KITTEN W. Mills Internet-Draft Yahoo! Inc. Intended status: Standards Track T. Showalter Expires: June 18, 2014 H. Tschofenig Nokia Solutions and Networks December 15, 2013 A set of SASL Mechanisms for OAuth draft-ietf-kitten-sasl-oauth-12.txt Abstract OAuth enables a third-party application to obtain limited access to a protected resource, either on behalf of a resource owner by orchestrating an approval interaction, or by allowing the third-party application to obtain access on its own behalf. This document defines how an application client uses credentials obtained via OAuth over the Simple Authentication and Security Layer (SASL) to access a protected resource at a resource serve. Thereby, it enables schemes defined within the OAuth framework for non-HTTP- based application protocols. Clients typically store the user's long-term credential. This does, however, lead to significant security vulnerabilities, for example, when such a credential leaks. A significant benefit of OAuth for usage in those clients is that the password is replaced by a shared secret with higher entropy, i.e., the token. Tokens typically provide limited access rights and can be managed and revoked separately from the user's long-term password. 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." Mills, et al. Expires June 18, 2014 [Page 1] Internet-Draft SASL OAuth December 2013 This Internet-Draft will expire on June 18, 2014. Copyright Notice Copyright (c) 2013 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. OAuth SASL Mechanism Specifications . . . . . . . . . . . . . 6 3.1. Initial Client Response . . . . . . . . . . . . . . . . . 7 3.1.1. Reserved Key/Values . . . . . . . . . . . . . . . . . 7 3.2. Server's Response . . . . . . . . . . . . . . . . . . . . 8 3.2.1. OAuth Identifiers in the SASL Context . . . . . . . . 8 3.2.2. Server Response to Failed Authentication . . . . . . 8 3.2.3. Completing an Error Message Sequence . . . . . . . . 9 3.3. OAuth Access Token Types using Keyed Message Digests . . 9 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.1. Successful Bearer Token Exchange . . . . . . . . . . . . 11 4.2. Failed Exchange . . . . . . . . . . . . . . . . . . . . . 11 4.3. SMTP Example of a Failed Negotiation . . . . . . . . . . 12 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 6. Internationalization Considerations . . . . . . . . . . . . . 14 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 7.1. SASL Registration . . . . . . . . . . . . . . . . . . . . 14 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1. Normative References . . . . . . . . . . . . . . . . . . 15 8.2. Informative References . . . . . . . . . . . . . . . . . 16 Appendix A. Acknowlegements . . . . . . . . . . . . . . . . . . 16 Appendix B. Document History . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 1. Introduction OAuth 1.0a [RFC5849] and OAuth 2.0 [RFC6749] are protocol frameworks that enable a third-party application to obtain limited access to a Mills, et al. Expires June 18, 2014 [Page 2] Internet-Draft SASL OAuth December 2013 protected resource, either on behalf of a resource owner by orchestrating an approval interaction, or by allowing the third-party application to obtain access on its own behalf. The core OAuth 2.0 specification [RFC6749] specifies the interaction between the OAuth client and the authorization server; it does not define the interaction between the OAuth client and the resource server for the access to a protected resource using an Access Token. Instead, the OAuth client to resource server interaction is described in separate specifications, such as the bearer token specification [RFC6750] and the MAC Token specification [I-D.ietf-oauth-v2-http-mac]. OAuth 1.0a included the protocol specification for the communication between the OAuth client and the resource server in [RFC5849]. The main use cases for OAuth 2.0 and OAuth 1.0a have so far focused on an HTTP-based environment only. This document integrates OAuth 1.0a and OAuth 2.0 into non-HTTP-based applications using the integration into SASL. Hence, this document takes advantage of the OAuth protocol and its deployment base to provide a way to use the Simple Authentication and Security Layer (SASL) [RFC4422] to gain access to resources when using non-HTTP-based protocols, such as the Internet Message Access Protocol (IMAP) [RFC3501] and SMTP [RFC5321], which is what this memo uses in the