Network Working Group E. Hammer-Lahav, Ed.
Internet-Draft Yahoo!
Intended status: Standards Track July 6, 2009
Expires: January 7, 2010
The OAuth Protocol: Web Delegation
draft-ietf-oauth-web-delegation-00
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Abstract
This document specifies the OAuth protocol web delegation method.
OAuth allows clients to access server resources on behalf of another
party (such a different client or an end user). This document
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defines a redirection-based user-agent process for end users to
authorize access to clients by substituting their credentials
(typically, a username and password pair) with a different set of
delegation-specific credentials.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 4
3. Redirection-Based Authorization . . . . . . . . . . . . . . . 4
3.1. Temporary Credentials . . . . . . . . . . . . . . . . . . 5
3.2. Resource Owner Authorization . . . . . . . . . . . . . . . 6
3.3. Token Credentials . . . . . . . . . . . . . . . . . . . . 8
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5.1. Credentials Transmission . . . . . . . . . . . . . . . . . 9
5.2. Phishing Attacks . . . . . . . . . . . . . . . . . . . . . 9
5.3. Scoping of Access Requests . . . . . . . . . . . . . . . . 10
5.4. Entropy of Secrets . . . . . . . . . . . . . . . . . . . . 10
5.5. Denial of Service / Resource Exhaustion Attacks . . . . . 10
5.6. Cross-Site Request Forgery (CSRF) . . . . . . . . . . . . 11
5.7. User Interface Redress . . . . . . . . . . . . . . . . . . 11
5.8. Automatic Processing of Repeat Authorizations . . . . . . 12
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . 12
Appendix A.1. Obtaining Temporary Credentials . . . . . . . . . 13
Appendix A.2. Requesting Resource Owner Authorization . . . . . 14
Appendix A.3. Obtaining Token Credentials . . . . . . . . . . . 14
Appendix A.4. Accessing protected resources . . . . . . . . . . 14
Appendix A.4.1. Generating Signature Base String . . . . . . . . . 14
Appendix A.4.2. Calculating Signature Value . . . . . . . . . . . 16
Appendix A.4.3. Requesting protected resource . . . . . . . . . . 16
Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . 16
Appendix C. Document History . . . . . . . . . . . . . . . . . 16
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1. Normative References . . . . . . . . . . . . . . . . . . . 17
6.2. Informative References . . . . . . . . . . . . . . . . . . 17
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 18
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1. Introduction
The OAuth protocol provides a method for servers to allow third-party
access to protected resources, without forcing their end users to
share their credentials. This pattern is common among services that
allow third-party developers to extend the service functionality, by
building applications using an open API.
For example, a web user (resource owner) can grant a printing service
(client) access to its private photos stored at a photo sharing
service (server), without sharing its credentials with the printing
service. Instead, the user authenticates directly with the photo
sharing service and issue the printing service delegation-specific
credentials.
OAuth introduces a third role to the traditional client-server
authentication model: the resource owner. In the OAuth model, the
client requests access to resources hosted by the server but not
controlled by the client, but by the resource owner. In addition,
OAuth allows the server to verify not only the resource owner's
credentials, but also those of the client making the request.
In order for the client to access resources, it first has to obtain
permission from the resource owner. This permission is expressed in
the form of a token and matching shared-secret. The purpose of the
token is to substitute the need for the resource owner to share its
server credentials (usually a username and password pair) with the
client. Unlike server credentials, tokens can be issued with a
restricted scope and limited lifetime.
This specification consists of two parts.
[draft-ietf-oauth-authentication] defines a method for making
authenticated HTTP requests using two sets of credentials, one
identifying the client making the request, and a second identifying
the resource owner on whose behalf the request is being made.
This document defines a redirection-based user agent process for end
users to authorize client access to their resources, by
authenticating directly with the server and provisioning tokens to
the client for use with the authentication method.
1.1. Terminology
client
An HTTP client (per [RFC2616]) capable of making OAuth-
authenticated requests per [draft-ietf-oauth-authentication].
