--- 1/draft-ietf-kitten-sasl-oauth-04.txt 2012-08-23 09:14:08.677926695 +0200 +++ 2/draft-ietf-kitten-sasl-oauth-05.txt 2012-08-23 09:14:08.717926882 +0200 @@ -1,35 +1,35 @@ KITTEN W. Mills Internet-Draft Yahoo! Inc. Intended status: Standards Track T. Showalter -Expires: February 21, 2013 +Expires: February 24, 2013 H. Tschofenig Nokia Siemens Networks - August 20, 2012 + August 23, 2012 - A SASL and GSS-API Mechanism for OAuth - draft-ietf-kitten-sasl-oauth-04 + A set of SASL and GSS-API Mechanisms for OAuth + draft-ietf-kitten-sasl-oauth-05 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 OAuth over the - Simple Authentication and Security Layer (SASL) or the Generic - Security Service Application Program Interface (GSS-API) to access a - protected resource at a resource serve. Thereby, it enables schemes - defined within the OAuth framework for non-HTTP-based application - protocols. + This document defines how an application client uses credentials + obtained via OAuth over the Simple Authentication and Security Layer + (SASL) or the Generic Security Service Application Program Interface + (GSS-API) 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 token. Tokens typically provided limited access rights and can be managed and revoked separately from the user's long-term credential (password). Status of this Memo @@ -39,61 +39,61 @@ 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 February 21, 2013. + This Internet-Draft will expire on February 24, 2013. Copyright Notice Copyright (c) 2012 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 . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 3. OAuth SASL Mechanism Specification . . . . . . . . . . . . . . 9 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7 + 3. OAuth SASL Mechanism Specification . . . . . . . . . . . . . . 8 3.1. Initial Client Response . . . . . . . . . . . . . . . . . 9 - 3.1.1. Reserved Key/Values in OAUTH . . . . . . . . . . . . . 10 - 3.1.2. Use of the gs2-header . . . . . . . . . . . . . . . . 11 - 3.2. Server's Response . . . . . . . . . . . . . . . . . . . . 11 + 3.1.1. Reserved Key/Values . . . . . . . . . . . . . . . . . 10 + 3.1.2. Use of the gs2-header . . . . . . . . . . . . . . . . 10 + 3.2. Server's Response . . . . . . . . . . . . . . . . . . . . 10 3.2.1. Mapping to SASL Identities . . . . . . . . . . . . . . 11 - 3.2.2. Server response to failed authentication. . . . . . . 12 + 3.2.2. Server response to failed authentication. . . . . . . 11 3.2.3. Completing an error message sequence. . . . . . . . . 12 - 3.3. Use of Signature Type Authorization . . . . . . . . . . . 13 - 3.4. Channel Binding . . . . . . . . . . . . . . . . . . . . . 14 - 4. GSS-API OAuth Mechanism Specification . . . . . . . . . . . . 15 - 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 - 5.1. Successful Bearer Token Exchange . . . . . . . . . . . . . 16 - 5.2. OAuth 1.0a Authorization with Channel Binding . . . . . . 17 - 5.3. Failed Exchange . . . . . . . . . . . . . . . . . . . . . 18 - 5.4. Failed Channel Binding . . . . . . . . . . . . . . . . . . 19 - 5.5. SMTP Example of a failed negotiation. . . . . . . . . . . 19 - 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21 - 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 - 7.1. SASL Registration . . . . . . . . . . . . . . . . . . . . 22 + 3.3. Use of Signature Type Authorization . . . . . . . . . . . 12 + 3.4. Channel Binding . . . . . . . . . . . . . . . . . . . . . 13 + 4. GSS-API OAuth Mechanism Specification . . . . . . . . . . . . 14 + 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 + 5.1. Successful Bearer Token Exchange . . . . . . . . . . . . . 15 + 5.2. OAuth 1.0a Authorization with Channel Binding . . . . . . 16 + 5.3. Failed Exchange . . . . . . . . . . . . . . . . . . . . . 17 + 5.4. Failed Channel Binding . . . . . . . . . . . . . . . . . . 18 + 5.5. SMTP Example of a failed negotiation. . . . . . . . . . . 18 + 6. Security Considerations . . . . . . . . . . . . . . . . . . . 20 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 + 7.1. SASL Registration . . . . . . . . . . . . . . . . . . . . 21 7.2. GSS-API Registration . . . . . . . . . . . . . . . . . . . 22 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8.1. Normative References . . . . . . . . . . . . . . . . . . . 