draft-ietf-oauth-v2-31.txt   rfc6749.txt 
OAuth Working Group D. Hardt, Ed. Internet Engineering Task Force (IETF) D. Hardt, Ed.
Internet-Draft Microsoft Request for Comments: 6749 Microsoft
Obsoletes: 5849 (if approved) July 31, 2012 Obsoletes: 5849 October 2012
Intended status: Standards Track Category: Standards Track
Expires: February 1, 2013 ISSN: 2070-1721
The OAuth 2.0 Authorization Framework The OAuth 2.0 Authorization Framework
draft-ietf-oauth-v2-31
Abstract Abstract
The OAuth 2.0 authorization framework enables a third-party The OAuth 2.0 authorization framework enables a third-party
application to obtain limited access to an HTTP service, either on application to obtain limited access to an HTTP service, either on
behalf of a resource owner by orchestrating an approval interaction behalf of a resource owner by orchestrating an approval interaction
between the resource owner and the HTTP service, or by allowing the between the resource owner and the HTTP service, or by allowing the
third-party application to obtain access on its own behalf. This third-party application to obtain access on its own behalf. This
specification replaces and obsoletes the OAuth 1.0 protocol described specification replaces and obsoletes the OAuth 1.0 protocol described
in RFC 5849. in RFC 5849.
Status of this Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering This is an Internet Standards Track document.
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on February 1, 2013. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6749.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction ....................................................4
1.1. Roles . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1. Roles ......................................................6
1.2. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 7 1.2. Protocol Flow ..............................................7
1.3. Authorization Grant . . . . . . . . . . . . . . . . . . . 8 1.3. Authorization Grant ........................................8
1.3.1. Authorization Code . . . . . . . . . . . . . . . . . . 8 1.3.1. Authorization Code ..................................8
1.3.2. Implicit . . . . . . . . . . . . . . . . . . . . . . . 8 1.3.2. Implicit ............................................8
1.3.3. Resource Owner Password Credentials . . . . . . . . . 9 1.3.3. Resource Owner Password Credentials .................9
1.3.4. Client Credentials . . . . . . . . . . . . . . . . . . 9 1.3.4. Client Credentials ..................................9
1.4. Access Token . . . . . . . . . . . . . . . . . . . . . . 9 1.4. Access Token ..............................................10
1.5. Refresh Token . . . . . . . . . . . . . . . . . . . . . . 10 1.5. Refresh Token .............................................10
1.6. TLS Version . . . . . . . . . . . . . . . . . . . . . . . 12 1.6. TLS Version ...............................................12
1.7. HTTP Redirections . . . . . . . . . . . . . . . . . . . . 12 1.7. HTTP Redirections .........................................12
1.8. Interoperability . . . . . . . . . . . . . . . . . . . . 12 1.8. Interoperability ..........................................12
1.9. Notational Conventions . . . . . . . . . . . . . . . . . 12 1.9. Notational Conventions ....................................13
2. Client Registration . . . . . . . . . . . . . . . . . . . . . 13 2. Client Registration ............................................13
2.1. Client Types . . . . . . . . . . . . . . . . . . . . . . 13 2.1. Client Types ..............................................14
2.2. Client Identifier . . . . . . . . . . . . . . . . . . . . 15 2.2. Client Identifier .........................................15
2.3. Client Authentication . . . . . . . . . . . . . . . . . . 15 2.3. Client Authentication .....................................16
2.3.1. Client Password . . . . . . . . . . . . . . . . . . . 15 2.3.1. Client Password ....................................16
2.3.2. Other Authentication Methods . . . . . . . . . . . . . 17 2.3.2. Other Authentication Methods .......................17
2.4. Unregistered Clients . . . . . . . . . . . . . . . . . . 17 2.4. Unregistered Clients ......................................17
3. Protocol Endpoints . . . . . . . . . . . . . . . . . . . . . . 17 3. Protocol Endpoints .............................................18
3.1. Authorization Endpoint . . . . . . . . . . . . . . . . . 17 3.1. Authorization Endpoint ....................................18
3.1.1. Response Type . . . . . . . . . . . . . . . . . . . . 18 3.1.1. Response Type ......................................19
3.1.2. Redirection Endpoint . . . . . . . . . . . . . . . . . 18 3.1.2. Redirection Endpoint ...............................19
3.2. Token Endpoint . . . . . . . . . . . . . . . . . . . . . 21 3.2. Token Endpoint ............................................21
3.2.1. Client Authentication . . . . . . . . . . . . . . . . 21 3.2.1. Client Authentication ..............................22
3.3. Access Token Scope . . . . . . . . . . . . . . . . . . . 22 3.3. Access Token Scope ........................................23
4. Obtaining Authorization . . . . . . . . . . . . . . . . . . . 22 4. Obtaining Authorization ........................................23
4.1. Authorization Code Grant . . . . . . . . . . . . . . . . 23 4.1. Authorization Code Grant ..................................24
4.1.1. Authorization Request . . . . . . . . . . . . . . . . 24 4.1.1. Authorization Request ..............................25
4.1.2. Authorization Response . . . . . . . . . . . . . . . . 25 4.1.2. Authorization Response .............................26
4.1.3. Access Token Request . . . . . . . . . . . . . . . . . 27 4.1.3. Access Token Request ...............................29
4.1.4. Access Token Response . . . . . . . . . . . . . . . . 28 4.1.4. Access Token Response ..............................30
4.2. Implicit Grant . . . . . . . . . . . . . . . . . . . . . 29 4.2. Implicit Grant ............................................31
4.2.1. Authorization Request . . . . . . . . . . . . . . . . 31 4.2.1. Authorization Request ..............................33
4.2.2. Access Token Response . . . . . . . . . . . . . . . . 32 4.2.2. Access Token Response ..............................35
4.3. Resource Owner Password Credentials Grant . . . . . . . . 35 4.3. Resource Owner Password Credentials Grant .................37
4.3.1. Authorization Request and Response . . . . . . . . . . 36 4.3.1. Authorization Request and Response .................39
4.3.2. Access Token Request . . . . . . . . . . . . . . . . . 36 4.3.2. Access Token Request ...............................39
4.3.3. Access Token Response . . . . . . . . . . . . . . . . 37 4.3.3. Access Token Response ..............................40
4.4. Client Credentials Grant ..................................40
4.4.1. Authorization Request and Response .................41
4.4.2. Access Token Request ...............................41
4.4.3. Access Token Response ..............................42
4.5. Extension Grants ..........................................42
4.4. Client Credentials Grant . . . . . . . . . . . . . . . . 37 5. Issuing an Access Token ........................................43
4.4.1. Authorization Request and Response . . . . . . . . . . 38 5.1. Successful Response .......................................43
4.4.2. Access Token Request . . . . . . . . . . . . . . . . . 38 5.2. Error Response ............................................45
4.4.3. Access Token Response . . . . . . . . . . . . . . . . 39 6. Refreshing an Access Token .....................................47
4.5. Extension Grants . . . . . . . . . . . . . . . . . . . . 39 7. Accessing Protected Resources ..................................48
5. Issuing an Access Token . . . . . . . . . . . . . . . . . . . 40 7.1. Access Token Types ........................................49
5.1. Successful Response . . . . . . . . . . . . . . . . . . . 40 7.2. Error Response ............................................49
5.2. Error Response . . . . . . . . . . . . . . . . . . . . . 41 8. Extensibility ..................................................50
6. Refreshing an Access Token . . . . . . . . . . . . . . . . . . 43 8.1. Defining Access Token Types ...............................50
7. Accessing Protected Resources . . . . . . . . . . . . . . . . 44 8.2. Defining New Endpoint Parameters ..........................50
7.1. Access Token Types . . . . . . . . . . . . . . . . . . . 44 8.3. Defining New Authorization Grant Types ....................51
7.2. Error Response . . . . . . . . . . . . . . . . . . . . . 45 8.4. Defining New Authorization Endpoint Response Types ........51
8. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 46 8.5. Defining Additional Error Codes ...........................51
8.1. Defining Access Token Types . . . . . . . . . . . . . . . 46 9. Native Applications ............................................52
8.2. Defining New Endpoint Parameters . . . . . . . . . . . . 46 10. Security Considerations .......................................53
8.3. Defining New Authorization Grant Types . . . . . . . . . 47 10.1. Client Authentication ....................................53
8.4. Defining New Authorization Endpoint Response Types . . . 47 10.2. Client Impersonation .....................................54
8.5. Defining Additional Error Codes . . . . . . . . . . . . . 47 10.3. Access Tokens ............................................55
9. Native Applications . . . . . . . . . . . . . . . . . . . . . 48 10.4. Refresh Tokens ...........................................55
10. Security Considerations . . . . . . . . . . . . . . . . . . . 49 10.5. Authorization Codes ......................................56
10.1. Client Authentication . . . . . . . . . . . . . . . . . . 49 10.6. Authorization Code Redirection URI Manipulation ..........56
10.2. Client Impersonation . . . . . . . . . . . . . . . . . . 50 10.7. Resource Owner Password Credentials ......................57
10.3. Access Tokens . . . . . . . . . . . . . . . . . . . . . . 50 10.8. Request Confidentiality ..................................58
10.4. Refresh Tokens . . . . . . . . . . . . . . . . . . . . . 51 10.9. Ensuring Endpoint Authenticity ...........................58
10.5. Authorization Codes . . . . . . . . . . . . . . . . . . . 51 10.10. Credentials-Guessing Attacks ............................58
10.6. Authorization Code Redirection URI Manipulation . . . . . 52 10.11. Phishing Attacks ........................................58
10.7. Resource Owner Password Credentials . . . . . . . . . . . 53 10.12. Cross-Site Request Forgery ..............................59
10.8. Request Confidentiality . . . . . . . . . . . . . . . . . 53 10.13. Clickjacking ............................................60
10.9. Endpoints Authenticity . . . . . . . . . . . . . . . . . 53 10.14. Code Injection and Input Validation .....................60
10.10. Credentials Guessing Attacks . . . . . . . . . . . . . . 54 10.15. Open Redirectors ........................................60
10.11. Phishing Attacks . . . . . . . . . . . . . . . . . . . . 54 10.16. Misuse of Access Token to Impersonate Resource
10.12. Cross-Site Request Forgery . . . . . . . . . . . . . . . 54 Owner in Implicit Flow ..................................61
10.13. Clickjacking . . . . . . . . . . . . . . . . . . . . . . 55 11. IANA Considerations ...........................................62
10.14. Code Injection and Input Validation . . . . . . . . . . . 56 11.1. OAuth Access Token Types Registry ........................62
10.15. Open Redirectors . . . . . . . . . . . . . . . . . . . . 56 11.1.1. Registration Template .............................62
10.16. Misuse of Access Token to Impersonate Resource Owner 11.2. OAuth Parameters Registry ................................63
in Implicit Flow . . . . . . . . . . . . . . . . . . . . 56 11.2.1. Registration Template .............................63
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 57 11.2.2. Initial Registry Contents .........................64
11.1. OAuth Access Token Type Registry . . . . . . . . . . . . 57 11.3. OAuth Authorization Endpoint Response Types Registry .....66
11.1.1. Registration Template . . . . . . . . . . . . . . . . 58 11.3.1. Registration Template .............................66
11.2. OAuth Parameters Registry . . . . . . . . . . . . . . . . 58 11.3.2. Initial Registry Contents .........................67
11.2.1. Registration Template . . . . . . . . . . . . . . . . 59 11.4. OAuth Extensions Error Registry ..........................67
11.2.2. Initial Registry Contents . . . . . . . . . . . . . . 59 11.4.1. Registration Template .............................68
11.3. OAuth Authorization Endpoint Response Type Registry . . . 61 12. References ....................................................68
11.3.1. Registration Template . . . . . . . . . . . . . . . . 62 12.1. Normative References .....................................68
11.3.2. Initial Registry Contents . . . . . . . . . . . . . . 62 12.2. Informative References ...................................70
11.4. OAuth Extensions Error Registry . . . . . . . . . . . . . 62
11.4.1. Registration Template . . . . . . . . . . . . . . . . 63
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Appendix A. Augmented Backus-Naur Form (ABNF) Syntax ..............71
12.1. Normative References . . . . . . . . . . . . . . . . . . 64 A.1. "client_id" Syntax ........................................71
12.2. Informative References . . . . . . . . . . . . . . . . . 65 A.2. "client_secret" Syntax ....................................71
Appendix A. Augmented Backus-Naur Form (ABNF) Syntax . . . . . . 66 A.3. "response_type" Syntax ....................................71
A.1. "client_id" Syntax . . . . . . . . . . . . . . . . . . . 66 A.4. "scope" Syntax ............................................72
A.2. "client_secret" Syntax . . . . . . . . . . . . . . . . . 66 A.5. "state" Syntax ............................................72
A.3. "response_type" Syntax . . . . . . . . . . . . . . . . . 66 A.6. "redirect_uri" Syntax .....................................72
A.4. "scope" Syntax . . . . . . . . . . . . . . . . . . . . . 67 A.7. "error" Syntax ............................................72
A.5. "state" Syntax . . . . . . . . . . . . . . . . . . . . . 67 A.8. "error_description" Syntax ................................72
A.6. "redirect_uri" Syntax . . . . . . . . . . . . . . . . . . 67 A.9. "error_uri" Syntax ........................................72
A.7. "error" Syntax . . . . . . . . . . . . . . . . . . . . . 67 A.10. "grant_type" Syntax .......................................73
A.8. "error_description" Syntax . . . . . . . . . . . . . . . 67 A.11. "code" Syntax .............................................73
A.9. "error_uri" Syntax . . . . . . . . . . . . . . . . . . . 67 A.12. "access_token" Syntax .....................................73
A.10. "grant_type" Syntax . . . . . . . . . . . . . . . . . . . 68 A.13. "token_type" Syntax .......................................73
A.11. "code" Syntax . . . . . . . . . . . . . . . . . . . . . . 68 A.14. "expires_in" Syntax .......................................73
A.12. "access_token" Syntax . . . . . . . . . . . . . . . . . . 68 A.15. "username" Syntax .........................................73
A.13. "token_type" Syntax . . . . . . . . . . . . . . . . . . . 68 A.16. "password" Syntax .........................................73
A.14. "expires_in" Syntax . . . . . . . . . . . . . . . . . . . 68 A.17. "refresh_token" Syntax ....................................74
A.15. "username" Syntax . . . . . . . . . . . . . . . . . . . . 68 A.18. Endpoint Parameter Syntax .................................74
A.16. "password" Syntax . . . . . . . . . . . . . . . . . . . . 69 Appendix B. Use of application/x-www-form-urlencoded Media Type ...74
A.17. "refresh_token" Syntax . . . . . . . . . . . . . . . . . 69 Appendix C. Acknowledgements ......................................75
A.18. Endpoint Parameter Syntax . . . . . . . . . . . . . . . . 69
Appendix B. Use of application/x-www-form-urlencoded Media
Type . . . . . . . . . . . . . . . . . . . . . . . . 69
Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 70
Appendix D. Document History . . . . . . . . . . . . . . . . . . 71
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 72
1. Introduction 1. Introduction
In the traditional client-server authentication model, the client In the traditional client-server authentication model, the client
requests an access restricted resource (protected resource) on the requests an access-restricted resource (protected resource) on the
server by authenticating with the server using the resource owner's server by authenticating with the server using the resource owner's
credentials. In order to provide third-party applications access to credentials. In order to provide third-party applications access to
restricted resources, the resource owner shares its credentials with restricted resources, the resource owner shares its credentials with
the third-party. This creates several problems and limitations: the third party. This creates several problems and limitations:
o Third-party applications are required to store the resource o Third-party applications are required to store the resource
owner's credentials for future use, typically a password in clear- owner's credentials for future use, typically a password in
text. clear-text.
o Servers are required to support password authentication, despite o Servers are required to support password authentication, despite
the security weaknesses inherent in passwords. the security weaknesses inherent in passwords.
o Third-party applications gain overly broad access to the resource o Third-party applications gain overly broad access to the resource
owner's protected resources, leaving resource owners without any owner's protected resources, leaving resource owners without any
ability to restrict duration or access to a limited subset of ability to restrict duration or access to a limited subset of
resources. resources.
o Resource owners cannot revoke access to an individual third-party
without revoking access to all third-parties, and must do so by o Resource owners cannot revoke access to an individual third party
changing their password. without revoking access to all third parties, and must do so by
changing the third party's password.
o Compromise of any third-party application results in compromise of o Compromise of any third-party application results in compromise of
the end-user's password and all of the data protected by that the end-user's password and all of the data protected by that
password. password.
OAuth addresses these issues by introducing an authorization layer OAuth addresses these issues by introducing an authorization layer
and separating the role of the client from that of the resource and separating the role of the client from that of the resource
owner. In OAuth, the client requests access to resources controlled owner. In OAuth, the client requests access to resources controlled
by the resource owner and hosted by the resource server, and is by the resource owner and hosted by the resource server, and is
issued a different set of credentials than those of the resource issued a different set of credentials than those of the resource
owner. owner.
Instead of using the resource owner's credentials to access protected Instead of using the resource owner's credentials to access protected
resources, the client obtains an access token - a string denoting a resources, the client obtains an access token -- a string denoting a
specific scope, lifetime, and other access attributes. Access tokens specific scope, lifetime, and other access attributes. Access tokens
are issued to third-party clients by an authorization server with the are issued to third-party clients by an authorization server with the
approval of the resource owner. The client uses the access token to approval of the resource owner. The client uses the access token to
access the protected resources hosted by the resource server. access the protected resources hosted by the resource server.
For example, an end-user (resource owner) can grant a printing For example, an end-user (resource owner) can grant a printing
service (client) access to her protected photos stored at a photo service (client) access to her protected photos stored at a photo-
sharing service (resource server), without sharing her username and sharing service (resource server), without sharing her username and
password with the printing service. Instead, she authenticates password with the printing service. Instead, she authenticates
directly with a server trusted by the photo sharing service directly with a server trusted by the photo-sharing service
(authorization server), which issues the printing service delegation- (authorization server), which issues the printing service delegation-
specific credentials (access token). specific credentials (access token).