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server
An HTTP server (per [RFC2616]) capable of accepting OAuth-
authenticated requests per [draft-ietf-oauth-authentication].
protected resource
An access-restricted resource (per [RFC2616]) which can be
obtained from the server using an OAuth-authenticated request
per [draft-ietf-oauth-authentication].
resource owner
An entity capable of accessing and controlling protected
resources by using credentials to authenticate with the server.
token
An unique identifier issued by the server and used by the
client to associate authenticated requests with the resource
owner whose authorization is requested or has been obtained by
the client. Tokens have a matching shared-secret that is used
by the client to establish its ownership of the token, and its
authority to represent the resource owner.
2. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. Redirection-Based Authorization
OAuth uses a set of token credentials to represent the authorization
granted to the client by the resource owner. Typically, token
credentials are issued by the server at the resource owner's request,
after authenticating the resource owner's identity using its server
credentials (usually a username and password pair).
There are many ways in which a resource owner can facilitate the
provisioning of token credentials. This section defines one such
way, using HTTP redirections and the resource owner's user agent.
This redirection-based authorization method includes three steps:
1. The client obtains a set of temporary credentials from the
server.
2. The resource owner authorizes the server to issue token
credentials to the client using the temporary credentials.
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3. The client uses the temporary credentials to request a set of
token credentials from the server, which will enable it to access
the resource owner's protected resources. The temporary
credentials discarded.
The temporary credentials MUST be revoked after being used once to
obtain the token credentials. It is RECOMMENDED that the temporary
credentials have a limited lifetime. Servers SHOULD enable resource
owners to revoke token credentials after they have been issued to
clients.
In order for the client to perform these steps, the server needs to
advertise the URIs of these three endpoints, as well as the HTTP
method (GET, POST, etc.) used to make each requests. To assist in
communicating these endpoint, each is given a name:
Temporary Credential Request
The endpoint used by the client to obtain temporary credentials
as described in Section 3.1.
Resource Owner Authorization
The endpoint to which the resource owner is redirected to grant
authorization as described in Section 3.2.
Token Request
The endpoint used by the client to request a set of token
credentials using the temporary credentials as described in
Section 3.3.
The three URIs MAY include a query component as defined by [RFC3986]
section 3, but if present, the query MUST NOT contain any parameters
beginning with the "oauth_" prefix.
The method in which the server advertises its three endpoint is
beyond the scope of this specification.
3.1. Temporary Credentials
The client obtains a set of temporary credentials from the server by
making an authenticated request per
[draft-ietf-oauth-authentication]. The client MUST use the HTTP
method advertised by the server. The HTTP POST method is
RECOMMENDED. The client constructs a request URI by adding the
following parameter to the Temporary Credential Request endpoint URI:
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oauth_callback: An absolute URL to which the server will redirect
the resource owner back when the Resource Owner Authorization
step (Section 3.2) is completed. If the client is unable to
receive callbacks or a callback URI has been established via
other means, the parameter value MUST be set to "oob" (case
sensitive), to indicate an out-of-band configuration.
Servers MAY specify additional parameters.
When making the request, the client authenticates using only the
client credentials. The client MUST omit the "oauth_token" protocol
parameter from the request and use an empty string as the token
secret value.
The server MUST verify that the request is valid per
[draft-ietf-oauth-authentication] and respond back to the client with
a set of temporary credentials. The temporary credentials are
included in the HTTP response body using the
"application/x-www-form-urlencoded" content type as defined by
[W3C.REC-html40-19980424].
The response contains the following parameters:
oauth_token
The temporary credentials identifier.
oauth_token_secret
The temporary credentials shared-secret.
oauth_callback_confirmed: MUST be present and set to "true". The
client MAY use this to confirm that the server received the
callback value.
Note that even though the parameter names include the term 'token',
these credentials are not token credentials, but are used in the next
two steps in a similar manner to token credentials.
For example (line breaks are for display purposes only):
oauth_token=ab3cd9j4ks73hf7g&oauth_token_secret=xyz4992k83j47x0b&
oauth_callback_confirmed=true
3.2. Resource Owner Authorization
Before the client requests a set of token credentials from the
server, it MUST send the user to the server to authorize the request.
The client constructs a request URI by adding the following
parameters to the Resource Owner Authorization endpoint URI:
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oauth_token
REQUIRED. The temporary credentials identifier obtained in
Section 3.1 in the "oauth_token" parameter. Servers MAY
declare this parameter as OPTIONAL, in which case they MUST
provide a way for the resource owner to indicate the identifier
through other means.