23 8.2. Informative References . . . . . . . . . . . . . . . . . . 24 Appendix A. Acknowlegements . . . . . . . . . . . . . . . . . . . 25 Appendix B. Document History . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28 1. Introduction @@ -145,30 +145,29 @@ The resulting framework allows new protocols to reuse existing mechanisms and allows old protocols to make use of new mechanisms. The framework also provides a protocol for securing subsequent protocol exchanges within a data security layer. The Generic Security Service Application Program Interface (GSS-API) [RFC2743] provides a framework for applications to support multiple authentication mechanisms through a unified interface. - This document defines a SASL mechanism for OAuth, but it conforms to + This document defines SASL mechanisms for OAuth, and it conforms to the new bridge between SASL and the GSS-API called GS2 [RFC5801]. - This means that this document defines both a SASL mechanism and a - GSS-API mechanism. Implementers may be interested in either the - SASL, the GSS-API, or even both mechanisms. To faciliate these two - variants, the description has been split into two parts, one part - that provides normative references for those interested in the SASL - OAuth mechanism (see Section 3), and a second part for those - implementers that wish to implement the GSS-API portion (see - Section 4). + This means that this document defines both SASL and GSS-API + mechanisms. Implementers may be interested in either the SASL, the + GSS-API, or even both mechanisms. To faciliate these two variants, + the description has been split into two parts, one part that provides + normative references for those interested in the SASL OAuth mechanism + (see Section 3), and a second part for those implementers that wish + to implement the GSS-API portion (see Section 4). When OAuth is integrated into SASL and the GSS-API 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 @@ -198,30 +197,20 @@ 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 [I-D.jones-appsawg-webfinger]. 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. - The client need not implement more than one authorization scheme, and - there are no mandatory to implement schemes. The server MUST - advertise at least one scheme if the OAUTH mechanism is offered. - During discovery the client might not find any schemes that it - supports, an OAuth 2.0 enabled client MAY attempt to fetch a - credential for a scheme it supports from a discovered OAuth 2.0 - authorization endpoint. If the client finds no schemes it supports - the client SHOULD provide feedback to the user that the requested - enpoint can not be supported. - ----+ +--------+ +---------------+ | | |--(A)-- Authorization Request --->| Resource | | | | | Owner | |Plain | |<-(B)------ Access Grant ---------| | |OAuth | | +---------------+ |2.0 | | | | | Client Credentials & +---------------+ | | |--(C)------ Access Grant -------->| Authorization | | | Client | | Server | | @@ -251,29 +240,39 @@ 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 message, not this memo. 3. OAuth SASL Mechanism Specification SASL is used as a generalized authentication method in a variety of - application layer protocols. This document defines two SASL - mechanisms for usage with OAuth: "OAUTH" and "OAUTH-PLUS". The - "OAUTH" SASL mechanism enables OAuth authorization schemes for SASL, - "OAUTH-PLUS" adds channel binding [RFC5056] capability for additional - security guarantees. + application layer protocols. This document defines the following + SASL mechanisms for usage with OAuth: - This mechanism is 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: + OAUTHBEARER Authorization using Bearer tokens. + + OAUTH10A Authorization using OAuth 1.0a tokens. + + OAUTH10A-PLUS Adds channel binding [RFC5056] capability to + OAUTH10A for additional security guarantees. + + Any new OAuth token scheme MAY define a new SASL mechanism compatible + with the mechanisms defined here by simply registering the new + name(s) and citing this specification for the further definition. + New channel binding enabled "-PLUS" mechanisms defined in this way + MUST include message integrity protection. + + 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 @@ -284,101 +283,109 @@ o Server responds with an error message. o Client sends an empty client reponse. o 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 GSS-API [RFC5801], which - carries the authorization ID as a hint. These key/value pairs carry - the equivalent values from an HTTP context in order to be able to + response includes a gs2-header as defined in GS2 [RFC5801], which + carries the authorization ID. These key/value pairs carry the + equivalent values from an HTTP context in order to be able to complete an OAuth style HTTP authorization. The client MUST send an - authorization ID in the gs2-header. 