| Network Working Group | E. Hammer-Lahav, Ed. |
| Internet-Draft | Yahoo! |
| Obsoletes: 5849 (if approved) | D. Recordon |
| Intended status: Standards Track | |
| Expires: January 26, 2012 | D. Hardt |
| Microsoft | |
| July 25, 2011 |
The OAuth 2.0 Authorization Protocol
draft-ietf-oauth-v2-19
The OAuth 2.0 authorization protocol enables a third-party application to obtain limited access to an HTTP service, either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, or by allowing the third-party application to obtain access on its own behalf.
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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/.
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This Internet-Draft will expire on January 26, 2012.
Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved.
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In the traditional client-server authentication model, the client accesses a protected resource on the server by authenticating with the server using the resource owner's credentials. In order to provide third-party applications access to protected resources, the resource owner shares its credentials with the third-party. This creates several problems and limitations:
OAuth addresses these issues by introducing an authorization layer and separating the role of the client from that of the resource owner. In OAuth, the client requests access to resources controlled by the resource owner and hosted by the resource server, and is issued a different set of credentials than those of the resource owner.
Instead of using the resource owner's credentials to access protected resources, the client obtains an access token - a string denoting a specific scope, lifetime, and other access attributes. Access tokens are issued to third-party clients by an authorization server with the approval of the resource owner. The client uses the access token to access the protected resources hosted by the resource server.
For example, an end-user (resource owner) can grant a printing service (client) access to her protected photos stored at a photo sharing service (resource server), without sharing her username and password with the printing service. Instead, she authenticates directly with a server trusted by the photo sharing service (authorization server) which issues the printing service delegation-specific credentials (access token).
This specification is designed for use with HTTP [RFC2616]. The use of OAuth with any transport protocol other than HTTP is undefined.
OAuth includes four roles working together to grant and provide access to protected resources - access restricted resources requiring authentication:
The interaction between the authorization server and resource server is beyond the scope of this specification. The authorization server may be the same server as the resource server or a separate entity. A single authorization server may issue access tokens accepted by multiple resource servers.
+--------+ +---------------+
| |--(A)- Authorization Request ->| Resource |
| | | Owner |
| |<-(B)-- Authorization Grant ---| |
| | +---------------+
| |
| | +---------------+
| |--(C)-- Authorization Grant -->| Authorization |
| Client | | Server |
| |<-(D)----- Access Token -------| |
| | +---------------+
| |
| | +---------------+
| |--(E)----- Access Token ------>| Resource |
| | | Server |
| |<-(F)--- Protected Resource ---| |
+--------+ +---------------+
The abstract flow illustrated in Figure 1 describes the interaction between the four roles and includes the following steps:
Access tokens are credentials used to access protected resources. An access token is a string representing an authorization issued to the client. The string is usually opaque to the client. Tokens represent specific scopes and durations of access, granted by the resource owner, and enforced by the resource server and authorization server.
The token may denote an identifier used to retrieve the authorization information, or self-contain the authorization information in a verifiable manner (i.e. a token string consisting of some data and a signature). Additional authentication credentials, which are beyond the scope of this specification, may be required in order for the client to use a token.
The access token provides an abstraction layer, replacing different authorization constructs (e.g. username and password) with a single token understood by the resource server. This abstraction enables issuing access tokens more restrictive than the authorization grant used to obtain them, as well as removing the resource server's need to understand a wide range of authentication methods.
Access tokens can have different formats, structures, and methods of utilization (e.g. cryptographic properties) based on the resource server security requirements. Access token attributes and the methods used to access protected resources are beyond the scope of this specification and are defined by companion specifications.
An authorization grant is a general term used to describe the intermediate credentials representing the resource owner authorization (to access its protected resources), and serves as an abstraction layer. An authorization grant is used by the client to obtain an access token.
This specification defines four grant types: authorization code, implicit, resource owner password credentials, and client credentials, as well as an extensibility mechanism for defining additional types.
The authorization code is obtained by using an authorization server as an intermediary between the client and resource owner. Instead of requesting authorization directly from the resource owner, the client directs the resource owner to an authorization server (via its user-agent as defined in [RFC2616]), which in turn directs the resource owner back to the client with the authorization code.
Before directing the resource owner back to the client with the authorization code, the authorization server authenticates the resource owner and obtains authorization. Because the resource owner only authenticates with the authorization server, the resource owner's credentials are never shared with the client.
The authorization code provides a few important security benefits such as the ability to authenticate the client and issuing the access token directly to the client without potentially exposing it to others, including the resource owner.
The authorization grant is implicit when an access token is issued to the client directly as the result of the resource owner authorization, without using intermediate credentials (such as an authorization code).
When issuing an implicit grant, the authorization server does not authenticate the client and the client identity is verified via the redirection URI used to deliver the access token to the client. The access token may be exposed to the resource owner or other applications with access to the resource owner's user-agent.
Implicit grants improve the responsiveness and efficiency of some clients (such as a client implemented as an in-browser application) since it reduces the number of round trips required to obtain an access token. However, this convenience should be weighted against the security implications of using implicit grants, especially when the authorization code grant type is available.
The resource owner password credentials (e.g. a username and password) can be used directly as an authorization grant to obtain an access token. The credentials should only be used when there is a high degree of trust between the resource owner and the client (e.g. its device operating system or a highly privileged application), and when other authorization grant types are not available (such as an authorization code).
Even though this grant type requires direct client access to the resource owner credentials, the resource owner credentials are used for a single request and are exchanged for an access token. Unlike the HTTP Basic authentication scheme defined in [RFC2617], this grant type (when combined with a refresh token) eliminates the need for the client to store the resource owner credentials for future use.
The client credentials (or other forms of client authentication) can be used as an authorization grant when the authorization scope is limited to the protected resources under the control of the client, or to protected resources previously arranged with the authorization server. Client credentials are used as an authorization grant typically when the client is acting on its own behalf (the client is also the resource owner).
Additional grant types may be defined to provide a bridge between OAuth and other protocols.
Refresh tokens are credentials used to obtain access tokens. Refresh tokens are issued to the client by the authorization server and are used to obtain a new access token when the current access token becomes invalid or expires, or to obtain additional access tokens with identical or narrower scope (access tokens may have a shorter lifetime and fewer permissions than authorized by the resource owner). Issuing a refresh token is optional and is included when issuing an access token.
A refresh token is a string representing the authorization granted to the client by the resource owner. The string is usually opaque to the client. The token denotes an identifier used to retrieve the authorization information. Unlike access tokens, refresh tokens are intended for use only with authorization servers and are never sent to resource servers.
