atomContributor*
& atomId
& atomLink*
& atomPublished?
& atomRights?
& atomSource?
& atomSummary?
& atomTitle
& atomUpdated
& rolieFormat
& extensionElement*)
}

6.2.1. Use of the "atom:content" Element

There MUST be exactly one atomContent element in the entry. Entry. The
content element MUST adhere to this definition: definition, which is a stricter
representation of the atom:content element defined in [RFC4287]:

atomContent =
element atom:content {
atomCommonAttributes,
attribute type { atomMediaType },
attribute src { atomUri },
empty
}

The type attribute MUST be identify the serialization type of the
content, for example, XML application/xml or JSON. application/json. A
prefixed media type MAY be used to reflect a specific model used with
a given serialization approach (e.g., application/rdf+xml). The src
attribute is a link MUST be an IRI that can be dereferenced to retrieve the payload.
related content data.

6.2.2. Use of the "atom:link" Element

There MAY

Link relations can be zero or more atom:link elements included in the entry. The
content element MUST adhere an atom:entry to this definition:

The link element follows the definition laid out in represent state
transitions for the Atom
Syndication Document. Entry.

If there entries with is a need to provide the same format and category but information in different data
models and/or serialization formats, separate Entry instances can be
included in the same or a different
type, it MUST Feed. Such an alternate content
representation can be linked to indicated using an atom:link having a rel
attribute with the "alternate" value "alternate".

An atom:feed MAY include additional link relation.

6.2.3. Use of the "rolie:format" Element

There MUST be exactly one rolie:format element in the Entry. This
format SHOULD be one of relationships not specified
in this document. If a client encounters an unknown link
relationship type, the formats listed under client MUST ignore the category of this
entry unrecognized link and
continue processing as discussed in if the and Content Model section. unrecognized link element did not
appear. The format is
contained in the content definition of this tag.

6.3. Link Relations

In addition to the standard new Link Relations defined by the Atom
specification, this specification defines the following relations that provide additional
Link Relation terms, which are introduced specifically
state transition extensions is discussed in support of
the Resource-Oriented Lightweight Information Exchange protocol.

TODO: This section needs to be expanded.

7. 7.3.

6.2.3. Use of OpenSearch

Implementers MUST support OpenSearch 1.1 [opensearch] as the
mechanism for describing how clients may form search requests.

Implementers MUST provide a link with "rolie:format" Element

As mentioned earlier, a relationship type key goal of
"search". This link SHALL return an Open Search Description Document
as defined in OpenSearch 1.1.

Implementers MUST fully qualify all OpenSearch URL template parameter
names using the defined XML namespaces, as appropriate.

8. Characterizing ROLIE Collections and Resources

This this specification does not require a particular security automation
information type or content format; rather, it provides extension
points using IANA tables is to allow for future extensions a
consumer to review a set of supported
information types and formats.

A given published security automation information type is respresented using
the "atom:category" element. In this way, an "atom:category" element
can be used to:

1.
resources, and then identify that an "app:collection" element in and retrieve any resources of interest.
The format of the data is a Service Document
points key criteria to an Atom feed that contains entries pertaining consider when deciding
what information to retrieve. For a
specific given type of security
automation information (see section
5.1.2), or

2. identify that an "atom:feed" element in an Atom feed contains
entries pertaining to a specific type of security automation
information (see section 6.1.1).

As mentioned earlier, a key goal of this specification is to allow a
consumer to identify security automation information resources of
interest, and then choose a suitable format of the information to
retrieve. For a given type of security automation information, it is
expected information, it is expected that a number of different
formats may be used to represent this information. To support this
use case, both the serialization format and the specific data model
expressed in that format must be known by the consumer.

The following sections rolie:format element is used to describe how information types are defined and
used, and how specific content formats are declared in ROLIE.

8.1. Identification of Security Automation Information Types

A security automation information type represents a class of
information that represents the same or similar information data model
[RFC3444]. Notional examples of used to
express the information types include:

indicator: Computing device- or network-related "observable features
and phenomenon that aid referenced in the forensic or proactive detection atom:content element of
malicious activity; and associated meta-data" (from
[I-D.ietf-mile-rfc5070-bis]).

incident: Information pertaining to and "derived analysis from
security incidents" (from [I-D.ietf-mile-rfc5070-bis]).

vulnerability reports: Information identifying and describing an
atom:entry. It also allows a
vulnerability in hardware or software.

configuration checklists: Content schema to be identified that can be
used to assess when parsing the
configuration settings related to installed software.

software tags: Metadata used to identify and characterize
installable software.

This is a short list to inspire thought on possible information
types, which will also include other information used to automate
security processes.

This document does not specific any information types. Instead,
information types in ROLIE are expected content to be defined in extension
documents that describe one verify or more new information types. This
allows better understand the information types used by ROLIE implementations to grow
over time
structure of the content.

There MUST be exactly one rolie:format element in an atom:entry. The
element MUST adhere to support new security automation use cases. These
extension documents this definition:

rolieFormat =
element rolie:format {
atomCommonAttributes,
attribute ns { atomURI },
attribute version { text } ?,
attribute schema-location { atomURI } ?,
attribute schema-type { atomMediaType } ?,
empty
}

The rolie:format element MUST provide a "ns" attribute that
identifies the data model of the resource referenced by the
atom:content element. For example, the namespace used may also enhance ROLIE be an XML
namespace URI, or an identifier that represents a serialized JSON
model. The URI used for the "ns" attribute value MUST be an absolute
or opaque URI. The resource representations identified by defining link relations, categories, and other AtomPub and Atom
Syndication Format data model extensions to address the
representational needs of specific information types. New
information types are added to ROLIE through registrations to URI need not be
resolvable.

The rolie:format element MAY provide a "version" attribute that
identifies the
IANA Security Resource Information Type registry defined in section
10.3.

8.2. General Use version of the "atom:category" Element format used for the related
atom:content.

The core extension point within this specification rolie:format element MAY provide a "schema-location" element that
is the ability to
define different security automation information types, which a URI that identifies a schema resource that can be used to characterize
validate the type of information contained in a ROLIE
resource collection. related atom:content.

The information type of a resource collection
is characterized using an "atom:category" rolie:format element with MAY provide a "scheme"
attribute value of "urn:ietf:params:rolie:information-type", and "schema-type" element, which
is a
"term" attribute value mime type identifying the specific information type
declared.