This specification is designed for use with HTTP ([RFC2616]). The This specification is designed for use with HTTP ([RFC2616]). The
use of OAuth over any other protocol than HTTP is out of scope. use of OAuth over any protocol other than HTTP is out of scope.
The OAuth 1.0 protocol ([RFC5849]), published as an informational The OAuth 1.0 protocol ([RFC5849]), published as an informational
document, was the result of a small ad-hoc community effort. This document, was the result of a small ad hoc community effort. This
standards-track specification builds on the OAuth 1.0 deployment Standards Track specification builds on the OAuth 1.0 deployment
experience, as well as additional use cases and extensibility experience, as well as additional use cases and extensibility
requirements gathered from the wider IETF community. The OAuth 2.0 requirements gathered from the wider IETF community. The OAuth 2.0
protocol is not backward compatible with OAuth 1.0. The two versions protocol is not backward compatible with OAuth 1.0. The two versions
may co-exist on the network and implementations may choose to support may co-exist on the network, and implementations may choose to
both. However, it is the intention of this specification that new support both. However, it is the intention of this specification
implementation support OAuth 2.0 as specified in this document, and that new implementations support OAuth 2.0 as specified in this
that OAuth 1.0 is used only to support existing deployments. The document and that OAuth 1.0 is used only to support existing
OAuth 2.0 protocol shares very few implementation details with the deployments. The OAuth 2.0 protocol shares very few implementation
OAuth 1.0 protocol. Implementers familiar with OAuth 1.0 should details with the OAuth 1.0 protocol. Implementers familiar with
approach this document without any assumptions as to its structure OAuth 1.0 should approach this document without any assumptions as to
and details. its structure and details.
1.1. Roles 1.1. Roles
OAuth defines four roles: OAuth defines four roles:
resource owner resource owner
An entity capable of granting access to a protected resource. An entity capable of granting access to a protected resource.
When the resource owner is a person, it is referred to as an end- When the resource owner is a person, it is referred to as an
user. end-user.
resource server resource server
The server hosting the protected resources, capable of accepting The server hosting the protected resources, capable of accepting
and responding to protected resource requests using access tokens. and responding to protected resource requests using access tokens.
client client
An application making protected resource requests on behalf of the An application making protected resource requests on behalf of the
resource owner and with its authorization. The term client does resource owner and with its authorization. The term "client" does
not imply any particular implementation characteristics (e.g. not imply any particular implementation characteristics (e.g.,
whether the application executes on a server, a desktop, or other whether the application executes on a server, a desktop, or other
devices). devices).
authorization server authorization server
The server issuing access tokens to the client after successfully The server issuing access tokens to the client after successfully
authenticating the resource owner and obtaining authorization. authenticating the resource owner and obtaining authorization.
The interaction between the authorization server and resource server The interaction between the authorization server and resource server
is beyond the scope of this specification. The authorization server is beyond the scope of this specification. The authorization server
may be the same server as the resource server or a separate entity. may be the same server as the resource server or a separate entity.
A single authorization server may issue access tokens accepted by A single authorization server may issue access tokens accepted by
multiple resource servers. multiple resource servers.
skipping to change at page 7, line 34 skipping to change at page 7, line 34
Figure 1: Abstract Protocol Flow Figure 1: Abstract Protocol Flow
The abstract OAuth 2.0 flow illustrated in Figure 1 describes the The abstract OAuth 2.0 flow illustrated in Figure 1 describes the
interaction between the four roles and includes the following steps: interaction between the four roles and includes the following steps:
(A) The client requests authorization from the resource owner. The (A) The client requests authorization from the resource owner. The
authorization request can be made directly to the resource owner authorization request can be made directly to the resource owner
(as shown), or preferably indirectly via the authorization (as shown), or preferably indirectly via the authorization
server as an intermediary. server as an intermediary.
(B) The client receives an authorization grant, which is a (B) The client receives an authorization grant, which is a
credential representing the resource owner's authorization, credential representing the resource owner's authorization,
expressed using one of four grant types defined in this expressed using one of four grant types defined in this
specification or using an extension grant type. The specification or using an extension grant type. The
authorization grant type depends on the method used by the authorization grant type depends on the method used by the
client to request authorization and the types supported by the client to request authorization and the types supported by the
authorization server. authorization server.
(C) The client requests an access token by authenticating with the (C) The client requests an access token by authenticating with the
authorization server and presenting the authorization grant. authorization server and presenting the authorization grant.
(D) The authorization server authenticates the client and validates (D) The authorization server authenticates the client and validates
the authorization grant, and if valid issues an access token. the authorization grant, and if valid, issues an access token.
(E) The client requests the protected resource from the resource (E) The client requests the protected resource from the resource
server and authenticates by presenting the access token. server and authenticates by presenting the access token.
(F) The resource server validates the access token, and if valid, (F) The resource server validates the access token, and if valid,
serves the request. serves the request.
The preferred method for the client to obtain an authorization grant The preferred method for the client to obtain an authorization grant
from the resource owner (depicted in steps (A) and (B)) is to use the from the resource owner (depicted in steps (A) and (B)) is to use the
authorization server as an intermediary, which is illustrated in authorization server as an intermediary, which is illustrated in
Figure 3. Figure 3 in Section 4.1.
1.3. Authorization Grant 1.3. Authorization Grant
An authorization grant is a credential representing the resource An authorization grant is a credential representing the resource
owner's authorization (to access its protected resources) used by the owner's authorization (to access its protected resources) used by the
client to obtain an access token. This specification defines four client to obtain an access token. This specification defines four
grant types: authorization code, implicit, resource owner password grant types -- authorization code, implicit, resource owner password
credentials, and client credentials, as well as an extensibility credentials, and client credentials -- as well as an extensibility
mechanism for defining additional types. mechanism for defining additional types.
1.3.1. Authorization Code 1.3.1. Authorization Code
The authorization code is obtained by using an authorization server The authorization code is obtained by using an authorization server
as an intermediary between the client and resource owner. Instead of as an intermediary between the client and resource owner. Instead of
requesting authorization directly from the resource owner, the client requesting authorization directly from the resource owner, the client
directs the resource owner to an authorization server (via its user- directs the resource owner to an authorization server (via its
agent as defined in [RFC2616]), which in turn directs the resource user-agent as defined in [RFC2616]), which in turn directs the
owner back to the client with the authorization code. resource owner back to the client with the authorization code.
Before directing the resource owner back to the client with the Before directing the resource owner back to the client with the
authorization code, the authorization server authenticates the authorization code, the authorization server authenticates the
resource owner and obtains authorization. Because the resource owner resource owner and obtains authorization. Because the resource owner
only authenticates with the authorization server, the resource only authenticates with the authorization server, the resource
owner's credentials are never shared with the client. owner's credentials are never shared with the client.
The authorization code provides a few important security benefits The authorization code provides a few important security benefits,
such as the ability to authenticate the client, and the transmission such as the ability to authenticate the client, as well as the
of the access token directly to the client without passing it through transmission of the access token directly to the client without
the resource owner's user-agent, potentially exposing it to others, passing it through the resource owner's user-agent and potentially
including the resource owner. exposing it to others, including the resource owner.
1.3.2. Implicit 1.3.2. Implicit
The implicit grant is a simplified authorization code flow optimized The implicit grant is a simplified authorization code flow optimized
for clients implemented in a browser using a scripting language such for clients implemented in a browser using a scripting language such
as JavaScript. In the implicit flow, instead of issuing the client as JavaScript. In the implicit flow, instead of issuing the client
an authorization code, the client is issued an access token directly an authorization code, the client is issued an access token directly
(as the result of the resource owner authorization). The grant type (as the result of the resource owner authorization). The grant type
is implicit as no intermediate credentials (such as an authorization is implicit, as no intermediate credentials (such as an authorization
code) are issued (and later used to obtain an access token). code) are issued (and later used to obtain an access token).
When issuing an access token during the implicit grant flow, the When issuing an access token during the implicit grant flow, the
authorization server does not authenticate the client. In some authorization server does not authenticate the client. In some
cases, the client identity can be verified via the redirection URI cases, the client identity can be verified via the redirection URI
used to deliver the access token to the client. The access token may 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 be exposed to the resource owner or other applications with access to
the resource owner's user-agent. the resource owner's user-agent.
Implicit grants improve the responsiveness and efficiency of some Implicit grants improve the responsiveness and efficiency of some
clients (such as a client implemented as an in-browser application) clients (such as a client implemented as an in-browser application),
since it reduces the number of round trips required to obtain an since it reduces the number of round trips required to obtain an
access token. However, this convenience should be weighed against access token. However, this convenience should be weighed against
the security implications of using implicit grants, such as those the security implications of using implicit grants, such as those
described in Section 10.3 and Section 10.16, especially when the described in Sections 10.3 and 10.16, especially when the
authorization code grant type is available. authorization code grant type is available.
1.3.3. Resource Owner Password Credentials 1.3.3. Resource Owner Password Credentials
The resource owner password credentials (i.e. username and password) The resource owner password credentials (i.e., username and password)
can be used directly as an authorization grant to obtain an access can be used directly as an authorization grant to obtain an access
token. The credentials should only be used when there is a high token. The credentials should only be used when there is a high
degree of trust between the resource owner and the client (e.g. the degree of trust between the resource owner and the client (e.g., the
client is part of the device operating system or a highly privileged client is part of the device operating system or a highly privileged
application), and when other authorization grant types are not application), and when other authorization grant types are not
available (such as an authorization code). available (such as an authorization code).
Even though this grant type requires direct client access to the Even though this grant type requires direct client access to the
resource owner credentials, the resource owner credentials are used resource owner credentials, the resource owner credentials are used
for a single request and are exchanged for an access token. This for a single request and are exchanged for an access token. This
grant type can eliminate the need for the client to store the grant type can eliminate the need for the client to store the
resource owner credentials for future use, by exchanging the resource owner credentials for future use, by exchanging the
credentials with a long-lived access token or refresh token. credentials with a long-lived access token or refresh token.
1.3.4. Client Credentials 1.3.4. Client Credentials
The client credentials (or other forms of client authentication) can The client credentials (or other forms of client authentication) can
be used as an authorization grant when the authorization scope is be used as an authorization grant when the authorization scope is
limited to the protected resources under the control of the client, limited to the protected resources under the control of the client,
or to protected resources previously arranged with the authorization or to protected resources previously arranged with the authorization
server. Client credentials are used as an authorization grant server. Client credentials are used as an authorization grant
typically when the client is acting on its own behalf (the client is typically when the client is acting on its own behalf (the client is
also the resource owner), or is requesting access to protected also the resource owner) or is requesting access to protected
resources based on an authorization previously arranged with the resources based on an authorization previously arranged with the
authorization server. authorization server.
1.4. Access Token 1.4. Access Token
Access tokens are credentials used to access protected resources. An Access tokens are credentials used to access protected resources. An
access token is a string representing an authorization issued to the access token is a string representing an authorization issued to the
client. The string is usually opaque to the client. Tokens client. The string is usually opaque to the client. Tokens
represent specific scopes and durations of access, granted by the represent specific scopes and durations of access, granted by the
resource owner, and enforced by the resource server and authorization resource owner, and enforced by the resource server and authorization
server. server.
The token may denote an identifier used to retrieve the authorization The token may denote an identifier used to retrieve the authorization
information, or self-contain the authorization information in a information or may self-contain the authorization information in a
verifiable manner (i.e. a token string consisting of some data and a verifiable manner (i.e., a token string consisting of some data and a
signature). Additional authentication credentials, which are beyond signature). Additional authentication credentials, which are beyond
the scope of this specification, may be required in order for the the scope of this specification, may be required in order for the
client to use a token. client to use a token.
The access token provides an abstraction layer, replacing different The access token provides an abstraction layer, replacing different
authorization constructs (e.g. username and password) with a single authorization constructs (e.g., username and password) with a single
token understood by the resource server. This abstraction enables token understood by the resource server. This abstraction enables
issuing access tokens more restrictive than the authorization grant issuing access tokens more restrictive than the authorization grant
used to obtain them, as well as removing the resource server's need used to obtain them, as well as removing the resource server's need
to understand a wide range of authentication methods. to understand a wide range of authentication methods.
Access tokens can have different formats, structures, and methods of Access tokens can have different formats, structures, and methods of
utilization (e.g. cryptographic properties) based on the resource utilization (e.g., cryptographic properties) based on the resource
server security requirements. Access token attributes and the server security requirements. Access token attributes and the
methods used to access protected resources are beyond the scope of methods used to access protected resources are beyond the scope of
this specification and are defined by companion specifications. this specification and are defined by companion specifications such
as [RFC6750].
1.5. Refresh Token 1.5. Refresh Token
Refresh tokens are credentials used to obtain access tokens. Refresh Refresh tokens are credentials used to obtain access tokens. Refresh
tokens are issued to the client by the authorization server and are tokens are issued to the client by the authorization server and are
used to obtain a new access token when the current access token used to obtain a new access token when the current access token
becomes invalid or expires, or to obtain additional access tokens becomes invalid or expires, or to obtain additional access tokens
with identical or narrower scope (access tokens may have a shorter with identical or narrower scope (access tokens may have a shorter
lifetime and fewer permissions than authorized by the resource lifetime and fewer permissions than authorized by the resource
owner). Issuing a refresh token is optional at the discretion of the owner). Issuing a refresh token is optional at the discretion of the
authorization server. If the authorization server issues a refresh authorization server. If the authorization server issues a refresh
token, it is included when issuing an access token (i.e. step (D) in token, it is included when issuing an access token (i.e., step (D) in
Figure 1). Figure 1).
A refresh token is a string representing the authorization granted to 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 by the resource owner. The string is usually opaque to
the client. The token denotes an identifier used to retrieve the the client. The token denotes an identifier used to retrieve the
authorization information. Unlike access tokens, refresh tokens are authorization information. Unlike access tokens, refresh tokens are
intended for use only with authorization servers and are never sent intended for use only with authorization servers and are never sent
to resource servers. to resource servers.
+--------+ +---------------+ +--------+ +---------------+
skipping to change at page 11, line 31 skipping to change at page 11, line 34
| |--(G)----------- Refresh Token ----------->| | | |--(G)----------- Refresh Token ----------->| |
| | | | | | | |
| |<-(H)----------- Access Token -------------| | | |<-(H)----------- Access Token -------------| |
+--------+ & Optional Refresh Token +---------------+ +--------+ & Optional Refresh Token +---------------+
Figure 2: Refreshing an Expired Access Token Figure 2: Refreshing an Expired Access Token
The flow illustrated in Figure 2 includes the following steps: The flow illustrated in Figure 2 includes the following steps:
(A) The client requests an access token by authenticating with the (A) The client requests an access token by authenticating with the
authorization server, and presenting an authorization grant. authorization server and presenting an authorization grant.
(B) The authorization server authenticates the client and validates (B) The authorization server authenticates the client and validates
the authorization grant, and if valid issues an access token and the authorization grant, and if valid, issues an access token
a refresh token. and a refresh token.
(C) The client makes a protected resource request to the resource (C) The client makes a protected resource request to the resource
server by presenting the access token. server by presenting the access token.
(D) The resource server validates the access token, and if valid, (D) The resource server validates the access token, and if valid,
serves the request. serves the request.
(E) Steps (C) and (D) repeat until the access token expires. If the (E) Steps (C) and (D) repeat until the access token expires. If the
client knows the access token expired, it skips to step (G), client knows the access token expired, it skips to step (G);
otherwise it makes another protected resource request. otherwise, it makes another protected resource request.
(F) Since the access token is invalid, the resource server returns (F) Since the access token is invalid, the resource server returns
an invalid token error. an invalid token error.
(G) The client requests a new access token by authenticating with (G) The client requests a new access token by authenticating with
the authorization server and presenting the refresh token. The the authorization server and presenting the refresh token. The
client authentication requirements are based on the client type client authentication requirements are based on the client type
and on the authorization server policies. and on the authorization server policies.
(H) The authorization server authenticates the client and validates (H) The authorization server authenticates the client and validates
the refresh token, and if valid issues a new access token (and the refresh token, and if valid, issues a new access token (and,
optionally, a new refresh token). optionally, a new refresh token).
Steps C, D, E, and F are outside the scope of this specification as Steps (C), (D), (E), and (F) are outside the scope of this
described in Section 7. specification, as described in Section 7.
1.6. TLS Version 1.6. TLS Version
Whenever TLS is used by this specification, the appropriate version Whenever Transport Layer Security (TLS) is used by this
(or versions) of TLS will vary over time, based on the widespread specification, the appropriate version (or versions) of TLS will vary
deployment and known security vulnerabilities. At the time of this over time, based on the widespread deployment and known security
writing, TLS version 1.2 [RFC5246] is the most recent version, but vulnerabilities. At the time of this writing, TLS version 1.2
has a very limited deployment base and might not be readily available [RFC5246] is the most recent version, but has a very limited
for implementation. TLS version 1.0 [RFC2246] is the most widely deployment base and might not be readily available for
deployed version, and will provide the broadest interoperability. implementation. TLS version 1.0 [RFC2246] is the most widely
deployed version and will provide the broadest interoperability.
Implementations MAY also support additional transport-layer security Implementations MAY also support additional transport-layer security
mechanisms that meet their security requirements. mechanisms that meet their security requirements.
1.7. HTTP Redirections 1.7. HTTP Redirections
This specification makes extensive use of HTTP redirections, in which This specification makes extensive use of HTTP redirections, in which
the client or the authorization server directs the resource owner's the client or the authorization server directs the resource owner's
user-agent to another destination. While the examples in this user-agent to another destination. While the examples in this
specification show the use of the HTTP 302 status code, any other specification show the use of the HTTP 302 status code, any other
skipping to change at page 12, line 37 skipping to change at page 12, line 49
1.8. Interoperability 1.8. Interoperability
OAuth 2.0 provides a rich authorization framework with well-defined OAuth 2.0 provides a rich authorization framework with well-defined
security properties. However, as a rich and highly extensible security properties. However, as a rich and highly extensible
framework with many optional components, on its own, this framework with many optional components, on its own, this
specification is likely to produce a wide range of non-interoperable specification is likely to produce a wide range of non-interoperable
implementations. implementations.
