draft-ietf-kitten-sasl-oauth-03.txt   draft-ietf-kitten-sasl-oauth-04.txt 
KITTEN W. Mills KITTEN W. Mills
Internet-Draft Yahoo! Inc. Internet-Draft Yahoo! Inc.
Intended status: Standards Track T. Showalter Intended status: Standards Track T. Showalter
Expires: February 7, 2013 Expires: February 21, 2013
H. Tschofenig H. Tschofenig
Nokia Siemens Networks Nokia Siemens Networks
August 6, 2012 August 20, 2012
A SASL and GSS-API Mechanism for OAuth A SASL and GSS-API Mechanism for OAuth
draft-ietf-kitten-sasl-oauth-03 draft-ietf-kitten-sasl-oauth-04
Abstract Abstract
OAuth enables a third-party application to obtain limited access to a OAuth enables a third-party application to obtain limited access to a
protected resource, either on behalf of a resource owner by protected resource, either on behalf of a resource owner by
orchestrating an approval interaction, or by allowing the third-party orchestrating an approval interaction, or by allowing the third-party
application to obtain access on its own behalf. application to obtain access on its own behalf.
This document defines how an application client uses OAuth over the This document defines how an application client uses OAuth over the
Simple Authentication and Security Layer (SASL) or the Generic Simple Authentication and Security Layer (SASL) or the Generic
skipping to change at page 2, line 4 skipping to change at page 2, line 4
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 7, 2013. This Internet-Draft will expire on February 21, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. OAuth SASL Mechanism Specification . . . . . . . . . . . . . . 8 3. OAuth SASL Mechanism Specification . . . . . . . . . . . . . . 9
3.1. Initial Client Response . . . . . . . . . . . . . . . . . 8 3.1. Initial Client Response . . . . . . . . . . . . . . . . . 9
3.1.1. Reserved Key/Values in OAUTH . . . . . . . . . . . . . 9 3.1.1. Reserved Key/Values in OAUTH . . . . . . . . . . . . . 10
3.2. Server's Response . . . . . . . . . . . . . . . . . . . . 9 3.1.2. Use of the gs2-header . . . . . . . . . . . . . . . . 11
3.2.1. Mapping to SASL Identities . . . . . . . . . . . . . . 9 3.2. Server's Response . . . . . . . . . . . . . . . . . . . . 11
3.2.2. Server response to failed authentication. . . . . . . 10 3.2.1. Mapping to SASL Identities . . . . . . . . . . . . . . 11
3.3. Use of Signature Type Authorization . . . . . . . . . . . 10 3.2.2. Server response to failed authentication. . . . . . . 12
3.4. Channel Binding . . . . . . . . . . . . . . . . . . . . . 11 3.2.3. Completing an error message sequence. . . . . . . . . 12
4. GSS-API OAuth Mechanism Specification . . . . . . . . . . . . 13 3.3. Use of Signature Type Authorization . . . . . . . . . . . 13
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.4. Channel Binding . . . . . . . . . . . . . . . . . . . . . 14
5.1. Successful Bearer Token Exchange . . . . . . . . . . . . . 14 4. GSS-API OAuth Mechanism Specification . . . . . . . . . . . . 15
5.2. MAC Authentication with Channel Binding . . . . . . . . . 14 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3. Failed Exchange . . . . . . . . . . . . . . . . . . . . . 15 5.1. Successful Bearer Token Exchange . . . . . . . . . . . . . 16
5.4. Failed Channel Binding . . . . . . . . . . . . . . . . . . 16 5.2. OAuth 1.0a Authorization with Channel Binding . . . . . . 17
6. Security Considerations . . . . . . . . . . . . . . . . . . . 17 5.3. Failed Exchange . . . . . . . . . . . . . . . . . . . . . 18
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 5.4. Failed Channel Binding . . . . . . . . . . . . . . . . . . 19
7.1. SASL Registration . . . . . . . . . . . . . . . . . . . . 18 5.5. SMTP Example of a failed negotiation. . . . . . . . . . . 19
7.2. GSS-API Registration . . . . . . . . . . . . . . . . . . . 18 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
8.1. Normative References . . . . . . . . . . . . . . . . . . . 19 7.1. SASL Registration . . . . . . . . . . . . . . . . . . . . 22
8.2. Informative References . . . . . . . . . . . . . . . . . . 20 7.2. GSS-API Registration . . . . . . . . . . . . . . . . . . . 22
Appendix A. Document History . . . . . . . . . . . . . . . . . . 21 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22 8.1. Normative References . . . . . . . . . . . . . . . . . . . 23
8.2. Informative References . . . . . . . . . . . . . . . . . . 24
Appendix A. Acknowlegements . . . . . . . . . . . . . . . . . . . 25
Appendix B. Document History . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28
1. Introduction 1. Introduction
OAuth [I-D.ietf-oauth-v2] enables a third-party application to obtain OAuth [I-D.ietf-oauth-v2] enables a third-party application to obtain
limited access to a protected resource, either on behalf of a limited access to a protected resource, either on behalf of a
resource owner by orchestrating an approval interaction, or by resource owner by orchestrating an approval interaction, or by
allowing the third-party application to obtain access on its own allowing the third-party application to obtain access on its own
behalf. The core OAuth specification [I-D.ietf-oauth-v2] does not behalf. The core OAuth specification [I-D.ietf-oauth-v2] does not
define the interaction between the client and the resource server define the interaction between the client and the resource server
with the access to a protected resource using an Access Token. This with the access to a protected resource using an Access Token. This
functionality is described in two separate specifications, namely functionality is described in separate specifications, for example
[I-D.ietf-oauth-v2-bearer], and [I-D.ietf-oauth-v2-http-mac], whereby [I-D.ietf-oauth-v2-bearer], [I-D.ietf-oauth-v2-http-mac], and OAuth
the focus is on an HTTP-based environment only. 1.0a [RFC5849] where the focus is on an HTTP-based environment only.