For example, format of the security automation information type "incident"
would be schema resource
identified as follows:

<atom:category scheme="urn:ietf:params:rolie:information-type"
term="incident"/>

The Uniform Resource Name (URN) [RFC2141]
"urn:ietf:params:rolie:information-type" by the "schema-location" attribute.

6.2.4. Requirements for a Standalone Entry

If an Entry is registered with IANA ever shared as
described in section 10.2.

Registered security automation information type values are defined in a standalone resource, separate from
its containing Feed, then the IANA table described in section 10.3.

8.3. Identification of Security Automation Information Formats

A given information type may following additional requirements
apply:

o The Entry MUST have a number atom:link element with rel="collection" and
href="[IRI of supported formats.
Each format is expected to have a specification that defines the data
model for containing Collection]". This allows the format. As described in section 6.2.3, Feed
or Feeds for which the
"rolie:format" element Entry is used a member to describe be discovered, along
with the specific data model
used to represent related information the resource referenced by a given "atom:entry".
By declaring Feed may contain. In the data model used in this way, a consumer can choose
to download or ignore case of
the resource, or look Entry have multiple containing Feeds, the Entry MUST have one
atom:link for alternate formats.
This saves each related Feed.

o The Entry MUST declare the consumer from downloading and parsing resources that information-type of the consumer is not interested in or resources expressed in formats
that are not understandable content
resource referenced by the consumer.

TODO: Need Entry (see Section 7.1.2).

7. Available Extension Points Provided by ROLIE

This specification does not require particular information types or
data formats, rather, ROLIE is intended to describe the structure be extended by additional
specifications that add new categories and use link relations. The
primary point of extension is through the rolie:format
element.

9. Formal Syntax for the ROLIE Schema

TODO: define a schema for information-type category,
which is used to enumerate the "rolie:format" element.

10. set of all types of information
supported by ROLIE. Additional specifications can register new
information-type records with IANA that serve as the main
characterizing feature of a ROLIE Collection or Resource. These
additional specifications defining new information-type values, can
describe requirements for including specific categories, link
relations, as well as, use of specific data formats supporting a
given information-type.

7.1. The Category Extension Point

The atom:category element, defined in RFC 4287 section 4.2.2
[RFC4287], provides a mechanism to provide additional categorization
information for a content resource in ROLIE. The ability to define
new categories is one of the core extension points provided by Atom.
A Category Document, defined in RFC 5023 section 7 [RFC5023],
provides a mechanism for an Atom repository to make discoverable the
atom:category terms and allowed values used by a given repository.

ROLIE adds to this existing Atom extension mechanism by allowing
ROLIE specific category extensions to be registered with IANA, and
additionally has assigned an information-type category that has
special meaning for implementations of ROLIE. These aspects are
discussed in the following subsections.

7.1.1. General Use of the "atom:category" Element

The atom:category element can be used for characterizing a ROLIE
Resource. As discussed earlier in this document, an atom:category
element has a "term" attribute that indicates the assigned category
value, and a "scheme" attribute that provides an identifier for the
category type. The "scheme" provides a means to describe how a set
of category terms should be used and provides a namespace that can be
used to differentiate terms provided by multiple organizations with
different semantic meaning.

To further differentiate category types used in ROLIE, an IANA sub-
registry has been established for ROLIE protocol parameters to
support the registration of new category "scheme" attribute values by
ROLIE extension specifications. Use of this extension point is
discussed in section 8.3.

7.1.2. Identification of Security Automation Information Types

A ROLIE specific extension point is provided through the
atom:category "scheme" value
"urn:ietf:params:rolie:category:information-type". This value is a
Uniform Resource Name (URN) [RFC2141] that is registered with IANA as
described in section 8.3. When used as the "scheme" attribute in
this way, the "term" attribute is expected to be a registered value
as defined in section Section 8.4. Through this mechanism a given
security automation information type can be used to:

1. identify that an "app:collection" element in a Service Document
points to an Atom Feed that contains entries pertaining to a
specific type of security automation information (see section
5.1.2), or

2. identify that an "atom:feed" element in an Atom Feed contains
entries pertaining to a specific type of security automation
information (see section 6.1.1).

3. identify the information-type of a standalone Resource (see
section 6.2.4).

For example, the notional security automation information type
"incident" would be identified as follows:

<atom:category
scheme="urn:ietf:params:rolie:category:information-type"
term="incident"/>

A security automation information type represents a class of
information that represents the same or similar information model
[RFC3444]. Notional examples of information types include:

indicator: Computing device- or network-related "observable features
and phenomenon that aid in the forensic or proactive detection of
malicious activity; and associated meta-data" (from
[I-D.ietf-mile-rfc5070-bis]).

incident: Information pertaining to and "derived analysis from
security incidents" (from [I-D.ietf-mile-rfc5070-bis]).

vulnerability reports: Information identifying and describing a
vulnerability in hardware or software.

configuration checklists: Content that can be used to assess the
configuration settings related to installed software.

software tags: Metadata used to identify and characterize
installable software.

This is a short list to inspire new engineering of information type
extensions that support the automation of security processes.

This document does not specific any information types. Instead,
information types in ROLIE are expected to be registered in extension
documents that describe one or more new information types. This
allows the information types used by ROLIE implementations to grow
over time to support new security automation use cases. These
extension documents may also enhance ROLIE Resource representations
by defining link relations, other categories, and other AtomPub and
Atom Syndication Format data model extensions to address the
representational needs of these specific information types. New
information types are added to ROLIE through registrations to the
IANA ROLIE Security Resource Information Type registry defined in
section 8.4.

7.2. The "rolie:format" Extension Point

Security automation data pertaining to a given information type may
be expressed using a number of supported formats. As described in
section 6.2.3, the rolie:format element is used to describe the
specific data model used to represent the Resource referenced by a
given "atom:entry". The structure provided by the rolie:format
element, provides a mechanism for extension within the atom:entry
model. ROLIE extensions MAY further restrict which data models are
allowed to be used for a given information-type

By declaring the data model used for a given Resource, a consumer can
choose to download or ignore the resource, or look for alternate
formats. This saves the consumer from downloading and parsing
resources that the consumer is not interested in or resources
expressed in formats that are not supported by the consumer.