In addition, this specification leaves a few required components In addition, this specification leaves a few required components
partially or fully undefined (e.g. client registration, authorization partially or fully undefined (e.g., client registration,
server capabilities, endpoint discovery). Without these components, authorization server capabilities, endpoint discovery). Without
clients must be manually and specifically configured against a these components, clients must be manually and specifically
specific authorization server and resource server in order to configured against a specific authorization server and resource
interoperate. server in order to interoperate.
This framework was designed with the clear expectation that future This framework was designed with the clear expectation that future
work will define prescriptive profiles and extensions necessary to work will define prescriptive profiles and extensions necessary to
achieve full web-scale interoperability. achieve full web-scale interoperability.
1.9. Notational Conventions 1.9. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
specification are to be interpreted as described in [RFC2119]. specification are to be interpreted as described in [RFC2119].
This specification uses the Augmented Backus-Naur Form (ABNF) This specification uses the Augmented Backus-Naur Form (ABNF)
notation of [RFC5234]. Additionally, the rule URI-Reference is notation of [RFC5234]. Additionally, the rule URI-reference is
included from Uniform Resource Identifier (URI) [RFC3986]. included from "Uniform Resource Identifier (URI): Generic Syntax"
[RFC3986].
Certain security-related terms are to be understood in the sense Certain security-related terms are to be understood in the sense
defined in [RFC4949]. These terms include, but are not limited to, defined in [RFC4949]. These terms include, but are not limited to,
"attack", "authentication", "authorization", "certificate", "attack", "authentication", "authorization", "certificate",
"confidentiality", "credential", "encryption", "identity", "sign", "confidentiality", "credential", "encryption", "identity", "sign",
"signature", "trust", "validate", and "verify". "signature", "trust", "validate", and "verify".
Unless otherwise noted, all the protocol parameter names and values Unless otherwise noted, all the protocol parameter names and values
are case sensitive. are case sensitive.
2. Client Registration 2. Client Registration
Before initiating the protocol, the client registers with the Before initiating the protocol, the client registers with the
authorization server. The means through which the client registers authorization server. The means through which the client registers
with the authorization server are beyond the scope of this with the authorization server are beyond the scope of this
specification, but typically involve end-user interaction with an specification but typically involve end-user interaction with an HTML
HTML registration form. registration form.
Client registration does not require a direct interaction between the Client registration does not require a direct interaction between the
client and the authorization server. When supported by the client and the authorization server. When supported by the
authorization server, registration can rely on other means for authorization server, registration can rely on other means for
establishing trust and obtaining the required client properties (e.g. establishing trust and obtaining the required client properties
redirection URI, client type). For example, registration can be (e.g., redirection URI, client type). For example, registration can
accomplished using a self-issued or third-party-issued assertion, or be accomplished using a self-issued or third-party-issued assertion,
by the authorization server performing client discovery using a or by the authorization server performing client discovery using a
trusted channel. trusted channel.
When registering a client, the client developer SHALL: When registering a client, the client developer SHALL:
o specify the client type as described in Section 2.1, o specify the client type as described in Section 2.1,
o provide its client redirection URIs as described in Section 3.1.2, o provide its client redirection URIs as described in Section 3.1.2,
and and
o include any other information required by the authorization server o include any other information required by the authorization server
(e.g. application name, website, description, logo image, the (e.g., application name, website, description, logo image, the
acceptance of legal terms). acceptance of legal terms).
2.1. Client Types 2.1. Client Types
OAuth defines two client types, based on their ability to OAuth defines two client types, based on their ability to
authenticate securely with the authorization server (i.e. ability to authenticate securely with the authorization server (i.e., ability to
maintain the confidentiality of their client credentials): maintain the confidentiality of their client credentials):
confidential confidential
Clients capable of maintaining the confidentiality of their Clients capable of maintaining the confidentiality of their
credentials (e.g. client implemented on a secure server with credentials (e.g., client implemented on a secure server with
restricted access to the client credentials), or capable of secure restricted access to the client credentials), or capable of secure
client authentication using other means. client authentication using other means.
public public
Clients incapable of maintaining the confidentiality of their Clients incapable of maintaining the confidentiality of their
credentials (e.g. clients executing on the device used by the credentials (e.g., clients executing on the device used by the
resource owner such as an installed native application or a web resource owner, such as an installed native application or a web
browser-based application), and incapable of secure client browser-based application), and incapable of secure client
authentication via any other means. authentication via any other means.
The client type designation is based on the authorization server's The client type designation is based on the authorization server's
definition of secure authentication and its acceptable exposure definition of secure authentication and its acceptable exposure
levels of client credentials. The authorization server SHOULD NOT levels of client credentials. The authorization server SHOULD NOT
make assumptions about the client type. make assumptions about the client type.
A client may be implemented as a distributed set of components, each A client may be implemented as a distributed set of components, each
with a different client type and security context (e.g. a distributed with a different client type and security context (e.g., a
client with both a confidential server-based component and a public distributed client with both a confidential server-based component
browser-based component). If the authorization server does not and a public browser-based component). If the authorization server
provide support for such clients, or does not provide guidance with does not provide support for such clients or does not provide
regard to their registration, the client SHOULD register each guidance with regard to their registration, the client SHOULD
component as a separate client. register each component as a separate client.
This specification has been designed around the following client This specification has been designed around the following client
profiles: profiles:
web application web application
A web application is a confidential client running on a web A web application is a confidential client running on a web
server. Resource owners access the client via an HTML user server. Resource owners access the client via an HTML user
interface rendered in a user-agent on the device used by the interface rendered in a user-agent on the device used by the
resource owner. The client credentials as well as any access resource owner. The client credentials as well as any access
token issued to the client are stored on the web server and are token issued to the client are stored on the web server and are
skipping to change at page 14, line 40 skipping to change at page 15, line 15
This specification has been designed around the following client This specification has been designed around the following client
profiles: profiles:
web application web application
A web application is a confidential client running on a web A web application is a confidential client running on a web
server. Resource owners access the client via an HTML user server. Resource owners access the client via an HTML user
interface rendered in a user-agent on the device used by the interface rendered in a user-agent on the device used by the
resource owner. The client credentials as well as any access resource owner. The client credentials as well as any access
token issued to the client are stored on the web server and are token issued to the client are stored on the web server and are
not exposed to or accessible by the resource owner. not exposed to or accessible by the resource owner.
user-agent-based application user-agent-based application
A user-agent-based application is a public client in which the A user-agent-based application is a public client in which the
client code is downloaded from a web server and executes within a client code is downloaded from a web server and executes within a
user-agent (e.g. web browser) on the device used by the resource user-agent (e.g., web browser) on the device used by the resource
owner. Protocol data and credentials are easily accessible (and owner. Protocol data and credentials are easily accessible (and
often visible) to the resource owner. Since such applications often visible) to the resource owner. Since such applications
reside within the user-agent, they can make seamless use of the reside within the user-agent, they can make seamless use of the
user-agent capabilities when requesting authorization. user-agent capabilities when requesting authorization.
native application native application
A native application is a public client installed and executed on A native application is a public client installed and executed on
the device used by the resource owner. Protocol data and the device used by the resource owner. Protocol data and
credentials are accessible to the resource owner. It is assumed credentials are accessible to the resource owner. It is assumed
that any client authentication credentials included in the that any client authentication credentials included in the
application can be extracted. On the other hand, dynamically application can be extracted. On the other hand, dynamically
issued credentials such as access tokens or refresh tokens can issued credentials such as access tokens or refresh tokens can
receive an acceptable level of protection. At a minimum, these receive an acceptable level of protection. At a minimum, these
credentials are protected from hostile servers with which the credentials are protected from hostile servers with which the
application may interact with. On some platforms these application may interact. On some platforms, these credentials
credentials might be protected from other applications residing on might be protected from other applications residing on the same
the same device. device.
2.2. Client Identifier 2.2. Client Identifier
The authorization server issues the registered client a client The authorization server issues the registered client a client
identifier - a unique string representing the registration identifier -- a unique string representing the registration
information provided by the client. The client identifier is not a information provided by the client. The client identifier is not a
secret; it is exposed to the resource owner, and MUST NOT be used secret; it is exposed to the resource owner and MUST NOT be used
alone for client authentication. The client identifier is unique to alone for client authentication. The client identifier is unique to
the authorization server. the authorization server.
The client identifier string size is left undefined by this The client identifier string size is left undefined by this
specification. The client should avoid making assumptions about the specification. The client should avoid making assumptions about the
identifier size. The authorization server SHOULD document the size identifier size. The authorization server SHOULD document the size
of any identifier it issues. of any identifier it issues.
2.3. Client Authentication 2.3. Client Authentication
If the client type is confidential, the client and authorization If the client type is confidential, the client and authorization
server establish a client authentication method suitable for the server establish a client authentication method suitable for the
security requirements of the authorization server. The authorization security requirements of the authorization server. The authorization
server MAY accept any form of client authentication meeting its server MAY accept any form of client authentication meeting its
security requirements. security requirements.
Confidential clients are typically issued (or establish) a set of Confidential clients are typically issued (or establish) a set of
client credentials used for authenticating with the authorization client credentials used for authenticating with the authorization
server (e.g. password, public/private key pair). server (e.g., password, public/private key pair).
The authorization server MAY establish a client authentication method The authorization server MAY establish a client authentication method
with public clients. However, the authorization server MUST NOT rely with public clients. However, the authorization server MUST NOT rely
on public client authentication for the purpose of identifying the on public client authentication for the purpose of identifying the
client. client.
The client MUST NOT use more than one authentication method in each The client MUST NOT use more than one authentication method in each
request. request.
2.3.1. Client Password 2.3.1. Client Password
Clients in possession of a client password MAY use the HTTP Basic Clients in possession of a client password MAY use the HTTP Basic
authentication scheme as defined in [RFC2617] to authenticate with authentication scheme as defined in [RFC2617] to authenticate with
the authorization server. The client identifier is encoded using the the authorization server. The client identifier is encoded using the
"application/x-www-form-urlencoded" encoding algorithm per Appendix B "application/x-www-form-urlencoded" encoding algorithm per
and the encoded value is used as the username; the client password is Appendix B, and the encoded value is used as the username; the client
encoded using the same algorithm and used as the password. The password is encoded using the same algorithm and used as the
authorization server MUST support the HTTP Basic authentication password. The authorization server MUST support the HTTP Basic
scheme for authenticating clients that were issued a client password. authentication scheme for authenticating clients that were issued a
client password.
For example (with extra line breaks for display purposes only): For example (with extra line breaks for display purposes only):
Authorization: Basic czZCaGRSa3F0Mzo3RmpmcDBaQnIxS3REUmJuZlZkbUl3 Authorization: Basic czZCaGRSa3F0Mzo3RmpmcDBaQnIxS3REUmJuZlZkbUl3
Alternatively, the authorization server MAY support including the Alternatively, the authorization server MAY support including the
client credentials in the request body using the following client credentials in the request-body using the following
parameters: parameters:
client_id client_id
REQUIRED. The client identifier issued to the client during REQUIRED. The client identifier issued to the client during
the registration process described by Section 2.2. the registration process described by Section 2.2.
client_secret client_secret
REQUIRED. The client secret. The client MAY omit the REQUIRED. The client secret. The client MAY omit the
parameter if the client secret is an empty string. parameter if the client secret is an empty string.
Including the client credentials in the request body using the two Including the client credentials in the request-body using the two
parameters is NOT RECOMMENDED, and SHOULD be limited to clients parameters is NOT RECOMMENDED and SHOULD be limited to clients unable
unable to directly utilize the HTTP Basic authentication scheme (or to directly utilize the HTTP Basic authentication scheme (or other
other password-based HTTP authentication schemes). The parameters password-based HTTP authentication schemes). The parameters can only
can only be transmitted in the request body and MUST NOT be included be transmitted in the request-body and MUST NOT be included in the
in the request URI. request URI.
For example, requesting to refresh an access token (Section 6) using For example, a request to refresh an access token (Section 6) using
the body parameters (with extra line breaks for display purposes the body parameters (with extra line breaks for display purposes
only): only):
POST /token HTTP/1.1 POST /token HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/x-www-form-urlencoded Content-Type: application/x-www-form-urlencoded
grant_type=refresh_token&refresh_token=tGzv3JOkF0XG5Qx2TlKWIA grant_type=refresh_token&refresh_token=tGzv3JOkF0XG5Qx2TlKWIA
&client_id=s6BhdRkqt3&client_secret=7Fjfp0ZBr1KtDRbnfVdmIw &client_id=s6BhdRkqt3&client_secret=7Fjfp0ZBr1KtDRbnfVdmIw
skipping to change at page 17, line 16 skipping to change at page 17, line 41
The authorization server MAY support any suitable HTTP authentication The authorization server MAY support any suitable HTTP authentication
scheme matching its security requirements. When using other scheme matching its security requirements. When using other
authentication methods, the authorization server MUST define a authentication methods, the authorization server MUST define a
mapping between the client identifier (registration record) and mapping between the client identifier (registration record) and
authentication scheme. authentication scheme.
2.4. Unregistered Clients 2.4. Unregistered Clients
This specification does not exclude the use of unregistered clients. This specification does not exclude the use of unregistered clients.
However, the use with such clients is beyond the scope of this However, the use of such clients is beyond the scope of this
specification, and requires additional security analysis and review specification and requires additional security analysis and review of
of its interoperability impact. its interoperability impact.
3. Protocol Endpoints 3. Protocol Endpoints
The authorization process utilizes two authorization server endpoints The authorization process utilizes two authorization server endpoints
(HTTP resources): (HTTP resources):
o Authorization endpoint - used by the client to obtain o Authorization endpoint - used by the client to obtain
authorization from the resource owner via user-agent redirection. authorization from the resource owner via user-agent redirection.
o Token endpoint - used by the client to exchange an authorization o Token endpoint - used by the client to exchange an authorization
grant for an access token, typically with client authentication. grant for an access token, typically with client authentication.
As well as one client endpoint: As well as one client endpoint:
o Redirection endpoint - used by the authorization server to return o Redirection endpoint - used by the authorization server to return
authorization credentials responses to the client via the resource responses containing authorization credentials to the client via
owner user-agent. the resource owner user-agent.
Not every authorization grant type utilizes both endpoints. Not every authorization grant type utilizes both endpoints.
Extension grant types MAY define additional endpoints as needed. Extension grant types MAY define additional endpoints as needed.
3.1. Authorization Endpoint 3.1. Authorization Endpoint
The authorization endpoint is used to interact with the resource The authorization endpoint is used to interact with the resource
owner and obtain an authorization grant. The authorization server owner and obtain an authorization grant. The authorization server
MUST first verify the identity of the resource owner. The way in MUST first verify the identity of the resource owner. The way in
which the authorization server authenticates the resource owner (e.g. which the authorization server authenticates the resource owner
username and password login, session cookies) is beyond the scope of (e.g., username and password login, session cookies) is beyond the
this specification. scope of this specification.
The means through which the client obtains the location of the The means through which the client obtains the location of the
authorization endpoint are beyond the scope of this specification, authorization endpoint are beyond the scope of this specification,
but the location is typically provided in the service documentation. but the location is typically provided in the service documentation.
The endpoint URI MAY include an "application/x-www-form-urlencoded" The endpoint URI MAY include an "application/x-www-form-urlencoded"
formatted (per Appendix B) query component ([RFC3986] section 3.4), formatted (per Appendix B) query component ([RFC3986] Section 3.4),
which MUST be retained when adding additional query parameters. The which MUST be retained when adding additional query parameters. The
endpoint URI MUST NOT include a fragment component. endpoint URI MUST NOT include a fragment component.
Since requests to the authorization endpoint result in user Since requests to the authorization endpoint result in user
authentication and the transmission of clear-text credentials (in the authentication and the transmission of clear-text credentials (in the
HTTP response), the authorization server MUST require the use of TLS HTTP response), the authorization server MUST require the use of TLS
as described in Section 1.6 when sending requests to the as described in Section 1.6 when sending requests to the
authorization endpoint. authorization endpoint.
The authorization server MUST support the use of the HTTP "GET" The authorization server MUST support the use of the HTTP "GET"
method [RFC2616] for the authorization endpoint, and MAY support the method [RFC2616] for the authorization endpoint and MAY support the
use of the "POST" method as well. use of the "POST" method as well.
Parameters sent without a value MUST be treated as if they were Parameters sent without a value MUST be treated as if they were
omitted from the request. The authorization server MUST ignore omitted from the request. The authorization server MUST ignore
unrecognized request parameters. Request and response parameters unrecognized request parameters. Request and response parameters
MUST NOT be included more than once. MUST NOT be included more than once.
3.1.1. Response Type 3.1.1. Response Type
The authorization endpoint is used by the authorization code grant The authorization endpoint is used by the authorization code grant
skipping to change at page 18, line 40 skipping to change at page 19, line 25
parameter: parameter:
response_type response_type
REQUIRED. The value MUST be one of "code" for requesting an REQUIRED. The value MUST be one of "code" for requesting an
authorization code as described by Section 4.1.1, "token" for authorization code as described by Section 4.1.1, "token" for
requesting an access token (implicit grant) as described by requesting an access token (implicit grant) as described by
Section 4.2.1, or a registered extension value as described by Section 4.2.1, or a registered extension value as described by
Section 8.4. Section 8.4.
Extension response types MAY contain a space-delimited (%x20) list of Extension response types MAY contain a space-delimited (%x20) list of
values, where the order of values does not matter (e.g. response type values, where the order of values does not matter (e.g., response
"a b" is the same as "b a"). The meaning of such composite response type "a b" is the same as "b a"). The meaning of such composite
types is defined by their respective specifications. response types is defined by their respective specifications.