examples. To illustrate the impact of integrating this specification into an OAuth-enabled application environment Figure 1 shows the abstract message flow of OAuth 2.0 [RFC6749]. As indicated in the figure, this document impacts the exchange of messages (E) and (F) since SASL is used for interaction between the client and the resource server instead of HTTP. Mills, et al. Expires June 18, 2014 [Page 3] Internet-Draft SASL OAuth December 2013 ----+ +--------+ +---------------+ | | |--(A)-- Authorization Request --->| Resource | | | | | Owner | |Plain | |<-(B)------ Access Grant ---------| | |OAuth | | +---------------+ |2.0 | | | | | Client Credentials & +---------------+ | | |--(C)------ Access Grant -------->| Authorization | | | Client | | Server | | | |<-(D)------ Access Token ---------| | | | | (w/ Optional Refresh Token) +---------------+ | | | ----+ | | ----+ | | +---------------+ | | | | | |OAuth | |--(E)------ Access Token -------->| Resource | |over | | | Server | |SASL | |<-(F)---- Protected Resource -----| | | | | | | | +--------+ +---------------+ | ----+ Figure 1: OAuth 2.0 Protocol Flow The Simple Authentication and Security Layer (SASL) is a framework for providing authentication and data security services in connection-oriented protocols via replaceable authentication mechanisms. It provides a structured interface between protocols and mechanisms. The resulting framework allows new protocols to reuse existing authentication protocols and allows old protocols to make use of new authentication mechanisms. The framework also provides a protocol for securing subsequent protocol exchanges within a data security layer. When OAuth is integrated into SASL the high-level steps are as follows: (A) The client requests authorization from the resource owner. The authorization request can be made directly to the resource owner (as shown), or preferably indirectly via the authorization server as an intermediary. Mills, et al. Expires June 18, 2014 [Page 4] Internet-Draft SASL OAuth December 2013 (B) The client receives an authorization grant which is a credential representing the resource owner's authorization, expressed using one of four grant types defined in this specification or using an extension grant type. The authorization grant type depends on the method used by the client to request authorization and the types supported by the authorization server. (C) The client requests an access token by authenticating with the authorization server and presenting the authorization grant. (D) The authorization server authenticates the client and validates the authorization grant, and if valid issues an access token. (E) The client requests the protected resource from the resource server and authenticates by presenting the access token. (F) The resource server validates the access token, and if valid, indicates a successful authentication. Again, steps (E) and (F) are not defined in [RFC6749] (but are described in, for example, [RFC6750] for the OAuth Bearer Token instead) and are the main functionality specified within this document. Consequently, the message exchange shown in Figure 1 is the result of this specification. The client will generally need to determine the authentication endpoints (and perhaps the service endpoints) before the OAuth 2.0 protocol exchange messages in steps (A)-(D) are executed. The discovery of the resource owner and authorization server endpoints is outside the scope of this specification. The client must discover those endpoints using a discovery mechanisms, such as Webfinger using host-meta [RFC7033]. In band discovery is not tenable if clients support the OAuth 2.0 password grant. Once credentials are obtained the client proceeds to steps (E) and (F) defined in this specification. OAuth 1.0 follows a similar model but uses a different terminology and does not separate the resource server from the authorization server. 