Figure 1 shows the abstract message flow as shown in Figure 1 of Figure 1 shows the abstract message flow as shown in Figure 1 of
[I-D.ietf-oauth-v2]. [I-D.ietf-oauth-v2].
+--------+ +---------------+ +--------+ +---------------+
| |--(A)- Authorization Request ->| Resource | | |--(A)- Authorization Request ->| Resource |
| | | Owner | | | | Owner |
| |<-(B)-- Authorization Grant ---| | | |<-(B)-- Authorization Grant ---| |
| | +---------------+ | | +---------------+
| | | |
| | +---------------+ | | +---------------+
| |--(C)-- Authorization Grant -->| Authorization | | |--(C)-- Authorization Grant -->| Authorization |
| Client | | Server | | Client | | Server |
| |<-(D)----- Access Token -------| | | |<-(D)----- Access Token -------| |
| | +---------------+ | | +---------------+
| | | |
| | +---------------+ | | +---h------------+
| |--(E)----- Access Token ------>| Resource | | |--(E)----- Access Token ------>| Resource |
| | | Server | | | | Server |
| |<-(F)--- Protected Resource ---| | | |<-(F)--- Protected Resource ---| |
+--------+ +---------------+ +--------+ +---------------+
Figure 1: Abstract OAuth 2.0 Protocol Flow Figure 1: Abstract OAuth 2.0 Protocol Flow
This document takes advantage of the OAuth protocol and its This document takes advantage of the OAuth protocol and its
deployment base to provide a way to use SASL [RFC4422] as well as the deployment base to provide a way to use SASL [RFC4422] as well as the
GSS-API [RFC2743] to gain access to resources when using non-HTTP- GSS-API [RFC2743] to gain access to resources when using non-HTTP-
based protocols, such as the Internet Message Access Protocol (IMAP) based protocols, such as the Internet Message Access Protocol (IMAP)
[RFC3501], which is what this memo uses in the examples. [RFC3501] and SMTP [RFC5321], which is what this memo uses in the
examples.
The Simple Authentication and Security Layer (SASL) is a framework The Simple Authentication and Security Layer (SASL) is a framework
for providing authentication and data security services in for providing authentication and data security services in
connection-oriented protocols via replaceable mechanisms. It connection-oriented protocols via replaceable mechanisms. It
provides a structured interface between protocols and mechanisms. provides a structured interface between protocols and mechanisms.
The resulting framework allows new protocols to reuse existing The resulting framework allows new protocols to reuse existing
mechanisms and allows old protocols to make use of new mechanisms. mechanisms and allows old protocols to make use of new mechanisms.
The framework also provides a protocol for securing subsequent The framework also provides a protocol for securing subsequent
protocol exchanges within a data security layer. protocol exchanges within a data security layer.
The Generic Security Service Application Program Interface (GSS-API) The Generic Security Service Application Program Interface (GSS-API)
[RFC2743] provides a framework for applications to support multiple [RFC2743] provides a framework for applications to support multiple
authentication mechanisms through a unified interface. authentication mechanisms through a unified interface.
This document defines a SASL mechanism for OAuth, but it conforms to This document defines a SASL mechanism for OAuth, but it conforms to
skipping to change at page 5, line 49 skipping to change at page 5, line 51
authorization server and presenting the authorization grant. authorization server and presenting the authorization grant.
(D) The authorization server authenticates the client and (D) The authorization server authenticates the client and
validates the authorization grant, and if valid issues an access validates the authorization grant, and if valid issues an access
token. token.
(E) The client requests the protected resource from the resource (E) The client requests the protected resource from the resource
server and authenticates by presenting the access token. server and authenticates by presenting the access token.
(F) The resource server validates the access token, and if valid, (F) The resource server validates the access token, and if valid,
serves the request. indicates a successful authentication.
Steps (E) and (F) are not defined in [I-D.ietf-oauth-v2] and are the Steps (E) and (F) are not defined in [I-D.ietf-oauth-v2] and are the
main functionality specified within this document. Consequently, the main functionality specified within this document. Consequently, the
message exchange shown in Figure 2 is the result of this message exchange shown in Figure 2 is the result of this
specification. The client will genrally need to determine the specification. The client will genrally need to determine the
authentication endpoints (and perhaps the service endpoints) before authentication endpoints (and perhaps the service endpoints) before
the OAuth 2.0 protocol exchange messages in steps (A)-(D) are the OAuth 2.0 protocol exchange messages in steps (A)-(D) are
executed. The discovery of the resource owner and authorization executed. The discovery of the resource owner and authorization
server endpoints is outside the scope of this specification. The server endpoints is outside the scope of this specification. The
client must discover those endpoints using a discovery mechanisms client must discover those endpoints using a discovery mechanisms
such as Webfinger using host-meta [I-D.jones-appsawg-webfinger]. In such as Webfinger using host-meta [I-D.jones-appsawg-webfinger]. In
band discovery is not tenable if clients support the OAuth 2.0 band discovery is not tenable if clients support the OAuth 2.0
password grant. Once credentials are obtained the client proceeds to password grant. Once credentials are obtained the client proceeds to
steps (E) and (F) defined in this specification. 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 | | | |--(A)-- Authorization Request --->| Resource | |
| | | Owner | |Plain | | | Owner | |Plain
| |<-(B)------ Access Grant ---------| | |OAuth | |<-(B)------ Access Grant ---------| | |OAuth
| | +---------------+ |2.0 | | +---------------+ |2.0
| | | | | |
| | Client Credentials & +---------------+ | | | Client Credentials & +---------------+ |
| |--(C)------ Access Grant -------->| Authorization | | | |--(C)------ Access Grant -------->| Authorization | |
| Client | | Server | | | Client | | Server | |
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| | | | |OAuth | | | | |OAuth
| |--(E)------ Access Token -------->| Resource | |over | |--(E)------ Access Token -------->| Resource | |over
| | | Server | |SASL/ | | | Server | |SASL/
| |<-(F)---- Protected Resource -----| | |GSS- | |<-(F)---- Protected Resource -----| | |GSS-
| | | | |API | | | | |API
+--------+ +---------------+ | +--------+ +---------------+ |
----+ ----+
Figure 2: OAuth SASL Architecture Figure 2: OAuth SASL Architecture
It is worthwhile to note that this specification is also compatible
with OAuth 1.0a [RFC5849].