If an authorization request is missing the "response_type" parameter, If an authorization request is missing the "response_type" parameter,
or if the response type is not understood, the authorization server or if the response type is not understood, the authorization server
MUST return an error response as described in Section 4.1.2.1. MUST return an error response as described in Section 4.1.2.1.
3.1.2. Redirection Endpoint 3.1.2. Redirection Endpoint
After completing its interaction with the resource owner, the After completing its interaction with the resource owner, the
authorization server directs the resource owner's user-agent back to authorization server directs the resource owner's user-agent back to
the client. The authorization server redirects the user-agent to the the client. The authorization server redirects the user-agent to the
client's redirection endpoint previously established with the client's redirection endpoint previously established with the
authorization server during the client registration process or when authorization server during the client registration process or when
making the authorization request. making the authorization request.
The redirection endpoint URI MUST be an absolute URI as defined by The redirection endpoint URI MUST be an absolute URI as defined by
[RFC3986] section 4.3. The endpoint URI MAY include an [RFC3986] Section 4.3. The endpoint URI MAY include an
"application/x-www-form-urlencoded" formatted (per Appendix B) query "application/x-www-form-urlencoded" formatted (per Appendix B) query
component ([RFC3986] section 3.4), which MUST be retained when adding component ([RFC3986] Section 3.4), which MUST be retained when adding
additional query parameters. The endpoint URI MUST NOT include a additional query parameters. The endpoint URI MUST NOT include a
fragment component. fragment component.
3.1.2.1. Endpoint Request Confidentiality 3.1.2.1. Endpoint Request Confidentiality
The redirection endpoint SHOULD require the use of TLS as described The redirection endpoint SHOULD require the use of TLS as described
in Section 1.6 when the requested response type is "code" or "token", in Section 1.6 when the requested response type is "code" or "token",
or when the redirection request will result in the transmission of or when the redirection request will result in the transmission of
sensitive credentials over an open network. This specification does sensitive credentials over an open network. This specification does
not mandate the use of TLS because at the time of this writing, not mandate the use of TLS because at the time of this writing,
requiring clients to deploy TLS is a significant hurdle for many requiring clients to deploy TLS is a significant hurdle for many
client developers. If TLS is not available, the authorization server client developers. If TLS is not available, the authorization server
SHOULD warn the resource owner about the insecure endpoint prior to SHOULD warn the resource owner about the insecure endpoint prior to
redirection (e.g. display a message during the authorization redirection (e.g., display a message during the authorization
request). request).
Lack of transport-layer security can have a severe impact on the Lack of transport-layer security can have a severe impact on the
security of the client and the protected resources it is authorized security of the client and the protected resources it is authorized
to access. The use of transport-layer security is particularly to access. The use of transport-layer security is particularly
critical when the authorization process is used as a form of critical when the authorization process is used as a form of
delegated end-user authentication by the client (e.g. third-party delegated end-user authentication by the client (e.g., third-party
sign-in service). sign-in service).
3.1.2.2. Registration Requirements 3.1.2.2. Registration Requirements
The authorization server MUST require the following clients to The authorization server MUST require the following clients to
register their redirection endpoint: register their redirection endpoint:
o Public clients. o Public clients.
o Confidential clients utilizing the implicit grant type. o Confidential clients utilizing the implicit grant type.
The authorization server SHOULD require all clients to register their The authorization server SHOULD require all clients to register their
redirection endpoint prior to utilizing the authorization endpoint. redirection endpoint prior to utilizing the authorization endpoint.
The authorization server SHOULD require the client to provide the The authorization server SHOULD require the client to provide the
complete redirection URI (the client MAY use the "state" request complete redirection URI (the client MAY use the "state" request
parameter to achieve per-request customization). If requiring the parameter to achieve per-request customization). If requiring the
registration of the complete redirection URI is not possible, the registration of the complete redirection URI is not possible, the
authorization server SHOULD require the registration of the URI authorization server SHOULD require the registration of the URI
skipping to change at page 20, line 11 skipping to change at page 20, line 50
registration of the complete redirection URI is not possible, the registration of the complete redirection URI is not possible, the
authorization server SHOULD require the registration of the URI authorization server SHOULD require the registration of the URI
scheme, authority, and path (allowing the client to dynamically vary scheme, authority, and path (allowing the client to dynamically vary
only the query component of the redirection URI when requesting only the query component of the redirection URI when requesting
authorization). authorization).
The authorization server MAY allow the client to register multiple The authorization server MAY allow the client to register multiple
redirection endpoints. redirection endpoints.
Lack of a redirection URI registration requirement can enable an Lack of a redirection URI registration requirement can enable an
attacker to use the authorization endpoint as open redirector as attacker to use the authorization endpoint as an open redirector as
described in Section 10.15. described in Section 10.15.
3.1.2.3. Dynamic Configuration 3.1.2.3. Dynamic Configuration
If multiple redirection URIs have been registered, if only part of If multiple redirection URIs have been registered, if only part of
the redirection URI has been registered, or if no redirection URI has the redirection URI has been registered, or if no redirection URI has
been registered, the client MUST include a redirection URI with the been registered, the client MUST include a redirection URI with the
authorization request using the "redirect_uri" request parameter. authorization request using the "redirect_uri" request parameter.
When a redirection URI is included in an authorization request, the When a redirection URI is included in an authorization request, the
authorization server MUST compare and match the value received authorization server MUST compare and match the value received
against at least one of the registered redirection URIs (or URI against at least one of the registered redirection URIs (or URI
components) as defined in [RFC3986] section 6, if any redirection components) as defined in [RFC3986] Section 6, if any redirection
URIs were registered. If the client registration included the full URIs were registered. If the client registration included the full
redirection URI, the authorization server MUST compare the two URIs redirection URI, the authorization server MUST compare the two URIs
using simple string comparison as defined in [RFC3986] section 6.2.1. using simple string comparison as defined in [RFC3986] Section 6.2.1.
3.1.2.4. Invalid Endpoint 3.1.2.4. Invalid Endpoint
If an authorization request fails validation due to a missing, If an authorization request fails validation due to a missing,
invalid, or mismatching redirection URI, the authorization server invalid, or mismatching redirection URI, the authorization server
SHOULD inform the resource owner of the error, and MUST NOT SHOULD inform the resource owner of the error and MUST NOT
automatically redirect the user-agent to the invalid redirection URI. automatically redirect the user-agent to the invalid redirection URI.
3.1.2.5. Endpoint Content 3.1.2.5. Endpoint Content
The redirection request to the client's endpoint typically results in The redirection request to the client's endpoint typically results in
an HTML document response, processed by the user-agent. If the HTML an HTML document response, processed by the user-agent. If the HTML
response is served directly as the result of the redirection request, response is served directly as the result of the redirection request,
any script included in the HTML document will execute with full any script included in the HTML document will execute with full
access to the redirection URI and the credentials it contains. access to the redirection URI and the credentials it contains.
The client SHOULD NOT include any third-party scripts (e.g. third- The client SHOULD NOT include any third-party scripts (e.g., third-
party analytics, social plug-ins, ad networks) in the redirection party analytics, social plug-ins, ad networks) in the redirection
endpoint response. Instead, it SHOULD extract the credentials from endpoint response. Instead, it SHOULD extract the credentials from
the URI and redirect the user-agent again to another endpoint without the URI and redirect the user-agent again to another endpoint without
exposing the credentials (in the URI or elsewhere). If third-party exposing the credentials (in the URI or elsewhere). If third-party
scripts are included, the client MUST ensure that its own scripts scripts are included, the client MUST ensure that its own scripts
(used to extract and remove the credentials from the URI) will (used to extract and remove the credentials from the URI) will
execute first. execute first.
3.2. Token Endpoint 3.2. Token Endpoint
The token endpoint is used by the client to obtain an access token by The token endpoint is used by the client to obtain an access token by
presenting its authorization grant or refresh token. The token presenting its authorization grant or refresh token. The token
endpoint is used with every authorization grant except for the endpoint is used with every authorization grant except for the
implicit grant type (since an access token is issued directly). implicit grant type (since an access token is issued directly).
The means through which the client obtains the location of the token The means through which the client obtains the location of the token
endpoint are beyond the scope of this specification but is typically endpoint are beyond the scope of this specification, but the location
provided in the service documentation. is typically provided in the service documentation.
The endpoint URI MAY include an "application/x-www-form-urlencoded" The endpoint URI MAY include an "application/x-www-form-urlencoded"
formatted (per Appendix B) query component ([RFC3986] section 3.4), formatted (per Appendix B) query component ([RFC3986] Section 3.4),
which MUST be retained when adding additional query parameters. The which MUST be retained when adding additional query parameters. The
endpoint URI MUST NOT include a fragment component. endpoint URI MUST NOT include a fragment component.
Since requests to the token endpoint result in the transmission of Since requests to the token endpoint result in the transmission of
clear-text credentials (in the HTTP request and response), the clear-text credentials (in the HTTP request and response), the
authorization server MUST require the use of TLS as described in authorization server MUST require the use of TLS as described in
Section 1.6 when sending requests to the token endpoint. Section 1.6 when sending requests to the token endpoint.
The client MUST use the HTTP "POST" method when making access token The client MUST use the HTTP "POST" method when making access token
requests. requests.
skipping to change at page 21, line 44 skipping to change at page 22, line 37
3.2.1. Client Authentication 3.2.1. Client Authentication
Confidential clients or other clients issued client credentials MUST Confidential clients or other clients issued client credentials MUST
authenticate with the authorization server as described in authenticate with the authorization server as described in
Section 2.3 when making requests to the token endpoint. Client Section 2.3 when making requests to the token endpoint. Client
authentication is used for: authentication is used for:
o Enforcing the binding of refresh tokens and authorization codes to o Enforcing the binding of refresh tokens and authorization codes to
the client they were issued to. Client authentication is critical the client they were issued to. Client authentication is critical
when an authorization code is transmitted to the redirection when an authorization code is transmitted to the redirection
endpoint over an insecure channel, or when the redirection URI has endpoint over an insecure channel or when the redirection URI has
not been registered in full. not been registered in full.
o Recovering from a compromised client by disabling the client or o Recovering from a compromised client by disabling the client or
changing its credentials, thus preventing an attacker from abusing changing its credentials, thus preventing an attacker from abusing
stolen refresh tokens. Changing a single set of client stolen refresh tokens. Changing a single set of client
credentials is significantly faster than revoking an entire set of credentials is significantly faster than revoking an entire set of
refresh tokens. refresh tokens.
o Implementing authentication management best practices, which o Implementing authentication management best practices, which
require periodic credential rotation. Rotation of an entire set require periodic credential rotation. Rotation of an entire set
of refresh tokens can be challenging, while rotation of a single of refresh tokens can be challenging, while rotation of a single
set of client credentials is significantly easier. set of client credentials is significantly easier.
skipping to change at page 22, line 27 skipping to change at page 23, line 22
protected resource.) protected resource.)
3.3. Access Token Scope 3.3. Access Token Scope
The authorization and token endpoints allow the client to specify the The authorization and token endpoints allow the client to specify the
scope of the access request using the "scope" request parameter. In scope of the access request using the "scope" request parameter. In
turn, the authorization server uses the "scope" response parameter to turn, the authorization server uses the "scope" response parameter to
inform the client of the scope of the access token issued. inform the client of the scope of the access token issued.
The value of the scope parameter is expressed as a list of space- The value of the scope parameter is expressed as a list of space-
delimited, case sensitive strings. The strings are defined by the delimited, case-sensitive strings. The strings are defined by the
authorization server. If the value contains multiple space-delimited authorization server. If the value contains multiple space-delimited
strings, their order does not matter, and each string adds an strings, their order does not matter, and each string adds an
additional access range to the requested scope. additional access range to the requested scope.
scope = scope-token *( SP scope-token ) scope = scope-token *( SP scope-token )
scope-token = 1*( %x21 / %x23-5B / %x5D-7E ) scope-token = 1*( %x21 / %x23-5B / %x5D-7E )
The authorization server MAY fully or partially ignore the scope The authorization server MAY fully or partially ignore the scope
requested by the client based on the authorization server policy or requested by the client, based on the authorization server policy or
the resource owner's instructions. If the issued access token scope the resource owner's instructions. If the issued access token scope
is different from the one requested by the client, the authorization is different from the one requested by the client, the authorization
server MUST include the "scope" response parameter to inform the server MUST include the "scope" response parameter to inform the
client of the actual scope granted. client of the actual scope granted.
If the client omits the scope parameter when requesting If the client omits the scope parameter when requesting
authorization, the authorization server MUST either process the authorization, the authorization server MUST either process the
request using a pre-defined default value, or fail the request request using a pre-defined default value or fail the request
indicating an invalid scope. The authorization server SHOULD indicating an invalid scope. The authorization server SHOULD
document its scope requirements and default value (if defined). document its scope requirements and default value (if defined).
4. Obtaining Authorization 4. Obtaining Authorization
To request an access token, the client obtains authorization from the To request an access token, the client obtains authorization from the
resource owner. The authorization is expressed in the form of an resource owner. The authorization is expressed in the form of an
authorization grant, which the client uses to request the access authorization grant, which the client uses to request the access
token. OAuth defines four grant types: authorization code, implicit, token. OAuth defines four grant types: authorization code, implicit,
resource owner password credentials, and client credentials. It also resource owner password credentials, and client credentials. It also
provides an extension mechanism for defining additional grant types. provides an extension mechanism for defining additional grant types.
4.1. Authorization Code Grant 4.1. Authorization Code Grant
The authorization code grant type is used to obtain both access The authorization code grant type is used to obtain both access
tokens and refresh tokens and is optimized for confidential clients. tokens and refresh tokens and is optimized for confidential clients.
As a redirection-based flow, the client must be capable of Since this is a redirection-based flow, the client must be capable of
interacting with the resource owner's user-agent (typically a web interacting with the resource owner's user-agent (typically a web
browser) and capable of receiving incoming requests (via redirection) browser) and capable of receiving incoming requests (via redirection)
from the authorization server. from the authorization server.
+----------+ +----------+
| Resource | | Resource |
| Owner | | Owner |
| | | |
+----------+ +----------+
^ ^
skipping to change at page 23, line 44 skipping to change at page 24, line 40
(A) (C) | | (A) (C) | |
| | | | | | | |
^ v | | ^ v | |
+---------+ | | +---------+ | |
| |>---(D)-- Authorization Code ---------' | | |>---(D)-- Authorization Code ---------' |
| Client | & Redirection URI | | Client | & Redirection URI |
| | | | | |
| |<---(E)----- Access Token -------------------' | |<---(E)----- Access Token -------------------'
+---------+ (w/ Optional Refresh Token) +---------+ (w/ Optional Refresh Token)
Note: The lines illustrating steps A, B, and C are broken into two Note: The lines illustrating steps (A), (B), and (C) are broken into
parts as they pass through the user-agent. two parts as they pass through the user-agent.
Figure 3: Authorization Code Flow Figure 3: Authorization Code Flow
The flow illustrated in Figure 3 includes the following steps: The flow illustrated in Figure 3 includes the following steps:
(A) The client initiates the flow by directing the resource owner's (A) The client initiates the flow by directing the resource owner's
user-agent to the authorization endpoint. The client includes user-agent to the authorization endpoint. The client includes
its client identifier, requested scope, local state, and a its client identifier, requested scope, local state, and a
redirection URI to which the authorization server will send the redirection URI to which the authorization server will send the
user-agent back once access is granted (or denied). user-agent back once access is granted (or denied).
skipping to change at page 24, line 10 skipping to change at page 25, line 12
Figure 3: Authorization Code Flow Figure 3: Authorization Code Flow
The flow illustrated in Figure 3 includes the following steps: The flow illustrated in Figure 3 includes the following steps:
(A) The client initiates the flow by directing the resource owner's (A) The client initiates the flow by directing the resource owner's
user-agent to the authorization endpoint. The client includes user-agent to the authorization endpoint. The client includes
its client identifier, requested scope, local state, and a its client identifier, requested scope, local state, and a
redirection URI to which the authorization server will send the redirection URI to which the authorization server will send the
user-agent back once access is granted (or denied). user-agent back once access is granted (or denied).
(B) The authorization server authenticates the resource owner (via (B) The authorization server authenticates the resource owner (via
the user-agent) and establishes whether the resource owner the user-agent) and establishes whether the resource owner
grants or denies the client's access request. grants or denies the client's access request.
(C) Assuming the resource owner grants access, the authorization (C) Assuming the resource owner grants access, the authorization
server redirects the user-agent back to the client using the server redirects the user-agent back to the client using the
redirection URI provided earlier (in the request or during redirection URI provided earlier (in the request or during
client registration). The redirection URI includes an client registration). The redirection URI includes an
authorization code and any local state provided by the client authorization code and any local state provided by the client
earlier. earlier.
(D) The client requests an access token from the authorization (D) The client requests an access token from the authorization
server's token endpoint by including the authorization code server's token endpoint by including the authorization code
received in the previous step. When making the request, the received in the previous step. When making the request, the
client authenticates with the authorization server. The client client authenticates with the authorization server. The client
includes the redirection URI used to obtain the authorization includes the redirection URI used to obtain the authorization
code for verification. code for verification.
(E) The authorization server authenticates the client, validates the (E) The authorization server authenticates the client, validates the
authorization code, and ensures the redirection URI received authorization code, and ensures that the redirection URI
matches the URI used to redirect the client in step (C). If received matches the URI used to redirect the client in
valid, the authorization server responds back with an access step (C). If valid, the authorization server responds back with
token and optionally, a refresh token. an access token and, optionally, a refresh token.