7.3. The Link Relation Extension Point

This document uses several link relations defined in the IANA Link
Relation Types registry [2]. Additional link relations can be
registered in this registry to allow new relationships to be
represented in ROLIE according to RFC 4287 section 4.2.7.2 [RFC4287].
Based on the preceding reference, if the link relation is too
specific or limited in the intended use, an absolute IRI can be used
in lieu of registering a new simple name with IANA.

8. IANA Considerations TODO

This document defines a resource-oriented approach to security
information sharing, where such information may include has a variety number of
security resource categories, such as software identifiers (e.g.
tags), incident reports, configuration assessment guidance,
vulnerability assessment guidance, and so on.

TODO: Complete registration request specifics.

10.1. IANA considerations described in the
following subsections.

8.1. XML Namespaces and Schema URNs

This document uses URNs to describe XML namespaces and XML schemas
conforming to a registry mechanism described in [RFC3688].

ROLIE XML Namespace The ROLIE namespace (rolie-1.0) has been
registered in the "ns" registry.

URI: urn:ietf:params:xml:ns:rolie-1.0

Registrant Contact: IESG

XML: None. Namespace URIs do not represent an XML specification.

ROLIE XML Schema The ROLIE schema (rolie-1.0) has been registered in
the "schema" registry.

URI: urn:ietf:params:xml:schema:rolie-1.0

Registrant Contact: IESG

XML: See section 9 A of this document.

10.2.

8.2. ROLIE Parameters URN Sub-namespace

IANA has added an entry to the "IETF URN Sub-namespace for Registered
Protocol Parameter Identifiers" registry located at
<http://www.iana.org/assignments/params/params.xml#params-1> as per
RFC3553 [RFC3553].

The entry is as follows:

Registry name: rolie

Specification: This document

Repository: ROLIE uses URNs URN Parameters. See Section 8.3 [TO BE REMOVED:
This registration should take place at the following location:
https://www.iana.org/assignments/rolie]

Index value: See Section 8.3

8.3. ROLIE URN Parameters

A new top-level registry has been created, entitled "Resource
Oriented Lightweight Information Exchange (ROLIE) Parameters". [TO
BE REMOVED: This registration should take place at the following
location: https://www.iana.org/assignments/rolie]

In this top-level registry, a sub-registry entitled "ROLIE URN
Parameters" has been created. Registration in this repository is via
the Specification Required policy [RFC5226]. Designated Expert
reviews should be routed through the MILE WG mailing list. Failing
this, the Designated Expert will be assigned by the IESG.

Each entry in this sub-registry must record the following fields:

Name: A URN segment that adheres to represent the pattern {type}:{label}.
The keywords are defined as follows:

{type}: The parameter type. The allowed values are "category"
and "format". "category" denotes a category schemes. extension as
discussed in Section 7.1, "format" denotes a additional
supported format as discussed in Section 7.2.

{label}: A required US-ASCII string that conforms to the URN
syntax requirements (see [RFC2141]). This section creates string must be
unique within the namespace defined by the {type} keyword.

Extension IRI: The identifier to use within ROLIE, which is the
full URN using the form: urn:ietf:params:rolie:{name}, where
{name} is the "name" field of this registration.

Reference: A static link to the specification and registers section that the
definition of the parameter can be found.

Sub-registry: An optional field that links to an IETF URN sub-namespace IANA sub-registry
for use this parameter. If the {type} is "category", the sub-registry
must contain a "name" field whose registered values MUST be US-
ASCII. The list of names are the allowed values of the "term"
attribute in the atom:category element. (See Section 7.1.2).

This repository has the following initial values:

8.4. ROLIE
specifications and future extensions.

TODO: Add entry for: "urn:ietf:params:rolie:category:information-
type"

10.3. Security Resource Information Type Registry

This document creates the following registry for IANA Sub-Registry

A new sub-registry has been created to manage: store ROLIE information-type
values.

Name of Registry: "Security Resource Information Type" "ROLIE Information-Types"

Location of Registry: https://www.iana.org/assignments/security-
resource-information-type
https://www.iana.org/assignments/rolie/category/information-type

Fields to record in the registry:

Full Name:

name: The full name of the security resource information type
as a string from the printable ASCII character set RFC0020 [RFC0020]
with individual embedded spaces allowed. The ABNF RFC5234 [RFC5234]
syntax for this field is:

1*VCHAR *(SP 1*VCHAR)

Security Resource Index:

index: This is an IANA-assigned positive integer that
identifies the registration. The first entry added to this
registry uses the value 1, and this value is incremented for
each subsequent entry added to the registry.

Description: A complete description of the security resource
information type as a string from the printable ASCII character
set RFC0020 with individual embedded spaces allowed. The ABNF
RFC5324 syntax for this field is:

1*VCHAR *(SP 1*VCHAR)

Specification URI/Reference:

reference: A list of one or more URIs [RFC3986] from which the
registered specification can be obtained. The registered
specification MUST be readily and publicly available from that
URI. The URI SHOULD be a stable reference.

Initial registry contents: None.

Allocation Policy: Specification required RFC5226 (which implies
expert review RFC5226).

The Designated Expert is expected to consult with the MILE (Managed
Incident Lightweight Exchange) working group or is successor if any
such WG exists (e.g., via email to the working group's mailing list).
The Designated Expert is expected to review the request and validate
the appropriateness of the name, description, and associated
specifications for the security resource category.

11. as per [RFC5226]

9. Security Considerations TODO

This document defines a resource-oriented approach to for lightweight
information exchange using HTTP, HTTP over TLS, the Atom Syndicate Syndication
Format, and the Atom Publishing Protocol. As such, implementers must
understand the security considerations described in those
specifications.

In addition, there are a number All that follows is guidance, more specific
instruction is out of additional scope for this document and will be located in
a dedicated informational document.

All security considerations measures SHOULD be enforced at the source, that are unique to this specification. is, a
provider SHOULD NOT return any Feed content or member Entry content
for which the client identity has not been specifically
authenticated, authorized, and audited.

The approach described herein is based upon all policy enforcements
being implemented at the point when a resource representation is
created. As such, producers sharing cyber security information using
this specification must take care to authenticate their HTTP clients
using a suitably strong user authentication mechanism. Sharing
communities that are exchanging information on well-known indicators
and incidents for purposes of public education may choose to rely
upon, e.g.
upon HTTP Authentication, Authentication or similar. However, sharing communities
that are engaged in sensitive collaborative analysis and/
or and/or
operational response for indicators and incidents targeting high
value information systems should adopt a suitably stronger user
authentication solution, such as TLS client certificates, or a risk-
based risk-based or multi-factor
approach. In general, trust in the sharing consortium will depend
upon the members maintaining adequate user authentication mechanisms.