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
The reader is assumed to be familiar with the terms used in the OAuth The reader is assumed to be familiar with the terms used in the OAuth
2.0 specification [I-D.ietf-oauth-v2]. 2.0 specification [I-D.ietf-oauth-v2].
In examples, "C:" and "S:" indicate lines sent by the client and In examples, "C:" and "S:" indicate lines sent by the client and
server respectively. Line breaks have been inserted for readability. server respectively. Line breaks have been inserted for readability.
Note that the IMAP SASL specification requires base64 encoding Note that the IMAP SASL specification requires base64 encoding
message, not this memo. message, not this memo.
3. OAuth SASL Mechanism Specification 3. OAuth SASL Mechanism Specification
SASL is used as a generalized authentication method in a variety of SASL is used as a generalized authentication method in a variety of
application layer protocols. This document defines two SASL application layer protocols. This document defines two SASL
mechanisms for usage with OAuth: "OAUTH" and "OAUTH-PLUS". The mechanisms for usage with OAuth: "OAUTH" and "OAUTH-PLUS". The
"OAUTH" SASL mechanism enables OAuth authorizattion schemes for SASL, "OAUTH" SASL mechanism enables OAuth authorization schemes for SASL,
"OAUTH-PLUS" adds channel binding [RFC5056] capability for additional "OAUTH-PLUS" adds channel binding [RFC5056] capability for additional
security guarantees. security guarantees.
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:
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 an empty client reponse.
o Server fails the authentication.
3.1. Initial Client Response 3.1. Initial Client Response
Client responses are a key/value pair sequence. These key/value Client responses are a key/value pair sequence. The initial client
pairs carry the equivalent values from an HTTP context in order to be response includes a gs2-header as defined in GSS-API [RFC5801], which
able to complete an OAuth style HTTP authorization. The ABNF carries the authorization ID as a hint. These key/value pairs carry
[RFC5234] syntax is 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:
kvsep = %x01 kvsep = %x01
key = 1*ALPHA key = 1*ALPHA
value = *(VCHAR | SP | HTAB | CR | LF ) value = *(VCHAR | SP | HTAB | CR | LF )
kvpair = key "=" value kvsep kvpair = key "=" value kvsep
client_resp = 1*kvpair 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: The following key/value pairs are defined in the client response:
auth (REQUIRED): The payload of the HTTP Authorization header for auth (REQUIRED): The payload of the HTTP Authorization header for
an equivalent HTTP OAuth authroization. an equivalent HTTP OAuth authroization.
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. host: Contains the host name to which the client connected.
port: Contains the port number represented as a decimal positive port: Contains the port number represented as a decimal positive
integer string without leading zeros to which the client integer string without leading zeros to which the client
connected. 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.
In authorization schemes that use signatures, the client MUST send In authorization schemes that use signatures, the client MUST send
host and port number key/values, and the server MUST fail an host and port number key/values, and the server MUST fail an
authorization request requiring signatures that does not have host authorization request requiring signatures that does not have host
and port values. and port values. For authorization schemes that require a scheme as
part of the URI being signed "http" is always used.
3.1.1. Reserved Key/Values in OAUTH 3.1.1. Reserved Key/Values in OAUTH
In the OAUTH mechanism values for path, query string and post body In the OAUTH mechanism values for path, query string and post body
are assigned default values. OAuth authorization schemes MAY define are assigned default values. OAuth authorization schemes MAY define
usage of these in the SASL context and extend this specification. usage of these in the SASL context and extend this specification.
For OAuth schemes that use request signatures the default values MUST For OAuth schemes that use request signatures the default values MUST
be used unless explict values are provided in the client response. be used unless explict values are provided in the client response.
The following key values are reserved for future use: The following key values are reserved for future use:
path (RESERVED): HTTP path data, the default value is "/". mthd (RESERVED): HTTP method for use in signatures, the default
value is "POST".
qs (RESERVED): HTTP query string, the default value is "". path (RESERVED): HTTP path data, the default value is "/".
post (RESERVED): HTTP post 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:
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.
3.2. Server's Response 3.2. Server's Response
The server validates the response per the specification for the The server validates the response per the specification for the
authorization scheme used. If the authorization scheme used includes authorization scheme used. If the authorization scheme used includes
signing of the request parameters the client must provide a client signing of the request parameters the client must provide a client
response that satisfies the data requirements for the scheme in use. response that satisfies the data requirements for the scheme in use.