4.1.1. Authorization Request 4.1.1. Authorization Request
The client constructs the request URI by adding the following The client constructs the request URI by adding the following
parameters to the query component of the authorization endpoint URI parameters to the query component of the authorization endpoint URI
using the "application/x-www-form-urlencoded" format, per Appendix B: using the "application/x-www-form-urlencoded" format, per Appendix B:
response_type response_type
REQUIRED. Value MUST be set to "code". REQUIRED. Value MUST be set to "code".
client_id client_id
REQUIRED. The client identifier as described in Section 2.2. REQUIRED. The client identifier as described in Section 2.2.
redirect_uri redirect_uri
OPTIONAL. As described in Section 3.1.2. OPTIONAL. As described in Section 3.1.2.
scope scope
OPTIONAL. The scope of the access request as described by OPTIONAL. The scope of the access request as described by
Section 3.3. Section 3.3.
state state
RECOMMENDED. An opaque value used by the client to maintain RECOMMENDED. An opaque value used by the client to maintain
state between the request and callback. The authorization state between the request and callback. The authorization
server includes this value when redirecting the user-agent back server includes this value when redirecting the user-agent back
to the client. The parameter SHOULD be used for preventing to the client. The parameter SHOULD be used for preventing
cross-site request forgery as described in Section 10.12. cross-site request forgery as described in Section 10.12.
The client directs the resource owner to the constructed URI using an The client directs the resource owner to the constructed URI using an
HTTP redirection response, or by other means available to it via the HTTP redirection response, or by other means available to it via the
user-agent. user-agent.
skipping to change at page 25, line 17 skipping to change at page 26, line 28
user-agent. user-agent.
For example, the client directs the user-agent to make the following For example, the client directs the user-agent to make the following
HTTP request using TLS (with extra line breaks for display purposes HTTP request using TLS (with extra line breaks for display purposes
only): only):
GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1 &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1
Host: server.example.com Host: server.example.com
The authorization server validates the request to ensure all required The authorization server validates the request to ensure that all
parameters are present and valid. If the request is valid, the required parameters are present and valid. If the request is valid,
authorization server authenticates the resource owner and obtains an the authorization server authenticates the resource owner and obtains
authorization decision (by asking the resource owner or by an authorization decision (by asking the resource owner or by
establishing approval via other means). establishing approval via other means).
When a decision is established, the authorization server directs the When a decision is established, the authorization server directs the
user-agent to the provided client redirection URI using an HTTP user-agent to the provided client redirection URI using an HTTP
redirection response, or by other means available to it via the user- redirection response, or by other means available to it via the
agent. user-agent.
4.1.2. Authorization Response 4.1.2. Authorization Response
If the resource owner grants the access request, the authorization If the resource owner grants the access request, the authorization
server issues an authorization code and delivers it to the client by server issues an authorization code and delivers it to the client by
adding the following parameters to the query component of the adding the following parameters to the query component of the
redirection URI using the "application/x-www-form-urlencoded" format, redirection URI using the "application/x-www-form-urlencoded" format,
per Appendix B: per Appendix B:
code code
skipping to change at page 26, line 23 skipping to change at page 27, line 33
authorization code string size is left undefined by this authorization code string size is left undefined by this
specification. The client should avoid making assumptions about code specification. The client should avoid making assumptions about code
value sizes. The authorization server SHOULD document the size of value sizes. The authorization server SHOULD document the size of
any value it issues. any value it issues.
4.1.2.1. Error Response 4.1.2.1. Error Response
If the request fails due to a missing, invalid, or mismatching If the request fails due to a missing, invalid, or mismatching
redirection URI, or if the client identifier is missing or invalid, redirection URI, or if the client identifier is missing or invalid,
the authorization server SHOULD inform the resource owner of the the authorization server SHOULD inform the resource owner of the
error, and MUST NOT automatically redirect the user-agent to the error and MUST NOT automatically redirect the user-agent to the
invalid redirection URI. invalid redirection URI.
If the resource owner denies the access request or if the request If the resource owner denies the access request or if the request
fails for reasons other than a missing or invalid redirection URI, fails for reasons other than a missing or invalid redirection URI,
the authorization server informs the client by adding the following the authorization server informs the client by adding the following
parameters to the query component of the redirection URI using the parameters to the query component of the redirection URI using the
"application/x-www-form-urlencoded" format, per Appendix B: "application/x-www-form-urlencoded" format, per Appendix B:
error error
REQUIRED. A single ASCII [USASCII] error code from the REQUIRED. A single ASCII [USASCII] error code from the
skipping to change at page 26, line 35 skipping to change at page 27, line 45
If the resource owner denies the access request or if the request If the resource owner denies the access request or if the request
fails for reasons other than a missing or invalid redirection URI, fails for reasons other than a missing or invalid redirection URI,
the authorization server informs the client by adding the following the authorization server informs the client by adding the following
parameters to the query component of the redirection URI using the parameters to the query component of the redirection URI using the
"application/x-www-form-urlencoded" format, per Appendix B: "application/x-www-form-urlencoded" format, per Appendix B:
error error
REQUIRED. A single ASCII [USASCII] error code from the REQUIRED. A single ASCII [USASCII] error code from the
following: following:
invalid_request invalid_request
The request is missing a required parameter, includes an The request is missing a required parameter, includes an
invalid parameter value, includes a parameter more than invalid parameter value, includes a parameter more than
once, or is otherwise malformed. once, or is otherwise malformed.
unauthorized_client unauthorized_client
The client is not authorized to request an authorization The client is not authorized to request an authorization
code using this method. code using this method.
access_denied access_denied
The resource owner or authorization server denied the The resource owner or authorization server denied the
request. request.
unsupported_response_type unsupported_response_type
The authorization server does not support obtaining an The authorization server does not support obtaining an
authorization code using this method. authorization code using this method.
invalid_scope invalid_scope
The requested scope is invalid, unknown, or malformed. The requested scope is invalid, unknown, or malformed.
server_error server_error
The authorization server encountered an unexpected The authorization server encountered an unexpected
condition that prevented it from fulfilling the request. condition that prevented it from fulfilling the request.
(This error code is needed because a 500 Internal Server (This error code is needed because a 500 Internal Server
Error HTTP status code cannot be returned to the client Error HTTP status code cannot be returned to the client
via a HTTP redirect.) via an HTTP redirect.)
temporarily_unavailable temporarily_unavailable
The authorization server is currently unable to handle The authorization server is currently unable to handle
the request due to a temporary overloading or maintenance the request due to a temporary overloading or maintenance
of the server. (This error code is needed because a 503 of the server. (This error code is needed because a 503
Service Unavailable HTTP status code cannot be returned Service Unavailable HTTP status code cannot be returned
to the client via a HTTP redirect.) to the client via an HTTP redirect.)
Values for the "error" parameter MUST NOT include characters Values for the "error" parameter MUST NOT include characters
outside the set %x20-21 / %x23-5B / %x5D-7E. outside the set %x20-21 / %x23-5B / %x5D-7E.
error_description error_description
OPTIONAL. A human-readable ASCII [USASCII] text providing OPTIONAL. Human-readable ASCII [USASCII] text providing
additional information, used to assist the client developer in additional information, used to assist the client developer in
understanding the error that occurred. understanding the error that occurred.
Values for the "error_description" parameter MUST NOT include Values for the "error_description" parameter MUST NOT include
characters outside the set %x20-21 / %x23-5B / %x5D-7E. characters outside the set %x20-21 / %x23-5B / %x5D-7E.
error_uri error_uri
OPTIONAL. A URI identifying a human-readable web page with OPTIONAL. A URI identifying a human-readable web page with
information about the error, used to provide the client information about the error, used to provide the client
developer with additional information about the error. developer with additional information about the error.
Values for the "error_uri" parameter MUST conform to the URI- Values for the "error_uri" parameter MUST conform to the
Reference syntax, and thus MUST NOT include characters outside URI-reference syntax and thus MUST NOT include characters
the set %x21 / %x23-5B / %x5D-7E. outside the set %x21 / %x23-5B / %x5D-7E.
state state
REQUIRED if a "state" parameter was present in the client REQUIRED if a "state" parameter was present in the client
authorization request. The exact value received from the authorization request. The exact value received from the
client. client.
For example, the authorization server redirects the user-agent by For example, the authorization server redirects the user-agent by
sending the following HTTP response: sending the following HTTP response:
HTTP/1.1 302 Found HTTP/1.1 302 Found
Location: https://client.example.com/cb?error=access_denied&state=xyz Location: https://client.example.com/cb?error=access_denied&state=xyz
skipping to change at page 28, line 39 skipping to change at page 30, line 21
Content-Type: application/x-www-form-urlencoded Content-Type: application/x-www-form-urlencoded
grant_type=authorization_code&code=SplxlOBeZQQYbYS6WxSbIA grant_type=authorization_code&code=SplxlOBeZQQYbYS6WxSbIA
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb
The authorization server MUST: The authorization server MUST:
o require client authentication for confidential clients or for any o require client authentication for confidential clients or for any
client that was issued client credentials (or with other client that was issued client credentials (or with other
authentication requirements), authentication requirements),
o authenticate the client if client authentication is included, o authenticate the client if client authentication is included,
o ensure the authorization code was issued to the authenticated
confidential client, or if the client is public, ensure the code o ensure that the authorization code was issued to the authenticated
was issued to "client_id" in the request, confidential client, or if the client is public, ensure that the
code was issued to "client_id" in the request,
o verify that the authorization code is valid, and o verify that the authorization code is valid, and
o ensure that the "redirect_uri" parameter is present if the o ensure that the "redirect_uri" parameter is present if the
"redirect_uri" parameter was included in the initial authorization "redirect_uri" parameter was included in the initial authorization
request as described in Section 4.1.1, and if included ensure request as described in Section 4.1.1, and if included ensure that
their values are identical. their values are identical.
4.1.4. Access Token Response 4.1.4. Access Token Response
If the access token request is valid and authorized, the If the access token request is valid and authorized, the
authorization server issues an access token and optional refresh authorization server issues an access token and optional refresh
token as described in Section 5.1. If the request client token as described in Section 5.1. If the request client
authentication failed or is invalid, the authorization server returns authentication failed or is invalid, the authorization server returns
an error response as described in Section 5.2. an error response as described in Section 5.2.
skipping to change at page 29, line 31 skipping to change at page 31, line 28
} }
4.2. Implicit Grant 4.2. Implicit Grant
The implicit grant type is used to obtain access tokens (it does not The implicit grant type is used to obtain access tokens (it does not
support the issuance of refresh tokens) and is optimized for public support the issuance of refresh tokens) and is optimized for public
clients known to operate a particular redirection URI. These clients clients known to operate a particular redirection URI. These clients
are typically implemented in a browser using a scripting language are typically implemented in a browser using a scripting language
such as JavaScript. such as JavaScript.
As a redirection-based flow, the client must be capable of Since this is a redirection-based flow, the client must be capable of
interacting with the resource owner's user-agent (typically a web interacting with the resource owner's user-agent (typically a web
browser) and capable of receiving incoming requests (via redirection) browser) and capable of receiving incoming requests (via redirection)
from the authorization server. from the authorization server.
Unlike the authorization code grant type in which the client makes Unlike the authorization code grant type, in which the client makes
separate requests for authorization and access token, the client separate requests for authorization and for an access token, the
receives the access token as the result of the authorization request. client receives the access token as the result of the authorization
request.
The implicit grant type does not include client authentication, and The implicit grant type does not include client authentication, and
relies on the presence of the resource owner and the registration of relies on the presence of the resource owner and the registration of
the redirection URI. Because the access token is encoded into the the redirection URI. Because the access token is encoded into the
redirection URI, it may be exposed to the resource owner and other redirection URI, it may be exposed to the resource owner and other
applications residing on the same device. applications residing on the same device.
+----------+ +----------+
| Resource | | Resource |
| Owner | | Owner |
skipping to change at page 30, line 38 skipping to change at page 32, line 38
| | | |
(A) (G) Access Token (A) (G) Access Token
| | | |
^ v ^ v
+---------+ +---------+
| | | |
| Client | | Client |
| | | |
+---------+ +---------+
Note: The lines illustrating steps A and B are broken into two parts Note: The lines illustrating steps (A) and (B) are broken into two
as they pass through the user-agent. parts as they pass through the user-agent.
Figure 4: Implicit Grant Flow Figure 4: Implicit Grant Flow
The flow illustrated in Figure 4 includes the following steps: The flow illustrated in Figure 4 includes the following steps:
(A) The client initiates the flow by directing the resource owner's (A) The client initiates the flow by directing the resource owner's
user-agent to the authorization endpoint. The client includes user-agent to the authorization endpoint. The client includes
its client identifier, requested scope, local state, and a its client identifier, requested scope, local state, and a
redirection URI to which the authorization server will send the redirection URI to which the authorization server will send the
user-agent back once access is granted (or denied). user-agent back once access is granted (or denied).
skipping to change at page 31, line 8 skipping to change at page 33, line 16
(A) The client initiates the flow by directing the resource owner's (A) The client initiates the flow by directing the resource owner's
user-agent to the authorization endpoint. The client includes user-agent to the authorization endpoint. The client includes
its client identifier, requested scope, local state, and a its client identifier, requested scope, local state, and a
redirection URI to which the authorization server will send the redirection URI to which the authorization server will send the
user-agent back once access is granted (or denied). user-agent back once access is granted (or denied).
(B) The authorization server authenticates the resource owner (via (B) The authorization server authenticates the resource owner (via
the user-agent) and establishes whether the resource owner the user-agent) and establishes whether the resource owner
grants or denies the client's access request. grants or denies the client's access request.
(C) Assuming the resource owner grants access, the authorization (C) Assuming the resource owner grants access, the authorization
server redirects the user-agent back to the client using the server redirects the user-agent back to the client using the
redirection URI provided earlier. The redirection URI includes redirection URI provided earlier. The redirection URI includes
the access token in the URI fragment. the access token in the URI fragment.
(D) The user-agent follows the redirection instructions by making a (D) The user-agent follows the redirection instructions by making a
request to the web-hosted client resource (which does not request to the web-hosted client resource (which does not
include the fragment per [RFC2616]). The user-agent retains the include the fragment per [RFC2616]). The user-agent retains the
fragment information locally. fragment information locally.
(E) The web-hosted client resource returns a web page (typically an (E) The web-hosted client resource returns a web page (typically an
HTML document with an embedded script) capable of accessing the HTML document with an embedded script) capable of accessing the
full redirection URI including the fragment retained by the full redirection URI including the fragment retained by the
user-agent, and extracting the access token (and other user-agent, and extracting the access token (and other
parameters) contained in the fragment. parameters) contained in the fragment.
(F) The user-agent executes the script provided by the web-hosted (F) The user-agent executes the script provided by the web-hosted
client resource locally, which extracts the access token and client resource locally, which extracts the access token.
passes it to the client.
See Section 1.3.2 and Section 9 for background on using the implicit (G) The user-agent passes the access token to the client.
grant. See Section 10.3 and Section 10.16 for important security
considerations when using the implicit grant. See Sections 1.3.2 and 9 for background on using the implicit grant.
See Sections 10.3 and 10.16 for important security considerations
when using the implicit grant.
4.2.1. Authorization Request 4.2.1. Authorization Request
The client constructs the request URI by adding the following The client constructs the request URI by adding the following
parameters to the query component of the authorization endpoint URI parameters to the query component of the authorization endpoint URI
using the "application/x-www-form-urlencoded" format, per Appendix B: using the "application/x-www-form-urlencoded" format, per Appendix B:
response_type response_type
REQUIRED. Value MUST be set to "token". REQUIRED. Value MUST be set to "token".
client_id client_id
REQUIRED. The client identifier as described in Section 2.2. REQUIRED. The client identifier as described in Section 2.2.
redirect_uri redirect_uri
OPTIONAL. As described in Section 3.1.2. OPTIONAL. As described in Section 3.1.2.
scope scope
OPTIONAL. The scope of the access request as described by OPTIONAL. The scope of the access request as described by
Section 3.3. Section 3.3.
state state
RECOMMENDED. An opaque value used by the client to maintain RECOMMENDED. An opaque value used by the client to maintain
state between the request and callback. The authorization state between the request and callback. The authorization
server includes this value when redirecting the user-agent back server includes this value when redirecting the user-agent back
to the client. The parameter SHOULD be used for preventing to the client. The parameter SHOULD be used for preventing
cross-site request forgery as described in Section 10.12. cross-site request forgery as described in Section 10.12.
The client directs the resource owner to the constructed URI using an The client directs the resource owner to the constructed URI using an
HTTP redirection response, or by other means available to it via the HTTP redirection response, or by other means available to it via the
user-agent. user-agent.
skipping to change at page 32, line 14 skipping to change at page 34, line 31
user-agent. user-agent.
For example, the client directs the user-agent to make the following For example, the client directs the user-agent to make the following
HTTP request using TLS (with extra line breaks for display purposes HTTP request using TLS (with extra line breaks for display purposes
only): only):
GET /authorize?response_type=token&client_id=s6BhdRkqt3&state=xyz GET /authorize?response_type=token&client_id=s6BhdRkqt3&state=xyz
&redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1 &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1
Host: server.example.com Host: server.example.com
The authorization server validates the request to ensure all required The authorization server validates the request to ensure that all
parameters are present and valid. The authorization server MUST required parameters are present and valid. The authorization server
verify that the redirection URI to which it will redirect the access MUST verify that the redirection URI to which it will redirect the
token matches a redirection URI registered by the client as described access token matches a redirection URI registered by the client as
in Section 3.1.2. described in Section 3.1.2.
If the request is valid, the authorization server authenticates the If the request is valid, the authorization server authenticates the
resource owner and obtains an authorization decision (by asking the resource owner and obtains an authorization decision (by asking the
resource owner or by establishing approval via other means). resource owner or by establishing approval via other means).
When a decision is established, the authorization server directs the When a decision is established, the authorization server directs the
user-agent to the provided client redirection URI using an HTTP user-agent to the provided client redirection URI using an HTTP
redirection response, or by other means available to it via the user- redirection response, or by other means available to it via the
agent. user-agent.