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]. The reader is assumed to be familiar with the terms used in the OAuth 2.0 specification [RFC6749]. Mills, et al. Expires June 18, 2014 [Page 5] Internet-Draft SASL OAuth December 2013 In examples, "C:" and "S:" indicate lines sent by the client and server respectively. Line breaks have been inserted for readability. Note that the IMAP SASL specification requires base64 encoding, see Section 4 of [RFC4648], not this memo. 3. OAuth SASL Mechanism Specifications SASL is used as an authentication framework in a variety of application layer protocols. This document defines the following SASL mechanisms for usage with OAuth: OAUTHBEARER: OAuth 2.0 bearer tokens, as described in [RFC6750]. RFC 6750 uses Transport Layer Security (TLS) to secure the protocol interaction between the client and the resource server. OAUTH10A: OAuth 1.0a MAC tokens (using the HMAC-SHA1 keyed message digest), as described in Section 3.4.2 of [RFC5849]. New extensions may be defined to add additional OAuth Access Token Types. Such a new SASL OAuth mechanism can be added by simply registering the new name(s) and citing this specification for the further definition. These mechanisms are client initiated and lock-step, the server always replying to a client message. In the case where the client has and correctly uses a valid token the flow is: o Client sends a valid and correct initial client response. o Server responds with a successful authentication. In the case where authorization fails the server sends an error result, then client MUST then send an additional message to the server in order to allow the server to finish the exchange. Some protocols and common SASL implementations do not support both sending a SASL message and finalizing a SASL negotiation, the additional client message in the error case deals with this problem. This exchange is: o Client sends an invalid initial client response. o Server responds with an error message. o Client sends a dummy client response. Mills, et al. Expires June 18, 2014 [Page 6] Internet-Draft SASL OAuth December 2013 o Server fails the authentication. 3.1. Initial Client Response Client responses are a key/value pair sequence. These key/value pairs carry the equivalent values from an HTTP context in order to be able to complete an OAuth style HTTP authorization. Unknown key/ value pairs MUST be ignored by the server. The ABNF [RFC5234] syntax is: kvsep = %x01 key = 1*ALPHA value = *(VCHAR / SP / HTAB / CR / LF ) kvpair = key "=" value kvsep client_resp = 0*kvpair kvsep The following key/value pairs are defined in the client response: auth (REQUIRED): The payload of the HTTP Authorization header for an equivalent HTTP OAuth authorization. host: Contains the host name to which the client connected. port: Contains the port number represented as a decimal positive integer string without leading zeros to which the client connected. qs: The HTTP query string. This is reserved for future use, the client SHOUD NOT send it, and has the default value of "". For OAuth token types that use keyed message digests the client MUST send host and port number key/values, and the server MUST fail an authorization request requiring keyed message digests that do not have host and port values. In OAuth 1.0a for example, the so-called "signature base string calculation" includes the reconstructed HTTP URL. 3.1.1. Reserved Key/Values Mills, et al. Expires June 18, 2014 [Page 7] Internet-Draft SASL OAuth December 2013 In these mechanisms values for path, query string and post body are assigned default values. OAuth authorization schemes MAY define usage of these in the SASL context and extend this specification. For OAuth Access Token Types that use request keyed message digest the default values MUST be used unless explicit values are provided in the client response. The following key values are reserved for future use: mthd (RESERVED): HTTP method, the default value is "POST". path (RESERVED): HTTP path data, the default value is "/". post (RESERVED): HTTP post data, the default value is "". 3.2. Server's Response The server validates the response per the specification for the OAuth Access Token Types used. If the OAuth Access Token Type utilizes a keyed message digest of the request parameters then the client must provide a client response that satisfies the data requirements for the scheme in use. The server responds to a successfully verified client message by completing the SASL negotiation. The authenticated identity reported by the SASL mechanism is the identity securely established for the client with the OAuth credential. The application, not the SASL mechanism, based on local access policy determines whether the identity reported by the mechanism is allowed access to the requested resource. Note that the semantics of the authz-id is specified by the SASL framework [RFC4422]. 