Security Assertion Markup Language (SAML) 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grants
draft-ietf-oauth-saml2-bearer-23
The information below is for an old version of the document that is already published as an RFC.
Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 7522.
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Authors | Brian Campbell , Chuck Mortimore , Michael B. Jones | ||
Last updated | 2015-10-14 (Latest revision 2014-11-12) | ||
Replaces | draft-campbell-oauth-saml | ||
RFC stream | Internet Engineering Task Force (IETF) | ||
Intended RFC status | Proposed Standard | ||
Formats | |||
Reviews | |||
Additional resources | Mailing list discussion | ||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Hannes Tschofenig | ||
Shepherd write-up | Show Last changed 2014-05-08 | ||
IESG | IESG state | Became RFC 7522 (Proposed Standard) | |
Action Holders |
(None)
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Consensus boilerplate | Yes | ||
Telechat date | (None) | ||
Responsible AD | Kathleen Moriarty | ||
Send notices to | (None) | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack |
draft-ietf-oauth-saml2-bearer-23
OAuth Working Group B. Campbell Internet-Draft Ping Identity Intended status: Standards Track C. Mortimore Expires: May 16, 2015 Salesforce M. Jones Microsoft November 12, 2014 SAML 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grants draft-ietf-oauth-saml2-bearer-23 Abstract This specification defines the use of a Security Assertion Markup Language (SAML) 2.0 Bearer Assertion as a means for requesting an OAuth 2.0 access token as well as for use as a means of client authentication. 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 working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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 May 16, 2015. Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. 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 to this document. Code Components extracted from this document must Campbell, et al. Expires May 16, 2015 [Page 1] Internet-Draft OAuth SAML Assertion Profiles November 2014 include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 2. HTTP Parameter Bindings for Transporting Assertions . . . . . 4 2.1. Using SAML Assertions as Authorization Grants . . . . . . 4 2.2. Using SAML Assertions for Client Authentication . . . . . 5 3. Assertion Format and Processing Requirements . . . . . . . . 6 3.1. Authorization Grant Processing . . . . . . . . . . . . . 8 3.2. Client Authentication Processing . . . . . . . . . . . . 9 4. Authorization Grant Example . . . . . . . . . . . . . . . . . 9 5. Interoperability Considerations . . . . . . . . . . . . . . . 11 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 12 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8.1. Sub-Namespace Registration of urn:ietf:params:oauth :grant-type:saml2-bearer . . . . . . . . . . . . . . . . 12 8.2. Sub-Namespace Registration of urn:ietf:params:oauth :client-assertion-type:saml2-bearer . . . . . . . . . . . 12 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 9.1. Normative References . . . . . . . . . . . . . . . . . . 13 9.2. Informative References . . . . . . . . . . . . . . . . . 14 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 14 Appendix B. Document History . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 1. Introduction The Security Assertion Markup Language (SAML) 2.0 [OASIS.saml-core-2.0-os] is an XML-based framework that allows identity and security information to be shared across security domains. The SAML specification, while primarily targeted at providing cross domain Web browser single sign-on, was also designed to be modular and extensible to facilitate use in other contexts. The Assertion, an XML security token, is a fundamental construct of SAML that is often adopted for use in other protocols and specifications. (Some examples include [OASIS.WSS-SAMLTokenProfile] and [OASIS.WS-Fed].) An Assertion is generally issued by an identity provider and consumed by a service provider who relies on its content to identify the Assertion's subject for security related purposes. Campbell, et al. Expires May 16, 2015 [Page 2] Internet-Draft OAuth SAML Assertion Profiles November 2014 The OAuth 2.0 Authorization Framework [RFC6749] provides a method for making authenticated HTTP requests to a resource using an access token. Access tokens are issued to third-party clients by an authorization server (AS) with the (sometimes implicit) approval of the resource owner. In OAuth, an authorization grant is an abstract term used to describe intermediate credentials that represent the resource owner authorization. An authorization grant is used by the client to obtain an access token. Several authorization grant types are defined to support a wide range of client types and