Security Assertion Markup Language (SAML) has found its usage on the Internet for Web Single Sign-On. Simple Authentication and Security Layer (SASL) and the Generic Security Service Application Program Interface (GSS-API) are application frameworks to generalize authentication. This memo specifies a SASL mechanism and GSS-API mechanism for SAML 2.0 that allows the integration of existing SAML Identity Providers with applications using SASL and GSS-API.
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 January 13, 2011.
Copyright (c) 2010 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 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.
3. Applicability for non-HTTP Use Cases
4. SAML SASL Mechanism Specification
4.3. Server Redirect
4.4. Client Empty Response and other
4.5. Outcome and parameters
5. SAML GSS-API Mechanism Specification
5.1. GSS-API Principal Name Types for SAML
6. Channel Binding
8. Security Considerations
8.1. Binding SAML subject identifiers to Authorization Identities
8.2. User Privacy
8.3. Collusion between RPs
9. IANA Considerations
10. Normative References
Appendix A. Acknowledgments
Appendix B. Changes
§ Authors' Addresses
Security Assertion Markup Language (SAML) 2.0 [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,” March 2005.) is a modular specification that provides various means for a user to be identified to a relying party (RP) through the exchange of (typically signed) assertions issued by an identity provider (IdP). It includes a number of protocols, protocol bindings [OASIS.saml‑bindings‑2.0‑os] (Cantor, S., Hirsch, F., Kemp, J., Philpott, R., and E. Maler, “Bindings for the OASIS Security Assertion Markup Language (SAML) V2.0,” March 2005.), and interoperability profiles [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,” March 2005.) designed for different use cases.
Simple Authentication and Security Layer (SASL) [RFC4422] (Melnikov, A. and K. Zeilenga, “Simple Authentication and Security Layer (SASL),” June 2006.) is a generalized mechanism for identifying and authenticating a user and for optionally negotiating a security layer for subsequent protocol interactions. SASL is used by application protocols like IMAP, POP and XMPP. The effect is to make modular authentication, so that newer authentication mechanisms can be added as needed. This memo specifies just such a mechanism.
The Generic Security Service Application Program Interface (GSS-API) [RFC2743] (Linn, J., “Generic Security Service Application Program Interface Version 2, Update 1,” January 2000.) provides a framework for applications to support multiple authentication mechanisms through a unified interface. This document defines a pure SASL mechanism for OpenID, but it conforms to the new bridge between SASL and the GSS-API called GS2 [I‑D.ietf‑sasl‑gs2] (Josefsson, S. and N. Williams, “Using GSS-API Mechanisms in SASL: The GS2 Mechanism Family,” January 2010.). This means that this document defines both a SASL mechanism and a GSS-API mechanism. We want to point out that the GSS-API interface is optional for SASL implementers, and the GSS-API considerations can be avoided in environments that uses SASL directly without GSS-API.
As currently envisioned, this mechanism is to allow the interworking between SASL and SAML in order to assert identity and other attributes to relying parties. As such, while servers (as relying parties) will advertise SASL mechanisms (including SAML), clients will select the SAML SASL mechanism as their SASL mechanism of choice.
The SAML mechanism described in this memo aims to re-use the available SAML deployment to a maximum extent and therefore does not establish a separate authentication, integrity and confidentiality mechanism. It is anticipated that existing security layers, such as Transport Layer Security (TLS), will continued to be used.
Figure 1 (Interworking Architecture) describes the interworking between SAML and SASL: this document requires enhancements to the Relying Party and to the Client (as the two SASL communication end points) but no changes to the SAML Identity Provider are necessary. To accomplish this goal some indirect messaging is tunneled within SASL, and some use of external methods is made.
+-----------+ | | >| Relying | / | Party | // | | // +-----------+ SAML/ // ^ HTTPs // +--|--+ // | S| | / S | A| | // A | M| | // S | L| | // L | | | // | | | </ +--|--+ +------------+ v | | +----------+ | SAML | HTTPs | | | Identity |<--------------->| Client | | Provider | | | +------------+ +----------+
| Figure 1: Interworking
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] (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.).
The reader is assumed to be familiar with the terms used in the SAML 2.0 specification.