4.2.2. Access Token Response 4.2.2. Access Token Response
If the resource owner grants the access request, the authorization If the resource owner grants the access request, the authorization
server issues an access token and delivers it to the client by adding server issues an access token and delivers it to the client by adding
the following parameters to the fragment component of the redirection the following parameters to the fragment component of the redirection
URI using the "application/x-www-form-urlencoded" format, per URI using the "application/x-www-form-urlencoded" format, per
Appendix B: Appendix B:
access_token access_token
skipping to change at page 32, line 39 skipping to change at page 35, line 15
4.2.2. Access Token Response 4.2.2. Access Token Response
If the resource owner grants the access request, the authorization If the resource owner grants the access request, the authorization
server issues an access token and delivers it to the client by adding server issues an access token and delivers it to the client by adding
the following parameters to the fragment component of the redirection the following parameters to the fragment component of the redirection
URI using the "application/x-www-form-urlencoded" format, per URI using the "application/x-www-form-urlencoded" format, per
Appendix B: Appendix B:
access_token access_token
REQUIRED. The access token issued by the authorization server. REQUIRED. The access token issued by the authorization server.
token_type token_type
REQUIRED. The type of the token issued as described in REQUIRED. The type of the token issued as described in
Section 7.1. Value is case insensitive. Section 7.1. Value is case insensitive.
expires_in expires_in
RECOMMENDED. The lifetime in seconds of the access token. For RECOMMENDED. The lifetime in seconds of the access token. For
example, the value "3600" denotes that the access token will example, the value "3600" denotes that the access token will
expire in one hour from the time the response was generated. expire in one hour from the time the response was generated.
If omitted, the authorization server SHOULD provide the If omitted, the authorization server SHOULD provide the
expiration time via other means or document the default value. expiration time via other means or document the default value.
scope scope
OPTIONAL, if identical to the scope requested by the client, OPTIONAL, if identical to the scope requested by the client;
otherwise REQUIRED. The scope of the access token as described otherwise, REQUIRED. The scope of the access token as
by Section 3.3. described by Section 3.3.
state state
REQUIRED if the "state" parameter was present in the client REQUIRED if the "state" parameter was present in the client
authorization request. The exact value received from the authorization request. The exact value received from the
client. client.
The authorization server MUST NOT issue a refresh token. The authorization server MUST NOT issue a refresh token.
For example, the authorization server redirects the user-agent by For example, the authorization server redirects the user-agent by
sending the following HTTP response (with extra line breaks for sending the following HTTP response (with extra line breaks for
display purposes only): display purposes only):
HTTP/1.1 302 Found HTTP/1.1 302 Found
Location: http://example.com/cb#access_token=2YotnFZFEjr1zCsicMWpAA Location: http://example.com/cb#access_token=2YotnFZFEjr1zCsicMWpAA
&state=xyz&token_type=example&expires_in=3600 &state=xyz&token_type=example&expires_in=3600
Developers should note that some user-agents do not support the Developers should note that some user-agents do not support the
inclusion of a fragment component in the HTTP "Location" response inclusion of a fragment component in the HTTP "Location" response
header field. Such clients will require using other methods for header field. Such clients will require using other methods for
redirecting the client than a 3xx redirection response. For example, redirecting the client than a 3xx redirection response -- for
returning an HTML page that includes a 'continue' button with an example, returning an HTML page that includes a 'continue' button
action linked to the redirection URI. with an action linked to the redirection URI.
The client MUST ignore unrecognized response parameters. The access The client MUST ignore unrecognized response parameters. The access
token string size is left undefined by this specification. The token string size is left undefined by this specification. The
client should avoid making assumptions about value sizes. The client should avoid making assumptions about value sizes. The
authorization server SHOULD document the size of any value it issues. authorization server SHOULD document the size of any value it issues.
4.2.2.1. Error Response 4.2.2.1. Error Response
If the request fails due to a missing, invalid, or mismatching If the request fails due to a missing, invalid, or mismatching
redirection URI, or if the client identifier is missing or invalid, redirection URI, or if the client identifier is missing or invalid,
the authorization server SHOULD inform the resource owner of the the authorization server SHOULD inform the resource owner of the
error, and MUST NOT automatically redirect the user-agent to the error and MUST NOT automatically redirect the user-agent to the
invalid redirection URI. invalid redirection URI.
If the resource owner denies the access request or if the request If the resource owner denies the access request or if the request
fails for reasons other than a missing or invalid redirection URI, fails for reasons other than a missing or invalid redirection URI,
the authorization server informs the client by adding the following the authorization server informs the client by adding the following
parameters to the fragment component of the redirection URI using the parameters to the fragment component of the redirection URI using the
"application/x-www-form-urlencoded" format, per Appendix B: "application/x-www-form-urlencoded" format, per Appendix B:
error error
REQUIRED. A single ASCII [USASCII] error code from the REQUIRED. A single ASCII [USASCII] error code from the
skipping to change at page 34, line 8 skipping to change at page 36, line 27
If the resource owner denies the access request or if the request If the resource owner denies the access request or if the request
fails for reasons other than a missing or invalid redirection URI, fails for reasons other than a missing or invalid redirection URI,
the authorization server informs the client by adding the following the authorization server informs the client by adding the following
parameters to the fragment component of the redirection URI using the parameters to the fragment component of the redirection URI using the
"application/x-www-form-urlencoded" format, per Appendix B: "application/x-www-form-urlencoded" format, per Appendix B:
error error
REQUIRED. A single ASCII [USASCII] error code from the REQUIRED. A single ASCII [USASCII] error code from the
following: following:
invalid_request invalid_request
The request is missing a required parameter, includes an The request is missing a required parameter, includes an
invalid parameter value, includes a parameter more than invalid parameter value, includes a parameter more than
once, or is otherwise malformed. once, or is otherwise malformed.
unauthorized_client unauthorized_client
The client is not authorized to request an access token The client is not authorized to request an access token
using this method. using this method.
access_denied access_denied
The resource owner or authorization server denied the The resource owner or authorization server denied the
request. request.
unsupported_response_type unsupported_response_type
The authorization server does not support obtaining an The authorization server does not support obtaining an
access token using this method. access token using this method.
invalid_scope invalid_scope
The requested scope is invalid, unknown, or malformed. The requested scope is invalid, unknown, or malformed.
server_error server_error
The authorization server encountered an unexpected The authorization server encountered an unexpected
condition that prevented it from fulfilling the request. condition that prevented it from fulfilling the request.
(This error code is needed because a 500 Internal Server (This error code is needed because a 500 Internal Server
Error HTTP status code cannot be returned to the client Error HTTP status code cannot be returned to the client
via a HTTP redirect.) via an HTTP redirect.)
temporarily_unavailable temporarily_unavailable
The authorization server is currently unable to handle The authorization server is currently unable to handle
the request due to a temporary overloading or maintenance the request due to a temporary overloading or maintenance
of the server. (This error code is needed because a 503 of the server. (This error code is needed because a 503
Service Unavailable HTTP status code cannot be returned Service Unavailable HTTP status code cannot be returned
to the client via a HTTP redirect.) to the client via an HTTP redirect.)
Values for the "error" parameter MUST NOT include characters Values for the "error" parameter MUST NOT include characters
outside the set %x20-21 / %x23-5B / %x5D-7E. outside the set %x20-21 / %x23-5B / %x5D-7E.
error_description error_description
OPTIONAL. A human-readable ASCII [USASCII] text providing OPTIONAL. Human-readable ASCII [USASCII] text providing
additional information, used to assist the client developer in additional information, used to assist the client developer in
understanding the error that occurred. understanding the error that occurred.
Values for the "error_description" parameter MUST NOT include Values for the "error_description" parameter MUST NOT include
characters outside the set %x20-21 / %x23-5B / %x5D-7E. characters outside the set %x20-21 / %x23-5B / %x5D-7E.
error_uri error_uri
OPTIONAL. A URI identifying a human-readable web page with OPTIONAL. A URI identifying a human-readable web page with
information about the error, used to provide the client information about the error, used to provide the client
developer with additional information about the error. developer with additional information about the error.
Values for the "error_uri" parameter MUST conform to the URI- Values for the "error_uri" parameter MUST conform to the
Reference syntax, and thus MUST NOT include characters outside URI-reference syntax and thus MUST NOT include characters
the set %x21 / %x23-5B / %x5D-7E. outside the set %x21 / %x23-5B / %x5D-7E.
state state
REQUIRED if a "state" parameter was present in the client REQUIRED if a "state" parameter was present in the client
authorization request. The exact value received from the authorization request. The exact value received from the
client. client.
For example, the authorization server redirects the user-agent by For example, the authorization server redirects the user-agent by
sending the following HTTP response: sending the following HTTP response:
HTTP/1.1 302 Found HTTP/1.1 302 Found
Location: https://client.example.com/cb#error=access_denied&state=xyz Location: https://client.example.com/cb#error=access_denied&state=xyz
4.3. Resource Owner Password Credentials Grant 4.3. Resource Owner Password Credentials Grant
The resource owner password credentials grant type is suitable in The resource owner password credentials grant type is suitable in
cases where the resource owner has a trust relationship with the cases where the resource owner has a trust relationship with the
client, such as the device operating system or a highly privileged client, such as the device operating system or a highly privileged
application. The authorization server should take special care when application. The authorization server should take special care when
enabling this grant type, and only allow it when other flows are not enabling this grant type and only allow it when other flows are not
viable. viable.
The grant type is suitable for clients capable of obtaining the This grant type is suitable for clients capable of obtaining the
resource owner's credentials (username and password, typically using resource owner's credentials (username and password, typically using
an interactive form). It is also used to migrate existing clients an interactive form). It is also used to migrate existing clients
using direct authentication schemes such as HTTP Basic or Digest using direct authentication schemes such as HTTP Basic or Digest
authentication to OAuth by converting the stored credentials to an authentication to OAuth by converting the stored credentials to an
access token. access token.
+----------+ +----------+
| Resource | | Resource |
| Owner | | Owner |
| | | |
skipping to change at page 36, line 7 skipping to change at page 38, line 39
| |<--(C)---- Access Token ---------<| | | |<--(C)---- Access Token ---------<| |
| | (w/ Optional Refresh Token) | | | | (w/ Optional Refresh Token) | |
+---------+ +---------------+ +---------+ +---------------+
Figure 5: Resource Owner Password Credentials Flow Figure 5: Resource Owner Password Credentials Flow
The flow illustrated in Figure 5 includes the following steps: The flow illustrated in Figure 5 includes the following steps:
(A) The resource owner provides the client with its username and (A) The resource owner provides the client with its username and
password. password.
(B) The client requests an access token from the authorization (B) The client requests an access token from the authorization
server's token endpoint by including the credentials received server's token endpoint by including the credentials received
from the resource owner. When making the request, the client from the resource owner. When making the request, the client
authenticates with the authorization server. authenticates with the authorization server.
(C) The authorization server authenticates the client and validates (C) The authorization server authenticates the client and validates
the resource owner credentials, and if valid issues an access the resource owner credentials, and if valid, issues an access
token. token.
4.3.1. Authorization Request and Response 4.3.1. Authorization Request and Response
The method through which the client obtains the resource owner The method through which the client obtains the resource owner
credentials is beyond the scope of this specification. The client credentials is beyond the scope of this specification. The client
MUST discard the credentials once an access token has been obtained. MUST discard the credentials once an access token has been obtained.
4.3.2. Access Token Request 4.3.2. Access Token Request
skipping to change at page 37, line 10 skipping to change at page 40, line 10
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded Content-Type: application/x-www-form-urlencoded
grant_type=password&username=johndoe&password=A3ddj3w grant_type=password&username=johndoe&password=A3ddj3w
The authorization server MUST: The authorization server MUST:
o require client authentication for confidential clients or for any o require client authentication for confidential clients or for any
client that was issued client credentials (or with other client that was issued client credentials (or with other
authentication requirements), authentication requirements),
o authenticate the client if client authentication is included, and o authenticate the client if client authentication is included, and
o validate the resource owner password credentials using its o validate the resource owner password credentials using its
existing password validation algorithm. existing password validation algorithm.
Since this access token request utilizes the resource owner's Since this access token request utilizes the resource owner's
password, the authorization server MUST protect the endpoint against password, the authorization server MUST protect the endpoint against
brute force attacks (e.g. using rate-limitation or generating brute force attacks (e.g., using rate-limitation or generating
alerts). alerts).
4.3.3. Access Token Response 4.3.3. Access Token Response
If the access token request is valid and authorized, the If the access token request is valid and authorized, the
authorization server issues an access token and optional refresh authorization server issues an access token and optional refresh
token as described in Section 5.1. If the request failed client token as described in Section 5.1. If the request failed client
authentication or is invalid, the authorization server returns an authentication or is invalid, the authorization server returns an
error response as described in Section 5.2. error response as described in Section 5.2.
skipping to change at page 38, line 19 skipping to change at page 41, line 22
| |<--(B)---- Access Token ---------<| | | |<--(B)---- Access Token ---------<| |
| | | | | | | |
+---------+ +---------------+ +---------+ +---------------+
Figure 6: Client Credentials Flow Figure 6: Client Credentials Flow
The flow illustrated in Figure 6 includes the following steps: The flow illustrated in Figure 6 includes the following steps:
(A) The client authenticates with the authorization server and (A) The client authenticates with the authorization server and
requests an access token from the token endpoint. requests an access token from the token endpoint.
(B) The authorization server authenticates the client, and if valid
(B) The authorization server authenticates the client, and if valid,
issues an access token. issues an access token.
4.4.1. Authorization Request and Response 4.4.1. Authorization Request and Response
Since the client authentication is used as the authorization grant, Since the client authentication is used as the authorization grant,
no additional authorization request is needed. no additional authorization request is needed.
4.4.2. Access Token Request 4.4.2. Access Token Request
The client makes a request to the token endpoint by adding the The client makes a request to the token endpoint by adding the
skipping to change at page 39, line 36 skipping to change at page 43, line 5
"example_parameter":"example_value" "example_parameter":"example_value"
} }
4.5. Extension Grants 4.5. Extension Grants
The client uses an extension grant type by specifying the grant type The client uses an extension grant type by specifying the grant type
using an absolute URI (defined by the authorization server) as the using an absolute URI (defined by the authorization server) as the
value of the "grant_type" parameter of the token endpoint, and by value of the "grant_type" parameter of the token endpoint, and by
adding any additional parameters necessary. adding any additional parameters necessary.
For example, to request an access token using a SAML 2.0 assertion For example, to request an access token using a Security Assertion
grant type as defined by [I-D.ietf-oauth-saml2-bearer], the client Markup Language (SAML) 2.0 assertion grant type as defined by
could make the following HTTP request using TLS (with extra line [OAuth-SAML2], the client could make the following HTTP request using
breaks for display purposes only): TLS (with extra line breaks for display purposes only):
POST /token HTTP/1.1 POST /token HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/x-www-form-urlencoded Content-Type: application/x-www-form-urlencoded
grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Asaml2- grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Asaml2-
bearer&assertion=PEFzc2VydGlvbiBJc3N1ZUluc3RhbnQ9IjIwMTEtMDU bearer&assertion=PEFzc2VydGlvbiBJc3N1ZUluc3RhbnQ9IjIwMTEtMDU
[...omitted for brevity...]aG5TdGF0ZW1lbnQ-PC9Bc3NlcnRpb24- [...omitted for brevity...]aG5TdGF0ZW1lbnQ-PC9Bc3NlcnRpb24-
If the access token request is valid and authorized, the If the access token request is valid and authorized, the
skipping to change at page 40, line 18 skipping to change at page 43, line 36
If the access token request is valid and authorized, the If the access token request is valid and authorized, the
authorization server issues an access token and optional refresh authorization server issues an access token and optional refresh
token as described in Section 5.1. If the request failed client token as described in Section 5.1. If the request failed client
authentication or is invalid, the authorization server returns an authentication or is invalid, the authorization server returns an
error response as described in Section 5.2. error response as described in Section 5.2.
5.1. Successful Response 5.1. Successful Response
The authorization server issues an access token and optional refresh The authorization server issues an access token and optional refresh
token, and constructs the response by adding the following parameters token, and constructs the response by adding the following parameters
to the entity body of the HTTP response with a 200 (OK) status code: to the entity-body of the HTTP response with a 200 (OK) status code:
access_token access_token
REQUIRED. The access token issued by the authorization server. REQUIRED. The access token issued by the authorization server.
token_type token_type
REQUIRED. The type of the token issued as described in REQUIRED. The type of the token issued as described in
Section 7.1. Value is case insensitive. Section 7.1. Value is case insensitive.
expires_in expires_in
RECOMMENDED. The lifetime in seconds of the access token. For RECOMMENDED. The lifetime in seconds of the access token. For
example, the value "3600" denotes that the access token will example, the value "3600" denotes that the access token will
expire in one hour from the time the response was generated. expire in one hour from the time the response was generated.
If omitted, the authorization server SHOULD provide the If omitted, the authorization server SHOULD provide the
expiration time via other means or document the default value. expiration time via other means or document the default value.
refresh_token refresh_token
OPTIONAL. The refresh token, which can be used to obtain new OPTIONAL. The refresh token, which can be used to obtain new
access tokens using the same authorization grant as described access tokens using the same authorization grant as described
in Section 6. in Section 6.
scope scope
OPTIONAL, if identical to the scope requested by the client, OPTIONAL, if identical to the scope requested by the client;
otherwise REQUIRED. The scope of the access token as described otherwise, REQUIRED. The scope of the access token as
by Section 3.3. described by Section 3.3.
The parameters are included in the entity body of the HTTP response The parameters are included in the entity-body of the HTTP response
using the "application/json" media type as defined by [RFC4627]. The using the "application/json" media type as defined by [RFC4627]. The
parameters are serialized into a JSON structure by adding each parameters are serialized into a JavaScript Object Notation (JSON)
parameter at the highest structure level. Parameter names and string structure by adding each parameter at the highest structure level.
values are included as JSON strings. Numerical values are included Parameter names and string values are included as JSON strings.
as JSON numbers. The order of parameters does not matter and can Numerical values are included as JSON numbers. The order of
vary. parameters does not matter and can vary.