user experiences. OAuth also allows for the definition of new extension grant types to support additional clients or to provide a bridge between OAuth and other trust frameworks. Finally, OAuth allows the definition of additional authentication mechanisms to be used by clients when interacting with the authorization server. The Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions] specification is an abstract extension to OAuth 2.0 that provides a general framework for the use of Assertions as client credentials and/or authorization grants with OAuth 2.0. This specification profiles the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions] specification to define an extension grant type that uses a SAML 2.0 Bearer Assertion to request an OAuth 2.0 access token as well as for use as client credentials. The format and processing rules for the SAML Assertion defined in this specification are intentionally similar, though not identical, to those in the Web Browser SSO Profile defined in the SAML Profiles [OASIS.saml-profiles-2.0-os] specification. This specification is reusing, to the extent reasonable, concepts and patterns from that well-established Profile. This document defines how a SAML Assertion can be used to request an access token when a client wishes to utilize an existing trust relationship, expressed through the semantics of (and digital signature or keyed message digest calculated over) the SAML Assertion, without a direct user approval step at the authorization server. It also defines how a SAML Assertion can be used as a client authentication mechanism. The use of an Assertion for client authentication is orthogonal to and separable from using an Assertion as an authorization grant. They can be used either in combination or separately. Client assertion authentication is nothing more than an alternative way for a client to authenticate to the token endpoint and must be used in conjunction with some grant type to form a complete and meaningful protocol request. Assertion authorization grants may be used with or without client authentication or identification. Whether or not client authentication is needed in conjunction with an assertion authorization grant, as well as the Campbell, et al. Expires May 16, 2015 [Page 3] Internet-Draft OAuth SAML Assertion Profiles November 2014 supported types of client authentication, are policy decisions at the discretion of the authorization server. The process by which the client obtains the SAML Assertion, prior to exchanging it with the authorization server or using it for client authentication, is out of scope. 1.1. Notational Conventions 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 RFC 2119 [RFC2119]. Unless otherwise noted, all the protocol parameter names and values are case sensitive. 1.2. Terminology All terms are as defined in The OAuth 2.0 Authorization Framework [RFC6749], the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions], and the Security Assertion Markup Language (SAML) 2.0 [OASIS.saml-core-2.0-os] specifications. 2. HTTP Parameter Bindings for Transporting Assertions The Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions] specification defines generic HTTP parameters for transporting Assertions during interactions with a token endpoint. This section defines specific parameters and treatments of those parameters for use with SAML 2.0 Bearer Assertions. 2.1. Using SAML Assertions as Authorization Grants To use a SAML Bearer Assertion as an authorization grant, the client uses an access token request as defined in Section 4 of the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions] specification with the following specific parameter values and encodings. The value of the "grant_type" parameter is "urn:ietf:params:oauth:grant-type:saml2-bearer". The value of the "assertion" parameter contains a single SAML 2.0 Assertion. It MUST NOT contain more than one SAML 2.0 assertion. The SAML Assertion XML data MUST be encoded using base64url, where the encoding adheres to the definition in Section 5 of RFC 4648 Campbell, et al. Expires May 16, 2015 [Page 4] Internet-Draft OAuth SAML Assertion Profiles November 2014 [RFC4648] and where the padding bits are set to zero. To avoid the need for subsequent encoding steps (by "application/x-www-form- urlencoded" [W3C.REC-html401-19991224], for example), the base64url encoded data MUST NOT be line wrapped and pad characters ("=") MUST NOT be included. The "scope" parameter may be used, as defined in the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions] specification, to indicate the requested scope. Authentication of the client is optional, as described in Section 3.2.1 of OAuth 2.0 [RFC6749] and consequently, the "client_id" is only needed when a form of client authentication that relies on the parameter is used. The following example demonstrates an Access Token Request with an assertion as an authorization grant (with extra line breaks for display purposes only): POST /token.oauth2 HTTP/1.1 Host: as.example.com Content-Type: application/x-www-form-urlencoded grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Asaml2-bearer& assertion=PHNhbWxwOl...