+--------+ +---------------+
| |--(A)------- Authorization Grant --------->| |
| | | |
| |<-(B)----------- Access Token -------------| |
| | & Refresh Token | |
| | | |
| | +----------+ | |
| |--(C)---- Access Token ---->| | | |
| | | | | |
| |<-(D)- Protected Resource --| Resource | | Authorization |
| Client | | Server | | Server |
| |--(E)---- Access Token ---->| | | |
| | | | | |
| |<-(F)- Invalid Token Error -| | | |
| | +----------+ | |
| | | |
| |--(G)----------- Refresh Token ----------->| |
| | | |
| |<-(H)----------- Access Token -------------| |
+--------+ & Optional Refresh Token +---------------+
The flow illustrated in Figure 2 includes the following steps:
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in this specification are to be interpreted as described in [RFC2119].
This specification uses the Augmented Backus-Naur Form (ABNF) notation of [RFC5234].
Certain security-related terms are to be understood in the sense defined in [RFC4949]. These terms include, but are not limited to, 'attack', 'authentication', 'authorization', 'certificate', 'confidentiality', 'credential', 'encryption', 'identity', 'sign', 'signature', 'trust', 'validate', and 'verify'.
Unless otherwise noted, all the protocol parameter names and values are case sensitive.
Before initiating the protocol, the client registers with the authorization server. The means through which the client registers with the authorization server are beyond the scope of this specification, but typically involve end-user interaction with an HTML registration form.
Client registration does not require a direct interaction between the client and the authorization server. When supported by the authorization server, registration can rely on other means for establishing trust and obtaining the required client properties (e.g. redirection URI, client type). For example, registration can be accomplished using a self-issued or third-party-issued assertion, or by the authorization server performing client discovery using a trusted channel.
OAuth defines two client types, based on their ability to authenticate securely with the authorization server (i.e. ability to maintain the confidentiality of their client credentials):
The client type designation is based on the authorization server's definition of secure authentication and its acceptable exposure levels of client credentials.
This specification has been designed around the following client profiles:
When registering a client, the client developer:
The authorization server issues the registered client a client identifier - a unique string representing the registration information provided by the client. The client identifier is not a secret, it is exposed to the resource owner, and cannot be used alone for client authentication.
If the client type is private, the client and authorization server establish a client authentication method suitable for the security requirements of the authorization server. The authorization server MAY accept any form of client authentication meeting its security requirements.
Private clients are typically issued (or establish) a set of client credentials used for authenticating with the authorization server (e.g. password, public/private key pair).
The authorization server SHOULD NOT make assumptions about the client type or accept the type information provided without establishing trust with the client or its developer. The authorization server MAY establish a client authentication method with public clients. However, the authorization server MUST NOT rely on public client authentication for the purpose of identifying the client.
The client MUST NOT use more than one authentication method in each request.
Clients in possession of a client password MAY use the HTTP Basic authentication scheme as defined in [RFC2617] to authenticate with the authorization server. The client identifier is used as the username, and the client password is used as the password.
For example (extra line breaks are for display purposes only):
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Alternatively, the authorization server MAY allow including the client credentials in the request body using the following parameters:
Including the client credentials in the request body using the two parameters is NOT RECOMMENDED, and should be limited to clients unable to directly utilize the HTTP Basic authentication scheme (or other password-based HTTP authentication schemes).
For example, requesting to refresh an access token (Section 6) using the body parameters (extra line breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
grant_type=refresh_token&refresh_token=tGzv3JOkF0XG5Qx2TlKWIA
&client_id=s6BhdRkqt3&client_secret=7Fjfp0ZBr1KtDRbnfVdmIw
The authorization server MUST require the use of a transport-layer security mechanism when sending requests to the token endpoint, as requests using this authentication method result in the transmission of clear-text credentials.
The authorization server MAY support any suitable HTTP authentication scheme matching its security requirements. When using other authentication methods, the authorization server MUST define a mapping between the client identifier (registration record) and authentication scheme.
This specification does not exclude the use of unregistered clients. However, the use with such clients is beyond the scope of this specification, and requires additional security analysis and review of its interoperability impact.
The authorization process utilizes two endpoints (HTTP resources):
Not every authorization grant type utilizes both endpoints. Extension grant types MAY define additional endpoints as needed.
The authorization endpoint is used to interact with the resource owner and obtain authorization which is expressed explicitly as an authorization code (later exchanged for an access token), or implicitly by direct issuance of an access token.
The authorization server MUST first verify the identity of the resource owner. The way in which the authorization server authenticates the resource owner (e.g. username and password login, session cookies) is beyond the scope of this specification.
The means through which the client obtains the location of the authorization endpoint are beyond the scope of this specification but the location is typically provided in the service documentation. The endpoint URI MAY include a query component as defined by [RFC3986] section 3, which MUST be retained when adding additional query parameters. The endpoint URI MUST NOT include a fragment component.
Since requests to the authorization endpoint result in user authentication and the transmission of clear-text credentials (in the HTTP response), the authorization server MUST require the use of a transport-layer security mechanism when sending requests to the authorization endpoint. The authorization server MUST support TLS 1.2 as defined in [RFC5246], and MAY support additional transport-layer mechanisms meeting its security requirements.
The authorization server MUST support the use of the HTTP GET method [RFC2616] for the authorization endpoint, and MAY support the use of the POST method as well.
Parameters sent without a value MUST be treated as if they were omitted from the request. The authorization server SHOULD ignore unrecognized request parameters. Request and response parameters MUST NOT be included more than once.
The authorization endpoint is used by the authorization code grant type and implicit grant type flows. The client informs the authorization server of the desired grant type using the following parameter:
If an authorization request is missing the response_type parameter, the authorization server SHOULD return an error response as described in Section 4.1.2.1.
After completing its interaction with the resource owner, the authorization server directs the resource owner's user-agent back to the client. The authorization server redirects the user-agent to the client's redirection endpoint previously established with the authorization server during the client registration process or when initiating the authorization request.
The redirection endpoint URI MUST be an absolute URI as defined by [RFC3986] section 4.3, MAY include a query component which MUST be retained by the authorization server when adding additional query parameters, and MUST NOT include a fragment component.
If a redirection request will result in the transmission of an authorization code or access token over an open network (between the resource owner's user-agent and the client), the client SHOULD require the use of a transport-layer security mechanism.
Lack of transport-layer security can have a severe impact on the security of the client and the protected resources it is authorized to access. The use of transport-layer security is particularly critical when the authorization process is used as a form of delegated end-user authentication by the client (e.g. third-party sign-in service).
The authorization server MUST require public clients to register their redirection URI, MUST require all clients to register their redirection URI prior to utilizing the implicit grant type, and SHOULD require all clients to register their redirection URI prior to utilizing the authorization code grant type.