The authorization server MUST include the HTTP "Cache-Control" The authorization server MUST include the HTTP "Cache-Control"
response header field [RFC2616] with a value of "no-store" in any response header field [RFC2616] with a value of "no-store" in any
response containing tokens, credentials, or other sensitive response containing tokens, credentials, or other sensitive
information, as well as the "Pragma" response header field [RFC2616] information, as well as the "Pragma" response header field [RFC2616]
with a value of "no-cache". with a value of "no-cache".
For example: For example:
HTTP/1.1 200 OK HTTP/1.1 200 OK
skipping to change at page 41, line 37 skipping to change at page 45, line 14
5.2. Error Response 5.2. Error Response
The authorization server responds with an HTTP 400 (Bad Request) The authorization server responds with an HTTP 400 (Bad Request)
status code (unless specified otherwise) and includes the following status code (unless specified otherwise) and includes the following
parameters with the response: parameters with the response:
error error
REQUIRED. A single ASCII [USASCII] error code from the REQUIRED. A single ASCII [USASCII] error code from the
following: following:
invalid_request invalid_request
The request is missing a required parameter, includes an The request is missing a required parameter, includes an
unsupported parameter value (other than grant type), unsupported parameter value (other than grant type),
repeats a parameter, includes multiple credentials, repeats a parameter, includes multiple credentials,
utilizes more than one mechanism for authenticating the utilizes more than one mechanism for authenticating the
client, or is otherwise malformed. client, or is otherwise malformed.
invalid_client invalid_client
Client authentication failed (e.g. unknown client, no Client authentication failed (e.g., unknown client, no
client authentication included, or unsupported client authentication included, or unsupported
authentication method). The authorization server MAY authentication method). The authorization server MAY
return an HTTP 401 (Unauthorized) status code to indicate return an HTTP 401 (Unauthorized) status code to indicate
which HTTP authentication schemes are supported. If the which HTTP authentication schemes are supported. If the
client attempted to authenticate via the "Authorization" client attempted to authenticate via the "Authorization"
request header field, the authorization server MUST request header field, the authorization server MUST
respond with an HTTP 401 (Unauthorized) status code, and respond with an HTTP 401 (Unauthorized) status code and
include the "WWW-Authenticate" response header field include the "WWW-Authenticate" response header field
matching the authentication scheme used by the client. matching the authentication scheme used by the client.
invalid_grant invalid_grant
The provided authorization grant (e.g. authorization The provided authorization grant (e.g., authorization
code, resource owner credentials) or refresh token is code, resource owner credentials) or refresh token is
invalid, expired, revoked, does not match the redirection invalid, expired, revoked, does not match the redirection
URI used in the authorization request, or was issued to URI used in the authorization request, or was issued to
another client. another client.
unauthorized_client unauthorized_client
The authenticated client is not authorized to use this The authenticated client is not authorized to use this
authorization grant type. authorization grant type.
unsupported_grant_type unsupported_grant_type
The authorization grant type is not supported by the The authorization grant type is not supported by the
authorization server. authorization server.
invalid_scope invalid_scope
The requested scope is invalid, unknown, malformed, or The requested scope is invalid, unknown, malformed, or
exceeds the scope granted by the resource owner. exceeds the scope granted by the resource owner.
Values for the "error" parameter MUST NOT include characters Values for the "error" parameter MUST NOT include characters
outside the set %x20-21 / %x23-5B / %x5D-7E. outside the set %x20-21 / %x23-5B / %x5D-7E.
error_description error_description
OPTIONAL. A human-readable ASCII [USASCII] text providing OPTIONAL. Human-readable ASCII [USASCII] text providing
additional information, used to assist the client developer in additional information, used to assist the client developer in
understanding the error that occurred. understanding the error that occurred.
Values for the "error_description" parameter MUST NOT include Values for the "error_description" parameter MUST NOT include
characters outside the set %x20-21 / %x23-5B / %x5D-7E. characters outside the set %x20-21 / %x23-5B / %x5D-7E.
error_uri error_uri
OPTIONAL. A URI identifying a human-readable web page with OPTIONAL. A URI identifying a human-readable web page with
information about the error, used to provide the client information about the error, used to provide the client
developer with additional information about the error. developer with additional information about the error.
Values for the "error_uri" parameter MUST conform to the URI- Values for the "error_uri" parameter MUST conform to the
Reference syntax, and thus MUST NOT include characters outside URI-reference syntax and thus MUST NOT include characters
the set %x21 / %x23-5B / %x5D-7E. outside the set %x21 / %x23-5B / %x5D-7E.
The parameters are included in the entity body of the HTTP response The parameters are included in the entity-body of the HTTP response
using the "application/json" media type as defined by [RFC4627]. The using the "application/json" media type as defined by [RFC4627]. The
parameters are serialized into a JSON structure by adding each parameters are serialized into a JSON structure by adding each
parameter at the highest structure level. Parameter names and string parameter at the highest structure level. Parameter names and string
values are included as JSON strings. Numerical values are included values are included as JSON strings. Numerical values are included
as JSON numbers. The order of parameters does not matter and can as JSON numbers. The order of parameters does not matter and can
vary. vary.
For example: For example:
HTTP/1.1 400 Bad Request HTTP/1.1 400 Bad Request
skipping to change at page 44, line 10 skipping to change at page 48, line 10
Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded Content-Type: application/x-www-form-urlencoded
grant_type=refresh_token&refresh_token=tGzv3JOkF0XG5Qx2TlKWIA grant_type=refresh_token&refresh_token=tGzv3JOkF0XG5Qx2TlKWIA
The authorization server MUST: The authorization server MUST:
o require client authentication for confidential clients or for any o require client authentication for confidential clients or for any
client that was issued client credentials (or with other client that was issued client credentials (or with other
authentication requirements), authentication requirements),
o authenticate the client if client authentication is included and o authenticate the client if client authentication is included and
ensure the refresh token was issued to the authenticated client, ensure that the refresh token was issued to the authenticated
and client, and
o validate the refresh token. o validate the refresh token.
If valid and authorized, the authorization server issues an access If valid and authorized, the authorization server issues an access
token as described in Section 5.1. If the request failed token as described in Section 5.1. If the request failed
verification or is invalid, the authorization server returns an error verification or is invalid, the authorization server returns an error
response as described in Section 5.2. response as described in Section 5.2.
The authorization server MAY issue a new refresh token, in which case 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 the client MUST discard the old refresh token and replace it with the
new refresh token. The authorization server MAY revoke the old new refresh token. The authorization server MAY revoke the old
refresh token after issuing a new refresh token to the client. If a refresh token after issuing a new refresh token to the client. If a
new refresh token is issued, the refresh token scope MUST be new refresh token is issued, the refresh token scope MUST be
identical to that of the refresh token included by the client in the identical to that of the refresh token included by the client in the
request. request.
7. Accessing Protected Resources 7. Accessing Protected Resources
The client accesses protected resources by presenting the access The client accesses protected resources by presenting the access
token to the resource server. The resource server MUST validate the token to the resource server. The resource server MUST validate the
access token and ensure it has not expired and that its scope covers access token and ensure that it has not expired and that its scope
the requested resource. The methods used by the resource server to covers the requested resource. The methods used by the resource
validate the access token (as well as any error responses) are beyond server to validate the access token (as well as any error responses)
the scope of this specification, but generally involve an interaction are beyond the scope of this specification but generally involve an
or coordination between the resource server and the authorization interaction or coordination between the resource server and the
server. authorization server.
The method in which the client utilizes the access token to The method in which the client utilizes the access token to
authenticate with the resource server depends on the type of access authenticate with the resource server depends on the type of access
token issued by the authorization server. Typically, it involves token issued by the authorization server. Typically, it involves
using the HTTP "Authorization" request header field [RFC2617] with an using the HTTP "Authorization" request header field [RFC2617] with an
authentication scheme defined by the access token type specification. authentication scheme defined by the specification of the access
token type used, such as [RFC6750].
7.1. Access Token Types 7.1. Access Token Types
The access token type provides the client with the information The access token type provides the client with the information
required to successfully utilize the access token to make a protected required to successfully utilize the access token to make a protected
resource request (along with type-specific attributes). The client resource request (along with type-specific attributes). The client
MUST NOT use an access token if it does not understand the token MUST NOT use an access token if it does not understand the token
type. type.
For example, the "bearer" token type defined in For example, the "bearer" token type defined in [RFC6750] is utilized
[I-D.ietf-oauth-v2-bearer] is utilized by simply including the access by simply including the access token string in the request:
token string in the request:
GET /resource/1 HTTP/1.1 GET /resource/1 HTTP/1.1
Host: example.com Host: example.com
Authorization: Bearer mF_9.B5f-4.1JqM Authorization: Bearer mF_9.B5f-4.1JqM
while the "mac" token type defined in [I-D.ietf-oauth-v2-http-mac] is while the "mac" token type defined in [OAuth-HTTP-MAC] is utilized by
utilized by issuing a MAC key together with the access token that is issuing a Message Authentication Code (MAC) key together with the
used to sign certain components of the HTTP requests: access token that is used to sign certain components of the HTTP
requests:
GET /resource/1 HTTP/1.1 GET /resource/1 HTTP/1.1
Host: example.com Host: example.com
Authorization: MAC id="h480djs93hd8", Authorization: MAC id="h480djs93hd8",
nonce="274312:dj83hs9s", nonce="274312:dj83hs9s",
mac="kDZvddkndxvhGRXZhvuDjEWhGeE=" mac="kDZvddkndxvhGRXZhvuDjEWhGeE="
The above examples are provided for illustration purposes only. The above examples are provided for illustration purposes only.
Developers are advised to consult the [I-D.ietf-oauth-v2-bearer] and Developers are advised to consult the [RFC6750] and [OAuth-HTTP-MAC]
[I-D.ietf-oauth-v2-http-mac] specifications before use. specifications before use.
Each access token type definition specifies the additional attributes Each access token type definition specifies the additional attributes
(if any) sent to the client together with the "access_token" response (if any) sent to the client together with the "access_token" response
parameter. It also defines the HTTP authentication method used to parameter. It also defines the HTTP authentication method used to
include the access token when making a protected resource request. include the access token when making a protected resource request.
7.2. Error Response 7.2. Error Response
If a resource access request fails, the resource server SHOULD inform If a resource access request fails, the resource server SHOULD inform
the client of the error. While the specifics of such error responses the client of the error. While the specifics of such error responses
are beyond the scope of this specification, this documents are beyond the scope of this specification, this document establishes
establishes a common registry in Section 11.4 for error values to be a common registry in Section 11.4 for error values to be shared among
shared among OAuth token authentication schemes. OAuth token authentication schemes.
New authentication schemes designed primarily for OAuth token New authentication schemes designed primarily for OAuth token
authentication SHOULD define a mechanism for providing an error authentication SHOULD define a mechanism for providing an error
status code to the client, in which the error values allowed are status code to the client, in which the error values allowed are
registered in the error registry established by this specification. registered in the error registry established by this specification.
Such schemes MAY limit the set of valid error codes to a subset of Such schemes MAY limit the set of valid error codes to a subset of
the registered values. If the error code is returned using a named the registered values. If the error code is returned using a named
parameter, the parameter name SHOULD be "error". parameter, the parameter name SHOULD be "error".
Other schemes capable of being used for OAuth token authentication, Other schemes capable of being used for OAuth token authentication,
but not primarily designed for that purpose, MAY bind their error but not primarily designed for that purpose, MAY bind their error
values to the registry in the same manner. values to the registry in the same manner.
New authentication schemes MAY choose to also specify the use of the New authentication schemes MAY choose to also specify the use of the
"error_description" and "error_uri" parameters to return error "error_description" and "error_uri" parameters to return error
skipping to change at page 46, line 13 skipping to change at page 50, line 23
New authentication schemes MAY choose to also specify the use of the New authentication schemes MAY choose to also specify the use of the
"error_description" and "error_uri" parameters to return error "error_description" and "error_uri" parameters to return error
information in a manner parallel to their usage in this information in a manner parallel to their usage in this
specification. specification.
8. Extensibility 8. Extensibility
8.1. Defining Access Token Types 8.1. Defining Access Token Types
Access token types can be defined in one of two ways: registered in Access token types can be defined in one of two ways: registered in
the access token type registry (following the procedures in the Access Token Types registry (following the procedures in
Section 11.1), or by using a unique absolute URI as its name. Section 11.1), or by using a unique absolute URI as its name.
Types utilizing a URI name SHOULD be limited to vendor-specific Types utilizing a URI name SHOULD be limited to vendor-specific
implementations that are not commonly applicable, and are specific to implementations that are not commonly applicable, and are specific to
the implementation details of the resource server where they are the implementation details of the resource server where they are
used. used.
All other types MUST be registered. Type names MUST conform to the All other types MUST be registered. Type names MUST conform to the
type-name ABNF. If the type definition includes a new HTTP type-name ABNF. If the type definition includes a new HTTP
authentication scheme, the type name SHOULD be identical to the HTTP authentication scheme, the type name SHOULD be identical to the HTTP
authentication scheme name (as defined by [RFC2617]). The token type authentication scheme name (as defined by [RFC2617]). The token type
"example" is reserved for use in examples. "example" is reserved for use in examples.
type-name = 1*name-char type-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA name-char = "-" / "." / "_" / DIGIT / ALPHA
8.2. Defining New Endpoint Parameters 8.2. Defining New Endpoint Parameters
New request or response parameters for use with the authorization New request or response parameters for use with the authorization
endpoint or the token endpoint are defined and registered in the endpoint or the token endpoint are defined and registered in the
parameters registry following the procedure in Section 11.2. OAuth Parameters registry following the procedure in Section 11.2.
Parameter names MUST conform to the param-name ABNF and parameter Parameter names MUST conform to the param-name ABNF, and parameter
values syntax MUST be well-defined (e.g., using ABNF, or a reference values syntax MUST be well-defined (e.g., using ABNF, or a reference
to the syntax of an existing parameter). to the syntax of an existing parameter).
param-name = 1*name-char param-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA name-char = "-" / "." / "_" / DIGIT / ALPHA
Unregistered vendor-specific parameter extensions that are not Unregistered vendor-specific parameter extensions that are not
commonly applicable, and are specific to the implementation details commonly applicable and that are specific to the implementation
of the authorization server where they are used SHOULD utilize a details of the authorization server where they are used SHOULD
vendor-specific prefix that is not likely to conflict with other utilize a vendor-specific prefix that is not likely to conflict with
registered values (e.g. begin with 'companyname_'). other registered values (e.g., begin with 'companyname_').
8.3. Defining New Authorization Grant Types 8.3. Defining New Authorization Grant Types
New authorization grant types can be defined by assigning them a New authorization grant types can be defined by assigning them a
unique absolute URI for use with the "grant_type" parameter. If the unique absolute URI for use with the "grant_type" parameter. If the
extension grant type requires additional token endpoint parameters, extension grant type requires additional token endpoint parameters,
they MUST be registered in the OAuth parameters registry as described they MUST be registered in the OAuth Parameters registry as described
by Section 11.2. by Section 11.2.
8.4. Defining New Authorization Endpoint Response Types 8.4. Defining New Authorization Endpoint Response Types
New response types for use with the authorization endpoint are New response types for use with the authorization endpoint are
defined and registered in the authorization endpoint response type defined and registered in the Authorization Endpoint Response Types
registry following the procedure in Section 11.3. Response type registry following the procedure in Section 11.3. Response type
names MUST conform to the response-type ABNF. names MUST conform to the response-type ABNF.
response-type = response-name *( SP response-name ) response-type = response-name *( SP response-name )
response-name = 1*response-char response-name = 1*response-char
response-char = "_" / DIGIT / ALPHA response-char = "_" / DIGIT / ALPHA
If a response type contains one or more space characters (%x20), it If a response type contains one or more space characters (%x20), it
is compared as a space-delimited list of values in which the order of 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, values does not matter. Only one order of values can be registered,
which covers all other arrangements of the same set of values. which covers all other arrangements of the same set of values.
For example, the response type "token code" is left undefined by this For example, the response type "token code" is left undefined by this
specification. However, an extension can define and register the specification. However, an extension can define and register the
"token code" response type. Once registered, the same combination "token code" response type. Once registered, the same combination
cannot be registered as "code token", but both values can be used to cannot be registered as "code token", but both values can be used to
denote the same response type. denote the same response type.
8.5. Defining Additional Error Codes 8.5. Defining Additional Error Codes
In cases where protocol extensions (i.e. access token types, In cases where protocol extensions (i.e., access token types,
extension parameters, or extension grant types) require additional extension parameters, or extension grant types) require additional
error codes to be used with the authorization code grant error error codes to be used with the authorization code grant error
response (Section 4.1.2.1), the implicit grant error response response (Section 4.1.2.1), the implicit grant error response
(Section 4.2.2.1), the token error response (Section 5.2), or the (Section 4.2.2.1), the token error response (Section 5.2), or the
resource access error response (Section 7.2), such error codes MAY be resource access error response (Section 7.2), such error codes MAY be
defined. defined.
Extension error codes MUST be registered (following the procedures in Extension error codes MUST be registered (following the procedures in
Section 11.4) if the extension they are used in conjunction with is a Section 11.4) if the extension they are used in conjunction with is a
registered access token type, a registered endpoint parameter, or an registered access token type, a registered endpoint parameter, or an
extension grant type. Error codes used with unregistered extensions extension grant type. Error codes used with unregistered extensions
MAY be registered. MAY be registered.
Error codes MUST conform to the error ABNF, and SHOULD be prefixed by Error codes MUST conform to the error ABNF and SHOULD be prefixed by
an identifying name when possible. For example, an error identifying an identifying name when possible. For example, an error identifying
an invalid value set to the extension parameter "example" SHOULD be an invalid value set to the extension parameter "example" SHOULD be
named "example_invalid". named "example_invalid".
error = 1*error-char error = 1*error-char
error-char = %x20-21 / %x23-5B / %x5D-7E error-char = %x20-21 / %x23-5B / %x5D-7E
9. Native Applications 9. Native Applications
Native applications are clients installed and executed on the device Native applications are clients installed and executed on the device
used by the resource owner (i.e. desktop application, native mobile used by the resource owner (i.e., desktop application, native mobile
application). Native applications require special consideration application). Native applications require special consideration
related to security, platform capabilities, and overall end-user related to security, platform capabilities, and overall end-user
experience. experience.