[omitted for brevity]...ZT4 2.2. Using SAML Assertions for Client Authentication To use a SAML Bearer Assertion for client authentication, the client uses the following parameter values and encodings. The value of the "client_assertion_type" parameter is "urn:ietf:params:oauth:client-assertion-type:saml2-bearer". The value of the "client_assertion" parameter MUST contain a single SAML 2.0 Assertion. The SAML Assertion XML data MUST be encoded using base64url, where the encoding adheres to the definition in Section 5 of RFC 4648 [RFC4648] and where the padding bits are set to zero. To avoid the need for subsequent encoding steps (by "application/x-www-form-urlencoded" [W3C.REC-html401-19991224], for example), the base64url encoded data SHOULD NOT be line wrapped and pad characters ("=") SHOULD NOT be included. The following example demonstrates a client authenticating using an assertion during the presentation of an authorization code grant in an Access Token Request (with extra line breaks for display purposes only): Campbell, et al. Expires May 16, 2015 [Page 5] Internet-Draft OAuth SAML Assertion Profiles November 2014 POST /token.oauth2 HTTP/1.1 Host: as.example.com Content-Type: application/x-www-form-urlencoded grant_type=authorization_code& code=vAZEIHjQTHuGgaSvyW9hO0RpusLzkvTOww3trZBxZpo& client_assertion_type=urn%3Aietf%3Aparams%3Aoauth %3Aclient-assertion-type%3Asaml2-bearer& client_assertion=PHNhbW...[omitted for brevity]...ZT 3. Assertion Format and Processing Requirements In order to issue an access token response as described in OAuth 2.0 [RFC6749] or to rely on an Assertion for client authentication, the authorization server MUST validate the Assertion according to the criteria below. Application of additional restrictions and policy are at the discretion of the authorization server. 1. The Assertion's <Issuer> element MUST contain a unique identifier for the entity that issued the Assertion. In the absence of an application profile specifying otherwise, compliant applications MUST compare Issuer values using the Simple String Comparison method defined in Section 6.2.1 of RFC 3986 [RFC3986]. 2. The Assertion MUST contain a <Conditions> element with an <AudienceRestriction> element with an <Audience> element that identifies the authorization server as an intended audience. Section 2.5.1.4 of Assertions and Protocols for the OASIS Security Assertion Markup Language [OASIS.saml-core-2.0-os] defines the <AudienceRestriction> and <Audience> elements and, in addition to the URI references discussed there, the token endpoint URL of the authorization server MAY be used as a URI that identifies the authorization server as an intended audience. The Authorization Server MUST reject any assertion that does not contain its own identity as the intended audience. In the absence of an application profile specifying otherwise, compliant applications MUST compare the audience values using the Simple String Comparison method defined in Section 6.2.1 of RFC 3986 [RFC3986]. As noted in Section 5, the precise strings to be used as the audience for a given Authorization Server must be configured out-of-band by the Authorization Server and the Issuer of the assertion. 3. The Assertion MUST contain a <Subject> element identifying the principal that is the subject of the Assertion. Additional information identifying the subject/principal MAY be included in an <AttributeStatement>. Campbell, et al. Expires May 16, 2015 [Page 6] Internet-Draft OAuth SAML Assertion Profiles November 2014 A. For the authorization grant, the Subject typically identifies an authorized accessor for which the access token is being requested (i.e., the resource owner or an authorized delegate), but in some cases, may be a pseudonymous identifier or other value denoting an anonymous user. B. For client authentication, the Subject MUST be the "client_id" of the OAuth client. 4. The Assertion MUST have an expiry that limits the time window during which it can be used. The expiry can be expressed either as the NotOnOrAfter attribute of the <Conditions> element or as the NotOnOrAfter attribute of a suitable <SubjectConfirmationData> element. 