In the OAUTH-PLUS mechanism the server examines the channel binding In the OAUTH-PLUS mechanism the server examines the channel binding
data, extracts the channel binding unique prefix, and extracts the data, extracts the channel binding unique prefix, and extracts the
raw channel biding data based on the channel binding type used. It raw channel biding data based on the channel binding type used. It
then computes it's own copy of the channel binding payload and 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/ compares that to the payload sent by the client in the cbdata key/
value. Those two must be equal for channel binding to succeed. value. Those two must be equal for channel binding to succeed.
The server responds to a successfully verified client message by The server responds to a successfully verified client message by
completing the SASL negotiation. The authentication scheme MUST completing the SASL negotiation. The authorization scheme MUST carry
carry the user ID to be used as the authorization identity (identity the user ID to be used as the authorization identity (identity to act
to act as). The server MUST use the ID obtained from the credential as). The server MUST use the ID obtained from the credential as the
as the user being authorized. user being authorized.
3.2.1. Mapping to SASL Identities 3.2.1. Mapping to SASL Identities
Some OAuth mechanisms can provide both an authorization identity and Some OAuth mechanisms can provide both an authorization identity and
an authentication identity. An example of this is OAuth 1.0a an authentication identity. An example of this is OAuth 1.0a
[RFC5849] where the consumer key (oauth_consumer_key) identifies the [RFC5849] where the consumer key (oauth_consumer_key) identifies the
entity using the token which equates to the SASL authentication entity using the token which equates to the SASL authentication
identity, and is authenticated using the shared secret. The identity, and is authenticated using the shared secret. The
authorization identity in the OAuth 1.0a case is carried in the token authorization identity in the OAuth 1.0a case is carried in the token
(per the requirement above), which SHOULD be validated independently. (per the requirement above), which SHOULD be validated independently.
skipping to change at page 10, line 22 skipping to change at page 12, line 22
result consists of the following values: result consists of the following values:
status (REQUIRED): The authorization error code. Valid error status (REQUIRED): The authorization error code. Valid error
codes are defined in the IANA [[need registry name]] registry codes are defined in the IANA [[need registry name]] registry
specified in the OAuth 2 core specification. specified in the OAuth 2 core specification.
schemes (REQUIRED): A space separated list of the OAuth schemes (REQUIRED): A space separated list of the OAuth
authorization schemes supported by the server, i.e. "bearer" or authorization schemes supported by the server, i.e. "bearer" or
"bearer mac". "bearer mac".
scope (OPTIONAL): The OAuth scope required to access the service. 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 If the resource server provides a scope the client SHOULD always
request scoped tokens from the token endpoint. The client MAY use a request scoped tokens from the token endpoint. The client MAY use a
scope other than the one provided by the resource server. Scopes scope other than the one provided by the resource server. Scopes
other than those advertised by the resource server are be defined by other than those advertised by the resource server are be defined by
the resource owner and provided in service documentation or discovery the resource owner and provided in service documentation or discovery
information (which is beyond the scope of this memo). If not present information (which is beyond the scope of this memo). If not present
then the client SHOULD presume an empty scope (unscoped token) is then the client SHOULD presume an empty scope (unscoped token) is
needed. needed.
If channel binding is in use and the channel binding fails the server 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 responds with a status code set to 412 to indicate that the channel
binding precondition failed. If the authentication scheme in use binding precondition failed. If the authentication scheme in use
does not include signing the server SHOULD revoke the presented does not include signing the server SHOULD revoke the presented
credential and the client SHOULD discard that credential. 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
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 3.3. Use of Signature Type Authorization
This mechanism supports authorization using signatures, which This mechanism supports authorization using signatures, which
requires that both client and server construct the string to be requires that both client and server construct the string to be
signed. OAuth 2 is designed for authentication/authorization to signed. OAuth 2 is designed for authentication/authorization to
access specific URIs. SASL is designed for user authentication, and access specific URIs. SASL is designed for user authentication, and
has no facility for being more specific. In this mechanism we has no facility for being more specific. In this mechanism we
require or define default values for the data elements from an HTTP require or define default values for the data elements from an HTTP
request which allow the signature base string to be constructed request which allow the signature base string to be constructed
properly. The default HTTP path is "/" and the default post body is properly. The default HTTP path is "/" and the default post body is
empty. These atoms are defined as extension points so that no empty. These atoms are defined as extension points so that no
changes are needed if there is a revision of SASL which supports more changes are needed if there is a revision of SASL which supports more
specific resource authorization, e.g. IMAP access to a specific specific resource authorization, e.g. IMAP access to a specific
folder or FTP access limited to a specific directory. folder or FTP access limited to a specific directory.
Using the example in the MAC specification Using the example in the OAuth 1.0a specification as a starting
[I-D.ietf-oauth-v2-http-mac] as a starting point, on an IMAP server point, on an IMAP server running on port 143 and given the OAuth 1.0a
running on port 143 and given the MAC style authorization request style authorization request (with %x01 shown as ^A and line breaks
(with %x01 shown as ^A and line breaks added for readability) below: added for readability) below:
host=server.example.com^A n,a=user@example.com,^A
user=user@example.com^A host=example.com^A
port=143^A port=143^A
auth=MAC token="h480djs93hd8",timestamp="137131200",nonce="dj83hs9s", auth=OAuth realm="Example",
signature="YTVjyNSujYs1WsDurFnvFi4JK6o="^A^A 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 normalized request string would be constructed per the MAC The signature base string would be constructed per the OAuth 1.0
specification [I-D.ietf-oauth-v2-http-mac]. In this example the specification [RFC5849] with the following things noted:
normalized request string with the new line separator character is
represented by "\n" for display purposes only would be:
h480djs93hi8\n o The method value is defaulted to POST.