3.2.1. OAuth Identifiers in the SASL Context In the OAuth framework the client may be authenticated by the authorization server and the resource owner is authenticated to the authorization server. OAuth access tokens may contain information about the authentication of the resource owner and about the client and may therefore make this information accessible to the resource server. If both identifiers are needed by an application the developer will need to provide a way to communicate that from the SASL mechanism back to the application. 3.2.2. Server Response to Failed Authentication Mills, et al. Expires June 18, 2014 [Page 8] Internet-Draft SASL OAuth December 2013 For a failed authentication the server returns a JSON [RFC4627] formatted error result, and fails the authentication. The error result consists of the following values: status (REQUIRED): The authorization error code. Valid error codes are defined in the IANA [[need registry name]] registry specified in the OAuth 2 core specification. scope (OPTIONAL): An OAuth scope which is valid to access the service. This may be empty which implies that unscoped tokens are required, or a space separated list. Use of a space separated list is NOT RECOMMENDED. If the resource server provides a scope then the client MUST always request scoped tokens from the token endpoint. If the resource server provides no scope to the client then the client SHOULD presume an empty scope (unscoped token) is needed. If channel binding is in use and the channel binding fails the server responds with a status code set to 412 to indicate that the channel binding precondition failed. If the authentication scheme in use does not include signing the server SHOULD revoke the presented credential and the client SHOULD discard that credential. 3.2.3. Completing an Error Message Sequence Section 3.6 of [RFC4422] explicitly prohibits additional information in an unsuccessful authentication outcome. Therefore, the error message is sent in a normal message. The client MUST then send an additional client response consisting of a single %x01 (control A) character to the server in order to allow the server to finish the exchange. 3.3. OAuth Access Token Types using Keyed Message Digests OAuth Access Token Types may use keyed message digests and the client and the resource server may need to perform a cryptographic computation for integrity protection and data origin authentication. OAuth is designed for access to resources identified by URIs. SASL is designed for user authentication, and has no facility for more fine-grained access control. In this specification we require or define default values for the data elements from an HTTP request which allow the signature base string to be constructed properly. The default HTTP path is "/" and the default post body is empty. These atoms are defined as extension points so that no changes are Mills, et al. Expires June 18, 2014 [Page 9] Internet-Draft SASL OAuth December 2013 needed if there is a revision of SASL which supports more specific resource authorization, e.g., IMAP access to a specific folder or FTP access limited to a specific directory. Using the example in the OAuth 1.0a specification as a starting point, on an IMAP server running on port 143 and given the OAuth 1.0a style authorization request (with %x01 shown as ^A and line breaks added for readability) below: n,a=user@example.com^A host=example.com^A user=user@example.com^A port=143^A auth=OAuth realm="Example", oauth_consumer_key="9djdj82h48djs9d2", oauth_token="kkk9d7dh3k39sjv7", oauth_signature_method="HMAC-SHA1", oauth_timestamp="137131201", oauth_nonce="7d8f3e4a", oauth_signature="Tm90IGEgcmVhbCBzaWduYXR1cmU%3D"^A^A The signature base string would be constructed per the OAuth 1.0 specification [RFC5849] with the following things noted: o The method value is defaulted to POST. o The scheme defaults to be "http", and any port number other than 80 is included. o The path defaults to "/". o The query string defaults to "". In this example the signature base string with line breaks added for readability would be: POST&http%3A%2F%2Fexample.com:143%2F&oauth_consumer_key%3D9djdj82h4 8djs9d2%26oauth_nonce%3D7d8f3e4a%26oauth_signature_method%3DHMAC-SH A1%26oauth_timestamp%3D137131201%26oauth_token%3Dkkk9d7dh3k39sjv7 4. Examples These examples illustrate exchanges between an IMAP and SMTP clients and servers. Note to implementers: The SASL OAuth method names are case insensitive. One example uses "Bearer" but that could as easily be "bearer", "BEARER", or "BeArEr". Mills, et al. Expires June 18, 2014 [Page 10] Internet-Draft SASL OAuth December 2013 4.1. Successful Bearer Token Exchange This example shows a successful OAuth 2.0 bearer token exchange. Note that line breaks are inserted for readability and the underlying TLS establishment is not shown either. S: * OK IMAP4rev1 Server Ready C: t0 CAPABILITY S: * CAPABILITY IMAP4rev1 AUTH=OAUTHBEARER SASL-IR S: t0 OK Completed C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20BaG9zdD1zZX J2ZXIuZXhhbXBsZS5jb20BcG9ydD0xNDMBYXV0aD1CZWFyZXIgdkY5ZGZ0NHFtV GMyTnZiM1JsY2tCaGJIUmhkbWx6ZEdFdVkyOXRDZz09AQE= S: t1 OK SASL authentication succeeded As required by IMAP [RFC3501], the payloads are base64-encoded. The decoded initial client response (with %x01 represented as ^A and long lines wrapped for readability) is: n,a=user@example.com^Ahost=server.example.com^Aport=143^A auth=Bearer vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg==^A^A The same credential used in an SMTP exchange is shown below. Note that line breaks are inserted for readability, and that the SMTP protocol terminates lines with CR and LF characters (ASCII values 0x0D and 0x0A), these are not displayed explicitly in the example. [connection begins] S: 220 mx.example.com ESMTP 12sm2095603fks.9 C: EHLO sender.example.com S: 250-mx.example.com at your service,[172.31.135.47] S: 250-SIZE 35651584 S: 250-8BITMIME S: 250-AUTH LOGIN PLAIN OAUTHBEARER S: 250-ENHANCEDSTATUSCODES S: 250 PIPELINING C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20BaG9zdD1zZX J2ZXIuZXhhbXBsZS5jb20BcG9ydD0xNDMBYXV0aD1CZWFyZXIgdkY5ZGZ0NHFtV GMyTnZiM1JsY2tCaGJIUmhkbWx6ZEdFdVkyOXRDZz09AQE= S: 235 Authentication successful. [connection continues...] 4.2. Failed Exchange This example shows a failed exchange because of the empty Authorization header, which is how a client can query for the needed scope. Note that line breaks are inserted for readability. Mills, et al. Expires June 18, 2014 [Page 11] Internet-Draft SASL OAuth December 2013 S: * CAPABILITY IMAP4rev1 AUTH=OAUTHBEARER SASL-IR IMAP4rev1 Server Ready S: t0 OK Completed C: t1 AUTHENTICATE OAUTHBEARER cD10bHMtdW5pcXVlLGE9dXNlckBleGFtcG xlLmNvbQFob3N0PXNlcnZlci5leGFtcGxlLmNvbQFwb3J0PTE0MwFhdXRoP QFjYmRhdGE9AQE= S: + ewoic3RhdHVzIjoiNDAxIgoic2NvcGUiOiJleGFtcGxlX3Njb3BlIgp9 C: + AQ== S: t1 NO SASL authentication failed The decoded initial client response is: n,a=user@example.com,^Ahost=server.example.com^A port=143^Aauth=^A^A The decoded server error response is: { "status":"401", "scope":"example_scope" } The client responds with the required dummy response. 4.3. SMTP Example of a Failed Negotiation This example shows an authorization failure in an SMTP exchange. Note that line breaks are inserted for readability, and that the SMTP protocol terminates lines with CR and LF characters (ASCII values 0x0D and 0x0A), these are not displayed explicitly in the example. [connection begins] S: 220 mx.example.com ESMTP 12sm2095603fks.9 C: EHLO sender.example.com S: 250-mx.example.com at your service,[172.31.135.47] S: 250-SIZE 35651584 S: 250-8BITMIME S: 250-AUTH LOGIN PLAIN OAUTHBEARER S: 250-ENHANCEDSTATUSCODES S: 250 PIPELINING C: AUTH OAUTHBEARER bixhPT1zb21ldXNlckBleGFtcGxlLmNvbQFhdXRoPUJlYXJlciB2 RjlkZnQ0cW1UYzJOdmIzUmxja0JoZEhSaGRtbHpkR0V1WTI5dENnPT0BAQ== S: 334 eyJzdGF0dXMiOiI0MDEiLCJzY2hlbWVzIjoiYmVhcmVyIG1hYyIsInNjb3BlIjoia HR0cHM6Ly9tYWlsLmdvb2dsZS5jb20vIn0K C: AQ== S: 535-5.7.1 Username and Password not accepted. Learn more at S: 535 5.7.1 http://support.example.com/mail/oauth [connection continues...] Mills, et al. Expires June 18, 2014 [Page 12] Internet-Draft SASL OAuth December 2013 The server returned an error message in the 334 SASL message, the client responds with the required dummy response, and the server finalizes the negotiation. 