5. The <Subject> element MUST contain at least one <SubjectConfirmation> element that has a Method attribute with a value of "urn:oasis:names:tc:SAML:2.0:cm:bearer". If the Assertion does not have a suitable NonOnOrAfter attribute on the <Conditions> element, the <SubjectConfirmation> element MUST contain a <SubjectConfirmationData> element. When present, the <SubjectConfirmationData> element MUST have a Recipient attribute with a value indicating the token endpoint URL of the authorization server (or an acceptable alias). The authorization server MUST verify that the value of the Recipient attribute matches the token endpoint URL (or an acceptable alias) to which the Assertion was delivered. The <SubjectConfirmationData> element MUST have a NotOnOrAfter attribute that limits the window during which the Assertion can be confirmed. The <SubjectConfirmationData> element MAY also contain an Address attribute limiting the client address from which the Assertion can be delivered. Verification of the Address is at the discretion of the authorization server. 6. The authorization server MUST reject the entire Assertion if the NotOnOrAfter instant on the <Conditions> element has passed (subject to allowable clock skew between systems). The authorization server MUST reject the <SubjectConfirmation> (but MAY still use the rest of the Assertion) if the NotOnOrAfter instant on the <SubjectConfirmationData> has passed (subject to allowable clock skew). Note that the authorization server may reject Assertions with a NotOnOrAfter instant that is unreasonably far in the future. The authorization server MAY ensure that Bearer Assertions are not replayed, by maintaining the set of used ID values for the length of time for which the Assertion would be considered valid based on the applicable NotOnOrAfter instant. Campbell, et al. Expires May 16, 2015 [Page 7] Internet-Draft OAuth SAML Assertion Profiles November 2014 7. If the Assertion issuer directly authenticated the subject, the Assertion SHOULD contain a single <AuthnStatement> representing that authentication event. If the Assertion was issued with the intention that the client act autonomously on behalf of the subject, an <AuthnStatement> SHOULD NOT be included and the client presenting the assertion SHOULD be identified in the <NameID> or similar element in the <SubjectConfirmation> element, or by other available means like SAML V2.0 Condition for Delegation Restriction [OASIS.saml-deleg-cs]. 8. Other statements, in particular <AttributeStatement> elements, MAY be included in the Assertion. 9. The Assertion MUST be digitally signed or have a Message Authentication Code applied by the issuer. The authorization server MUST reject assertions with an invalid signature or Message Authentication Code. 10. Encrypted elements MAY appear in place of their plain text counterparts as defined in [OASIS.saml-core-2.0-os]. 11. The authorization server MUST reject an Assertion that is not valid in all other respects per [OASIS.saml-core-2.0-os], such as (but not limited to) all content within the Conditions element including the NotOnOrAfter and NotBefore attributes, unknown condition types, etc. 3.1. Authorization Grant Processing Assertion authorization grants may be used with or without client authentication or identification. Whether or not client authentication is needed in conjunction with an assertion authorization grant, as well as the supported types of client authentication, are policy decisions at the discretion of the authorization server. However, if client credentials are present in the request, the authorization server MUST validate them. If the Assertion is not valid (including if its subject confirmation requirements cannot be met), the authorization server constructs an error response as defined in OAuth 2.0 [RFC6749]. The value of the "error" parameter MUST be the "invalid_grant" error code. The authorization server MAY include additional information regarding the reasons the Assertion was considered invalid using the "error_description" or "error_uri" parameters. Campbell, et al. Expires May 16, 2015 [Page 8] Internet-Draft OAuth SAML Assertion Profiles November 2014 For example: HTTP/1.1 400 Bad Request Content-Type: application/json Cache-Control: no-store { "error":"invalid_grant", "error_description":"Audience validation failed" } 3.2. Client Authentication Processing If the client Assertion is not valid (including if its subject confirmation requirements cannot be met), the authorization server constructs an error response as defined in OAuth 2.0 [RFC6749]. The value of the "error" parameter MUST be the "invalid_client" error code. The authorization server MAY include additional information regarding the reasons the Assertion was considered invalid using the "error_description" or "error_uri" parameters. 