--- 1/draft-ietf-kitten-sasl-oauth-14.txt 2014-07-22 23:14:29.988115472 -0700 +++ 2/draft-ietf-kitten-sasl-oauth-15.txt 2014-07-22 23:14:30.028116442 -0700 @@ -1,21 +1,21 @@ KITTEN W. Mills -Internet-Draft Yahoo! Inc. +Internet-Draft Skype Intended status: Standards Track T. Showalter -Expires: September 7, 2014 +Expires: January 23, 2015 H. Tschofenig ARM Ltd. - March 6, 2014 + July 22, 2014 A set of SASL Mechanisms for OAuth - draft-ietf-kitten-sasl-oauth-14.txt + draft-ietf-kitten-sasl-oauth-15.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 @@ -38,21 +38,21 @@ 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 September 7, 2014. + This Internet-Draft will expire on January 23, 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 @@ -67,34 +67,35 @@ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. OAuth SASL Mechanism Specifications . . . . . . . . . . . . . 6 3.1. Initial Client Response . . . . . . . . . . . . . . . . . 7 3.1.1. Reserved Key/Values . . . . . . . . . . . . . . . . . 8 3.2. Server's Response . . . . . . . . . . . . . . . . . . . . 8 3.2.1. OAuth Identifiers in the SASL Context . . . . . . . . 8 3.2.2. Server Response to Failed Authentication . . . . . . 9 3.2.3. Completing an Error Message Sequence . . . . . . . . 9 3.3. OAuth Access Token Types using Keyed Message Digests . . 9 - 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 10 + 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 11 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 . . . . . . . . . . . . . . . . . . 17 - Appendix B. Document History . . . . . . . . . . . . . . . . . . 17 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 + 4.2. Successful OAuth 1.0a Token Exchange . . . . . . . . . . 12 + 4.3. Failed Exchange . . . . . . . . . . . . . . . . . . . . . 13 + 4.4. SMTP Example of a Failed Negotiation . . . . . . . . . . 13 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 + 6. Internationalization Considerations . . . . . . . . . . . . . 15 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 + 7.1. SASL Registration . . . . . . . . . . . . . . . . . . . . 16 + 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 + 8.1. Normative References . . . . . . . . . . . . . . . . . . 16 + 8.2. Informative References . . . . . . . . . . . . . . . . . 17 + Appendix A. Acknowlegements . . . . . . . . . . . . . . . . . . 18 + Appendix B. Document History . . . . . . . . . . . . . . . . . . 18 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 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 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 @@ -164,22 +165,22 @@ 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. (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 + expressed using one of the grant types defined in [RFC6749] or + [RFC5849] 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. @@ -261,48 +262,45 @@ 1. Client sends an invalid initial client response. 2. Server responds with an error message. 3. Client sends a dummy client response. 4. Server fails the authentication. 3.1. Initial Client Response - Client responses are a key/value pair sequence. The initial client - response includes a gs2-header as defined in GS2 [RFC5801] which is - defined here as a stub for compatibility with GS2 if a GS2 mechanism - is formally defined, but this document does not define one. 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: + Client responses are a GS2 [RFC5801] header followed by a key/value + pair sequence, or may be empty. The gs2-header is defined here for + compatibility with GS2 if a GS2 mechanism is formally defined, but + this document does not define one. 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 - gs2-header = ALPHA "," value - client_resp = gs2-header kvsep 0*kvpair kvsep + ;;gs2-header = See RFC 5801 + client_resp = (gs2-header kvsep 0*kvpair kvsep) / kvsep - The GS2 + The GS2 header MAY include the user name associated with the resource + being accessed, the "authzid". It is worth noting that application + protocols are allowed to require an authzid, as are specific server + implementations. 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. - user (REQUIRED): Contains the user name being authenticated. The - server MAY use this as a routing or database lookup hint. The - server MUST NOT use this as authoritative, the user name MUST - be asserted by the OAuth credential. - 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 @@ -367,20 +365,29 @@ status (REQUIRED): The authorization error code. Valid error codes are defined in the IANA "OAuth Extensions Error 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 scope value. If a scope is specified then a single scope is preferred, use of a space separated list of scopes is NOT RECOMMENDED. + oauth-configuration (OPTIONAL): The URL for for a document + following the OpenID Provider Configuration Information schema + as described in OpenID Connect Discovery [OpenID.Discovery] + section 3 that is appropriate for the user. This document MUST + have all OAuth related data elements populated. The server MAY + return different URLs for users in different domains and the + client SHOULD NOT cache a single returned value and assume it + applies for all users/domains that the server suports. + 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. 