Servers MAY specify additional parameters.
The client redirects the resource owner to the constructed URI using
an HTTP redirection response, or by other means available to it via
the resource owner's user agent. The request MUST use the HTTP GET
method.
The way in which the server handles the authorization request is
beyond the scope of this specification. However, the server MUST
first verify the identity of the resource owner.
When asking the resource owner to authorize the requested access, the
server SHOULD present to the resource owner information about the
client requesting access based on the association of the temporary
credentials with the client identity. When displaying any such
information, the server SHOULD indicate if the information has been
verified.
After receiving an authorization decision from the resource owner,
the server redirects the resource owner to the callback URI if one
was provided in the "oauth_callback" parameter or by other means.
To make sure that the resource owner granting access is the same
resource owner returning back to the client to complete the process,
the server MUST generate a verification code: an unguessable value
passed to the client via the resource owner and REQUIRED to complete
the process. The server constructs the request URI by adding the
following parameter to the callback URI query component:
oauth_token
The temporary credentials identifier the resource owner
authorized or denied access to.
oauth_verifier: The verification code.
If the callback URI already includes a query component, the server
MUST append the OAuth parameters to the end of the existing query.
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For example (line breaks are for display purposes only):
http://client.example.net/cb?state=1&oauth_token=ab3cd9j4ks73hf7g&
oauth_verifier=473829k9302sa
If the client did not provide a callback URI, the server SHOULD
display the value of the verification code, and instruct the resource
owner to manually inform the client that authorization is completed.
If the server knows a client to be running on a limited device it
SHOULD ensure that the verifier value is suitable for manual entry.
3.3. Token Credentials
The client obtains a set of token credentials from the server by
making an authenticated request per
[draft-ietf-oauth-authentication]. The client MUST use the HTTP
method advertised by the server. The HTTP POST method is
RECOMMENDED. The client constructs a request URI by adding the
following parameter to the Token Request endpoint URI:
oauth_verifier: The verification code received from the server in
the previous step.
When making the request, the client authenticates using the client
credentials as well as the temporary credentials. The temporary
credentials are used as a substitution for token credentials in the
authenticated request.
The server MUST verify the validity of the request per
[draft-ietf-oauth-authentication], ensure that the resource owner has
authorized the provisioning of token credentials to the client, and
that the temporary credentials have not expired or used before. The
server MUST also verify the verification code received from the
client. If the request is valid and authorized, the token
credentials are included in the HTTP response body using the
"application/x-www-form-urlencoded" content type as defined by
[W3C.REC-html40-19980424].
The response contains the following parameters:
oauth_token
The token identifier.
oauth_token_secret
The token shared-secret.
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For example:
oauth_token=j49ddk933skd9dks&oauth_token_secret=ll399dj47dskfjdk
The token credentials issued by the server MUST reflect the exact
scope, duration, and other attributes approved by the resource owner.
Once the client receives the token credentials, it can proceed to
access protected resources on behalf of the resource owner by making
an authenticated request per [draft-ietf-oauth-authentication] using
the client credentials and the token credentials received.
4. IANA Considerations
This memo includes no request to IANA.
5. Security Considerations
As stated in [RFC2617], the greatest sources of risks are usually
found not in the core protocol itself but in policies and procedures
surrounding its use. Implementers are strongly encouraged to assess
how this protocol addresses their security requirements.
5.1. Credentials Transmission
The OAuth specification does not describe any mechanism for
protecting tokens and shared-secrets from eavesdroppers when they are
transmitted from the server to the client during the authorization
phase. Servers should ensure that these transmissions are protected
using transport-layer mechanisms such as TLS or SSL.
5.2. Phishing Attacks
Wide deployment of OAuth and similar protocols may cause resource
owners to become inured to the practice of being redirected to
websites where they are asked to enter their passwords. If resource
owners are not careful to verify the authenticity of these websites
before entering their credentials, it will be possible for attackers
to exploit this practice to steal resource owners' passwords.
Servers should attempt to educate resource owners about the risks
phishing attacks pose, and should provide mechanisms that make it
easy for resource owners to confirm the authenticity of their sites.