The authorization server SHOULD require the client to provide the complete redirection URI (the client MAY use the state request parameter to achieve per-request customization). The authorization server MAY allow the client to register multiple redirection URIs. If requiring the registration of the complete redirection URI is not possible, the authorization server SHOULD require the registration of the URI scheme, authority, and path.
If multiple redirection URIs have been registered, if only part of the redirection URI has been registered, or if no redirection URI has been registered, the client MUST include a redirection URI with the authorization request using the redirect_uri request parameter.
When a redirection URI is included in an authorization request, the authorization server MUST compare and match the value received against at least one of the registered redirection URIs (or URI components) as defined in [RFC3986] section 6, if any redirection URIs were registered.
If the authorization server allows the client to dynamically change the query component of the redirection URI, the client MUST ensure that manipulation of the query component by an attacker cannot lead to an abuse of the redirection endpoint as an open redirector.
If an authorization request fails validation due to a missing, invalid, or mismatching redirection URI, the authorization server SHOULD inform the resource owner of the error, and MUST NOT automatically redirect the user-agent to the invalid redirection URI.
The authorization server SHOULD NOT redirect the user-agent to unregistered or untrusted URIs to prevent the authorization endpoint from being used as an open redirector.
The redirection request to the client's endpoint typically results in an HTML document response, processed by the user-agent. If the HTML response is served directly as the result of the redirection request, any script included in the HTML document will execute with full access to the redirection URI and the credentials it contains.
The client SHOULD NOT include any third-party scripts in the redirection endpoint response. Instead, it should extract the credentials from the URI and redirect the user-agent again to another endpoint without the credentials in the URI.
The client MUST NOT include any untrusted third-party scripts in the redirection endpoint response (e.g. third-party analytics, social plug-ins, ad networks) without first ensuring that its own scripts used to extract and remove the credentials from the URI will execute first.
The token endpoint is used by the client to obtain an access token by presenting its authorization grant or refresh token. The token endpoint is used with every authorization grant except for the implicit grant type (since an access token is issued directly).
The means through which the client obtains the location of the token endpoint are beyond the scope of this specification but is typically provided in the service documentation. The endpoint URI MAY include a query component, which MUST be retained when adding additional query parameters.
Since requests to the token endpoint result in the transmission of clear-text credentials (in the HTTP request and response), the authorization server MUST require the use of a transport-layer security mechanism when sending requests to the token endpoint. The authorization server MUST support TLS 1.2 as defined in [RFC5246], and MAY support additional transport-layer mechanisms meeting its security requirements.
The client MUST use the HTTP POST method when making access token requests.
Parameters sent without a value MUST be treated as if they were omitted from the request. The authorization server SHOULD ignore unrecognized request parameters. Request and response parameters MUST NOT be included more than once.
Private clients, clients issued client credentials, or clients assigned other authentication requirements, MUST authenticate with the authorization server as described in Section 2.4 when making requests to the token endpoint. Client authentication is used for:
The security ramifications of allowing unauthenticated access by public clients to the token endpoint MUST be considered, as well as the issuance of refresh tokens to public clients, their scope, and lifetime.
To request an access token, the client obtains authorization from the resource owner. The authorization is expressed in the form of an authorization grant which the client uses to request the access token. OAuth defines four grant types: authorization code, implicit, resource owner password credentials, and client credentials. It also provides an extension mechanism for defining additional grant types.
The authorization code grant type is used to obtain both access tokens and refresh tokens and is optimized for private clients. As a redirection-based flow, the client must be capable of interacting with the resource owner's user-agent (typically a web browser) and capable of receiving incoming requests (via redirection) from the authorization server.
+----------+
| resource |
| owner |
| |
+----------+
^
|
(B)
+----|-----+ Client Identifier +---------------+
| -+----(A)-- & Redirection URI ---->| |
| User- | | Authorization |
| Agent -+----(B)-- User authenticates --->| Server |
| | | |
| -+----(C)-- Authorization Code ---<| |
+-|----|---+ +---------------+
| | ^ v
(A) (C) | |
| | | |
^ v | |
+---------+ | |
| |>---(D)-- Authorization Code ---------' |
| Client | & Redirection URI |
| | |
| |<---(E)----- Access Token -------------------'
+---------+ (w/ Optional Refresh Token)
The flow illustrated in Figure 5 includes the following steps:
The client constructs the request URI by adding the following parameters to the query component of the authorization endpoint URI using the application/x-www-form-urlencoded format as defined by [W3C.REC-html401-19991224]:
The client directs the resource owner to the constructed URI using an HTTP redirection response, or by other means available to it via the user-agent.
For example, the client directs the user-agent to make the following HTTP request using transport-layer security (extra line breaks are for display purposes only):
GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1
Host: server.example.com
The authorization server validates the request to ensure all required parameters are present and valid. If the request is valid, the authorization server authenticates the resource owner and obtains an authorization decision (by asking the resource owner or by establishing approval via other means).
When a decision is established, the authorization server directs the user-agent to the provided client redirection URI using an HTTP redirection response, or by other means available to it via the user-agent.
If the resource owner grants the access request, the authorization server issues an authorization code and delivers it to the client by adding the following parameters to the query component of the redirection URI using the application/x-www-form-urlencoded format:
For example, the authorization server redirects the user-agent by sending the following HTTP response:
HTTP/1.1 302 Found
Location: https://client.example.com/cb?code=SplxlOBeZQQYbYS6WxSbIA
&state=xyz
The client SHOULD ignore unrecognized response parameters. The authorization code string size is left undefined by this specification. The client should avoid making assumptions about code value sizes. The authorization server should document the size of any value it issues.
If the request fails due to a missing, invalid, or mismatching redirection URI, or if the client identifier provided is invalid, the authorization server SHOULD inform the resource owner of the error, and MUST NOT automatically redirect the user-agent to the invalid redirection URI.
If the resource owner denies the access request or if the request fails for reasons other than a missing or invalid redirection URI, the authorization server informs the client by adding the following parameters to the query component of the redirection URI using the application/x-www-form-urlencoded format:
For example, the authorization server redirects the user-agent by sending the following HTTP response:
HTTP/1.1 302 Found
Location: https://client.example.com/cb?error=access_denied&state=xyz
The client makes a request to the token endpoint by adding the following parameters using the application/x-www-form-urlencoded format in the HTTP request entity-body:
If the client type is private or was issued client credentials (or assigned other authentication requirements), the client MUST authenticate with the authorization server as described in Section 3.2.1.
For example, the client makes the following HTTP using transport-layer security (extra line breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
grant_type=authorization_code&code=SplxlOBeZQQYbYS6WxSbIA
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb
The authorization server MUST:
If the access token request is valid and authorized, the authorization server issues an access token and optional refresh token as described in Section 5.1. If the request client authentication failed or is invalid, the authorization server returns an error response as described in Section 5.2.