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. The ABNF [RFC5234] syntax is: + authorization ID in the gs2-header. 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 ;; gs2-header = As defined in GSS-API initial_client_resp = gs2-header kvsep client_resp 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 authroization. + user (REQUIRED): The authorization ID. 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. In OAUTH this is reserved, the client - SHOUD NOT send it, and has the default value of "". In OAUTH- - PLUS this carries a single key value pair "cbdata" for the - channel binding data payload formatted as an HTTP query string. + qs: The HTTP query string. In non-channel binding mechanisms + this is reserved, the client SHOUD NOT send it, and has the + default value of "". In "-PLUS" variants this carries a single + key value pair "cbdata" for the channel binding data payload + formatted as an HTTP query string. In authorization schemes that use signatures, the client MUST send host and port number key/values, and the server MUST fail an authorization request requiring signatures that does not have host - and port values. For authorization schemes that require a scheme as - part of the URI being signed "http" is always used. + and port values. For authorization schemes that require a URI scheme + as part of the data being signed "http" is always used. In OAuth + 1.0a for example, the signature base string includes the + reconstructed HTTP URL. -3.1.1. Reserved Key/Values in OAUTH +3.1.1. Reserved Key/Values - In the OAUTH mechanism values for path, query string and post body - are assigned default values. OAuth authorization schemes MAY define + 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 schemes that use request signatures the default values MUST be used unless explict values are provided in the client response. The following key values are reserved for future use: mthd (RESERVED): HTTP method for use in signatures, the default value is "POST". path (RESERVED): HTTP path data, the default value is "/". post (RESERVED): HTTP post data, the default value is "". 3.1.2. Use of the gs2-header - The gs2-header is used as follows: + The OAuth scheme related mechanisms are also GSS-API mechanisms, see + Section 4 for further detail. The gs2-header is used as follows: o The "gs2-nonstd-flag" MUST NOT be present. o The "gs2-authzid" carries the authorization identity as specified in [RFC5801]. - In the OAUTH mechanism the "gs2-cb-flag" MUST be set to "n" because - channel-binding [RFC5056] data is not expected. In the OAUTH-PLUS - mechanism the "gs2-cb-flag" MUST be set appropriately by the client. + In the non "-PLUS" mechanisms the "gs2-cb-flag" MUST be set to "n" + because channel-binding [RFC5056] data is not expected. In the + OAUTH10A-PLUS mechanism (or other -PLUS variants based on this + specification) the "gs2-cb-flag" MUST be set appropriately by the + client. 3.2. Server's Response The server validates the response per the specification for the authorization scheme used. If the authorization scheme used includes signing of the request parameters the client must provide a client response that satisfies the data requirements for the scheme in use. - In the OAUTH-PLUS mechanism the server examines the channel binding - data, extracts the channel binding unique prefix, and extracts the - raw channel biding data based on the channel binding type used. It - then computes it's own copy of the channel binding payload and - compares that to the payload sent by the client in the cbdata key/ - value. Those two must be equal for channel binding to succeed. + In a "-PLUS" mechanism the server examines the channel binding data, + extracts the channel binding unique prefix, and extracts the raw + channel biding data based on the channel binding type used. It then + computes it's own copy of the channel binding payload and compares + that to the payload sent by the client in the cbdata key/value. + Those two must be equal for channel binding to succeed. The server responds to a successfully verified client message by completing the SASL negotiation. The authorization scheme MUST carry the user ID to be used as the authorization identity (identity to act as). The server MUST use the ID obtained from the credential as the user being authorized. 