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5.3. Scoping of Access Requests
By itself, OAuth does not provide any method for scoping the access
rights granted to a client. However, most applications do require
greater granularity of access rights. For example, servers may wish
to make it possible to grant access to some protected resources but
not others, or to grant only limited access (such as read-only
access) to those protected resources.
When implementing OAuth, servers should consider the types of access
resource owners may wish to grant clients, and should provide
mechanisms to do so. Servers should also take care to ensure that
resource owners understand the access they are granting, as well as
any risks that may be involved.
5.4. Entropy of Secrets
Unless a transport-layer security protocol is used, eavesdroppers
will have full access to OAuth requests and signatures, and will thus
be able to mount offline brute-force attacks to recover the
credentials used. Servers should be careful to assign shared-secrets
which are long enough, and random enough, to resist such attacks for
at least the length of time that the shared-secrets are valid.
For example, if shared-secrets are valid for two weeks, servers
should ensure that it is not possible to mount a brute force attack
that recovers the shared-secret in less than two weeks. Of course,
servers are urged to err on the side of caution, and use the longest
secrets reasonable.
It is equally important that the pseudo-random number generator
(PRNG) used to generate these secrets be of sufficiently high
quality. Many PRNG implementations generate number sequences that
may appear to be random, but which nevertheless exhibit patterns or
other weaknesses which make cryptanalysis or brute force attacks
easier. Implementers should be careful to use cryptographically
secure PRNGs to avoid these problems.
5.5. Denial of Service / Resource Exhaustion Attacks
The OAuth protocol has a number of features which may make resource
exhaustion attacks against servers possible. For example, if a
server includes a nontrivial amount of entropy in token shared-
secrets as recommended above, then an attacker may be able to exhaust
the server's entropy pool very quickly by repeatedly obtaining
temporary credentials from the server.
Similarly, OAuth requires servers to track used nonces. If an
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attacker is able to use many nonces quickly, the resources required
to track them may exhaust available capacity. And again, OAuth can
require servers to perform potentially expensive computations in
order to verify the signature on incoming requests. An attacker may
exploit this to perform a denial of service attack by sending a large
number of invalid requests to the server.
Resource Exhaustion attacks are by no means specific to OAuth.
However, OAuth implementers should be careful to consider the
additional avenues of attack that OAuth exposes, and design their
implementations accordingly. For example, entropy starvation
typically results in either a complete denial of service while the
system waits for new entropy or else in weak (easily guessable)
secrets. When implementing OAuth, servers should consider which of
these presents a more serious risk for their application and design
accordingly.
5.6. Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) is a web-based attack whereby HTTP
requests are transmitted from a user that the website trusts or has
authenticated. CSRF attacks on OAuth approvals can allow an attacker
to obtain authorization to protected resources without the consent of
the User. Servers SHOULD strongly consider best practices in CSRF
prevention at all OAuth endpoints.
CSRF attacks on OAuth callback URIs hosted by client are also
possible. Clients should prevent CSRF attacks on OAuth callback URIs
by verifying that the resource owner at the client site intended to
complete the OAuth negotiation with the server.
5.7. User Interface Redress
Servers should protect the authorization process against UI Redress
attacks (also known as "clickjacking"). As of the time of this
writing, no complete defenses against UI redress are available.
Servers can mitigate the risk of UI redress attacks through the
following techniques:
o Javascript frame busting.
o Javascript frame busting, and requiring that browsers have
javascript enabled on the authorization page.
o Browser-specific anti-framing techniques.
o Requiring password reentry before issuing OAuth tokens.
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5.8. Automatic Processing of Repeat Authorizations
Servers may wish to automatically process authorization requests
(Section 3.2) from clients which have been previously authorized by
the resource owner. When the resource owner is redirected to the
server to grant access, the server detects that the resource owner
has already granted access to that particular client. Instead of
prompting the resource owner for approval, the server automatically
redirects the resource owner back to the client.
If the client credentials are compromised, automatic processing
creates additional security risks. An attacker can use the stolen
client credentials to redirect the resource owner to the server with
an authorization request. The server will then grant access to the
resource owner's data without the resource owner's explicit approval,
or even awareness of an attack. If no automatic approval is
implemented, an attacker must use social engineering to convince the
resource owner to approve access.