Collaborating consortiums may benefit from the adoption of a
federated identity solution, such as those based upon SAML-core
[SAML-core] and SAML-bind [SAML-bind] and SAML-prof [SAML-prof] for
Web-based authentication and cross-organizational single sign-on.
Dependency on a trusted third party identity provider implies that
appropriate care must be exercised to sufficiently secure the
Identity provider. Any attacks on the federated identity system
would present a risk to the CSIRT, as a relying party. Potential
mitigations include deployment of a federation-aware identity
provider that is under the control of the information sharing
consortium, with suitably stringent technical and management
controls.

All security measures MUST be enforced at the source, that is, a
provider SHALL NOT return any feed content or member entry content
for which the client identity has not been specifically
authenticated, authorized, and audited.

Sharing communities that have a requirement for forward message
security (such that client systems are required to participate in
providing message level security and/or distributed authorization
policy enforcement), MUST use TODO.

The implementation details of the authorization scheme chosen by a
ROLIE-compliant provider are out of scope for this specification.
Implementers are free to choose any suitable authorization mechanism
that is capable of fulfilling the policy enforcement requirements
relevant to their consortium and/or organization.

Authorization of resource representations is the responsibility of
the source system, i.e. based on the authenticated user identity
associated with an HTTP(S) request. The required authorization
policies that are to be enforced must therefore be managed by the
security administrators of the source system. Various authorization
architectures would be suitable for this purpose, such as RBAC [3]
and/or ABAC, as embodied in XACML [XACML]. In particular,
implementers adopting XACML may benefit from the capability to
represent their authorization policies in a standardized,
interoperable format. Note that implementers are free to choose any
suitable authorization mechanism that is capable of fulfilling the
policy enforcement requirements relevant to their consortium and/or
organization.

Additional security requirements such as enforcing message-level
security at the destination system could supplement the security
enforcements performed at the source system, however these
destination-provided policy enforcements are out of scope for this
specification. Implementers requiring this capability should
consider leveraging, e.g. the <RIDPolicy> element in the RID schema.
Refer to RFC6545 section 9 for more information.

When security policies relevant to the source system are to be
enforced at both the source and destination systems, implementers
must take care to avoid unintended interactions of the separately
enforced policies. Potential risks will include unintended denial of
service and/or unintended information leakage. These problems may be
mitigated by avoiding any dependence upon enforcements performed at
the destination system. When distributed enforcement is unavoidable,
the usage of a standard language (e.g. XACML) for the expression of
authorization policies will enable the source and destination systems
to better coordinate and align their respective policy expressions.

Adoption of the information sharing approach described in this
document will enable users to more easily perform correlations across
separate, and potentially unrelated, cyber security information
providers. A client may succeed in assembling a data set that would
not have been permitted within the context of the authorization
policies of either provider when considered individually. Thus,
providers may face a risk of an attacker obtaining an access that
constitutes an undetected separation of duties (SOD) violation. It
is important to note that this risk is not unique to this
specification, and a similar potential for abuse exists with any
other cyber security information sharing protocol. However, the wide
availability of tools for HTTP clients and Atom feed Feed handling implies
that the resources and technical skills required for a successful
exploit may be less than it was previously. This risk can be best
mitigated through appropriate vetting of the client at account
provisioning time. In addition, any increase in the risk of this
type of abuse should be offset by the corresponding increase in
effectiveness that this specification affords to the defenders.

While it is a goal of this specification to enable more agile cyber
security information sharing across a broader and varying
constituency, there is nothing in this specification that necessarily
requires this type of deployment. A cyber security information
sharing consortium may chose to adopt this specification while
continuing to operate as a gated community with strictly limited
membership.

12.

10. Acknowledgements

The author authors gratefully acknowledges acknowledge the valuable contributions of Tom
Maguire, Kathleen Moriarty, and Vijayanand Bharadwaj. These
individuals provided detailed review comments on earlier drafts, and
made many suggestions that have helped to improve this document .

13. document.

11. References
13.1.

11.1. Normative References

[RFC0020] Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, DOI 10.17487/RFC0020, October 1969,
<http://www.rfc-editor.org/info/rfc20>.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.

[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.

[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.

[RFC4287] Nottingham, M., Ed. and R. Sayre, Ed., "The Atom
Syndication Format", RFC 4287, DOI 10.17487/RFC4287,
December 2005, <http://www.rfc-editor.org/info/rfc4287>.

[RFC5005] Nottingham, M., "Feed Paging and Archiving", RFC 5005,
DOI 10.17487/RFC5005, September 2007,
<http://www.rfc-editor.org/info/rfc5005>.

[RFC5023] Gregorio, J., Ed. and B. de hOra, Ed., "The Atom
Publishing Protocol", RFC 5023, DOI 10.17487/RFC5023,
October 2007, <http://www.rfc-editor.org/info/rfc5023>.

[RFC5070] Danyliw, R., Meijer, J., and Y. Demchenko, "The Incident
Object Description Exchange Format", RFC 5070,
DOI 10.17487/RFC5070, December 2007,
<http://www.rfc-editor.org/info/rfc5070>.

[RFC6546] Trammell, B., "Transport of Real-time Inter-network
Defense (RID) Messages over HTTP/TLS", RFC 6546,
DOI 10.17487/RFC6546, April 2012,
<http://www.rfc-editor.org/info/rfc6546>.

[RFC3553] Mealling, M., Masinter, L., Hardie, T., and G. Klyne, "An
IETF URN Sub-namespace for Registered Protocol
Parameters", BCP 73, RFC 3553, DOI 10.17487/RFC3553, June
2003, <http://www.rfc-editor.org/info/rfc3553>.

[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.

[W3C.REC-xml-names-20091208]
Bray, T., Hollander, D., Layman, A., Tobin, R., and H.
Thompson, "Namespaces in XML 1.0 (Third Edition)", World
Wide Web Consortium Recommendation REC-xml-names-20091208,
December 2009,
<http://www.w3.org/TR/2009/REC-xml-names-20091208>.

[RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
NETCONF Protocol over Transport Layer Security (TLS) with
Mutual X.509 Authentication", RFC 7589,
DOI 10.17487/RFC7589, June 2015,
<http://www.rfc-editor.org/info/rfc7589>.