An example successful response:
HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache
{
"access_token":"2YotnFZFEjr1zCsicMWpAA",
"token_type":"example",
"expires_in":3600,
"refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA",
"example_parameter":"example_value"
}
The implicit grant type is used to obtain access tokens (it does not support the issuance of refresh tokens) and is optimized for public clients known to operate a particular redirection URI. These clients are typically implemented in a browser using a scripting language such as JavaScript.
As a redirection-based flow, the client must be capable of interacting with the resource owner's user-agent (typically a web browser) and capable of receiving incoming requests (via redirection) from the authorization server.
Unlike the authorization code grant type in which the client makes separate requests for authorization and access token, the client receives the access token as the result of the authorization request.
The implicit grant type does not include client authentication, and relies on the presence of the resource owner and the registration of the redirection URI. Because the access token is encoded into the redirection URI, it may be exposed to the resource owner and other applications residing on its device.
+----------+
| Resource |
| Owner |
| |
+----------+
^
|
(B)
+----|-----+ Client Identifier +---------------+
| -+----(A)-- & Redirection URI --->| |
| User- | | Authorization |
| Agent -|----(B)-- User authenticates -->| Server |
| | | |
| |<---(C)--- Redirection URI ----<| |
| | with Access Token +---------------+
| | in Fragment
| | +---------------+
| |----(D)--- Redirection URI ---->| Web-Hosted |
| | without Fragment | Client |
| | | Resource |
| (F) |<---(E)------- Script ---------<| |
| | +---------------+
+-|--------+
| |
(A) (G) Access Token
| |
^ v
+---------+
| |
| Client |
| |
+---------+
The flow illustrated in Figure 11 includes the following steps:
The client constructs the request URI by adding the following parameters to the query component of the authorization endpoint URI using the application/x-www-form-urlencoded format:
The client directs the resource owner to the constructed URI using an HTTP redirection response, or by other means available to it via the user-agent.
For example, the client directs the user-agent to make the following HTTP request using transport-layer security (extra line breaks are for display purposes only):
GET /authorize?response_type=token&client_id=s6BhdRkqt3&state=xyz
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1
Host: server.example.com
The authorization server validates the request to ensure all required parameters are present and valid. The authorization server MUST verify that the redirection URI to which it will redirect the access token matches a redirection URI registered by the client as described in Section 3.1.2.
If the request is valid, the authorization server authenticates the resource owner and obtains an authorization decision (by asking the resource owner or by establishing approval via other means).
When a decision is established, the authorization server directs the user-agent to the provided client redirection URI using an HTTP redirection response, or by other means available to it via the user-agent.
If the resource owner grants the access request, the authorization server issues an access token and delivers it to the client by adding the following parameters to the fragment component of the redirection URI using the application/x-www-form-urlencoded format:
For example, the authorization server redirects the user-agent by sending the following HTTP response (URI extra line breaks are for display purposes only):
HTTP/1.1 302 Found
Location: http://example.com/rd#access_token=2YotnFZFEjr1zCsicMWpAA
&state=xyz&token_type=example&expires_in=3600
Developers should note that some HTTP client implementations do not support the inclusion of a fragment component in the HTTP Location response header field. Such client will require using other methods for redirecting the client than a 3xx redirection response. For example, returning an HTML page which includes a 'continue' button with an action linked to the redirection URI.
The client SHOULD ignore unrecognized response parameters. The access token string size is left undefined by this specification. The client should avoid making assumptions about value sizes. The authorization server should document the size of any value it issues.
If the request fails due to a missing, invalid, or mismatching redirection URI, or if the client identifier provided is invalid, the authorization server SHOULD inform the resource owner of the error, and MUST NOT automatically redirect the user-agent to the invalid redirection URI.
If the resource owner denies the access request or if the request fails for reasons other than a missing or invalid redirection URI, the authorization server informs the client by adding the following parameters to the fragment component of the redirection URI using the application/x-www-form-urlencoded format:
For example, the authorization server redirects the user-agent by sending the following HTTP response:
HTTP/1.1 302 Found
Location: https://client.example.com/cb#error=access_denied&state=xyz
The resource owner password credentials grant type is suitable in cases where the resource owner has a trust relationship with the client, such as its device operating system or a highly privileged application. The authorization server should take special care when enabling the grant type, and only when other flows are not viable.
The grant type is suitable for clients capable of obtaining the resource owner credentials (username and password, typically using an interactive form). It is also used to migrate existing clients using direct authentication schemes such as HTTP Basic or Digest authentication to OAuth by converting the stored credentials to an access token.
+----------+
| Resource |
| Owner |
| |
+----------+
v
| Resource Owner
(A) Password Credentials
|
v
+---------+ +---------------+
| |>--(B)---- Resource Owner ------->| |
| | Password Credentials | Authorization |
| Client | | Server |
| |<--(C)---- Access Token ---------<| |
| | (w/ Optional Refresh Token) | |
+---------+ +---------------+
The flow illustrated in Figure 15 includes the following steps:
The method through which the client obtains the resource owner credentials is beyond the scope of this specification. The client MUST discard the credentials once an access token has been obtained.
The client makes a request to the token endpoint by adding the following parameters using the application/x-www-form-urlencoded format in the HTTP request entity-body:
If the client type is private or was issued client credentials (or assigned other authentication requirements), the client MUST authenticate with the authorization server as described in Section 3.2.1.
For example, the client makes the following HTTP request using transport-layer security (extra line breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
grant_type=password&username=johndoe&password=A3ddj3w
The authorization server MUST:
Since this access token request utilizes the resource owner's password, the authorization server MUST protect the endpoint against brute force attacks.
If the access token request is valid and authorized, the authorization server issues an access token and optional refresh token as described in Section 5.1. If the request failed client authentication or is invalid, the authorization server returns an error response as described in Section 5.2.
An example successful response:
HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache
{
"access_token":"2YotnFZFEjr1zCsicMWpAA",
"token_type":"example",
"expires_in":3600,
"refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA",
"example_parameter":"example_value"
}
The client can request an access token using only its client credentials (or other supported means of authentication) when the client is requesting access to the protected resources under its control, or those of another resource owner which has been previously arranged with the authorization server (the method of which is beyond the scope of this specification).
The client credentials grant type MUST only be used by private clients.
+---------+ +---------------+
| | | |
| |>--(A)- Client Authentication --->| Authorization |
| Client | | Server |
| |<--(B)---- Access Token ---------<| |
| | | |
+---------+ +---------------+
The flow illustrated in Figure 18 includes the following steps:
Since the client authentication is used as the authorization grant, no additional authorization request is needed.