4. Authorization Grant Example The following examples illustrate what a conforming Assertion and an access token request would look like. The example shows an assertion issued and signed by the SAML Identity Provider identified as "https://saml-idp.example.com". The subject of the assertion is identified by email address as "brian@example.com", who authenticated to the Identity Provider by means of a digital signature where the key was validated as part of an X.509 Public Key Infrastructure. The intended audience of the assertion is "https://saml-sp.example.net", which is an identifier for a SAML Service Provider with which the authorization server identifies itself. The assertion is sent as part of an access token request to the authorization server's token endpoint at "https://authz.example.net/token.oauth2". Campbell, et al. Expires May 16, 2015 [Page 9] Internet-Draft OAuth SAML Assertion Profiles November 2014 Below is an example SAML 2.0 Assertion (whitespace formatting is for display purposes only): <Assertion IssueInstant="2010-10-01T20:07:34.619Z" ID="ef1xsbZxPV2oqjd7HTLRLIBlBb7" Version="2.0" xmlns="urn:oasis:names:tc:SAML:2.0:assertion"> <Issuer>https://saml-idp.example.com</Issuer> <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"> [...omitted for brevity...] </ds:Signature> <Subject> <NameID Format="urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress"> brian@example.com </NameID> <SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer"> <SubjectConfirmationData NotOnOrAfter="2010-10-01T20:12:34.619Z" Recipient="https://authz.example.net/token.oauth2"/> </SubjectConfirmation> </Subject> <Conditions> <AudienceRestriction> <Audience>https://saml-sp.example.net</Audience> </AudienceRestriction> </Conditions> <AuthnStatement AuthnInstant="2010-10-01T20:07:34.371Z"> <AuthnContext> <AuthnContextClassRef> urn:oasis:names:tc:SAML:2.0:ac:classes:X509 </AuthnContextClassRef> </AuthnContext> </AuthnStatement> </Assertion> Figure 1: Example SAML 2.0 Assertion Campbell, et al. Expires May 16, 2015 [Page 10] Internet-Draft OAuth SAML Assertion Profiles November 2014 To present the Assertion shown in the previous example as part of an access token request, for example, the client might make the following HTTPS request (with extra line breaks for display purposes only): POST /token.oauth2 HTTP/1.1 Host: authz.example.net Content-Type: application/x-www-form-urlencoded grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Asaml2- bearer&assertion=PEFzc2VydGlvbiBJc3N1ZUluc3RhbnQ9IjIwMTEtMDU [...omitted for brevity...]aG5TdGF0ZW1lbnQ-PC9Bc3NlcnRpb24- Figure 2: Example Request 5. Interoperability Considerations Agreement between system entities regarding identifiers, keys, and endpoints is required in order to achieve interoperable deployments of this profile. Specific items that require agreement are as follows: values for the issuer and audience identifiers, the location of the token endpoint, the key used to apply and verify the digital signature over the assertion, one-time use restrictions on assertions, maximum assertion lifetime allowed, and the specific subject and attribute requirements of the assertion. The exchange of such information is explicitly out of scope for this specification and typical deployment of it will be done alongside existing SAML Web SSO deployments that have already established a means of exchanging such information. Metadata for the OASIS Security Assertion Markup Language (SAML) V2.0 [OASIS.saml-metadata-2.0-os] is one common method of exchanging SAML related information about system entities. The RSA-SHA256 algorithm, from [RFC6931], is a mandatory to implement XML signature algorithm for this profile. 6. Security Considerations The security considerations described within the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions], The OAuth 2.0 Authorization Framework [RFC6749], and the Security and Privacy Considerations for the OASIS Security Assertion Markup Language (SAML) V2.0 [OASIS.saml-sec-consider-2.0-os] specifications are all applicable to this document. The specification does not mandate replay protection for the SAML assertion usage for either the authorization grant or for client Campbell, et al. Expires May 16, 2015 [Page 11] Internet-Draft OAuth SAML Assertion Profiles November 2014 authentication. It is an optional feature, which implementations may employ at their own discretion. 7. Privacy Considerations A SAML Assertion may contain privacy-sensitive information and, to prevent disclosure of such information to unintended parties, should only be transmitted over encrypted channels, such as TLS. In cases where it is desirable to prevent disclosure of certain information to the client, the Subject and/or individual attributes of a SAML Assertion should be encrypted to the authorization server. Deployments should determine the minimum amount of information necessary to complete the exchange and include only that information in an Assertion (typically by limiting what information is included in an <AttributeStatement> or omitting it altogether). In some cases, the Subject can be a value representing an anonymous or pseudonymous user, as described in Section 6.3.1 of the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants [I-D.ietf-oauth-assertions]. 