[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<http://www.rfc-editor.org/info/rfc5280>.

[RFC4642] Murchison, K., Vinocur, J., and C. Newman, "Using
Transport Layer Security (TLS) with Network News Transfer
Protocol (NNTP)", RFC 4642, DOI 10.17487/RFC4642, October
2006, <http://www.rfc-editor.org/info/rfc4642>.

[relax-NG]
Clark, J., Ed., "RELAX NG Compact Syntax", 11 2002,
<https://www.oasis-open.org/committees/relax-ng/compact-
20021121.html>.

[opensearch]
Clinton, D., "OpenSearch 1.1 draft 5 specification", OASIS
Committee Specification saml-core-2.0-os, 2011,
<http://www.opensearch.org/Specifications/OpenSearch/1.1>.

[SAML-core]
Cantor, S., Kemp, J., Philpott, R., and E. Maler,
"Assertions and Protocol for the OASIS Security Assertion
Markup Language (SAML) V2.0", OASIS Standard saml-core-
2.0-os, March 2005, <http://docs.oasis-
open.org/security/saml/v2.0/saml-core-2.0-os.pdf>.

[SAML-prof]
Hughes, J., Cantor, S., Hodges, J., Hirsch, F., Mishra,
P., Philpott, R., and E. Maler, "Profiles for the OASIS
Security Assertion Markup Language (SAML) V2.0", OASIS
Standard OASIS.saml-profiles-2.0-os, March 2005,
<http://docs.oasis-open.org/security/saml/v2.0/
saml-profiles-2.0-os.pdf>.

[SAML-bind]
Cantor, S., Hirsch, F., Kemp, J., Philpott, R., and E.
Maler, "Bindings for the OASIS Security Assertion Markup
Language (SAML) V2.0", OASIS Standard saml-bindings-
2.0-os, March 2005, <http://docs.oasis-
open.org/security/saml/v2.0/saml-bindings-2.0-os.pdf>.

13.2.

11.2. Informative References

[RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141,
May 1997, <http://www.rfc-editor.org/info/rfc2141>.

[RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between
Information Models and Data Models", RFC 3444,
DOI 10.17487/RFC3444, January 2003,
<http://www.rfc-editor.org/info/rfc3444>.

[RFC6545] Moriarty, K., "Real-time Inter-network Defense (RID)",
RFC 6545, DOI 10.17487/RFC6545, April 2012,
<http://www.rfc-editor.org/info/rfc6545>.

[I-D.ietf-mile-rfc5070-bis]
Danyliw, R., "The Incident Object Description Exchange
Format v2", draft-ietf-mile-rfc5070-bis-25 draft-ietf-mile-rfc5070-bis-26 (work in
progress), June October 2016.

[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>.

[xmldsig] Bartel, M., Boyer, J., Fox, B., LaMacchia, B., and E.
Simon, "XML Signature Syntax and Processing (Second
Edition)", June 2008, <https://www.w3.org/TR/xmldsig-
core/>.

[xmlenc] Imamura, T., Dillaway, B., and E. Simon, "XML Encryption
Syntax and Processing", December 2002,
<https://www.w3.org/TR/xmlenc-core/>.

[XACML] Rissanen, E., "eXtensible Access Control Markup Language
(XACML) Version 3.0", August 2010, <http://docs.oasis-
open.org/xacml/3.0/xacml-3.0-core-spec-cs-01-en.pdf>.

[REST] Fielding, R., "Architectural Styles and the Design of
Network-based Software Architectures", 2000,
<http://www.ics.uci.edu/~fielding/pubs/dissertation/
top.htm>.

13.3.

11.3. URIs

[1] https://www.iana.org/assignments/link-relations/link-
relations.xhtml

[2] https://www.iana.org/assignments/link-relations/link-
relations.xhtml

[3] http://csrc.nist.gov/groups/SNS/rbac/

Appendix A. Use Case Relax NG Compact Schema for ROLIE

This appendix is informative.

The Relax NG schema below defines the rolie:format element.

# -*- rnc -*-
# RELAX NG Compact Syntax Grammar for the rolie:format element

namespace rolie = "urn:ietf:params:xml:ns:rolie-1.0"
namespace atom = "http://www.w3.org/2005/Atom"

# rolie:format

rolieFormat =
element rolie:format {
atom:atomCommonAttributes,
attribute ns { atom:atomURI },
attribute version { text } ?,
attribute schema-location { atom:atomURI } ?,
attribute schema-type { atom:atomMediaType } ?,
empty
}

Appendix B. Examples

A.1. of Use

B.1. Service Discovery

This section provides a non-normative example of a client doing
service discovery. TODO: Standardize location of doc?

An Atom service document enables a client to dynamically discover
what feeds Feeds a particular publisher makes available. Thus, a provider
uses an Atom service document to enable clients or other authorized
parties to determine what specific information the provider makes
available to the community. The While the service document is at a
required location, the service document could also be made available
at any well known location, such as via a link from the
CSIRT's producer's
home page. One common technique is to include a link in the
<HEAD> section of the organization's home page, as shown below:

Example of bootstrapping Service Document discovery:

A client may then format an HTTP GET request to retrieve the service
document:
document from the specified location:

GET /provider/svcdoc.xml /rolie/servicedocument
Host: www.example.org
Accept: application/atomsvc+xml

Notice the use of the HTTP Accept: request header, indicating the
MIME type for Atom service discovery. The response to this GET
request will be an XML document that contains information on the
specific feed collections Feed Collections that are provided by the CSIRT. provider.

Example HTTP GET response:

HTTP/1.1 200 OK
Date: Fri, 24 Aug 2012 17:09:11 GMT
Content-Length: 570
Content-Type: application/atomsvc+xml;charset="utf-8"

<?xml version="1.0" encoding="UTF-8"?>
<service xmlns="http://www.w3.org/2007/app"
xmlns:atom="http://www.w3.org/2005/Atom"
xmlns:xml="http://www.w3.org/XML/1998/namespace"
xml:lang="en-US">
xmlns:atom="http://www.w3.org/2005/Atom">
<workspace>
<atom:title type="text">Incidents</atom:title> type="text">Vulnerabilities</atom:title>
<collection href="http://example.org/provider/incidents"> href="http://example.org/provider/vulns">
<atom:title type="text">Incidents type="text">Vulnerabilities Feed</atom:title>
<categories fixed="yes">
<atom:category
scheme="urn:ietf:params:rolie:information-type"
scheme="urn:ietf:params:rolie:category:information-type"
term="vulnerability"/>
</categories>
<accept>application/atom+xml; type=entry</accept>
</collection>
</workspace>
</service>

This simple Service Document example shows that this server provides
one workspace, named "Incidents". "Vunerabilities". Within that workspace, the
producer makes one feed collection Feed Collection available. When attempting to GET
or POST entries to that feed collection, the client must indicate a
content type of application/atom+xml.