The client makes a request to the token endpoint by adding the following parameters using the application/x-www-form-urlencoded format in the HTTP request entity-body:
The client MUST authenticate with the authorization server as described in Section 3.2.1.
For example, the client makes the following HTTP request using transport-layer security (extra line breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
grant_type=client_credentials
The authorization server MUST authenticate the client.
If the access token request is valid and authorized, the authorization server issues an access token as described in Section 5.1. A refresh token SHOULD NOT be included. If the request failed client authentication or is invalid, the authorization server returns an error response as described in Section 5.2.
An example successful response:
HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache
{
"access_token":"2YotnFZFEjr1zCsicMWpAA",
"token_type":"example",
"expires_in":3600,
"example_parameter":"example_value"
}
The client uses an extension grant type by specifying the grant type using an absolute URI (defined by the authorization server) as the value of the grant_type parameter of the token endpoint, and by adding any additional parameters necessary.
For example, to request an access token using a SAML 2.0 assertion grant type as defined by [I-D.ietf-oauth-saml2-bearer], the client makes the following HTTP request using transport-layer security (line breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
grant_type=http%3A%2F%2Foauth.net%2Fgrant_type%2Fassertion%2F
saml%2F2.0%2Fbearer&assertion=PEFzc2VydGlvbiBJc3N1ZUluc3RhbnQ
[...omitted for brevity...]V0aG5TdGF0ZW1lbnQ-PC9Bc3NlcnRpb24-
If the access token request is valid and authorized, the authorization server issues an access token and optional refresh token as described in Section 5.1. If the request failed client authentication or is invalid, the authorization server returns an error response as described in Section 5.2.
If the access token request is valid and authorized, the authorization server issues an access token and optional refresh token as described in Section 5.1. If the request failed client authentication or is invalid, the authorization server returns an error response as described in Section 5.2.
The authorization server issues an access token and optional refresh token, and constructs the response by adding the following parameters to the entity body of the HTTP response with a 200 (OK) status code:
The parameters are included in the entity body of the HTTP response using the application/json media type as defined by [RFC4627]. The parameters are serialized into a JSON structure by adding each parameter at the highest structure level. Parameter names and string values are included as JSON strings. Numerical values are included as JSON numbers.
The authorization server MUST include the HTTP Cache-Control response header field [RFC2616] with a value of no-store in any response containing tokens, credentials, or other sensitive information, as well as the Pragma response header field [RFC2616] with a value of no-cache.
For example:
HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache
{
"access_token":"2YotnFZFEjr1zCsicMWpAA",
"token_type":"example",
"expires_in":3600,
"refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA",
"example_parameter":"example_value"
}
The client SHOULD ignore unrecognized response parameters. The sizes of tokens and other values received from the authorization server are left undefined. The client should avoid making assumptions about value sizes. The authorization server should document the size of any value it issues.
The authorization server responds with an HTTP 400 (Bad Request) status code and includes the following parameters with the response:
The parameters are included in the entity body of the HTTP response using the application/json media type as defined by [RFC4627]. The parameters are serialized into a JSON structure by adding each parameter at the highest structure level. Parameter names and string values are included as JSON strings. Numerical values are included as JSON numbers.
For example:
HTTP/1.1 400 Bad Request
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache
{
"error":"invalid_request"
}
If the authorization server issued a refresh token to the client, the client makes a refresh request to the token endpoint by adding the following parameters using the application/x-www-form-urlencoded format in the HTTP request entity-body:
Because refresh tokens are typically long-lasting credentials used to request additional access tokens, the refresh token is bound to the client it was issued. If the client type is private or was issued client credentials (or assigned other authentication requirements), the client MUST authenticate with the authorization server as described in Section 3.2.1.
For example, the client makes the following HTTP request using transport-layer security (extra line breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
grant_type=refresh_token&refresh_token=tGzv3JOkF0XG5Qx2TlKWIA
The authorization server MUST:
If valid and authorized, the authorization server issues an access token as described in Section 5.1. If the request failed verification or is invalid, the authorization server returns an error response as described in Section 5.2.
The authorization server MAY issue a new refresh token, in which case the client MUST discard the old refresh token and replace it with the new refresh token. The authorization server MAY revoke the old refresh token after issuing a new refresh token to the client. If a new refresh token is issued, its scope MUST be identical to that of the refresh token included in the request.
The client accesses protected resources by presenting the access token to the resource server. The resource server MUST validate the access token and ensure it has not expired and that its scope covers the requested resource. The methods used by the resource server to validate the access token (as well as any error responses) are beyond the scope of this specification, but generally involve an interaction or coordination between the resource server and the authorization server.
The method in which the client utilized the access token to authenticate with the resource server depends on the type of access token issued by the authorization server. Typically, it involves using the HTTP Authorization request header field [RFC2617] with an authentication scheme defined by the access token type specification.
The access token type provides the client with the information required to successfully utilize the access token to make a protected resource request (along with type-specific attributes). The client MUST NOT use an access token if it does not understand or does not trust the token type.
For example, the bearer token type defined in [I-D.ietf-oauth-v2-bearer] is utilized by simply including the access token string in the request:
GET /resource/1 HTTP/1.1
Host: example.com
Authorization: Bearer 7Fjfp0ZBr1KtDRbnfVdmIw
while the mac token type defined in [I-D.ietf-oauth-v2-http-mac] is utilized by issuing a MAC key together with the access token which is used to sign certain components of the HTTP requests:
GET /resource/1 HTTP/1.1
Host: example.com
Authorization: MAC id="h480djs93hd8",
nonce="274312:dj83hs9s",
mac="kDZvddkndxvhGRXZhvuDjEWhGeE="
The above examples are provided for illustration purposes only. Developers are advised to consult the [I-D.ietf-oauth-v2-bearer] and [I-D.ietf-oauth-v2-http-mac] specifications before use.
Each access token type definition specifies the additional attributes (if any) sent to the client together with the access_token response parameter. It also defines the HTTP authentication method used to include the access token when making a protected resource request.
Access token types can be defined in one of two ways: registered in the access token type registry (following the procedures in Section 11.1), or use a unique absolute URI as its name.
Types utilizing a URI name SHOULD be limited to vendor-specific implementations that are not commonly applicable, and are specific to the implementation details of the resource server where they are used.
All other types MUST be registered. Type names MUST conform to the type-name ABNF. If the type definition includes a new HTTP authentication scheme, the type name SHOULD be identical to the HTTP authentication scheme name (as defined by [RFC2617]).
type-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA
New request or response parameters for use with the authorization endpoint or the token endpoint are defined and registered in the parameters registry following the procedure in Section 11.2.