3.2.1. Mapping to SASL Identities Some OAuth mechanisms can provide both an authorization identity and @@ -397,24 +404,20 @@ 3.2.2. Server response to failed authentication. 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. - schemes (REQUIRED): A space separated list of the OAuth - authorization schemes supported by the server, i.e. "bearer" or - "bearer mac". - 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 the client SHOULD always request scoped tokens from the token endpoint. The client MAY use a scope other than the one provided by the resource server. Scopes other than those advertised by the resource server are be defined by the resource owner and provided in service documentation or discovery @@ -423,21 +426,21 @@ 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. - If the client gets an error message form the server it MUST send an + If the client gets an error message from the server it MUST send an empty client response consisting of a single %x01 (control A) character, which is a correctly formatted client response with no key/value pairs. The server then completes the SASL negotiation with a failure result. 3.3. Use of Signature Type Authorization This mechanism supports authorization using signatures, which requires that both client and server construct the string to be signed. OAuth 2 is designed for authentication/authorization to @@ -451,20 +454,21 @@ 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 @@ -485,45 +489,49 @@ 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 3.4. Channel Binding The channel binding data is carried in the "qs" (query string) key value pair formatted as a standard HTTP query parameter with the name "cbdata". Channel binding requires that the channel binding data be integrity protected end-to-end in order to protect against man-in- - the-middle attacks. All authorization schemes offered in an OAUTH- - PLUS mechanism MUST provide integrity protection. It should be noted + the-middle attacks. All authorization schemes offered with "-PLUS" + mechanisms MUST provide integrity protection. It should be noted that while the Bearer token scheme specifies SSL for normal usage it - offers no integrity protection and is not suitable for use in OAUTH- - PLUS. + offers no integrity protection and is not suitable for use with + channel binding. The channel binding data is computed by the client based on it's choice of preferred channel binding type. As specified in [RFC5056], the channel binding information MUST start with the channel binding unique prefix, followed by a colon (ASCII 0x3A), followed by a base64 encoded channel binding payload. The channel binding payload is the raw data from the channel binding type. For example, if the client is using tls-unique for channel binding then the raw channel binding data is the TLS finished message as specified in section 3.1 of [RFC5929]. 4. GSS-API OAuth Mechanism Specification Note: The normative references in this section are informational for SASL implementers, but they are normative for GSS-API implementers. The SASL OAuth mechanism is also a GSS-API mechanism and the messages - described in Section 3 are the same, but + described in Section 3 are the same with the following changes to the + GS2 related elements: - 1. the initial context token header is prefixed to the client's + 1. the GS2 header on the client's first message and the following + %x01 (control A) are excluded when used as a GSS-API mechanism. + + 2. the initial context token header is prefixed to the client's first authentication message (context token), as described in Section 3.1 of RFC 2743, The GSS-API mechanism OID for OAuth is [[TBD: IANA]]. OAuth security contexts always have the mutual_state flag (GSS_C_MUTUAL_FLAG) set to TRUE. OAuth supports credential delegation, therefore security contexts may have the deleg_state flag (GSS_C_DELEG_FLAG) set to either TRUE or FALSE. @@ -562,78 +570,82 @@ insensitive. One example uses "Bearer" but that could as easily be "bearer", "BEARER", or "BeArEr". 