137131200\n
dj83hs9s\n o The scheme defaults to be "http", and any port number other than
\n 80 is included.
GET\n
server.example.com\n o The path defaults to "/".
143\n
/\n o The query string defaults to "".
\n
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
3.4. Channel Binding 3.4. Channel Binding
If the specification for the underlying authorization scheme requires The channel binding data is carried in the "qs" (query string) key
a security layer, such as TLS [RFC5246], the server SHOULD only offer value pair formatted as a standard HTTP query parameter with the name
a mechanism where channel binding can be enabled. "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
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.
The channel binding data is computed by the client based on it's The channel binding data is computed by the client based on it's
choice of preferred channel binding type. As specified in [RFC5056], choice of preferred channel binding type. As specified in [RFC5056],
the channel binding information MUST start with the channel binding the channel binding information MUST start with the channel binding
unique prefix, followed by a colon (ASCII 0x3A), followed by a base64 unique prefix, followed by a colon (ASCII 0x3A), followed by a base64
encoded channel binding payload. The channel binding payload is the encoded channel binding payload. The channel binding payload is the
raw data from the channel binding type if the raw channel binding raw data from the channel binding type. For example, if the client
data is less than 500 bytes. If the raw channel binding data is 500 is using tls-unique for channel binding then the raw channel binding
bytes or larger then a SHA-1 [RFC3174] hash of the raw channel data is the TLS finished message as specified in section 3.1 of
binding data is computed. [RFC5929].
If the client is using tls-unique for a channel binding then the raw
channel binding data equals the first TLS finished message. This is
under the 500 byte limit, so the channel binding payload sent to the
server would be the base64 encoded first TLS finished message.
In the case where the client has chosen tls-endpoint, the raw channel
binding data is the certificate of the server the client connected
to, which will frequently be 500 bytes or more. If it is then the
channel binding payload is the base64 encoded SHA-1 hash of the
server certificate.
4. GSS-API OAuth Mechanism Specification 4. GSS-API OAuth Mechanism Specification
Note: The normative references in this section are informational for Note: The normative references in this section are informational for
SASL implementers, but they are normative for GSS-API implementers. SASL implementers, but they are normative for GSS-API implementers.
The SASL OAuth mechanism is also a GSS-API mechanism and the messages 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, but
1. the GS2 header on the client's first message is excluded when 1. the initial context token header is prefixed to the client's
OAUTH is used as a GSS-API mechanism, and first authentication message (context token), as described in
Section 3.1 of RFC 2743,
2. 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]]. The GSS-API mechanism OID for OAuth is [[TBD: IANA]].
OAuth security contexts always have the mutual_state flag OAuth security contexts always have the mutual_state flag
(GSS_C_MUTUAL_FLAG) set to TRUE. OAuth supports credential (GSS_C_MUTUAL_FLAG) set to TRUE. OAuth supports credential
delegation, therefore security contexts may have the deleg_state flag delegation, therefore security contexts may have the deleg_state flag
(GSS_C_DELEG_FLAG) set to either TRUE or FALSE. (GSS_C_DELEG_FLAG) set to either TRUE or FALSE.
The mutual authentication property of this mechanism relies on The mutual authentication property of this mechanism relies on
successfully comparing the TLS server identity with the negotiated successfully comparing the TLS server identity with the negotiated
skipping to change at page 14, line 16 skipping to change at page 16, line 16
These example illustrate exchanges between an IMAP client and an IMAP These example illustrate exchanges between an IMAP client and an IMAP
server. server.
Note to implementers: Authorization scheme names are case Note to implementers: Authorization scheme names are case
insensitive. One example uses "Bearer" but that could as easily be insensitive. One example uses "Bearer" but that could as easily be
"bearer", "BEARER", or "BeArEr". "bearer", "BEARER", or "BeArEr".
5.1. Successful Bearer Token Exchange 5.1. Successful Bearer Token Exchange
This example shows a successful OAuth 2.0 bearer token exchange with This example shows a successful OAuth 2.0 bearer token exchange.
an initial client response. Note that line breaks are inserted for Note that line breaks are inserted for readability.
readability.
S: * IMAP4rev1 Server Ready S: * IMAP4rev1 Server Ready
C: t0 CAPABILITY C: t0 CAPABILITY
S: * CAPABILITY IMAP4rev1 AUTH=OAUTH S: * CAPABILITY IMAP4rev1 AUTH=OAUTH
S: t0 OK Completed S: t0 OK Completed
C: t1 AUTHENTICATE OAUTH aG9zdD1zZXJ2ZXIuZXhhbXBsZS5jb20BcG9ydD0xNDMB C: t1 AUTHENTICATE OAUTH bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2VydmVy
dXNlcj11c2VyQGV4YW1wbGUuY29tAWF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk5 LmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk5
2YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB 2YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB
S: +
S: t1 OK SASL authentication succeeded S: t1 OK SASL authentication succeeded
As required by IMAP [RFC3501], the payloads are base64-encoded. The As required by IMAP [RFC3501], the payloads are base64-encoded. The
decoded initial client response (with %x01 represented as ^A and long decoded initial client response (with %x01 represented as ^A and long
lines wrapped for readability) is: lines wrapped for readability) is:
host=server.example.com^Aport=143^Auser=user@example.com^A n,a=user@example.com,^Ahost=server.example.com^Aport=143^A
auth=Bearer vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg==^A^A auth=Bearer vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg==^A^A
The line containing just a "+" and a space is an empty response from The same credential used in an SMTP exchange is shown below. Note
the server. This response contains error information, and in the that line breaks are inserted for readability, and that the SMTP
success case the error response is empty. Like other messages, and protocol terminates lines with CR and LF characters (ASCII values
in accordance with the IMAP SASL binding, the empty response is 0x0D and 0x0A), these are not displayed explicitly in the example.
base64-encoded.