Parameter names MUST conform to the param-name ABNF and parameter values syntax MUST be well-defined (e.g., using ABNF, or a reference to the syntax of an existing parameter).
param-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA
Unregistered vendor-specific parameter extensions that are not commonly applicable, and are specific to the implementation details of the authorization server where they are used SHOULD utilize a vendor-specific prefix that is not likely to conflict with other registered values (e.g. begin with 'companyname_').
New authorization grant types can be defined by assigning them a unique absolute URI for use with the grant_type parameter. If the extension grant type requires additional token endpoint parameters, they MUST be registered in the OAuth parameters registry as described by Section 11.2.
New response types for use with the authorization endpoint are defined and registered in the authorization endpoint response type registry following the procedure in Section 11.3. Response type names MUST conform to the response-type ABNF.
response-type = response-name *( SP response-name )
response-name = 1*response-char
response-char = "_" / DIGIT / ALPHA
If a response type contains one of more space characters (%x20), it is compared as a space-delimited list of values in which the order of values does not matter. Only one order of values can be registered, which covers all other arrangements of the same set of values.
For example, the response type token code is left undefined by this specification. However, an extension can define and register the token code response type. Once registered, the same combination cannot be registered as code token, but both values can be used to denote the same response type.
In cases where protocol extensions (i.e. access token types, extension parameters, or extension grant types) require additional error codes to be used with the authorization code grant error response (Section 4.1.2.1), the implicit grant error response (Section 4.2.2.1), or the token error response (Section 5.2), such error codes MAY be defined.
Extension error codes MUST be registered (following the procedures in Section 11.4) if the extension they are used in conjunction with is a registered access token type, a registered endpoint parameter, or an extension grant type. Error codes used with unregistered extensions MAY be registered.
Error codes MUST conform to the error-code ABNF, and SHOULD be prefixed by an identifying name when possible. For example, an error identifying an invalid value set to the extension parameter example should be named example_invalid.
error-code = ALPHA *error-char
error-char = "-" / "." / "_" / DIGIT / ALPHA
Native applications are clients installed and executed on the resource owner's device (i.e. desktop application, native mobile application). Native applications may require special consideration related to security, platform capabilities, and overall end-user experience.
The authorization endpoint requires interaction between the client and the resource owner's user-agent. Native applications can invoke an external user-agent or embed a user-agent within the application. For example:
When choosing between an external or embedded user-agent, developers should consider:
When choosing between the implicit grant type and the authorization code grant type, the following should be considered:
As a flexible and extensible framework, OAuth's security considerations depend on many factors. The following sections provide implementers with security guidelines focused on the three client profiles described in Section 2.1: web application, user-agent-based application, and native application.
A comprehensive OAuth security model and analysis, as well as background for the protocol design is provided by [I-D.ietf-oauth-v2-threatmodel].
The authorization server establishes client credentials with web application clients for the purpose of client authentication. The authorization server is encouraged to consider stronger client authentication means than a client password. Web application clients MUST ensure confidentiality of client passwords and other client credentials.
The authorization server MUST NOT issue client passwords or other client credentials to native application or user-agent-based application clients for the purpose of client authentication. The authorization server MAY issue a client password or other credentials for a specific installation of a native application client on a specific device.
When client authentication is not possible, the authorization server SHOULD employ other means to validate the client's identity. For example, by requiring the registration of the client redirection URI or enlisting the resource owner to confirm identity. The authorization server must consider the security implications of interacting with unauthenticated clients and take measures to limit the potential exposure of other credentials (e.g. refresh tokens) issued to such clients.
A malicious client can impersonate another client and obtain access to protected resources, if the impersonated client fails to, or is unable to, keep is client credentials confidential.
The authorization server MUST authenticate the client whenever possible. If the authorization server cannot authenticate the client due to the client nature, the authorization server MUST require the registration of any redirection URI used for receiving authorization, and SHOULD utilize other means to protect resource owners from such malicious clients. For example, engage the resource owner to assist in identifying the client and its origin.
The authorization server SHOULD enforce explicit resource owner authentication and provide the resource owner with information about the client and the requested authorization scope and lifetime. It is up to the resource owner to review the information in the context of the current client, and authorize the request.
The authorization server SHOULD NOT process repeated authorization requests automatically (without active resource owner interaction) without authenticating the client or relying on other measures to ensure the repeated request comes from the original client and not an impersonator.
Access token (as well as any access token type-specific attributes) MUST be kept confidential in transit and storage, and only shared among the authorization server, the resource servers the access token is valid for, and the client to whom the access token is issued.
When using the implicit grant type, the access token is transmitted in the URI fragment, which can expose it to unauthorized parties.
The authorization server MUST ensure that access tokens cannot be generated, modified, or guessed to produce valid access tokens.
The client SHOULD request access tokens with the minimal scope and lifetime necessary. The authorization server SHOULD take the client identity into account when choosing how to honor the requested scope and lifetime, and MAY issue an access token with a less rights than requested.
Authorization servers MAY issue refresh tokens to web application clients and native application clients.
Refresh tokens MUST be kept confidential in transit and storage, and shared only among the authorization server and the client to whom the refresh tokens were issued. The authorization server MUST maintain the binding between a refresh token and the client to whom it was issued.
The authorization server MUST verify the binding between the refresh token and client identity whenever the client identity can be authenticated. When client authentication is not possible, the authorization server SHOULD deploy other means to detect refresh token abuse.
For example, the authorization server could employ refresh tokens rotation in which a new refresh token is issued with every access token refresh response. The previous refresh token is invalidated but retained by the authorization server. If a refresh token is compromised and subsequently used by both the attacker and the legitimate client, one of them will present an invalidated refresh token which will inform the authorization server of the breach.
The authorization server MUST ensure that refresh tokens cannot be generated, modified, or guessed to produce valid refresh tokens.
The transmission of authorization codes SHOULD be made over a secure channel, and the client SHOULD implement TLS for use with its redirection URI if the URI identifies a network resource. Effort should be made to keep authorization codes confidential. Since authorization codes are transmitted via user-agent redirections, they could potentially be disclosed through user-agent history and HTTP referrer headers.
Authorization codes operate as plaintext bearer credentials, used to verify that the resource owner who granted authorization at the authorization server, is the same resource owner returning to the client to complete the process. Therefore, if the client relies on the authorization code for its own resource owner authentication, the client redirection endpoint MUST require TLS.
Authorization codes MUST be short lived and single use. If the authorization server observes multiple attempts to exchange an authorization code for an access token, the authorization server SHOULD attempt to revoke all access tokens already granted based on the compromised authorization code.
If the client can be authenticated, the authorization servers MUST authenticate the client and ensure that the authorization code was issued to the same client.
An attacker can leverage the authorization code grant type by tricking a resource owner to authorize access to a legitimate client, but using a client account under the control of the attacker. The only difference between a valid request and the attack request is in how the victim reached the authorization server to grant access.