While SAML itself is merely a markup language, its common use case these days is with HTTP. What follows is a typical flow:
When considering this flow in the context of SASL, we note that while the RP and the client both must change their code to implement this SASL mechanism, the IdP must remain untouched. The RP already has some sort of session (probably a TCP connection) established with the client. However, it may be necessary to redirect a SASL client to another application or handler. This will be discussed below. The steps are shown from below:
Please note: What is described here is the case in which the client has not previously authenticated. If the client can handle SAML internally it is possible that the client already holds a valid SAML authentication token so that the user does not need to be involved in the process anymore, but that would still be external to SASL.
With all of this in mind, the flow appears as follows:
SASL Serv. Client IdP |>-----(1)----->| | Advertisement | | | |<-----(2)-----<| | Initiation | | | |>-----(3)----->| | Authentication Request | | | |<-----(4)-----<| | Empty Response | | | | |< - - - - - ->| Client<>IDP | | | Authentication | | | |<- - - - - - - - - - - - - - -| Authentication Statement | | | |>-----(6)----->| | SASL completion with | | | status | | | ----- = SASL - - - = HTTP or HTTPs (external to SASL)
| Figure 2: Authentication flow |
Based on the previous figure, the following operations are performed with the SAML SASL mechanism:
To advertise that a server supports SAML 2.0, during application session initiation, it displays the name "SAML20" in the list of supported SASL mechanisms.
A client initiates a "SAML20" authentication with SASL by sending the GS2 header followed by the authentication identifier. The GS2 header carries the optional authorization identity.
initial-response = gs2-header Idp-Identifier IdP-Identifier = Identifier ; IdP identifier Identifier = URI ; IdP URI
The "gs2-header" is specified in [I‑D.ietf‑sasl‑gs2] (Josefsson, S. and N. Williams, “Using GSS-API Mechanisms in SASL: The GS2 Mechanism Family,” January 2010.), and it is used as follows. The "gs2-nonstd-flag" MUST NOT be present. Regarding the channel binding "gs2-cb-flag" field, see Section 5. The "gs2- authzid" carries the optional authorization identity. URI is specified in [RFC3986] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.).
The SASL Server transmits a redirect to the IdP that the user provided, with a SAML authentication request in the form of a SAML assertion as one of the parameters.
The SASL client hands the URI it received from the server in the previous step to either a browser or other appropriate handler to continue authentication externally while sending an empty response to the SASL server. The URI is encoded according to Section 3.4 of the SAML bindings 2.0 specification (Cantor, S., Hirsch, F., Kemp, J., Philpott, R., and E. Maler, “Bindings for the OASIS Security Assertion Markup Language (SAML) V2.0,” March 2005.) [OASIS.saml‑bindings‑2.0‑os].
The SAML authentication having completed externally, the SASL server will transmit the outcome
This section and its sub-sections and all normative references of it not referenced elsewhere in this document are INFORMATIONAL for SASL implementors, but they are NORMATIVE for GSS-API implementors.
The SAML SASL mechanism is actually also a GSS-API mechanism. The messages are the same, but
a) the GS2 header on the client's first message and channel binding data is excluded when SAML is used as a GSS-API mechanism, and
b) the RFC2743 section 3.1 initial context token header is prefixed to the client's first authentication message (context token).
The GSS-API mechanism OID for SAML is XXXXX
SAML security contexts always have the mutual_state flag (GSS_C_MUTUAL_FLAG) set to TRUE. SAML does not support credential delegation, therefore SCRAM security contexts alway have the deleg_state flag (GSS_C_DELEG_FLAG) set to FALSE.
The SAML mechanism does not support per-message tokens or GSS_Pseudo_random.