5.1. Successful Bearer Token Exchange This example shows a successful OAuth 2.0 bearer token exchange. Note that line breaks are inserted for readability. S: * IMAP4rev1 Server Ready C: t0 CAPABILITY - S: * CAPABILITY IMAP4rev1 AUTH=OAUTH + S: * CAPABILITY IMAP4rev1 AUTH=OAUTHBEARER S: t0 OK Completed - C: t1 AUTHENTICATE OAUTH bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2VydmVy - LmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk5 - 2YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB + C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20BaG9zdD1zZX + J2ZXIuZXhhbXBsZS5jb20BdXNlcj11c2VyQGV4YW1wbGUuY29tAXBvcnQ9MTQzA + WF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk52YjNSbGNrQmhiSFJoZG1semRHRXVZ + Mjl0Q2c9PQEB 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 + n,a=user@example.com^Ahost=server.example.com^Auser=user@example.com^A + port=143^Aauth=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 OAUTH + S: 250-AUTH LOGIN PLAIN OAUTHBEARER S: 250-ENHANCEDSTATUSCODES S: 250-PIPELINING - C: t1 AUTHENTICATE OAUTH bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2VydmVy - LmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk5 - 2YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB + C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20BaG9zdD1zZX + J2ZXIuZXhhbXBsZS5jb20BdXNlcj11c2VyQGV4YW1wbGUuY29tAXBvcnQ9MTQzA + WF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk52YjNSbGNrQmhiSFJoZG1semRHRXVZ + Mjl0Q2c9PQEB S: 235 Authentication successful. [connection continues...] 5.2. OAuth 1.0a Authorization with Channel Binding This example shows channel binding in the context of an OAuth 1.0a signed authorization request. Note that line breaks are inserted for readability. -S: * CAPABILITY IMAP4rev1 AUTH=OAUTH SASL-IR IMAP4rev1 Server Ready + S: * CAPABILITY IMAP4rev1 AUTH=OAUTH10A-PLUS SASL-IR IMAP4rev1 Server + Ready S: t0 OK Completed -C: t1 AUTHENTICATE OAUTH-PLUS eSxhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2Vydm - VyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9T0F1dGggcmVhbG09IkV4YW1wbGUi - LG9hdXRoX2NvbnN1bWVyX2tleT0iOWRqZGo4Mmg0OGRqczlkMiIsb2F1dGhfdG9rZW - 49ImtrazlkN2RoM2szOXNqdjciLG9hdXRoX3NpZ25hdHVyZV9tZXRob2Q9IkhNQUMt - U0hBMSIsb2F1dGhfdGltZXN0YW1wPSIxMzcxMzEyMDEiLG9hdXRoX25vbmNlPSI3ZD - hmM2U0YSIsb2F1dGhfc2lnbmF0dXJlPSJTU2R0SUdFZ2JHbDBkR3hsSUhSbFlTQndi - M1F1IgFxcz1jYmRhdGE9dGxzLXVuaXF1ZTpTRzkzSUdKcFp5QnBjeUJoSUZSTVV5Qm - 1hVzVoYkNCdFpYTnpZV2RsUHdvPQEB + C: t1 AUTHENTICATE OAUTH10A-PLUS eSxhPXVzZXJAZXhhbXBsZS5jb20BaG9zdD1zZ + XJ2ZXIuZXhhbXBsZS5jb20BcG9ydD0xNDMBYXV0aD1PQXV0aCByZWFsbT0iRXhhb + XBsZSIsb2F1dGhfY29uc3VtZXJfa2V5PSI5ZGpkajgyaDQ4ZGpzOWQyIixvYXV0a + F90b2tlbj0ia2trOWQ3ZGgzazM5c2p2NyIsb2F1dGhfc2lnbmF0dXJlX21ldGhvZ + D0iSE1BQy1TSEExIixvYXV0aF90aW1lc3RhbXA9IjEzNzEzMTIwMSIsb2F1dGhfb + m9uY2U9IjdkOGYzZTRhIixvYXV0aF9zaWduYXR1cmU9IlNTZHRJR0VnYkdsMGRHe + GxJSFJsWVNCd2IzUXUiAXFzPWNiZGF0YT10bHMtdW5pcXVlOlNHOTNJR0pwWnlCc + GN5QmhJRlJNVXlCbWFXNWhiQ0J0WlhOellXZGxQd289AQE= 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: - y,a=user@example.com,^A + y,a=user@example.com^A host=server.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="SSdtIGEgbGl0dGxlIHRlYSBwb3Qu"^A qs=cbdata=tls-unique:SG93IGJpZyBpcyBhIFRMUyBmaW5hbCBtZXNzYWdlPwo=^A^A @@ -645,101 +657,102 @@ j82h48djs9d2%26oauth_nonce%3D7d8f3e4a%26oauth_signature_method%3DHM AC-SHA1%26oauth_timestamp%3D137131201%26oauth_token%3Dkkk9d7dh3k39s jv7 5.3. 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=OAUTH SASL-IR IMAP4rev1 Server Ready + S: * CAPABILITY IMAP4rev1 AUTH=OAUTHBEARER SASL-IR IMAP4rev1 Server + Ready S: t0 OK Completed - C: t1 AUTHENTICATE OAUTH bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2Vy - dmVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AQE= - S: + ewoic3RhdHVzIjoiNDAxIiwKInNjaGVtZXMiOiJiZWFyZXIiLAoic2NvcGUi - OiJleGFtcGxlX3Njb3BlIgp9 + C: t1 AUTHENTICATE OAUTHBEARER bixhPXVzZXJAZXhhbXBsZS5jb20BaG9zdD + 1zZXJ2ZXIuZXhhbXBsZS5jb20BdXNlcj11c2VyQGV4YW1wbGUuY29tAXBvc + nQ9MTQzAWF1dGg9AQE= + 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^Aport=143^Aauth=^A^A + n,a=user@example.com,^Ahost=server.example.com^Auser=user@example. + com^Aport=143^Aauth=^A^A The decoded server error response is: { "status":"401", - "schemes":"bearer", "scope":"example_scope" } The client responds with the required empty response. 