Once at the authorization server, the victim is prompted with a normal, valid request on behalf of a legitimate and familiar client. The attacker then uses the victim's authorization to gain access to the information authorized by the victim (via the client).
In order to prevent such an attack, authorization servers MUST ensure that the redirection URI used to obtain the authorization code, is the same as the redirection URI provided when exchanging the authorization code for an access token. The authorization server SHOULD require the client to register their redirection URI and if provided, MUST validate the redirection URI received in the authorization request against the registered value.
The resource owner password credentials grant type is often used for legacy or migration reasons. It reduces the overall risk of storing username and password by the client, but does not eliminate the need to expose highly privileged credentials to the client.
This grant type carries a higher risk than other grant types because it maintains the password anti-pattern this protocol seeks to avoid. The client could abuse the password or the password could unintentionally be disclosed to an attacker (e.g. via log files or other records kept by the client).
Additionally, because the resource owner does not have control over the authorization process (the resource owner involvement ends when it hands over its credentials to the client), the client can obtain access tokens with a broader scope and longer lifetime than desired by the resource owner. The authorization server SHOULD restrict the scope and lifetime of access tokens issued via this grant type.
The authorization server and client SHOULD minimize use of this grant type and utilize other grant types whenever possible.
Access tokens, refresh tokens, resource owner passwords, and client credentials MUST NOT be transmitted in the clear. Authorization codes SHOULD NOT be transmitted in the clear.
In order to prevent man-in-the-middle and phishing attacks, the authorization server MUST implement and require TLS with server authentication as defined by [RFC2818] for any request sent to the authorization and token endpoints. The client MUST validate the authorization server's TLS certificate in accordance with its requirements for server identity authentication.
The authorization server MUST prevent attackers from guessing access tokens, authorization codes, refresh tokens, resource owner passwords, and client credentials.
When generating tokens and other credentials not intended for handling by end-users, the authorization server MUST use a reasonable level of entropy in order to mitigate the risk of guessing attacks. The authorization server MUST utilize other means to protect credentials intended for end-user usage.
Wide deployment of this and similar protocols may cause end-users to become inured to the practice of being redirected to websites where they are asked to enter their passwords. If end-users 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.
Service providers should attempt to educate end-users about the risks phishing attacks pose, and should provide mechanisms that make it easy for end-users to confirm the authenticity of their sites. Client developers should consider the security implications of how they interact with the user-agent (e.g., external, embedded), and the ability of the end-user to verify the authenticity of the authorization server.
To reduce the risk of phishing attacks, the authorization servers MUST utilize TLS on every endpoint used for end-user interaction.
Cross-site request forgery (CSRF) is a web-based attack whereby HTTP requests are transmitted from the user-agent of an end-user the server trusts or has authenticated. CSRF attacks on the authorization endpoint can allow an attacker to obtain authorization without the consent of the resource owner.
The state request parameter SHOULD be used to mitigate against CSRF attacks, particularly for login CSRF attacks. CSRF attacks against the client's redirection URI allow an attacker to inject their own authorization code or access token, which can result in the client using an access token associated with the attacker's account rather than the victim's. Depending on the nature of the client and the protected resources, this can have undesirable and damaging effects.
It is strongly RECOMMENDED that the client includes the state request parameter with authorization requests to the authorization server. The state request parameter MUST contain a non-guessable value, and the client MUST keep it in a location accessible only by the client or the user-agent (i.e., protected by same-origin policy).
For example, using a DOM variable (protected by JavaScript or other DOM-binding language's enforcement of SOP [[ add reference ]]), HTTP cookie, or HTML5 client-side storage. The authorization server includes the value of the state parameter when redirecting the user-agent back to the client which MUST then ensure the received value matches the stored value.
[[ Rework to use specification terminology ]]
Clickjacking is the process of tricking end-users into revealing confidential information or taking control of their device while clicking on seemingly innocuous web pages. In more detail, a malicious site loads the target site in a transparent iframe overlaid on top of a set of dummy buttons which are carefully constructed to be placed directly under important buttons on the target site. When a user clicks a visible button, they are actually clicking a button (such as an "Authorize" button) on the hidden page.
To prevent clickjacking (and phishing attacks), native applications SHOULD use external browsers instead of embedding browsers in an iframe when requesting end-user authorization. For newer browsers, avoidance of iframes can be enforced by the authorization server using the x-frame-options header [[ Add reference ]]. This header can have two values, deny and sameorigin, which will block any framing or framing by sites with a different origin, respectively. For older browsers, javascript framebusting techniques can be used but may not be effective in all browsers.
A code injection attack occurs when an input or otherwise external variable is used by an application in which that input can cause modification of the application logic when used unsanitized. This may allow an attacker to gain access to the application device or its data, cause denial of service, or a wide range of malicious side-effects.
The Authorization server and client MUST validate and sanitize any value received, and in particular, the value of the state and redirect_uri parameters.
This specification establishes the OAuth access token type registry.
Access token types are registered on the advice of one or more Designated Experts (appointed by the IESG or their delegate), with a Specification Required (using terminology from [RFC5226]). However, to allow for the allocation of values prior to publication, the Designated Expert(s) may approve registration once they are satisfied that such a specification will be published.
Registration requests should be sent to the [TBD]@ietf.org mailing list for review and comment, with an appropriate subject (e.g., "Request for access toke type: example"). [[ Note to RFC-EDITOR: The name of the mailing list should be determined in consultation with the IESG and IANA. Suggested name: oauth-ext-review. ]]
Within at most 14 days of the request, the Designated Expert(s) will either approve or deny the registration request, communicating this decision to the review list and IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful.
Decisions (or lack thereof) made by the Designated Expert can be first appealed to Application Area Directors (contactable using app-ads@tools.ietf.org email address or directly by looking up their email addresses on http://www.iesg.org/ website) and, if the appellant is not satisfied with the response, to the full IESG (using the iesg@iesg.org mailing list).
IANA should only accept registry updates from the Designated Expert(s), and should direct all requests for registration to the review mailing list.
This specification establishes the OAuth parameters registry.
Additional parameters for inclusion in the authorization endpoint request, the authorization endpoint response, the token endpoint request, or the token endpoint response, are registered on the advice of one or more Designated Experts (appointed by the IESG or their delegate), with a Specification Required (using terminology from [RFC5226]). However, to allow for the allocation of values prior to publication, the Designated Expert(s) may approve registration once they are satisfied that such a specification will be published.
Registration requests should be sent to the [TBD]@ietf.org mailing list for review and comment, with an appropriate subject (e.g., "Request for parameter: example"). [[ Note to RFC-EDITOR: The name of the mailing list should be determined in consultation with the IESG and IANA. Suggested name: oauth-ext-review. ]]
Within at most 14 days of the request, the Designated Expert(s) will either approve or deny the registration request, communicating this decision to the review list and IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful.