Servers can mitigate the risks associated with automatic processing
by limiting the scope of token credentials obtained through automated
approvals. Tokens credentials obtained through explicit resource
owner consent can remain unaffected. clients can mitigate the risks
associated with automatic processing by protecting their client
credentials.
Appendix A. Examples
In this example, photos.example.net is a photo sharing website
(server), and printer.example.com is a photo printing service
(client). Jane (resource owner) would like printer.example.com to
print a private photo stored at photos.example.net.
When Jane signs-into photos.example.net using her username and
password, she can access the photo by requesting the URI
"http://photos.example.net/photo?file=vacation.jpg" (which also
supports the optional "size" parameter). Jane does not want to share
her username and password with printer.example.com, but would like it
to access the photo and print it.
The server documentation advertises support for the "HMAC-SHA1" and
"PLAINTEXT" methods, with "PLAINTEXT" restricted to secure (HTTPS)
requests. It also advertises the following endpoint URIs:
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Temporary Credential Request
https://photos.example.net/initiate, using HTTP POST
Resource Owner Authorization URI:
http://photos.example.net/authorize, using HTTP GET
Token Request URI:
https://photos.example.net/token, using HTTP POST
The printer.example.com has already established client credentials
with photos.example.net:
Client Identifier
"dpf43f3p2l4k3l03"
Client Shared-Secret:
"kd94hf93k423kf44"
When printer.example.com attempts to print the request photo, it
receives an HTTP response with a 401 (Unauthorized) status code, and
a challenge to use OAuth:
WWW-Authenticate: OAuth realm="http://photos.example.net/"
Appendix A.1. Obtaining Temporary Credentials
The client sends the following HTTPS POST request to the server:
POST /initiate HTTP/1.1
Host: photos.example.net
Authorization: OAuth realm="http://photos.example.com/",
oauth_consumer_key="dpf43f3p2l4k3l03",
oauth_signature_method="PLAINTEXT",
oauth_signature="kd94hf93k423kf44%26",
oauth_timestamp="1191242090",
oauth_nonce="hsu94j3884jdopsl",
oauth_version="1.0",
oauth_callback="http%3A%2F%2Fprinter.example.com%2Fready"
The server validates the request and replies with a set of temporary
credentials in the body of the HTTP response:
oauth_token=hh5s93j4hdidpola&oauth_token_secret=hdhd0244k9j7ao03&
oauth_callback_confirmed=true
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Appendix A.2. Requesting Resource Owner Authorization
The client redirects Jane's browser to the server's Resource Owner
Authorization endpoint URI to obtain Jane's approval for accessing
her private photos.
http://photos.example.net/authorize?oauth_token=hh5s93j4hdidpola
The server asks Jane to sign-in using her username and password and
if successful, asks her if she approves granting printer.example.com
access to her private photos. Jane approves the request and is
redirects her back to the client's callback URI:
http://printer.example.com/ready?
oauth_token=hh5s93j4hdidpola&oauth_verifier=hfdp7dh39dks9884
Appendix A.3. Obtaining Token Credentials
After being informed by the callback request that Jane approved
authorized access, printer.example.com requests a set of token
credentials using its temporary credentials:
POST /token HTTP/1.1
Host: photos.example.net
Authorization: OAuth realm="http://photos.example.com/",
oauth_consumer_key="dpf43f3p2l4k3l03",
oauth_token="hh5s93j4hdidpola",
oauth_signature_method="PLAINTEXT",
oauth_signature="kd94hf93k423kf44%26hdhd0244k9j7ao03",
oauth_timestamp="1191242092",
oauth_nonce="dji430splmx33448",
oauth_version="1.0"
oauth_verifier="hfdp7dh39dks9884"
The server validates the request and replies with a set of token
credentials in the body of the HTTP response:
oauth_token=nnch734d00sl2jdk&oauth_token_secret=pfkkdhi9sl3r4s00
Appendix A.4. Accessing protected resources
The printer is now ready to request the private photo. Since the
photo URI does not use HTTPS, the "HMAC-SHA1" method is required.