5.2. MAC Authentication with Channel Binding [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-ENHANCEDSTATUSCODES
S: 250-PIPELINING
C: t1 AUTHENTICATE OAUTH bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2VydmVy
LmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9QmVhcmVyIHZGOWRmdDRxbVRjMk5
2YjNSbGNrQmhiSFJoZG1semRHRXVZMjl0Q2c9PQEB
S: 235 Authentication successful.
[connection continues...]
This example shows a channel binding failure. The example sends the 5.2. OAuth 1.0a Authorization with Channel Binding
same request as above, but in the context of an OAUTH-PLUS exchange
the channel binding information is missing. Note that line breaks This example shows channel binding in the context of an OAuth 1.0a
are inserted for readability. 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=OAUTH SASL-IR IMAP4rev1 Server Ready
S: t0 OK Completed S: t0 OK Completed
C: t1 AUTHENTICATE OAUTH-PLUS aG9zdD1zZXJ2ZXIuZXhhbXBsZS5jb20BdXNlcj11c2 C: t1 AUTHENTICATE OAUTH-PLUS eSxhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2Vydm
VyQGV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9TUFDIHRva2VuPSJoNDgwZGpzOTNo VyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9T0F1dGggcmVhbG09IkV4YW1wbGUi
ZDgiLHRpbWVzdGFtcD0iMTM3MTMxMjAwIixub25jZT0iZGo4M2hzOXMiLHNpZ25hdH LG9hdXRoX2NvbnN1bWVyX2tleT0iOWRqZGo4Mmg0OGRqczlkMiIsb2F1dGhfdG9rZW
VyZT0iWVRWanlOU3VqWXMxV3NEdXJGbnZGaTRKSzZvPSIBY2JkYXRhPVNHOTNJR0pw 49ImtrazlkN2RoM2szOXNqdjciLG9hdXRoX3NpZ25hdHVyZV9tZXRob2Q9IkhNQUMt
WnlCcGN5QmhJRlJNVXlCbWFXNWhiQ0J0WlhOellXZGxQd289AQE= U0hBMSIsb2F1dGhfdGltZXN0YW1wPSIxMzcxMzEyMDEiLG9hdXRoX25vbmNlPSI3ZD
S: + hmM2U0YSIsb2F1dGhfc2lnbmF0dXJlPSJTU2R0SUdFZ2JHbDBkR3hsSUhSbFlTQndi
M1F1IgFxcz1jYmRhdGE9dGxzLXVuaXF1ZTpTRzkzSUdKcFp5QnBjeUJoSUZSTVV5Qm
1hVzVoYkNCdFpYTnpZV2RsUHdvPQEB
S: t1 OK SASL authentication succeeded S: t1 OK SASL authentication succeeded
As required by IMAP [RFC3501], the payloads are base64-encoded. The As required by IMAP [RFC3501], the payloads are base64-encoded. The
decoded initial client response (with %x01 represented as ^A and long decoded initial client response (with %x01 represented as ^A and
lines wrapped for readability) is: lines wrapped for readability) is:
- y,a=user@example.com,^A
host=server.example.com^A host=server.example.com^A
user=user@example.com^A
port=143^A port=143^A
auth=MAC token="h480djs93hd8",timestamp="137131200",nonce="dj83hs9s", auth=OAuth realm="Example",
signature="YTVjyNSujYs1WsDurFnvFi4JK6o="^A oauth_consumer_key="9djdj82h48djs9d2",
cbdata=SG93IGJpZyBpcyBhIFRMUyBmaW5hbCBtZXNzYWdlPwo=^A^A 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
The line containing just a "+" and a space is an empty response from In this example the signature base string with line breaks added for
the server. This response contains discovery information, and in the readability would be:
success case no discovery information is necessary so the response is
empty. Like other messages, and in accordance with the IMAP SASL POST&http%3A%2F%2Fserver.example.com:143%2F&cbdata=tls-unique:SG93I
binding, the empty response is base64-encoded. GJpZyBpcyBhIFRMUyBmaW5hbCBtZXNzYWdlPwo=%26oauth_consumer_key%3D9djd
j82h48djs9d2%26oauth_nonce%3D7d8f3e4a%26oauth_signature_method%3DHM
AC-SHA1%26oauth_timestamp%3D137131201%26oauth_token%3Dkkk9d7dh3k39s
jv7
5.3. Failed Exchange 5.3. Failed Exchange
This example shows a failed exchange because of the empty This example shows a failed exchange because of the empty
Authorization header, which is how a client can query for the needed Authorization header, which is how a client can query for the needed
scope. Note that line breaks are inserted for readability. scope. Note that line breaks are inserted for readability.