8. IANA Considerations 8.1. Sub-Namespace Registration of urn:ietf:params:oauth:grant- type:saml2-bearer This is a request to IANA to please register the value "grant- type:saml2-bearer" in the registry urn:ietf:params:oauth established in An IETF URN Sub-Namespace for OAuth [RFC6755]. o URN: urn:ietf:params:oauth:grant-type:saml2-bearer o Common Name: SAML 2.0 Bearer Assertion Grant Type Profile for OAuth 2.0 o Change controller: IESG o Specification Document: [[this document]] 8.2. Sub-Namespace Registration of urn:ietf:params:oauth:client- assertion-type:saml2-bearer This is a request to IANA to please register the value "client- assertion-type:saml2-bearer" in the registry urn:ietf:params:oauth established in An IETF URN Sub-Namespace for OAuth [RFC6755]. o URN: urn:ietf:params:oauth:client-assertion-type:saml2-bearer Campbell, et al. Expires May 16, 2015 [Page 12] Internet-Draft OAuth SAML Assertion Profiles November 2014 o Common Name: SAML 2.0 Bearer Assertion Profile for OAuth 2.0 Client Authentication o Change controller: IESG o Specification Document: [[this document]] 9. References 9.1. Normative References [I-D.ietf-oauth-assertions] Campbell, B., Mortimore, C., Jones, M., and Y. Goland, "Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants", draft-ietf-oauth-assertions (work in progress), October 2014. [OASIS.saml-core-2.0-os] 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>. [OASIS.saml-deleg-cs] Cantor, S., Ed., "SAML V2.0 Condition for Delegation Restriction", Nov 2009. [OASIS.saml-sec-consider-2.0-os] Hirsch, F., Philpott, R., and E. Maler, "Security and Privacy Considerations for the OASIS Security Markup Language (SAML) V2.0", OASIS Standard saml-sec-consider- 2.0-os, March 2005, <http://docs.oasis- open.org/security/saml/v2.0/saml-sec-consider-2.0-os.pdf>. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, October 2006. [RFC6749] Hardt, D., "The OAuth 2.0 Authorization Framework", RFC 6749, October 2012. Campbell, et al. Expires May 16, 2015 [Page 13] Internet-Draft OAuth SAML Assertion Profiles November 2014 [RFC6931] Eastlake, D., "Additional XML Security Uniform Resource Identifiers (URIs)", RFC 6931, April 2013. 9.2. Informative References [OASIS.WS-Fed] Goodner, M. and T. Nadalin, "Web Services Federation Language (WS-Federation) Version 1.2", May 2009, <http://docs.oasis-open.org/wsfed/federation/v1.2/os/ ws-federation-1.2-spec-os.html>. [OASIS.WSS-SAMLTokenProfile] Monzillo, R., Kaler, C., Nadalin, T., Hallam-Baker, P., and C. Milono, "Web Services Security SAML Token Profile Version 1.1.1", May 2012, <http://docs.oasis-open.org/wss- m/wss/v1.1.1/wss-SAMLTokenProfile-v1.1.1.html>. [OASIS.saml-metadata-2.0-os] Cantor, S., Moreh, J., Philpott, R., and E. Maler, "Metadata for the Security Assertion Markup Language (SAML) V2.0", OASIS Standard saml-metadata-2.0-os, March 2005, <http://docs.oasis-open.org/security/saml/v2.0/ saml-metadata-2.0-os.pdf>. [OASIS.saml-profiles-2.0-os] 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>. [RFC6755] Campbell, B. and H. Tschofenig, "An IETF URN Sub-Namespace for OAuth", RFC 6755, October 2012. [W3C.REC-html401-19991224] Raggett, D., Hors, A., and I. Jacobs, "HTML 4.01 Specification", World Wide Web Consortium Recommendation REC-html401-19991224, December 1999, <http://www.w3.org/TR/1999/REC-html401-19991224>. Appendix A. Acknowledgements The following people contributed wording and concepts to this document: Paul Madsen, Patrick Harding, Peter Motykowski, Eran Hammer, Peter Saint-Andre, Ian Barnett, Eric Fazendin, Torsten Lodderstedt, Susan Harper, Scott Tomilson, Scott Cantor, Hannes Tschofenig, David Waite, Phil Hunt, and Mukesh Bhatnagar. Campbell, et al. Expires May 16, 2015 [Page 14] Internet-Draft OAuth SAML Assertion Profiles November 2014 Appendix B. Document History [[ to be removed by RFC editor before publication as an RFC ]] draft-ietf-oauth-saml2-bearer-23 o Fix typo per http://www.ietf.org/mail-archive/web/oauth/current/ msg13790.html draft-ietf-oauth-saml2-bearer-22 o Changes/suggestions from IESG reviews. draft-ietf-oauth-saml2-bearer-21 o Added Privacy Considerations section per AD review discussion http://www.ietf.org/mail-archive/web/oauth/current/msg13148.html and http://www.ietf.org/mail-archive/web/oauth/current/ msg13144.html draft-ietf-oauth-saml2-bearer-20 o Clarified some text around the treatment of subject based on the rough rough consensus from the thread staring at http://www.ietf.org/mail-archive/web/oauth/current/msg12630.html draft-ietf-oauth-saml2-bearer-19 o Updated references. draft-ietf-oauth-saml2-bearer-18 o Clean up language around subject per http://www.ietf.org/mail- archive/web/oauth/current/msg12254.html. o As suggested in http://www.ietf.org/mail- archive/web/oauth/current/msg12253.html stated that "In the absence of an application profile specifying otherwise, compliant