A server may also offer a number of different feeds, Feeds, each containing
different types of security automation information. In the following
example, the feeds Feeds have been categorized. This categorization will
help the clients to decide which feeds Feeds will meet their needs.

HTTP/1.1 200 OK
Date: Fri, 24 Aug 2012 17:10:11 GMT
Content-Length: 1912
Content-Type: application/atomsvc+xml;charset="utf-8"

<?xml version="1.0" encoding='utf-8'?>
<service xmlns="http://www.w3.org/2007/app"
xmlns:atom="http://www.w3.org/2005/Atom">
<workspace>
<atom:title>Public Security Information Sharing</atom:title>
<collection
href="http://example.org/provider/public/vulnerabilties">
href="http://example.org/provider/public/vulns">
<atom:title>Public Vulnerabilities</atom:title>
<accept>application/atom+xml; type=entry</accept>
<link rel="service"
href="www.example.com/rolie/servicedocument">
<categories fixed="yes">
<atom:category
scheme="urn:ietf:params:rolie:information-type"
scheme="urn:ietf:params:rolie:category:information-type"
term="vulnerability"/>
</categories>
</collection>
<collection
href="http://example.org/provider/public/incidents">
<atom:title>Public Incidents</atom:title>
<accept>application/atom+xml; type=entry</accept>
<categories fixed="yes">
<atom:category
scheme="urn:ietf:params:rolie:information-type"
term="incident"/>
</categories>
</collection>
</workspace>
<workspace>
<atom:title>Private Consortium Sharing</atom:title>
<collection
href="http://example.org/provider/private/incidents" >
href="http://example.org/provider/private/vulns">
<atom:title>Incidents</atom:title>
<accept>application/atom+xml;type=entry</accept>
<link rel="service"
href="www.example.com/rolie/servicedocument">
<categories fixed="yes">
<atom:category
scheme="urn:ietf:params:rolie:information-type"
term="incident"/>
scheme="urn:ietf:params:rolie:category:information-type"
term="incidents"/>
</categories>
</collection>
</workspace>
</service>

In this example, the CSIRT provider is providing making available a total of three feed
collections, two Feed
Collections, organized into two different workspaces. The first
workspace contains two feeds, a Feed consisting of publicly available software vulnerabilities and publicly available incidents,
respectively.
vulnerabilities. The second workspace provides one additional feed,
vulnerability Feed, for use by a sharing consortium. The feed contains incident information
containing entries related to three purposes: traceback, mitigation,
and reporting. The entries in this feed are categorized with a
restriction of either "Need-to-Know" or "private". private sharing consortium. An
appropriately authenticated and authorized client may then proceed to
make GET requests for one or more of these feeds. Feeds. The publicly
provided incident information may be accessible with or without
authentication. However, users accessing the feed Feed targeted to the
private sharing consortium would be expected to authenticate, and
appropriate authorization policies would subsequently be enforced by
the feed provider.

A.2. Feed Retrieval

This section provides a non-normative example of a client retrieving
an incident feed. TODO

Having discovered the available security information sharing feeds,
an authenticated and authorized client who is a member of the private
sharing consortium may be interested in receiving the feed of known
incidents. The client may retrieve this feed by performing an HTTP
GET operation on the indicated URL.

Example HTTP GET request for a Feed:

GET /provider/private/incidents
Host: www.example.org
Accept: application/atom+xml

The corresponding HTTP response would be an XML document containing
the incidents feed:

Example HTTP GET response for a Feed:

HTTP/1.1 200 OK
Date: Fri, 24 Aug 2012 17:20:11 GMT
Content-Length: 2882
Content-Type: application/atom+xml;type=feed;charset="utf-8"

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom"
xml:lang="en-US">

<generator version="1.0">
Example Provider ROLIE Feed Generator

</generator>
<id>http://www.example.org/provider/private/incidents</id>
<title type="text">
Atom formatted representation of
a feed of XML incident documents
</title>

<atom:category
scheme="urn:ietf:params:rolie:information-type"
term="incident"/>
<updated>2012-05-04T18:13:51.0Z</updated>
<author>
<email>provider@example.org</email>
<name>Example Provider</name>
</author>

<link href="http://www.example.org/provider/private/incidents"
rel="self" type="application/atom+xml"/>

<entry>
<id>
http://www.example.org/provider/private/incidents/123456
</id>
<title>Sample Incident</title>

<link
href="http://www.example.org/provider/private/incidents/12345"
rel="self" type="application/atom+xml"/>

<link
href="http://www.example.org/provider/private/incidents/12345"
rel="alternate" type="xml"/>

<published>2014-08-04T18:13:51.0Z</published>
<updated>2014-08-05T18:13:51.0Z</updated>
<summary>A short description of this resource</summary>
</entry>

</feed>
This feed document has two atom entries, one of which has been
elided. The completed entry illustrates an Atom <entry> element that
provides a summary of essential details about one particular
incident. Based upon this summary information and the provided
category information, a client may choose to do an HTTP GET operation
to retrieve the full details of the incident. This example
exemplifies by
the benefits a RESTful alternative has to traditional
point-to-point messaging systems.

A.3. Entry Feed provider.

B.2. Feed Retrieval

This section provides a non-normative example of a client retrieving
an incident as an Atom entry. TODO Feed.

Having retrieved the feed of interest, the client may then decide
based on discovered the description and/or category available security information that one sharing Feeds, a
client who is a member of the
entries general public may be interested in
receiving the feed is Feed of further interest. public vulnerabilities. The client may
retrieve this incident Entry Feed by performing an HTTP GET operation on the
indicated URL.