SAML supports standard generic name syntaxes for acceptors such as GSS_C_NT_HOSTBASED_SERVICE (see [RFC2743] (Linn, J., “Generic Security Service Application Program Interface Version 2, Update 1,” January 2000.), Section 4.1). SAML supports only a single name type for initiators: GSS_C_NT_USER_NAME. GSS_C_NT_USER_NAME is the default name type for SAML. The query, display, and exported name syntaxes for SAML principal names are all the same. There are no SAML-specific name syntaxes -- applications should use generic GSS-API name types such as GSS_C_NT_USER_NAME and GSS_C_NT_HOSTBASED_SERVICE (see [RFC2743] (Linn, J., “Generic Security Service Application Program Interface Version 2, Update 1,” January 2000.), Section 4). The exported name token does, of course, conform to [RFC2743] (Linn, J., “Generic Security Service Application Program Interface Version 2, Update 1,” January 2000.), Section 3.2. GSS-API name attributes may be defined in the future to hold the SAML Subject Identifier.
The "gs2-cb-flag" MUST use "n" because channel binding data cannot be integrity protected by the SAML negotiation.
Suppose the user has an identity at the SAML IdP saml.example.org and a Jabber Identifier (JID) "email@example.com", and wishes to authenticate his XMPP connection to xmpp.example.com. The authentication on the wire would then look something like the following:
Step 1: Client initiates stream to server:
<stream:stream xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' to='example.com' version='1.0'>
Step 2: Server responds with a stream tag sent to client:
<stream:stream xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' id='some_id' from='example.com' version='1.0'>
Step 3: Server informs client of available authentication mechanisms:
<stream:features> <mechanisms xmlns='urn:ietf:params:xml:ns:xmpp-sasl'> <mechanism>DIGEST-MD5</mechanism> <mechanism>PLAIN</mechanism> <mechanism>SAML20</mechanism> </mechanisms> </stream:features>
Step 4: Client selects an authentication mechanism:
<auth xmlns='urn:ietf:params:xml:ns:xmpp-sasl' mechanism='SAML20'> https://saml.example.org</auth>
Step 5: Server sends a BASE64 (Josefsson, S., “The Base16, Base32, and Base64 Data Encodings,” October 2006.) [RFC4648] encoded challenge to client in the form of an HTTP Redirect to the SAML IdP with the SAML Authentication Request as specified in the redirection url:
SFRUUC8xLjEgMzAyIE9iamVjdCBNb3ZlZCBEYXRlOiAyMiBPY3QgMjAwOSAwNzowMDo0OS BHTVQgTG9jYXRpb246DQpodHRwczovL3NhbWwuZXhhbXBsZS5vcmcvU0FNTC9Ccm93c2Vy P1NBTUxSZXF1ZXN0PQ0KUEhOaGJXeHdPa0YxZEdodVVtVnhkV1Z6ZENCNGJXeHVjenB6WV cxc2NEMGlkWEp1T205aGMybHpPbTVoYldWek9uUmpPbE5CVFV3Ng0KTWk0d09uQnliM1J2 WTI5c0lnMEtJQ0FnSUVsRVBTSmZZbVZqTkRJMFptRTFNVEF6TkRJNE9UQTVZVE13Wm1ZeF pUTXhNVFk0TXpJMw0KWmpjNU5EYzBPVGcwSWlCV1pYSnphVzl1UFNJeUxqQWlEUW9nSUNB Z1NYTnpkV1ZKYm5OMFlXNTBQU0l5TURBM0xURXlMVEV3VkRFeA0KT2pNNU9qTTBXaUlnUm 05eVkyVkJkWFJvYmowaVptRnNjMlVpRFFvZ0lDQWdTWE5RWVhOemFYWmxQU0ptWVd4elpT SU5DaUFnSUNCUQ0KY205MGIyTnZiRUpwYm1ScGJtYzlJblZ5YmpwdllYTnBjenB1WVcxbG