applications MUST compare the audience/issuer values using the Simple String Comparison method defined in Section 6.2.1 of RFC 3986." o Clarify the potentially confusing language about the AS confirming the assertion http://www.ietf.org/mail-archive/web/oauth/current/ msg12255.html. Campbell, et al. Expires May 16, 2015 [Page 15] Internet-Draft OAuth SAML Assertion Profiles November 2014 o Combine the two items about AuthnStatement and drop the word presenter as discussed in http://www.ietf.org/mail- archive/web/oauth/current/msg12257.html. o Added one-time use, maximum lifetime, and specific subject and attribute requirements to Interoperability Considerations based on http://www.ietf.org/mail-archive/web/oauth/current/msg12252.html. o Reword security considerations and mention that replay protection is not mandated based on http://www.ietf.org/mail- archive/web/oauth/current/msg12259.html. draft-ietf-oauth-saml2-bearer-17 o Stated that issuer and audience values SHOULD be compared using the Simple String Comparison method defined in Section 6.2.1 of RFC 3986 unless otherwise specified by the application. draft-ietf-oauth-saml2-bearer-16 o Changed title from "SAML 2.0 Bearer Assertion Profiles for OAuth 2.0" to "SAML 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grants" to be more explicit about the scope of the document per http://www.ietf.org/mail-archive/web/oauth/current/ msg11063.html. o Fixed typo in text identifying the presenter from "or similar element, the" to "or similar element in the". o Numbered the list of processing rules. o Smallish editorial cleanups to try and improve readability and comprehensibility. o Cleaner split out of the processing rules in cases where they differ for client authentication and authorization grants. o Clarified the parameters that are used/available for authorization grants. o Added Interoperability Considerations section and info reference to SAML Metadata. o Added more explanatory context to the example in Section 4. draft-ietf-oauth-saml2-bearer-15 o Reference RFC 6749 and RFC 6755. Campbell, et al. Expires May 16, 2015 [Page 16] Internet-Draft OAuth SAML Assertion Profiles November 2014 o Update draft-ietf-oauth-assertions reference to -06. o Remove extraneous word per http://www.ietf.org/mail- archive/web/oauth/current/msg10055.html draft-ietf-oauth-saml2-bearer-14 o Add more text to intro explaining that an assertion grant type can be used with or without client authentication/identification and that client assertion authentication is nothing more than an alternative way for a client to authenticate to the token endpoint o Add examples to Sections 2.1 and 2.2 o Update references draft-ietf-oauth-saml2-bearer-13 o Update references: oauth-assertions-04, oauth-urn-sub-ns-05, oauth -28 o Changed "Description" to "Specification Document" in both registration requests in IANA Considerations per changes to the template in ietf-oauth-urn-sub-ns(-03) o Added "(or an acceptable alias)" so that it's in both sentences about Recipient and the token endpoint URL so there's no ambiguity o Update area and workgroup (now Security and OAuth was Internet and nothing) draft-ietf-oauth-saml2-bearer-12 o updated reference to draft-ietf-oauth-v2 from -25 to -26 and draft-ietf-oauth-assertions from -02 to -03 draft-ietf-oauth-saml2-bearer-11 o Removed text about limited lifetime access tokens and the SHOULD NOT on issuing refresh tokens. The text was moved to draft-ietf- oauth-assertions-02 and somewhat modified per http://www.ietf.org/ mail-archive/web/oauth/current/msg08298.html. o Fixed typo/missing word per http://www.ietf.org/mail- archive/web/oauth/current/msg08733.html. o Added Terminology section. Campbell, et al. Expires May 16, 2015 [Page 17] Internet-Draft OAuth SAML Assertion Profiles November 2014 draft-ietf-oauth-saml2-bearer-10 o fix a spelling mistake draft-ietf-oauth-saml2-bearer-09 o Attempt to address an ambiguity around validation requirements when the Conditions element contain a NotOnOrAfter and SubjectConfirmation/SubjectConfirmationData does too. Basically it needs to have at least one bearer SubjectConfirmation element but that element can omit SubjectConfirmationData, if Conditions has an expiry on it. Otherwise, a valid SubjectConfirmation must have a SubjectConfirmationData with Recipient and NotOnOrAfter. And any SubjectConfirmationData that has those elements needs to have them checked. o clarified that AudienceRestriction is under Conditions (even though it's implied by schema) o fix a typo draft-ietf-oauth-saml2-bearer-08 o fix some typos draft-ietf-oauth-saml2-bearer-07 o update reference from draft-campbell-oauth-urn-sub-ns to draft- ietf-oauth-urn-sub-ns o Updated to reference draft-ietf-oauth-v2-20 draft-ietf-oauth-saml2-bearer-06 o Fix three typos NamseID->NameID and (2x) Namspace->Namespace draft-ietf-oauth-saml2-bearer-05 