Decisions (or lack thereof) made by the Designated Expert can be first appealed to Application Area Directors (contactable using app-ads@tools.ietf.org email address or directly by looking up their email addresses on http://www.iesg.org/ website) and, if the appellant is not satisfied with the response, to the full IESG (using the iesg@iesg.org mailing list).
IANA should only accept registry updates from the Designated Expert(s), and should direct all requests for registration to the review mailing list.
The OAuth Parameters Registry's initial contents are:
This specification establishes the OAuth authorization endpoint response type registry.
Additional response type for use with the authorization endpoint are registered on the advice of one or more Designated Experts (appointed by the IESG or their delegate), with a Specification Required (using terminology from [RFC5226]). However, to allow for the allocation of values prior to publication, the Designated Expert(s) may approve registration once they are satisfied that such a specification will be published.
Registration requests should be sent to the [TBD]@ietf.org mailing list for review and comment, with an appropriate subject (e.g., "Request for response type: example"). [[ Note to RFC-EDITOR: The name of the mailing list should be determined in consultation with the IESG and IANA. Suggested name: oauth-ext-review. ]]
Within at most 14 days of the request, the Designated Expert(s) will either approve or deny the registration request, communicating this decision to the review list and IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful.
Decisions (or lack thereof) made by the Designated Expert can be first appealed to Application Area Directors (contactable using app-ads@tools.ietf.org email address or directly by looking up their email addresses on http://www.iesg.org/ website) and, if the appellant is not satisfied with the response, to the full IESG (using the iesg@iesg.org mailing list).
IANA should only accept registry updates from the Designated Expert(s), and should direct all requests for registration to the review mailing list.
The OAuth Authorization Endpoint Response Type Registry's initial contents are:
This specification establishes the OAuth extensions error registry.
Additional error codes used together with other protocol extensions (i.e. extension grant types, access token types, or extension parameters) are registered on the advice of one or more Designated Experts (appointed by the IESG or their delegate), with a Specification Required (using terminology from [RFC5226]). However, to allow for the allocation of values prior to publication, the Designated Expert(s) may approve registration once they are satisfied that such a specification will be published.
Registration requests should be sent to the [TBD]@ietf.org mailing list for review and comment, with an appropriate subject (e.g., "Request for error code: example"). [[ Note to RFC-EDITOR: The name of the mailing list should be determined in consultation with the IESG and IANA. Suggested name: oauth-ext-review. ]]
Within at most 14 days of the request, the Designated Expert(s) will either approve or deny the registration request, communicating this decision to the review list and IANA. Denials should include an explanation and, if applicable, suggestions as to how to make the request successful.
Decisions (or lack thereof) made by the Designated Expert can be first appealed to Application Area Directors (contactable using app-ads@tools.ietf.org email address or directly by looking up their email addresses on http://www.iesg.org/ website) and, if the appellant is not satisfied with the response, to the full IESG (using the iesg@iesg.org mailing list).
IANA should only accept registry updates from the Designated Expert(s), and should direct all requests for registration to the review mailing list.
The initial OAuth 2.0 protocol specification was edited by David Recordon, based on two previous publications: the OAuth 1.0 community specification [RFC5849], and OAuth WRAP (OAuth Web Resource Authorization Profiles) [I-D.draft-hardt-oauth-01]. The Security Considerations section was drafted by Torsten Lodderstedt, Mark McGloin, Phil Hunt, and Anthony Nadalin.
The OAuth 1.0 community specification was edited by Eran Hammer-Lahav and 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.
The OAuth WRAP specification was edited by Dick Hardt and authored by Brian Eaton, Yaron Goland, Dick Hardt, and Allen Tom.
This specification is the work of the OAuth Working Group which includes dozens of active and dedicated participants. In particular, the following individuals contributed ideas, feedback, and wording which shaped and formed the final specification:
Michael Adams, Andrew Arnott, Dirk Balfanz, Aiden Bell, Scott Cantor, Marcos Caceres, Blaine Cook, Brian Campbell, Brian Eaton, Leah Culver, Bill de hÓra, Brian Eaton, Brian Ellin, Igor Faynberg, George Fletcher, Tim Freeman, Evan Gilbert, Yaron Goland, Brent Goldman, Kristoffer Gronowski, Justin Hart, Dick Hardt, Craig Heath, Phil Hunt, Michael B. Jones, John Kemp, Mark Kent, Raffi Krikorian, Chasen Le Hara, Rasmus Lerdorf, Torsten Lodderstedt, Hui-Lan Lu, Paul Madsen, Alastair Mair, Eve Maler, James Manger, Mark McGloin, Laurence Miao, Chuck Mortimore, Anthony Nadalin, Justin Richer, Peter Saint-Andre, Nat Sakimura, Rob Sayre, Marius Scurtescu, Naitik Shah, Luke Shepard, Vlad Skvortsov, Justin Smith, Jeremy Suriel, Christian Stübner, Paul Tarjan, Allen Tom, Franklin Tse, Nick Walker, Shane Weeden, and Skylar Woodward.
| [RFC5849] | Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849, April 2010. |
| [I-D.ietf-oauth-v2-bearer] | Jones, M, Hardt, D and D Recordon, "The OAuth 2.0 Protocol: Bearer Tokens", Internet-Draft draft-ietf-oauth-v2-bearer-04, March 2011. |
| [I-D.ietf-oauth-saml2-bearer] | Campbell, B and C Mortimore, "SAML 2.0 Bearer Assertion Grant Type Profile for OAuth 2.0", Internet-Draft draft-ietf-oauth-saml2-bearer-03, February 2011. |
| [I-D.ietf-oauth-v2-http-mac] | Hammer-Lahav, E, Barth, A and B Adida, "HTTP Authentication: MAC Access Authentication", Internet-Draft draft-ietf-oauth-v2-http-mac-00, May 2011. |
| [I-D.ietf-oauth-v2-threatmodel] | Lodderstedt, T, McGloin, M and P Hunt, "OAuth 2.0 Threat Model and Security Considerations", Internet-Draft draft-ietf-oauth-v2-threatmodel-00, July 2011. |
| [OASIS.saml-core-2.0-os] | Cantor, S., Kemp, J., Philpott, R. and E. Maler, "Assertions and Protocol for the OASIS Security Assertion Markup Language (SAML) V2.0", OASIS Standard saml-core-2.0-os, March 2005. |
| [I-D.draft-hardt-oauth-01] | Hardt, D, Tom, A, Eaton, B and Y Goland, "OAuth Web Resource Authorization Profiles", January 2010. |