5. Security Considerations OAuth 1.0a and OAuth 2 allows for a variety of deployment scenarios, and the security properties of these profiles vary. As shown in Figure 1 this specification is aimed to be integrated into a larger OAuth deployment. Application developers therefore need to understand the needs of their security requirements based on a threat assessment before selecting a specific SASL OAuth mechanism. For OAuth 2.0 a detailed security document [RFC6819] provides guidance to select those OAuth 2.0 components that help to mitigate threats for a given deployment. For OAuth 1.0a Section 4 of RFC 5849 [RFC5849] provides guidance specific to OAuth 1.0. This document specifies three SASL Mechanisms for OAuth and each comes with different security properties. OAUTHBEARER: This mechanism borrows from OAuth 2.0 bearer tokens [RFC6750]. It relies on the application using TLS to protect the OAuth 2.0 Bearer Token exchange; without TLS usage at the application layer this method is completely insecure. Consequently, TLS MUST be provided by the application when choosing this authentication mechanism. OAUTH10A: This mechanism re-uses OAuth 1.0a MAC tokens (using the HMAC-SHA1 keyed message digest), as described in Section 3.4.2 of [RFC5849]. To compute the keyed message digest in the same way was in RFC 5839 this specification conveys additional parameters between the client and the server. This SASL mechanism only supports client authentication. If server-side authentication is desireable then it must be provided by the application underneath the SASL layer. The use of TLS is strongly RECOMMENDED. Additionally, the following aspects are worth pointing out: An access token is not equivalent to the user's long term password. Care has to be taken when these OAuth credentials are used for actions like changing passwords (as it is possible with some protocols, e.g., XMPP). The resource server should ensure that actions taken in the authenticated channel are appropriate to the strength of the presented credential. Lifetime of the appliation sessions. Mills, et al. Expires June 18, 2014 [Page 13] Internet-Draft SASL OAuth December 2013 It is possible that SASL will be authenticating a connection and the life of that connection may outlast the life of the access token used to establish it. This is a common problem in application protocols where connections are long-lived, and not a problem with this mechanism per se. Resource servers may unilaterally disconnect clients in accordance with the application protocol. Access tokens have a lifetime. Reducing the lifetime of an access token provides security benefits and OAuth 2.0 introduces refresh tokens to obtain new access token on the fly without any need for a human interaction. Additionally, a previously obtained access token may be revoked or rendered invalid at any time by the authorization server. The client may request a new access token for each connection to a resource server, but it should cache and re-use valid credentials. 6. Internationalization Considerations The identifer asserted by the OAuth authorization server about the resource owner inside the access token may be displayed to a human. For example, when SASL is used in the context of IMAP the resource server may assert the resource owner's email address to the IMAP server for usage in an email-based application. The identifier may therefore contain internationalized characters and an application needs to ensure that the mapping between the identifier provided by OAuth is suitable for use with the application layer protocol SASL is incorporated into. At the time of writing the standardization of the various claims in the access token (in JSON format) is still ongoing, see [I-D.ietf-oauth-json-web-token]. Once completed it will provide a standardized format for exchanging identity information between the authorization server and the resource server. 7. IANA Considerations 7.1. SASL Registration The IANA is requested to register the following SASL profile: SASL mechanism profile: OAUTHBEARER Security Considerations: See this document Published Specification: See this document Mills, et al. Expires June 18, 2014 [Page 14] Internet-Draft SASL OAuth December 2013 For further information: Contact the authors of this document. Owner/Change controller: the IETF Note: None The IANA is requested to register the following SASL profile: SASL mechanism profile: OAUTH10A Security Considerations: See this document Published Specification: See this document For further information: Contact the authors of this document. Owner/Change controller: the IETF Note: None 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3174] Eastlake, D. and P. Jones, "US Secure Hash Algorithm 1 (SHA1)", RFC 3174, September 2001. [RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and Security Layer (SASL)", RFC 4422, June 2006. [RFC4627] Crockford, D., "The application/json Media Type for JavaScript Object Notation (JSON)", RFC 4627, July 2006. [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, October 2006. [RFC5056] Williams, N., "On the Use of Channel Bindings to Secure Channels", RFC 5056, November 2007. [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008. [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, August 2008. Mills, et al. Expires June 18, 2014 [Page 15] Internet-Draft SASL OAuth December 2013 [RFC5849] Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849, April 2010. [RFC6749] Hardt, D., "The OAuth 2.0 Authorization Framework", RFC 6749, October 2012. [RFC6750] Jones, M. and D. Hardt, "The OAuth 2.0 Authorization Framework: Bearer Token Usage", RFC 6750, October 2012. 