S: * CAPABILITY IMAP4rev1 AUTH=OAUTH SASL-IR IMAP4rev1 Server Ready S: * CAPABILITY IMAP4rev1 AUTH=OAUTH SASL-IR IMAP4rev1 Server Ready
S: t0 OK Completed S: t0 OK Completed
C: t1 AUTHENTICATE OAUTH aG9zdD1zZXJ2ZXIuZXhhbXBsZS5jb20BdXNlcj11 C: t1 AUTHENTICATE OAUTH bixhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2Vy
c2VyQGV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AQE= dmVyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AQE=
S: + eyJzdGF0dXMiOiI0MDEiLCJzY2hlbWVzIjoiYmVhcmVyIG1hYyIsInNjb3Bl S: + ewoic3RhdHVzIjoiNDAxIiwKInNjaGVtZXMiOiJiZWFyZXIiLAoic2NvcGUi
IjoiZXhhbXBsZV9zY29wZSJ9 OiJleGFtcGxlX3Njb3BlIgp9
C: + AQ==
S: t1 NO SASL authentication failed S: t1 NO SASL authentication failed
The decoded initial client response is: The decoded initial client response is:
host=server.example.com^Auser=user@example.com^Aport=143^Aauth=^A^A n,a=user@example.com,^Ahost=server.example.com^Aport=143^Aauth=^A^A
The decoded server error response is: The decoded server error response is:
{ {
"status":"401", "status":"401",
"schemes":"bearer mac", "schemes":"bearer",
"scope":"example_scope" "scope":"example_scope"
} }
The client responds with the required empty response.
5.4. Failed Channel Binding 5.4. Failed Channel Binding
This example shows a channel binding failure in an empty request. This example shows a channel binding failure in an empty request.
The channel binding information is empty. Note that line breaks are The channel binding information is empty. Note that line breaks are
inserted for readability. inserted for readability.
S: * CAPABILITY IMAP4rev1 AUTH=OAUTH SASL-IR IMAP4rev1 Server Ready S: * CAPABILITY IMAP4rev1 AUTH=OAUTH OAUTH-PLUS SASL-IR IMAP4rev1 Server
S: t0 OK Completed Ready
C: t1 AUTHENTICATE OAUTH aG9zdD1zZXJ2ZXIuZXhhbXBsZS5jb20BdXNlcj11 S: t0 OK Completed
c2VyQGV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AWNiZGF0YT0BAQ== C: t1 AUTHENTICATE OAUTH-PLUS eSxhPXVzZXJAZXhhbXBsZS5jb20sAWhvc3Q9c2Vydm
S: + eyJzdGF0dXMiOiI0MTIiLCJzY2hlbWVzIjoiYmVhcmVyIG1hYyIsInNjb3Bl VyLmV4YW1wbGUuY29tAXBvcnQ9MTQzAWF1dGg9AWNiZGF0YT0BAQ==
IjoiZXhhbXBsZV9zY29wZSJ9 S: + ewoic3RhdHVzIjoiNDEyIiwKInNjaGVtZXMiOiJiZWFyZXIgb2F1dGgiLAoi
S: t1 NO SASL authentication failed c2NvcGUiOiJleGFtcGxlX3Njb3BlIgp9
C: + AQ==
S: t1 NO SASL authentication failed
The decoded initial client response is: The decoded initial client response is:
host=server.example.com^Auser=user@example.com^Aport=143^A y,a=user@example.com,^A
host=server.example.com^Aport=143^A
auth=^Acbdata=^A^A auth=^Acbdata=^A^A
The decoded server response is: The decoded server response is:
{ {
"status":"412", "status":"412",
"schemes":"bearer mac", "schemes":"bearer oauth",
"scope":"example_scope" "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-ENHANCEDSTATUSCODES
S: 250-PIPELINING
C: AUTH OAUTH dXNlcj1zb21ldXNlckBleGFtcGxlLmNvbQFhdXRoPUJlYXJlciB2RjlkZn
Q0cW1UYzJOdmIzUmxja0JoZEhSaGRtbHpkR0V1WTI5dENnPT0BAQo=
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.
6. Security Considerations 6. Security Considerations
This mechanism does not provide a security layer, but does provide a This mechanism does not provide a security layer, but does provide a
provision for channel binding. The OAuth 2 specification provision for channel binding. The OAuth 2 specification
[I-D.ietf-oauth-v2] allows for a variety of usages, and the security [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 properties of these profiles vary. The usage of bearer tokens, for
example, provide security features similar to cookies. Applications example, provide security features similar to cookies. Applications
using this mechanism SHOULD exercise the same level of care using using this mechanism SHOULD exercise the same level of care using
this mechanism as they would in using the SASL PLAIN mechanism. In this mechanism as they would in using the SASL PLAIN mechanism. In
particular, TLS 1.2 or an equivalent secure channel MUST be particular, TLS 1.2 or an equivalent secure channel MUST be
implemented and its usage is RECOMMENDED. implemented and its usage is RECOMMENDED.
Channel binding in this mechanism has different properties based on The channel binding in this mechanism has different properties based
the authentication scheme used. Channel binding to TLS with a bearer on the authentication scheme used. The integrity guarantee for
token provides only a binding to the TLS layer. Authentication channel binding depends on the quality of the guarantee in the the
schemes like MAC tokens can implement a signature over the channel authorization scheme.
binding information. These provide additional protection against a
man in the middle attacks, and the MAC authorization header is bound
to the channel and only valid in that context.
It is possible that SASL will be authenticating a connection and the It is possible that SASL will be authenticating a connection and the
life of that connection may outlast the life of the token used to life of that connection may outlast the life of the token used to
authenticate it. This is a common problem in application protocols authenticate it. This is a common problem in application protocols
where connections are long-lived, and not a problem with this where connections are long-lived, and not a problem with this
mechanism per se. Servers MAY unilaterally disconnect clients in mechanism per se. Servers MAY unilaterally disconnect clients in
accordance with the application protocol. accordance with the application protocol.