5.4. Failed Channel Binding This example shows a channel binding failure in an empty request. The channel binding information is empty. Note that line breaks are inserted for readability. -S: * CAPABILITY IMAP4rev1 AUTH=OAUTH OAUTH-PLUS SASL-IR IMAP4rev1 Server + S: * CAPABILITY IMAP4rev1 AUTH=OAUTH10A-PLUS SASL-IR IMAP4rev1 Server Ready S: t0 OK Completed -C: t1 AUTHENTICATE OAUTH-PLUS eSxhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2Vydm - VyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AWNiZGF0YT0BAQ== -S: + ewoic3RhdHVzIjoiNDEyIiwKInNjaGVtZXMiOiJiZWFyZXIgb2F1dGgiLAoi - c2NvcGUiOiJleGFtcGxlX3Njb3BlIgp9 + C: t1 AUTHENTICATE OAUTH10A-PLUS eSxhPXVzZXJAZXhhbXBsZS5jb20sAWhv + c3Q9c2VydmVyLmV4YW1wbGUuY29tAXVzZXI9dXNlckBleGFtcGxlLmNvbQF + wb3J0PTE0MwFhdXRoPQFjYmRhdGE9AQE= + S: + ewoic3RhdHVzIjoiNDEyIiwKInNjb3BlIjoiZXhhbXBsZV9zY29wZSIKfQ== C: + AQ== S: t1 NO SASL authentication failed The decoded initial client response is: - y,a=user@example.com,^A - host=server.example.com^Aport=143^A - auth=^Acbdata=^A^A + y,a=user@example.com,^Ahost=server.example.com^A + user=user@example.com^Aport=143^Aauth=^Acbdata=^A^A The decoded server response is: { "status":"412", - "schemes":"bearer oauth", "scope":"example_scope" } The client responds with the required empty response. 5.5. 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 OAUTH +S: 250-AUTH LOGIN PLAIN OAUTHBEARER S: 250-ENHANCEDSTATUSCODES S: 250-PIPELINING -C: AUTH OAUTH dXNlcj1zb21ldXNlckBleGFtcGxlLmNvbQFhdXRoPUJlYXJlciB2RjlkZn - Q0cW1UYzJOdmIzUmxja0JoZEhSaGRtbHpkR0V1WTI5dENnPT0BAQo= +C: AUTH OAUTHBEARER dXNlcj1zb21ldXNlckBleGFtcGxlLmNvbQFhdXRoPUJlYXJlciB2 + RjlkZnQ0cW1UYzJOdmIzUmxja0JoZEhSaGRtbHpkR0V1WTI5dENnPT0BAQo= 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 client responds with the required empty response. + The server returned an error message in the 334 SASL message, the + client responds with the required empty response, and the server + finalizes the negotiation. 6. Security Considerations This mechanism does not provide a security layer, but does provide a provision for channel binding. The OAuth 2 specification [I-D.ietf-oauth-v2] allows for a variety of usages, and the security properties of these profiles vary. The usage of bearer tokens, for example, provide security features similar to cookies. Applications using this mechanism SHOULD exercise the same level of care using this mechanism as they would in using the SASL PLAIN mechanism. In @@ -770,50 +783,64 @@ 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 access credentials that appear to be valid. 7. IANA Considerations 7.1. SASL Registration The IANA is requested to register the following SASL profile: - SASL mechanism profile: OAUTH + SASL mechanism profile: OAUTHBEARER 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 The IANA is requested to register the following SASL profile: - SASL mechanism profile: OAUTH-PLUS + 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 + + The IANA is requested to register the following SASL profile: + + SASL mechanism profile: OAUTH10A-PLUS 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 7.2. GSS-API Registration - IANA is further requested to assign an OID for this GSS mechanism in - the SMI numbers registry, with the prefix of + IANA is further requested to assign an OID for thESE GSS mechanismS + in the SMI numbers registry, with the prefix of iso.org.dod.internet.security.mechanisms (1.3.6.1.5.5) and to reference this specification in the registry. 8. References 8.1. Normative References [I-D.ietf-oauth-v2] Hardt, D., "The OAuth 2.0 Authorization Framework", draft-ietf-oauth-v2-31 (work in progress), August 2012. @@ -897,20 +924,34 @@ 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, and Nico Williams. Appendix B. Document History [[ to be removed by RFC editor before publication as an RFC ]] + -05 + + o Fixed the GS2 header language again. + + 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.