N6cDBZenBUUVUxTU9qSXVNRHBpYVc1a2FXNW5jenBJVkZSUQ0KTFZCUFUxUWlEUW9nSUNB Z1FYTnpaWEowYVc5dVEyOXVjM1Z0WlhKVFpYSjJhV05sVlZKTVBRMEtJQ0FnSUNBZ0lDQW lhSFIwY0hNNg0KTHk5NGJYQndMbVY0WVcxd2JHVXVZMjl0TDFOQlRVd3ZRWE56WlhKMGFX OXVRMjl1YzNWdFpYSlRaWEoyYVdObElqNE5DaUE4YzJGdA0KYkRwSmMzTjFaWElnZUcxc2 JuTTZjMkZ0YkQwaWRYSnVPbTloYzJsek9tNWhiV1Z6T25Sak9sTkJUVXc2TWk0d09tRnpj MlZ5ZEdsdg0KYmlJK0RRb2dJQ0FnSUdoMGRIQnpPaTh2ZUcxd2NDNWxlR0Z0Y0d4bExtTn ZiUTBLSUR3dmMyRnRiRHBKYzNOMVpYSStEUW9nUEhOaA0KYld4d09rNWhiV1ZKUkZCdmJH bGplU0I0Yld4dWN6cHpZVzFzY0QwaWRYSnVPbTloYzJsek9tNWhiV1Z6T25Sak9sTkJUVX c2TWk0dw0KT25CeWIzUnZZMjlzSWcwS0lDQWdJQ0JHYjNKdFlYUTlJblZ5YmpwdllYTnBj enB1WVcxbGN6cDBZenBUUVUxTU9qSXVNRHB1WVcxbA0KYVdRdFptOXliV0YwT25CbGNuTn BjM1JsYm5RaURRb2dJQ0FnSUZOUVRtRnRaVkYxWVd4cFptbGxjajBpZUcxd2NDNWxlR0Z0 Y0d4bA0KTG1OdmJTSWdRV3hzYjNkRGNtVmhkR1U5SW5SeWRXVWlJQzgrRFFvZ1BITmhiV3 h3T2xKbGNYVmxjM1JsWkVGMWRHaHVRMjl1ZEdWNA0KZEEwS0lDQWdJQ0I0Yld4dWN6cHpZ VzFzY0QwaWRYSnVPbTloYzJsek9tNWhiV1Z6T25Sak9sTkJUVXc2TWk0d09uQnliM1J2WT I5cw0KSWlBTkNpQWdJQ0FnSUNBZ1EyOXRjR0Z5YVhOdmJqMGlaWGhoWTNRaVBnMEtJQ0E4 YzJGdGJEcEJkWFJvYmtOdmJuUmxlSFJEYkdGeg0KYzFKbFpnMEtJQ0FnSUNBZ2VHMXNibk 02YzJGdGJEMGlkWEp1T205aGMybHpPbTVoYldWek9uUmpPbE5CVFV3Nk1pNHdPbUZ6YzJW eQ0KZEdsdmJpSStEUW9nb0NBZ0lDQjFjbTQ2YjJGemFYTTZibUZ0WlhNNmRHTTZVMEZOVE RveUxqQTZZV002WTJ4aGMzTmxjenBRWVhOeg0KZDI5eVpGQnliM1JsWTNSbFpGUnlZVzV6 Y0c5eWRBMEtJQ0E4TDNOaGJXdzZRWFYwYUc1RGIyNTBaWGgwUTJ4aGMzTlNaV1krRFFvZw 0KUEM5ellXMXNjRHBTWlhGMVpYTjBaV1JCZFhSb2JrTnZiblJsZUhRK0lBMEtQQzl6WVcx c2NEcEJkWFJvYmxKbGNYVmxjM1Er
The decoded challenge is:
HTTP/1.1 302 Object Moved Date: 22 Oct 2009 07:00:49 GMT Location: https://saml.example.org/SAML/Browser?SAMLRequest= PHNhbWxwOkF1dGhuUmVxdWVzdCB4bWxuczpzYW1scD0idXJuOm9hc2lzOm5hbWVzOnRjOl NBTUw6Mi4wOnByb3RvY29sIg0KICAgIElEPSJfYmVjNDI0ZmE1MTAzNDI4OTA5YTMwZmYx ZTMxMTY4MzI3Zjc5NDc0OTg0IiBWZXJzaW9uPSIyLjAiDQogICAgSXNzdWVJbnN0YW50PS IyMDA3LTEyLTEwVDExOjM5OjM0WiIgRm9yY2VBdXRobj0iZmFsc2UiDQogICAgSXNQYXNz aXZlPSJmYWxzZSINCiAgICBQcm90b2NvbEJpbmRpbmc9InVybjpvYXNpczpuYW1lczp0Yz pTQU1MOjIuMDpiaW5kaW5nczpIVFRQLVBPU1QiDQogICAgQXNzZXJ0aW9uQ29uc3VtZXJT ZXJ2aWNlVVJMPQ0KICAgICAgICAiaHR0cHM6Ly94bXBwLmV4YW1wbGUuY29tL1NBTUwvQX NzZXJ0aW9uQ29uc3VtZXJTZXJ2aWNlIj4NCiA8c2FtbDpJc3N1ZXIgeG1sbnM6c2FtbD0i dXJuOm9hc2lzOm5hbWVzOnRjOlNBTUw6Mi4wOmFzc2VydGlvbiI+DQogICAgIGh0dHBzOi 8veG1wcC5leGFtcGxlLmNvbQ0KIDwvc2FtbDpJc3N1ZXI+DQogPHNhbWxwOk5hbWVJRFBv bGljeSB4bWxuczpzYW1scD0idXJuOm9hc2lzOm5hbWVzOnRjOlNBTUw6Mi4wOnByb3RvY2 9sIg0KICAgICBGb3JtYXQ9InVybjpvYXNpczpuYW1lczp0YzpTQU1MOjIuMDpuYW1laWQt Zm9ybWF0OnBlcnNpc3RlbnQiDQogICAgIFNQTmFtZVF1YWxpZmllcj0ieG1wcC5leGFtcG xlLmNvbSIgQWxsb3dDcmVhdGU9InRydWUiIC8+DQogPHNhbWxwOlJlcXVlc3RlZEF1dGhu Q29udGV4dA0KICAgICB4bWxuczpzYW1scD0idXJuOm9hc2lzOm5hbWVzOnRjOlNBTUw6Mi 4wOnByb3RvY29sIiANCiAgICAgICAgQ29tcGFyaXNvbj0iZXhhY3QiPg0KICA8c2FtbDpB dXRobkNvbnRleHRDbGFzc1JlZg0KICAgICAgeG1sbnM6c2FtbD0idXJuOm9hc2lzOm5hbW VzOnRjOlNBTUw6Mi4wOmFzc2VydGlvbiI+DQogoCAgICB1cm46b2FzaXM6bmFtZXM6dGM6 U0FNTDoyLjA6YWM6Y2xhc3NlczpQYXNzd29yZFByb3RlY3RlZFRyYW5zcG9ydA0KICA8L3 NhbWw6QXV0aG5Db250ZXh0Q2xhc3NSZWY+DQogPC9zYW1scDpSZXF1ZXN0ZWRBdXRobkNv bnRleHQ+IA0KPC9zYW1scDpBdXRoblJlcXVlc3Q+