Example HTTP GET request for an Entry: a Feed:

GET /provider/private/incidents/123456 /provider/vulns
Host: www.example.org
Accept: application/atom+xml

The corresponding HTTP response would be an XML document containing
the incident:

Example HTTP GET response for an Entry:

HTTP/1.1 200 OK
Date: Fri, 24 Aug 2012 17:30:11 GMT
Content-Length: 4965
Content-Type: application/atom+xml;type=entry;charset="utf-8"

<?xml version="1.0" encoding="UTF-8"?>
<entry>
<id>http://www.example.org/provider/private/incidents/123456</id>
<title>Sample Incident</title>

<link href="http://www.example.org/csirt/private/incidents/123456"
rel="self" type="application/atom+xml"/>

<link href="http://www.example.org/csirt/private/incidents/123456"
rel="alternate" type="IODEF"/>
<published>2012-08-04T18:13:51.0Z</published>
<updated>2012-08-05T18:13:51.0Z</updated>

<atom:category
scheme="urn:ietf:params:rolie:information-type"
term="incident"/>
<summary>A short description of this incident resource</summary>

<link href="http://www.example.org/csirt/private/incidents/123456"
rel="edit"/>

<link href="http://www.example.org/csirt/private/incidents/123457"
rel="next"/>
<link href="http://www.example.org/csirt/private/incidents/123455"
rel="previous"/>

<link href="http://www.example.org/csirt/private/incidents"
rel="up"/>

<content type="application/xml">
<xml>
<tag>
<data> Example </data>
</tag>
</xml>
</content>
</entry>

As can be seen in the example response, above, an XML document is
contained within the Atom <content> element. The client may now
process the XML document as needed.

Note also that, as described previously, the content of the Atom
<category> element is application-defined. The Atom categories have
been assigned based on the IANA table content model.

Finally, it should be noted that in order to optimize the client
experience, and avoid

The corresponding HTTP response would be an additional round trip, a feed provider may
choose to include XML document containing
the entry content inline, as part incidents Feed:

Example HTTP GET response for a Feed:

HTTP/1.1 200 OK
Date: Fri, 24 Aug 2012 17:20:11 GMT
Content-Length: 2882
Content-Type: application/atom+xml;type=feed;charset="utf-8"

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom"
xml:lang="en-US">
<id>http://www.example.org/provider/vulns</id>
<title type="text">
Atom formatted representation of the
a feed
document. That is, an Atom of XML incident documents
</title>
<atom:category
scheme="urn:ietf:params:rolie:category:information-type"
term="vulnerability"/>
<updated>2012-05-04T18:13:51.0Z</updated>
<link rel="self" href="http://example.org/provider/vulns" />
<link rel="service"
href="http://example.org/rolie/servicedocument"/>
<entry> element within a
<rolie:format ns="urn:ietf:params:xml:ns:exampleformat"/>
<id>
http://www.example.org/provider/vulns/123456
</id>
<title>Sample Incident</title>
<published>2014-08-04T18:13:51.0Z</published>
<updated>2014-08-05T18:13:51.0Z</updated>
<summary>A short description of this resource</summary>
<content type="application/xml"
src="http://www.example.org/provider/vulns/123456/data"
</entry>

</feed>

This Feed document
may contain has two atom entries, one of which has been
elided. The completed Entry illustrates an Atom <content> <entry> element as that
provides a child. In summary of essential details about one particular
incident. Based upon this case, summary information and the provided
category information, a client will receive may choose to do an HTTP GET operation
to retrieve the full content details of the entries within the feed.
The decision of whether to include incident. This example
exemplifies the entry content inline or to
include it as a link is benefits a design choice left RESTful alternative has to the feed provider
(e.g. based upon local environmental factors such as the number of
entries contained in a feed, the available network bandwidth, the
available server compute cycles, the expected client usage patterns,
etc.).

A.4. Use Case: Search traditional
point-to-point messaging systems.

B.3. Entry Retrieval

This section provides a non-normative example of a search use case.

The following example provides a RESTful solution to handling search
results. Note client retrieving
an incident as an Atom Entry.

Having retrieved the Feed of interest, the client may then decide
based on the description and/or category information that one of the
entries in the RESTful approach described herein there Feed is
no requirement to define a query language. Instead, implementations of further interest. The client may provide support for search operations via existing search
facilities, and advertise these capabilities via an appropriate URL
template. Clients dynamically retrieve
this incident Entry by performing an HTTP GET operation on the search description
document, and invoke specific searches via
indicated URL.

Example HTTP GET request for an instantiated URL
template.

An Entry:

GET /provider/vulns/123456
Host: www.example.org
Accept: application/atom+xml

The corresponding HTTP response body may include a link relationship of type
"search." This link provides a reference to would be an OpenSearch
description document. XML document containing
the incident:

Example HTTP GET response that includes a "search" link: for an Entry:

HTTP/1.1 200 OK
Date: Fri, 24 Aug 2012 17:20:11 17:30:11 GMT
Content-Length: nnnn 4965
Content-Type: application/atom+xml;type=feed;charset="utf-8" application/atom+xml;type=entry;charset="utf-8"

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/Atom file:/
C:/schemas/atom.xsd
urn:ietf:params:xml:ns:iodef-1.0
file:/C:/schemas/iodef-1.0.xsd"
xml:lang="en-US">

<entry>

</entry>

</feed>

The OpenSearch Description document contains the information needed
by a client to request a search. An example of an Open Search
<id>http://www.example.org/provider/vulns/123456</id>
<title>Sample Incident</title>
<published>2012-08-04T18:13:51.0Z</published>
<updated>2012-08-05T18:13:51.0Z</updated>
<atom:category
scheme="urn:ietf:params:rolie:category:information-type"
term="incident"/>
<summary>A short description document is shown below:

Example HTTP response that includes a "search" link:

<?xml version="1.0" encoding="UTF-8"?>
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
<ShortName>CSIRT search example</ShortName>
<Description>Cyber security information
sharing consortium search interface</Description>
<Tags>example csirt indicator search</Tags>
<Contact>admin@example.org</Contact>

<Url type="application/opensearchdescription+xml" rel="self"
template="http://www.example.com/csirt/opensearchdescription.xml"/>
<Url type="application/atom+xml" rel="results"
template="http://www.example.org/csirt?q={searchTerms}&amp;
format=Atom+xml"/>
<LongName>www.example.org CSIRT search</LongName>
<Query role="example" searchTerms="incident" />
<Language>en-us</Language>
<OutputEncoding>UTF-8</OutputEncoding>
<InputEncoding>UTF-8</InputEncoding>
</OpenSearchDescription>

The OpenSearch Description document shown above contains two <Url>
elements that contain parametrized URL templates. These templates
provide a representation of how the client should make search
requests. The exact format of the query string, including the
parametrization is specified by the feed provider

This OpenSearch Description Document also contains an example of a
<Query> element. Each <Query> element describes a specific search
request that can be made by the client. Note that the parameters of
the <Query> element correspond to the URL template parameters. In this way, a provider may fully describe the search interface
available to incident resource</summary>
<rolie:format ns="urn:ietf:params:xml:ns:exampleformat"/>
<content type="application/xml"
src="http://www.example.org/provider/vulns/123456/data">
</content>
</entry>

As can be seen in the clients. The search section, example response, above, provides
specific NORMATIVE requirements for the use of Open Search.