Appendix A.4.1. Generating Signature Base String
To generate the signature, it first needs to generate the signature
base string. The request contains the following parameters
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("oauth_signature" excluded) which need to be ordered and
concatenated into a normalized string:
oauth_consumer_key
"dpf43f3p2l4k3l03"
oauth_token
"nnch734d00sl2jdk"
oauth_signature_method
"HMAC-SHA1"
oauth_timestamp
"1191242096"
oauth_nonce
"kllo9940pd9333jh"
oauth_version
"1.0"
file
"vacation.jpg"
size
"original"
The following inputs are used to generate the signature base string:
1. The HTTP request method: "GET"
2. The request URI: "http://photos.example.net/photos"
3. The encoded normalized request parameters string: "file=vacation.
jpg&oauth_consumer_key=dpf43f3p2l4k3l03&oauth_nonce=kllo9940pd933
3jh&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1191242096&o
auth_token=nnch734d00sl2jdk&oauth_version=1.0&size=original"
The signature base string is (line breaks are for display purposes
only):
GET&http%3A%2F%2Fphotos.example.net%2Fphotos&file%3Dvacation.jpg%26
oauth_consumer_key%3Ddpf43f3p2l4k3l03%26oauth_nonce%3Dkllo9940pd933
3jh%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D119124
2096%26oauth_token%3Dnnch734d00sl2jdk%26oauth_version%3D1.0%26size%
3Doriginal
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Appendix A.4.2. Calculating Signature Value
HMAC-SHA1 produces the following "digest" value as a base64-encoded
string (using the signature base string as "text" and
"kd94hf93k423kf44&pfkkdhi9sl3r4s00" as "key"):
tR3+Ty81lMeYAr/Fid0kMTYa/WM=
Appendix A.4.3. Requesting protected resource
All together, the client request for the photo is:
GET /photos?file=vacation.jpg&size=original HTTP/1.1
Host: photos.example.com
Authorization: OAuth realm="http://photos.example.net/",
oauth_consumer_key="dpf43f3p2l4k3l03",
oauth_token="nnch734d00sl2jdk",
oauth_signature_method="HMAC-SHA1",
oauth_signature="tR3%2BTy81lMeYAr%2FFid0kMTYa%2FWM%3D",
oauth_timestamp="1191242096",
oauth_nonce="kllo9940pd9333jh",
oauth_version="1.0"
The photos.example.net sever validates the request and responds with
the requested photo.
Appendix B. Acknowledgments
This specification is directly based on the [OAuth Core 1.0 Revision
A] community specification which was the product of the OAuth
community. OAuth was modeled after existing proprietary protocols
and best practices that have been independently implemented by
various web sites. This specification was orignially authored by:
Mark Atwood, Dirk Balfanz, Darren Bounds, Richard M. Conlan, Blaine
Cook, Leah Culver, Breno de Medeiros, Brian Eaton, Kellan Elliott-
McCrea, Larry Halff, Eran Hammer-Lahav, Ben Laurie, Chris Messina,
John Panzer, Sam Quigley, David Recordon, Eran Sandler, Jonathan
Sergent, Todd Sieling, Brian Slesinsky, and Andy Smith.
Appendix C. Document History
[[ To be removed by the RFC editor before publication as an RFC. ]]
-00
Hammer-Lahav Expires January 7, 2010 [Page 16]
Internet-Draft OAuth July 2009
o Transitioned from the individual submission draft-hammer-oauth-02
to working group draft.
o Split draft-hammer-oauth-02 into two drafts, one dealing with web
delegation (this draft) and another dealing with authentication
draft-ietf-oauth-web-authentication.
o Updated draft with changes from OAuth Core 1.0 Revision A to fix a
session fixation exploit.
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A., and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication",
RFC 2617, June 1999.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
[W3C.REC-html40-19980424]
Hors, A., Jacobs, I., and D. Raggett, "HTML 4.0
Specification", World Wide Web Consortium
Recommendation REC-html40-19980424, April 1998,
<http://www.w3.org/TR/1998/REC-html40-19980424>.
[draft-ietf-oauth-authentication]
Hammer-Lahav, E., Ed., "The OAuth Protocol:
Authentication".
6.2. Informative References
[OAuth Core 1.0 Revision A]
OAuth, OCW., "OAuth Core 1.0".
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Internet-Draft OAuth July 2009
Author's Address
Eran Hammer-Lahav (editor)
Yahoo!
Email: eran@hueniverse.com
URI: http://hueniverse.com
Hammer-Lahav Expires January 7, 2010 [Page 18]