An OAuth credential is not equivalent to the password or primary An OAuth credential is not equivalent to the password or primary
account credential. There are protocols like XMPP that allow actions account credential. There are protocols like XMPP that allow actions
like change password. The server SHOULD ensure that actions taken in like change password. The server SHOULD ensure that actions taken in
the authenticated channel are appropriate to the strength of the the authenticated channel are appropriate to the strength of the
presented credential. presented credential.
Tokens have a lifetime associated with them. Reducing the lifetime Tokens have a lifetime associated with them. Reducing the lifetime
of a token provides security benefits in case that tokens leak. In of a token provides security benefits in the case that tokens leak.
addition a previously obtained token MAY be revoked or rendered In addition a previously obtained token MAY be revoked or rendered
invalid at any time. The client MAY request a new access token for 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 each connection to a resource server, but it SHOULD cache and re-use
access credentials that appear to be valid. access credentials that appear to be valid.
7. IANA Considerations 7. IANA Considerations
7.1. SASL Registration 7.1. SASL Registration
The IANA is requested to register the following SASL profile: The IANA is requested to register the following SASL profile:
skipping to change at page 19, line 19 skipping to change at page 23, line 19
[I-D.ietf-oauth-v2] [I-D.ietf-oauth-v2]
Hardt, D., "The OAuth 2.0 Authorization Framework", Hardt, D., "The OAuth 2.0 Authorization Framework",
draft-ietf-oauth-v2-31 (work in progress), August 2012. draft-ietf-oauth-v2-31 (work in progress), August 2012.
[I-D.ietf-oauth-v2-bearer] [I-D.ietf-oauth-v2-bearer]
Jones, M. and D. Hardt, "The OAuth 2.0 Authorization Jones, M. and D. Hardt, "The OAuth 2.0 Authorization
Framework: Bearer Token Usage", Framework: Bearer Token Usage",
draft-ietf-oauth-v2-bearer-23 (work in progress), draft-ietf-oauth-v2-bearer-23 (work in progress),
August 2012. August 2012.
[I-D.ietf-oauth-v2-http-mac]
Hammer-Lahav, E., "HTTP Authentication: MAC Access
Authentication", draft-ietf-oauth-v2-http-mac-01 (work in
progress), February 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A., and L. Stewart, "HTTP Leach, P., Luotonen, A., and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication", Authentication: Basic and Digest Access Authentication",
skipping to change at page 20, line 8 skipping to change at page 23, line 52
[RFC5056] Williams, N., "On the Use of Channel Bindings to Secure [RFC5056] Williams, N., "On the Use of Channel Bindings to Secure
Channels", RFC 5056, November 2007. Channels", RFC 5056, November 2007.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
October 2008.
[RFC5801] Josefsson, S. and N. Williams, "Using Generic Security [RFC5801] Josefsson, S. and N. Williams, "Using Generic Security
Service Application Program Interface (GSS-API) Mechanisms Service Application Program Interface (GSS-API) Mechanisms
in Simple Authentication and Security Layer (SASL): The in Simple Authentication and Security Layer (SASL): The
GS2 Mechanism Family", RFC 5801, July 2010. GS2 Mechanism Family", RFC 5801, July 2010.
[RFC5849] Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849, [RFC5849] Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849,
April 2010. April 2010.
[RFC5929] Altman, J., Williams, N., and L. Zhu, "Channel Bindings [RFC5929] Altman, J., Williams, N., and L. Zhu, "Channel Bindings
for TLS", RFC 5929, July 2010. for TLS", RFC 5929, July 2010.
skipping to change at page 20, line 29 skipping to change at page 24, line 27
[RFC5988] Nottingham, M., "Web Linking", RFC 5988, October 2010. [RFC5988] Nottingham, M., "Web Linking", RFC 5988, October 2010.
[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
Verification of Domain-Based Application Service Identity Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509 within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer (PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, March 2011. Security (TLS)", RFC 6125, March 2011.
8.2. Informative References 8.2. Informative References
[I-D.ietf-oauth-v2-http-mac]
Hammer-Lahav, E., "HTTP Authentication: MAC Access
Authentication", draft-ietf-oauth-v2-http-mac-01 (work in
progress), February 2012.
[I-D.jones-appsawg-webfinger] [I-D.jones-appsawg-webfinger]
Jones, P., Salgueiro, G., and J. Smarr, "WebFinger", Jones, P., Salgueiro, G., and J. Smarr, "WebFinger",
draft-jones-appsawg-webfinger-06 (work in progress), draft-jones-appsawg-webfinger-06 (work in progress),
June 2012. June 2012.
[RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION [RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION
4rev1", RFC 3501, March 2003. 4rev1", RFC 3501, March 2003.
Appendix A. Document History 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 ]] [[ to be removed by RFC editor before publication as an RFC ]]
-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 -03
o Added user field into examples and fixed egregious errors there as o Added user field into examples and fixed egregious errors there as
well. well.
o Added text reminding developers that Authorization scheme names o Added text reminding developers that Authorization scheme names
are case insensitive. are case insensitive.
-02 -02
skipping to change at page 21, line 37 skipping to change at page 28, line 5
o Replacing HTTP as the message format and adjusted all examples. o Replacing HTTP as the message format and adjusted all examples.
-00 -00
o Renamed draft into proper IETF naming format now that it's o Renamed draft into proper IETF naming format now that it's
adopted. adopted.
o Minor fixes. o Minor fixes.
-00
o Initial revision
Authors' Addresses Authors' Addresses
William Mills William Mills
Yahoo! Inc. Yahoo! Inc.
Phone: Phone:
Email: wmills@yahoo-inc.com Email: wmills@yahoo-inc.com
Tim Showalter Tim Showalter
 End of changes. 62 change blocks. 
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