Appendix B. XACML Guidance

ROLIE assumes that all authorization policy enforcement an XML document is provided
at the source server. The implementation details of the
authorization scheme chosen by a ROLIE-compliant provider are out of
scope for this specification. Implementers are free
linked to choose any
suitable authorization mechanism that is capable of fulfilling in the
policy enforcement requirements relevant to their consortium and/or
organization.

It is well known that one attributes of the major barriers to information
sharing is ensuring acceptable use of Atom <content> element. The
client may now process the information shared. In XML document as needed.

Note also that, as described previously, the
case of ROLIE, one way to lower that barrier may be to develop a
XACML profile. Use content of XACML would allow a ROLIE-compliant provider
to express their information sharing authorization policies in a
standards-compliant, and machine-readable format.

This improved interoperability may, in turn, enable more agile
interactions in the cyber security sharing community. For example, a
peer CSIRT, or another interested stakeholder such as an auditor,
would be able to review and compare CSIRT sharing policies using
appropriate tooling.

The XACML 3.0 standard Atom
<category> element is application-defined. The Atom categories have
been assigned based upon on the notion IANA table content model.

Finally, it should be noted that authorization
policies are defined in terms of predicate logic expressions written
against the attributes associated with one or more of order to optimize the following
four entities:

o SUBJECT

o ACTION

o RESOURCE

o ENVIRONMENT

Thus, client
experience, and avoid an additional round trip, a suitable approach Feed provider may
choose to a XACML 3.0 profile for ROLIE
authorization policies could begin by using the 3-tuple of [SUBJECT,
ACTION, RESOURCE] where:

o SUBJECT is the suitably authenticated identity include certain Entry elements inline, as part of the requestor.

o ACTION is the associated HTTP method, GET, PUT, POST, DELETE,
HEAD, (PATCH).

o RESOURCE is Feed
document. That is, an XPath expression that uniquely identifies Atom <entry> element within a Feed document
may contain arbitrary non-required Atom elements as children. In
this case, the
instance or type of client will receive the ROLIE resource being requested.

Implementers who have more explicit information on
entries from within the Feed. The decision of whether to include
extra Entry elements inline or to include it as a need may also choose link is a design
choice left to evaluate the Feed provider (e.g. based upon
the additional ENVIRONMENT factors, local environmental
factors such as current threat level, and
so on. One could also write policy to consider the CVSS score
associated with the resource, or the lifecycle phase number of the resource
(vulnerability unverified, confirmed, patch available, etc.), and so
on.

Having these policies expressed entries contained in a standards-compliant and machine-
readable format could improve Feed, the
available network bandwidth, the available server compute cycles, the agility
expected client usage patterns, etc.).

Appendix C. Change History

Changes in draft-ietf-mile-rolie-04 since draft-ietf-mile-rolie-04
version, July 8, 2016 to October 31, 2016

o Further specification and effectiveness clarification of a
cyber security information sharing group or consortium, requirements

o IANA Considerations and enable
better cyber defenses.

Appendix C. Relax NG extension system fleshed out and
described.

o Examples and References updated.

o Schema for created.

o Fixed both internal section and external document referencing.

o Removed XACML Guidance Appendix. This will be added to a future
draft on ROLIE Extensions

TODO

Appendix D. Change Tracking Authentication and Access Control.

Changes made in draft-ietf-mile-rolie-03 since draft-ietf-mile-
rolie-02 version, May 27, 2016 to July 8, 2015

o Atom Syndication and Atom Pub requirements split and greatly
expanded for increased justification and technical specification.

o Reintroduction and reformatting of some use case examples in order
to provide some guidance on use.

o Established rough version of IANA table extension system along
with explanations of said system.

o Re-organized document to put non-vital information in appendices.

Changes made in draft-ietf-mile-rolie-02 since draft-field-mile-rolie-01 draft-field-mile-
rolie-01 version, December, 2015 to May 27, 2016:

o All CSIRT and IODEF/RID material moved to companion CSIRT document
TODO: add reference

o Recast document into a more general use perspective. The
implication of CSIRTs as the defacto end-user has been removed
where ever possible. All of the original CSIRT based use cases
remain completely supported by this document, it has been opened
up to support many other use cases.

o Changed the content model to broaden support of representation

o Edited and rewrote much of sections 1,2 and 3 in order to
accomplish a broader scope and greater readability

o Removed any requirements from the Background section and, if not
already stated, placed them in the requirements section

o Re-formatted the requirements section to make it clearer that it
contains the lions-share of the requirements of the specification

Changes made in draft-ietf-mile-rolie-01 since draft-field-mile-
rolie-02 version, August 15, 2013 to December 2, 2015:

o Added section specifying the use of RFC5005 for Archive and Paging
of feeds. Feeds.

o Added section describing use of atom categories that correspond to
IODEF expectation class and impact classes. See: normative-
expectation-impact

o Dropped references to adoption of a MILE-specific HTTP media type
parameter.

o Updated IANA Considerations section to clarify that no IANA
actions are required.

Authors' Addresses
John P. Field
Pivotal Software, Inc.
625 Avenue of the Americas
New York, New York
USA

Phone: (646)792-5770
Email: jfield@pivotal.io

Stephen A. Banghart
National Institute of Standards and Technology
100 Bureau Drive
Gaithersburg, Maryland
USA

Phone: (301)975-4288
Email: sab3@nist.gov

David Waltermire
National Institute of Standards and Technology
100 Bureau Drive
Gaithersburg, Maryland 20877
USA

Email: david.waltermire@nist.gov