o Allow for subject confirmation data to be optional when Conditions contain audience and NotOnOrAfter o Rework most of the spec to profile draft-ietf-oauth-assertions for both authn and authz including (but not limited to): * remove requirement for issuer to be urn:oasis:names:tc:SAML:2.0:nameid-format:entity * change wording on Subject requirements Campbell, et al. Expires May 16, 2015 [Page 18] Internet-Draft OAuth SAML Assertion Profiles November 2014 o using a MAY, explicitly say that the Audience can be token endpoint URL of the authorization server o Change title to be more generic (allowing for client authn too) o added client authentication to the abstract o register and use urn:ietf:params:oauth:grant-type:saml2-bearer for grant type rather than http://oauth.net/grant_type/saml/2.0/bearer o register urn:ietf:params:oauth:client-assertion-type:saml2-bearer o remove scope parameter as it is defined in http://tools.ietf.org/html/draft-ietf-oauth-assertions o remove assertion param registration because it [should] be in http://tools.ietf.org/html/draft-ietf-oauth-assertions o fix typo(s) and update/add references draft-ietf-oauth-saml2-bearer-04 o Changed the grant_type URI from "http://oauth.net/grant_type/assertion/saml/2.0/bearer" to "http://oauth.net/grant_type/saml/2.0/bearer" - dropping the word assertion from the path. Recent versions of draft-ietf-oauth-v2 no longer refer to extension grants using the word assertion so this URI is more reflective of that. It also more closely aligns with the grant type URI in draft-jones-oauth-jwt-bearer-00 which is "http://oauth.net/grant_type/jwt/1.0/bearer". o Added "case sensitive" to scope definition to align with draft- ietf-oauth-v2-15/16. o Updated to reference draft-ietf-oauth-v2-16 draft-ietf-oauth-saml2-bearer-03 o Cleanup of some editorial issues. draft-ietf-oauth-saml2-bearer-02 o Added scope parameter with text copied from draft-ietf-oauth-v2-12 (the reorg of draft-ietf-oauth-v2-12 made it so scope wasn't really inherited by this spec anymore) Campbell, et al. Expires May 16, 2015 [Page 19] Internet-Draft OAuth SAML Assertion Profiles November 2014 o Change definition of the assertion parameter to be more generally applicable per the suggestion near the end of http://www.ietf.org/ mail-archive/web/oauth/current/msg05253.html o Editorial changes based on feedback draft-ietf-oauth-saml2-bearer-01 o Update spec name when referencing draft-ietf-oauth-v2 (The OAuth 2.0 Protocol Framework -> The OAuth 2.0 Authorization Protocol) o Update wording in Introduction to talk about extension grant types rather than the assertion grant type which is a term no longer used in OAuth 2.0 o Updated to reference draft-ietf-oauth-v2-12 and denote as work in progress o Update Parameter Registration Request to use similar terms as draft-ietf-oauth-v2-12 and remove Related information part o Add some text giving discretion to AS on rejecting assertions with unreasonably long validity window. draft-ietf-oauth-saml2-bearer-00 o Added Parameter Registration Request for "assertion" to IANA Considerations. o Changed document name to draft-ietf-oauth-saml2-bearer in anticipation of becoming an OAUTH WG item. o Attempt to move the entire definition of the 'assertion' parameter into this draft (it will no longer be defined in OAuth 2 Protocol Framework). draft-campbell-oauth-saml-01 o Updated to reference draft-ietf-oauth-v2-11 and reflect changes from -10 to -11. o Updated examples. o Relaxed processing rules to allow for more than one SubjectConfirmation element. o Removed the 'MUST NOT contain a NotBefore attribute' on SubjectConfirmationData. Campbell, et al. Expires May 16, 2015 [Page 20] Internet-Draft OAuth SAML Assertion Profiles November 2014 o Relaxed wording that ties the subject of the Assertion to the resource owner. o Added some wording about identifying the client when the subject hasn't directly authenticated including an informative reference to SAML V2.0 Condition for Delegation Restriction. o Added a few examples to the language about verifying that the Assertion is valid in all other respects. o Added some wording to the introduction about the similarities to Web SSO in the format and processing rules o Changed the grant_type (was assertion_type) URI from http://oauth.net/assertion_type/saml/2.0/bearer to http://oauth.net/grant_type/assertion/saml/2.0/bearer o Changed title to include "Grant Type" in it. o Editorial updates based on feedback from the WG and others (including capitalization of Assertion when referring to SAML). draft-campbell-oauth-saml-00 o Initial I-D Authors' Addresses Brian Campbell Ping Identity Email: brian.d.campbell@gmail.com Chuck Mortimore Salesforce.com Email: cmortimore@salesforce.com Michael B. Jones Microsoft Email: mbj@microsoft.com URI: http://self-issued.info/ Campbell, et al. Expires May 16, 2015 [Page 21]