Where the decoded SAMLRequest looks like:
<samlp:AuthnRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" ID="_bec424fa5103428909a30ff1e31168327f79474984" Version="2.0" IssueInstant="2007-12-10T11:39:34Z" ForceAuthn="false" IsPassive="false" ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" AssertionConsumerServiceURL= "https://xmpp.example.com/SAML/AssertionConsumerService"> <saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"> https://xmpp.example.com </saml:Issuer> <samlp:NameIDPolicy xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:persistent" SPNameQualifier="xmpp.example.com" AllowCreate="true" /> <samlp:RequestedAuthnContext xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" Comparison="exact"> <saml:AuthnContextClassRef xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"> Ê urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport </saml:AuthnContextClassRef> </samlp:RequestedAuthnContext> </samlp:AuthnRequest>
Step 5 (alt): Server returns error to client:
<failure xmlns='urn:ietf:params:xml:ns:xmpp-sasl'> <incorrect-encoding/> </failure> </stream:stream>
Step 6: Client sends a BASE64 encoded empty response to the challenge:
<response xmlns='urn:ietf:params:xml:ns:xmpp-sasl'> = </response>
[ The client now sends the URL to a browser for processing. The browser engages in a normal SAML authentication flow (external to SASL), like redirection to the Identity Provider (https://saml.example.org), the user logs into https://saml.example.org, and agrees to authenticate to xmpp.example.com. A redirect is passed back to the client browser who sends the AuthN response to the server, containing the subject-identifier as an attribute. If the AuthN response doesn't contain the JID, the server maps the subject-identifier received from the IdP to a JID]
Step 7: Server informs client of successful authentication:
Step 7 (alt): Server informs client of failed authentication:
<failure xmlns='urn:ietf:params:xml:ns:xmpp-sasl'> <temporary-auth-failure/> </failure> </stream:stream>
Step 8: Client initiates a new stream to server:
<stream:stream xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' to='example.com' version='1.0'>
Step 9: Server responds by sending a stream header to client along with any additional features (or an empty features element):
<stream:stream xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' id='c2s_345' from='example.com' version='1.0'> <stream:features> <bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'/> <session xmlns='urn:ietf:params:xml:ns:xmpp-session'/> </stream:features>
Step 10: Client binds a resource:
<iq type='set' id='bind_1'> <bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'> <resource>someresource</resource> </bind> </iq>
Step 11: Server informs client of successful resource binding:
<iq type='result' id='bind_1'> <bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'> <jid>firstname.lastname@example.org/someresource</jid> </bind> </iq>
Please note: line breaks were added to the base64 for clarity.