8.2. Informative References [I-D.ietf-oauth-json-web-token] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token (JWT)", draft-ietf-oauth-json-web-token-13 (work in progress), November 2013. [I-D.ietf-oauth-v2-http-mac] Richer, J., Mills, W., Tschofenig, H., and P. Hunt, "OAuth 2.0 Message Authentication Code (MAC) Tokens", draft-ietf- oauth-v2-http-mac-04 (work in progress), July 2013. [RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1", RFC 3501, March 2003. [RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321, October 2008. [RFC6819] Lodderstedt, T., McGloin, M., and P. Hunt, "OAuth 2.0 Threat Model and Security Considerations", RFC 6819, January 2013. [RFC7033] Jones, P., Salgueiro, G., Jones, M., and J. Smarr, "WebFinger", RFC 7033, September 2013. Appendix A. Acknowlegements The authors would like to thank the members of the Kitten working group, and in addition and specifically: Simon Josefson, Torsten Lodderstadt, Ryan Troll, Alexey Melnikov, Jeffrey Hutzelman, and Nico Williams. This document was produced under the chairmanship of Alexey Melnikov, Tom Yu, Shawn Emery, Josh Howlett, Sam Hartman. The supervising area directors was Stephen Farrell. Appendix B. Document History [[ to be removed by RFC editor before publication as an RFC ]] Mills, et al. Expires June 18, 2014 [Page 16] Internet-Draft SASL OAuth December 2013 -12 o Removed -PLUS components from the specification. -11 o Removed GSS-API components from the specification. o Updated security consideration section. -10 o Clarifications throughout the document in response to the feedback from Jeffrey Hutzelman. -09 o Incorporated review by Alexey and Hannes. o Clarified the three OAuth SASL mechanisms. o Updated references o Extended acknowledgements -08 o Fixed the channel binding examples for p=$cbtype o More tuning of the authcid language and edited and renamed 3.2.1. -07 o Struck the MUST langiage from authzid. o -06 o Removed the user field. Fixed the examples again. o Added canonicalization language. o -05 o Fixed the GS2 header language again. Mills, et al. Expires June 18, 2014 [Page 17] Internet-Draft SASL OAuth December 2013 o Separated out different OAuth schemes into different SASL mechanisms. Took out the scheme in the error return. Tuned up the IANA registrations. o Added the user field back into the SASL message. o Fixed the examples (again). o -04 o Changed user field to be carried in the gs2-header, and made gs2 header explicit in all cases. o Converted MAC examples to OAuth 1.0a. Moved MAC to an informative reference. o Changed to sending an empty client response (single control-A) as the second message of a failed sequence. o Fixed channel binding prose to refer to the normative specs and removed the hashing of large channel binding data, which brought mroe problems than it solved. o Added a SMTP examples for Bearer use case. -03 o Added user field into examples and fixed egregious errors there as well. o Added text reminding developers that Authorization scheme names are case insensitive. -02 o Added the user data element back in. o Minor editorial changes. -01 o Ripping out discovery. Changed to refer to I-D.jones-appsawg- webfinger instead of WF and SWD older drafts. o Replacing HTTP as the message format and adjusted all examples. Mills, et al. Expires June 18, 2014 [Page 18] Internet-Draft SASL OAuth December 2013 -00 o Renamed draft into proper IETF naming format now that it's adopted. o Minor fixes. Authors' Addresses William Mills Yahoo! Inc. Email: wmills_92105@yahoo.com Tim Showalter Email: tjs@psaux.com Hannes Tschofenig Nokia Solutions and Networks Linnoitustie 6 Espoo 02600 Finland Phone: +358 (50) 4871445 Email: Hannes.Tschofenig@gmx.net URI: http://www.tschofenig.priv.at Mills, et al. Expires June 18, 2014 [Page 19]