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 @@ -403,31 +410,30 @@ These atoms are defined as extension points so that no changes are 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 + 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 + oauth_signature="Tm90IGEgcmVhbCBzaWduYXR1cmU"^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 "/". @@ -453,105 +459,144 @@ 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 biwBdXNlcj11c2VyQGV4YW1wbGUuY29tAWhvc3Q9c2Vyd - mVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk52YjN - SbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB + C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2 + VydmVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDRxb + VRjMk52YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB 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,^Auser=user@example.com^Ahost=server.example.com^Aport=143^A + 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 biwBdXNlcj11c2VyQGV4YW1wbGUuY29tAWhvc - 3Q9c2VydmVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWR - mdDRxbVRjMk52YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB + C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c + 2VydmVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDR + xbVRjMk52YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB S: 235 Authentication successful. [connection continues...] -4.2. Failed Exchange +4.2. Successful OAuth 1.0a Token Exchange + + This example shows a successful OAuth 1.0a token exchange. Note that + line breaks are inserted for readability and the underlying TLS + establishment is not shown. Signature computation is discussed in + Section 3.3. + + S: * OK IMAP4rev1 Server Ready + C: t0 CAPABILITY + S: * CAPABILITY IMAP4rev1 AUTH=OAUTHBEARER OAUTH10A SASL-IR + S: t0 OK Completed + C: t1 AUTHENTICATE OAUTH10A bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9ZXhhb + XBsZS5jb20BcG9ydD0xNDMBYXV0aD1PQXV0aCByZWFsbT0iRXhhbXBsZSIsb2F1 + dGhfY29uc3VtZXJfa2V5PSI5ZGpkajgyaDQ4ZGpzOWQyIixvYXV0aF90b2tlbj0 + ia2trOWQ3ZGgzazM5c2p2NyIsb2F1dGhfc2lnbmF0dXJlX21ldGhvZD0iSE1BQy + 1TSEExIixvYXV0aF90aW1lc3RhbXA9IjEzNzEzMTIwMSIsb2F1dGhfbm9uY2U9I + jdkOGYzZTRhIixvYXV0aF9zaWduYXR1cmU9IlRtOTBJR0VnY21WaGJDQnphV2R1 + WVhSMWNtVSUzRCIBAQ== + 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 + lines wrapped for readability) is: + + n,a=user@example.com,^A + host=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="SSdtIGEgbGl0dGxlIHRlYSBwb3Qu"^A^A + +4.3. 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. S: * CAPABILITY IMAP4rev1 AUTH=OAUTHBEARER SASL-IR IMAP4rev1 Server Ready S: t0 OK Completed -C: t1 AUTHENTICATE OAUTHBEARER biwBdXNlcj11c2VyQGV4YW1wbGUuY29tAWhvc3Q9c2Vyd - mVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AWNiZGF0YT0BAQ== -S: + ewoic3RhdHVzIjoiNDAxIgoic2NvcGUiOiJleGFtcGxlX3Njb3BlIgp9 + C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20sAW + hvc3Q9c2VydmVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AQE= + S: + eyJzdGF0dXMiOiI0MDEiLCJzY29wZSI6ImV4YW1wbGVfc2NvcGUiLCJv + cGVuaWQtY29uZmlndXJhdGlvbiI6Imh0dHBzOi8vZXhhbXBsZS5jb20v + LndlbGwta25vd24vb3BlbmlkLWNvbmZpZ3VyYXRpb24ifQ== C: + AQ== S: t1 NO SASL authentication failed The decoded initial client response is: - n,^Auser=user@example.com^Ahost=server.example.com^A + 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" +"scope":"example_scope", +"openid-configuration":"https://example.com/.well-known/openid-configuration" } The client responds with the required dummy response. -4.3. SMTP Example of a Failed Negotiation +4.4. 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 biwBdXNlcj1zb21ldXNlckBleGFtcGxlLmNvbQFhdXRoPUJlYXJl +C: AUTH OAUTHBEARER bix1c2VyPXNvbWV1c2VyQGV4YW1wbGUuY29tLAFhdXRoPUJlYXJl ciB2RjlkZnQ0cW1UYzJOdmIzUmxja0JoZEhSaGRtbHpkR0V1WTI5dENnPT0BAQ== 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...] + 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 @@ -600,23 +645,23 @@ 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. + rendered invalid at any time. 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 @@ -657,20 +703,24 @@ For further information: Contact the authors of this document. Owner/Change controller: the IETF Note: None 8. References 8.1. Normative References + [OpenID.Discovery] + Sakimura, N., Bradley, J., Jones, M., and E. Jay, "OpenID + Connect Discovery 1.0", July 2011. + [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 @@ -696,22 +746,22 @@ [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-18 (work in - progress), March 2014. + (JWT)", draft-ietf-oauth-json-web-token-25 (work in + progress), July 2014. [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-05 (work in progress), January 2014. [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. @@ -739,22 +789,32 @@ Williams, and Matt Miller. This document was produced under the chairmanship of Alexey Melnikov, Tom Yu, Shawn Emery, Josh Howlett, Sam Hartman. The supervising area director was Stephen Farrell. Appendix B. Document History [[ to be removed by RFC editor before publication as an RFC ]] - -14 + -15 + + o Last call feedack on the GS2 stuff being ripped out completely. + o Removed the "user" parameter and put stuff back into the + gs2-header. Call out that the authzid goes in the gs2-header with + some prose about when it might be required. Very comparable to + -10. + + o Added an OAuth 1.0A example explicitly. + + -14 o Last call feedack on RFC citations needed, small editorial. o Added the "user" parameter back, which was pulled when we started down the GS2 path. Same language as -03. o Defined a stub GS2 header to make sure that when the GS2 bride is defined for this that nothing will break when it actually starts to get populated. -13 @@ -861,25 +921,26 @@ -00 o Renamed draft into proper IETF naming format now that it's adopted. o Minor fixes. Authors' Addresses William Mills - Yahoo! Inc. + Skype Email: wmills_92105@yahoo.com Tim Showalter Email: tjs@psaux.com + Hannes Tschofenig ARM Ltd. 110 Fulbourn Rd Cambridge CB1 9NJ Great Britain Email: Hannes.tschofenig@gmx.net URI: http://www.tschofenig.priv.at