This section will address only security considerations associated with the use of SAML with SASL applications. For considerations relating to SAML in general, the reader is referred to the SAML specification and to other literature. Similarly, for general SASL Security Considerations, the reader is referred to that specification.
As specified in [RFC4422] (Melnikov, A. and K. Zeilenga, “Simple Authentication and Security Layer (SASL),” June 2006.), the server is responsible for binding credentials to a specific authorization identity. It is therefore necessary that only specific trusted IdPs be allowed. This is typical part of SAML trust establishment between RP's and IdP.
The IdP is aware of each RP that a user logs into. There is nothing in the protocol to hide this information from the IdP. It is not a requirement to track the visits, but there is nothing that prohibits the collection of information. SASL servers should be aware that SAML IdPs will track - to some extent - user access to their services.
It is possible for RPs to link data that they have collected on you. By using the same identifier to log into every RP, collusion between RPs is possible. In SAML, targeted identity was introduced. Targeted identity allows the IdP to transform the identifier the user typed in to an opaque identifier. This way the RP would never see the actual user identifier, but a randomly generated identifier. This is an option the user has to understand and decide to use if the IdP is supporting it.
The IANA is requested to register the following SASL profile:
SASL mechanism profile: SAML20
Security Considerations: See this document
Published Specification: See this document
For further information: Contact the authors of this document.
Owner/Change controller: the IETF
|[I-D.ietf-sasl-gs2]||Josefsson, S. and N. Williams, “Using GSS-API Mechanisms in SASL: The GS2 Mechanism Family,” draft-ietf-sasl-gs2-20 (work in progress), January 2010 (TXT).|
|[OASIS.saml-bindings-2.0-os]||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.|
|[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.|
|[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.|
|[RFC2119]||Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” BCP 14, RFC 2119, March 1997 (TXT, HTML, XML).|
|[RFC2616]||Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, “Hypertext Transfer Protocol -- HTTP/1.1,” RFC 2616, June 1999 (TXT, PS, PDF, HTML, XML).|
|[RFC2743]||Linn, J., “Generic Security Service Application Program Interface Version 2, Update 1,” RFC 2743, January 2000 (TXT).|
|[RFC3986]||Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” STD 66, RFC 3986, January 2005 (TXT, HTML, XML).|
|[RFC4422]||Melnikov, A. and K. Zeilenga, “Simple Authentication and Security Layer (SASL),” RFC 4422, June 2006 (TXT).|
|[RFC4648]||Josefsson, S., “The Base16, Base32, and Base64 Data Encodings,” RFC 4648, October 2006 (TXT).|
The authors would like to thank Scott Cantor, Joe Hildebrand, Josh Howlett, Leif Johansson, Simon Josefsson, Diego Lopez, Hank Mauldin, RL 'Bob' Morgan and Hannes Tschofenig for their review and contributions.
This section to be removed prior to publication.
|Cisco Systems, Inc.|
|Amsterdam, Noord-Holland 1101 CH|
|Phone:||+31 20 357 1752|
|Cisco Systems GmbH|
|Wallisellen, ZH CH-8304|
|Phone:||+41 44 878 9200|