The authorization endpoint requires interaction between the client The authorization endpoint requires interaction between the client
and the resource owner's user-agent. Native applications can invoke and the resource owner's user-agent. Native applications can invoke
an external user-agent or embed a user-agent within the application. an external user-agent or embed a user-agent within the application.
For example: For example:
o External user-agent - the native application can capture the o External user-agent - the native application can capture the
skipping to change at page 48, line 31 skipping to change at page 52, line 40
For example: For example:
o External user-agent - the native application can capture the o External user-agent - the native application can capture the
response from the authorization server using a redirection URI response from the authorization server using a redirection URI
with a scheme registered with the operating system to invoke the with a scheme registered with the operating system to invoke the
client as the handler, manual copy-and-paste of the credentials, client as the handler, manual copy-and-paste of the credentials,
running a local web server, installing a user-agent extension, or running a local web server, installing a user-agent extension, or
by providing a redirection URI identifying a server-hosted by providing a redirection URI identifying a server-hosted
resource under the client's control, which in turn makes the resource under the client's control, which in turn makes the
response available to the native application. response available to the native application.
o Embedded user-agent - the native application obtains the response o Embedded user-agent - the native application obtains the response
by directly communicating with the embedded user-agent by by directly communicating with the embedded user-agent by
monitoring state changes emitted during the resource load, or monitoring state changes emitted during the resource load, or
accessing the user-agent's cookies storage. accessing the user-agent's cookies storage.
When choosing between an external or embedded user-agent, developers When choosing between an external or embedded user-agent, developers
should consider: should consider the following:
o An external user-agent may improve completion rate, as the
resource owner may already have an active session with the
authorization server, removing the need to re-authenticate. It
provides a familiar end-user experience and functionality. The
resource owner may also rely on user-agent features or extensions
to assist with authentication (e.g., password manager, 2-factor
device reader).
o An External user-agent may improve completion rate as the resource
owner may already have an active session with the authorization
server removing the need to re-authenticate. It provides a
familiar end-user experience and functionality. The resource
owner may also rely on user-agent features or extensions to assist
with authentication (e.g. password manager, 2-factor device
reader).
o An embedded user-agent may offer improved usability, as it removes o An embedded user-agent may offer improved usability, as it removes
the need to switch context and open new windows. the need to switch context and open new windows.
o An embedded user-agent poses a security challenge because resource o An embedded user-agent poses a security challenge because resource
owners are authenticating in an unidentified window without access owners are authenticating in an unidentified window without access
to the visual protections found in most external user-agents. An to the visual protections found in most external user-agents. An
embedded user-agent educates end-users to trust unidentified embedded user-agent educates end-users to trust unidentified
requests for authentication (making phishing attacks easier to requests for authentication (making phishing attacks easier to
execute). execute).
When choosing between the implicit grant type and the authorization When choosing between the implicit grant type and the authorization
code grant type, the following should be considered: code grant type, the following should be considered:
skipping to change at page 49, line 14 skipping to change at page 53, line 24
embedded user-agent educates end-users to trust unidentified embedded user-agent educates end-users to trust unidentified
requests for authentication (making phishing attacks easier to requests for authentication (making phishing attacks easier to
execute). execute).
When choosing between the implicit grant type and the authorization When choosing between the implicit grant type and the authorization
code grant type, the following should be considered: code grant type, the following should be considered:
o Native applications that use the authorization code grant type o Native applications that use the authorization code grant type
SHOULD do so without using client credentials, due to the native SHOULD do so without using client credentials, due to the native
application's inability to keep client credentials confidential. application's inability to keep client credentials confidential.
o When using the implicit grant type flow, a refresh token is not o When using the implicit grant type flow, a refresh token is not
returned, which requires repeating the authorization process once returned, which requires repeating the authorization process once
the access token expires. the access token expires.
10. Security Considerations 10. Security Considerations
As a flexible and extensible framework, OAuth's security As a flexible and extensible framework, OAuth's security
considerations depend on many factors. The following sections considerations depend on many factors. The following sections
provide implementers with security guidelines focused on the three provide implementers with security guidelines focused on the three
client profiles described in Section 2.1: web application, user- client profiles described in Section 2.1: web application,
agent-based application, and native application. user-agent-based application, and native application.
A comprehensive OAuth security model and analysis, as well as A comprehensive OAuth security model and analysis, as well as
background for the protocol design, is provided by background for the protocol design, is provided by
[I-D.ietf-oauth-v2-threatmodel]. [OAuth-THREATMODEL].
10.1. Client Authentication 10.1. Client Authentication
The authorization server establishes client credentials with web The authorization server establishes client credentials with web
application clients for the purpose of client authentication. The application clients for the purpose of client authentication. The
authorization server is encouraged to consider stronger client authorization server is encouraged to consider stronger client
authentication means than a client password. Web application clients authentication means than a client password. Web application clients
MUST ensure confidentiality of client passwords and other client MUST ensure confidentiality of client passwords and other client
credentials. credentials.
The authorization server MUST NOT issue client passwords or other The authorization server MUST NOT issue client passwords or other
client credentials to native application or user-agent-based client credentials to native application or user-agent-based
application clients for the purpose of client authentication. The application clients for the purpose of client authentication. The
authorization server MAY issue a client password or other credentials authorization server MAY issue a client password or other credentials
for a specific installation of a native application client on a for a specific installation of a native application client on a
specific device. specific device.
When client authentication is not possible, the authorization server When client authentication is not possible, the authorization server
SHOULD employ other means to validate the client's identity. For SHOULD employ other means to validate the client's identity -- for
example, by requiring the registration of the client redirection URI example, by requiring the registration of the client redirection URI
or enlisting the resource owner to confirm identity. A valid or enlisting the resource owner to confirm identity. A valid
redirection URI is not sufficient to verify the client's identity redirection URI is not sufficient to verify the client's identity
when asking for resource owner authorization, but can be used to when asking for resource owner authorization but can be used to
prevent delivering credentials to a counterfeit client after prevent delivering credentials to a counterfeit client after
obtaining resource owner authorization. obtaining resource owner authorization.
The authorization server must consider the security implications of The authorization server must consider the security implications of
interacting with unauthenticated clients and take measures to limit interacting with unauthenticated clients and take measures to limit
the potential exposure of other credentials (e.g. refresh tokens) the potential exposure of other credentials (e.g., refresh tokens)
issued to such clients. issued to such clients.
10.2. Client Impersonation 10.2. Client Impersonation
A malicious client can impersonate another client and obtain access A malicious client can impersonate another client and obtain access
to protected resources, if the impersonated client fails to, or is to protected resources if the impersonated client fails to, or is
unable to, keep its client credentials confidential. unable to, keep its client credentials confidential.
The authorization server MUST authenticate the client whenever The authorization server MUST authenticate the client whenever
possible. If the authorization server cannot authenticate the client possible. If the authorization server cannot authenticate the client
due to the client's nature, the authorization server MUST require the due to the client's nature, the authorization server MUST require the
registration of any redirection URI used for receiving authorization registration of any redirection URI used for receiving authorization
responses, and SHOULD utilize other means to protect resource owners responses and SHOULD utilize other means to protect resource owners
from such potentially malicious clients. For example, the from such potentially malicious clients. For example, the
authorization server can engage the resource owner to assist in authorization server can engage the resource owner to assist in
identifying the client and its origin. identifying the client and its origin.
The authorization server SHOULD enforce explicit resource owner The authorization server SHOULD enforce explicit resource owner
authentication and provide the resource owner with information about authentication and provide the resource owner with information about
the client and the requested authorization scope and lifetime. It is the client and the requested authorization scope and lifetime. It is
up to the resource owner to review the information in the context of up to the resource owner to review the information in the context of
the current client, and authorize or deny the request. the current client and to authorize or deny the request.
The authorization server SHOULD NOT process repeated authorization The authorization server SHOULD NOT process repeated authorization
requests automatically (without active resource owner interaction) requests automatically (without active resource owner interaction)
without authenticating the client or relying on other measures to without authenticating the client or relying on other measures to
ensure the repeated request comes from the original client and not an ensure that the repeated request comes from the original client and
impersonator. not an impersonator.
10.3. Access Tokens 10.3. Access Tokens
Access token credentials (as well as any confidential access token Access token credentials (as well as any confidential access token
attributes) MUST be kept confidential in transit and storage, and attributes) MUST be kept confidential in transit and storage, and
only shared among the authorization server, the resource servers the only shared among the authorization server, the resource servers the
access token is valid for, and the client to whom the access token is access token is valid for, and the client to whom the access token is
issued. Access token credentials MUST only be transmitted using TLS issued. Access token credentials MUST only be transmitted using TLS
as described in Section 1.6 with server authentication as defined by as described in Section 1.6 with server authentication as defined by
[RFC2818]. [RFC2818].
When using the implicit grant type, the access token is transmitted When using the implicit grant type, the access token is transmitted
in the URI fragment, which can expose it to unauthorized parties. in the URI fragment, which can expose it to unauthorized parties.
The authorization server MUST ensure that access tokens cannot be The authorization server MUST ensure that access tokens cannot be
generated, modified, or guessed to produce valid access tokens by generated, modified, or guessed to produce valid access tokens by
unauthorized parties. unauthorized parties.
The client SHOULD request access tokens with the minimal scope The client SHOULD request access tokens with the minimal scope
necessary. The authorization server SHOULD take the client identity necessary. The authorization server SHOULD take the client identity
into account when choosing how to honor the requested scope, and MAY into account when choosing how to honor the requested scope and MAY
issue an access token with a less rights than requested. issue an access token with less rights than requested.
This specification does not provide any methods for the resource This specification does not provide any methods for the resource
server to ensure that an access token presented to it by a given server to ensure that an access token presented to it by a given
client was issued to that client by the authorization server. client was issued to that client by the authorization server.
10.4. Refresh Tokens 10.4. Refresh Tokens
Authorization servers MAY issue refresh tokens to web application Authorization servers MAY issue refresh tokens to web application
clients and native application clients. clients and native application clients.
skipping to change at page 52, line 16 skipping to change at page 56, line 29
could potentially be disclosed through user-agent history and HTTP could potentially be disclosed through user-agent history and HTTP
referrer headers. referrer headers.
Authorization codes operate as plaintext bearer credentials, used to Authorization codes operate as plaintext bearer credentials, used to
verify that the resource owner who granted authorization at the verify that the resource owner who granted authorization at the
authorization server is the same resource owner returning to the authorization server is the same resource owner returning to the
client to complete the process. Therefore, if the client relies on client to complete the process. Therefore, if the client relies on
the authorization code for its own resource owner authentication, the the authorization code for its own resource owner authentication, the
client redirection endpoint MUST require the use of TLS. client redirection endpoint MUST require the use of TLS.
Authorization codes MUST be short lived and single use. If the Authorization codes MUST be short lived and single-use. If the
authorization server observes multiple attempts to exchange an authorization server observes multiple attempts to exchange an
authorization code for an access token, the authorization server authorization code for an access token, the authorization server
SHOULD attempt to revoke all access tokens already granted based on SHOULD attempt to revoke all access tokens already granted based on
the compromised authorization code. the compromised authorization code.
If the client can be authenticated, the authorization servers MUST If the client can be authenticated, the authorization servers MUST
authenticate the client and ensure that the authorization code was authenticate the client and ensure that the authorization code was
issued to the same client. issued to the same client.
10.6. Authorization Code Redirection URI Manipulation 10.6. Authorization Code Redirection URI Manipulation
skipping to change at page 52, line 38 skipping to change at page 56, line 51
When requesting authorization using the authorization code grant When requesting authorization using the authorization code grant
type, the client can specify a redirection URI via the "redirect_uri" type, the client can specify a redirection URI via the "redirect_uri"
parameter. If an attacker can manipulate the value of the parameter. If an attacker can manipulate the value of the
redirection URI, it can cause the authorization server to redirect redirection URI, it can cause the authorization server to redirect
the resource owner user-agent to a URI under the control of the the resource owner user-agent to a URI under the control of the
attacker with the authorization code. attacker with the authorization code.
An attacker can create an account at a legitimate client and initiate An attacker can create an account at a legitimate client and initiate
the authorization flow. When the attacker's user-agent is sent to the authorization flow. When the attacker's user-agent is sent to
the authorization server to grant access, the attacker grabs the the authorization server to grant access, the attacker grabs the
authorization URI provided by the legitimate client, and replaces the authorization URI provided by the legitimate client and replaces the
client's redirection URI with a URI under the control of the client's redirection URI with a URI under the control of the
attacker. The attacker then tricks the victim into following the attacker. The attacker then tricks the victim into following the
manipulated link to authorize access to the legitimate client. manipulated link to authorize access to the legitimate client.
Once at the authorization server, the victim is prompted with a Once at the authorization server, the victim is prompted with a
normal, valid request on behalf of a legitimate and trusted client, normal, valid request on behalf of a legitimate and trusted client,
and authorizes the request. The victim is then redirected to an and authorizes the request. The victim is then redirected to an
endpoint under the control of the attacker with the authorization endpoint under the control of the attacker with the authorization
code. The attacker completes the authorization flow by sending the code. The attacker completes the authorization flow by sending the
authorization code to the client using the original redirection URI authorization code to the client using the original redirection URI
skipping to change at page 53, line 19 skipping to change at page 57, line 32
authorization code for an access token. The authorization server authorization code for an access token. The authorization server
MUST require public clients and SHOULD require confidential clients MUST require public clients and SHOULD require confidential clients
to register their redirection URIs. If a redirection URI is provided to register their redirection URIs. If a redirection URI is provided
in the request, the authorization server MUST validate it against the in the request, the authorization server MUST validate it against the
registered value. registered value.
10.7. Resource Owner Password Credentials 10.7. Resource Owner Password Credentials
The resource owner password credentials grant type is often used for The resource owner password credentials grant type is often used for
legacy or migration reasons. It reduces the overall risk of storing legacy or migration reasons. It reduces the overall risk of storing
username and password by the client, but does not eliminate the need usernames and passwords by the client but does not eliminate the need
to expose highly privileged credentials to the client. to expose highly privileged credentials to the client.
This grant type carries a higher risk than other grant types because This grant type carries a higher risk than other grant types because
it maintains the password anti-pattern this protocol seeks to avoid. it maintains the password anti-pattern this protocol seeks to avoid.
The client could abuse the password or the password could The client could abuse the password, or the password could
unintentionally be disclosed to an attacker (e.g. via log files or unintentionally be disclosed to an attacker (e.g., via log files or
other records kept by the client). other records kept by the client).
Additionally, because the resource owner does not have control over Additionally, because the resource owner does not have control over
the authorization process (the resource owner involvement ends when the authorization process (the resource owner's involvement ends when
it hands over its credentials to the client), the client can obtain it hands over its credentials to the client), the client can obtain
access tokens with a broader scope than desired by the resource access tokens with a broader scope than desired by the resource
owner. The authorization server should consider the scope and owner. The authorization server should consider the scope and
lifetime of access tokens issued via this grant type. lifetime of access tokens issued via this grant type.
The authorization server and client SHOULD minimize use of this grant The authorization server and client SHOULD minimize use of this grant
type and utilize other grant types whenever possible. type and utilize other grant types whenever possible.
10.8. Request Confidentiality 10.8. Request Confidentiality
Access tokens, refresh tokens, resource owner passwords, and client Access tokens, refresh tokens, resource owner passwords, and client
credentials MUST NOT be transmitted in the clear. Authorization credentials MUST NOT be transmitted in the clear. Authorization
codes SHOULD NOT be transmitted in the clear. codes SHOULD NOT be transmitted in the clear.
The "state" and "scope" parameters SHOULD NOT include sensitive The "state" and "scope" parameters SHOULD NOT include sensitive
client or resource owner information in plain text as they can be client or resource owner information in plain text, as they can be
transmitted over insecure channels or stored insecurely. transmitted over insecure channels or stored insecurely.
10.9. Endpoints Authenticity 10.9. Ensuring Endpoint Authenticity
In order to prevent man-in-the-middle attacks, the authorization In order to prevent man-in-the-middle attacks, the authorization
server MUST require the use of TLS with server authentication as server MUST require the use of TLS with server authentication as
defined by [RFC2818] for any request sent to the authorization and defined by [RFC2818] for any request sent to the authorization and
token endpoints. The client MUST validate the authorization server's token endpoints. The client MUST validate the authorization server's
TLS certificate as defined by [RFC6125], and in accordance with its TLS certificate as defined by [RFC6125] and in accordance with its
requirements for server identity authentication. requirements for server identity authentication.
10.10. Credentials Guessing Attacks 10.10. Credentials-Guessing Attacks
The authorization server MUST prevent attackers from guessing access The authorization server MUST prevent attackers from guessing access
tokens, authorization codes, refresh tokens, resource owner tokens, authorization codes, refresh tokens, resource owner
passwords, and client credentials. passwords, and client credentials.
The probability of an attacker guessing generated tokens (and other The probability of an attacker guessing generated tokens (and other
credentials not intended for handling by end-users) MUST be less than credentials not intended for handling by end-users) MUST be less than
or equal to 2^(-128) and SHOULD be less than or equal to 2^(-160). or equal to 2^(-128) and SHOULD be less than or equal to 2^(-160).
The authorization server MUST utilize other means to protect The authorization server MUST utilize other means to protect
skipping to change at page 54, line 32 skipping to change at page 58, line 47
10.11. Phishing Attacks 10.11. Phishing Attacks
Wide deployment of this and similar protocols may cause end-users to Wide deployment of this and similar protocols may cause end-users to
become inured to the practice of being redirected to websites where become inured to the practice of being redirected to websites where
they are asked to enter their passwords. If end-users are not they are asked to enter their passwords. If end-users are not
careful to verify the authenticity of these websites before entering careful to verify the authenticity of these websites before entering
their credentials, it will be possible for attackers to exploit this their credentials, it will be possible for attackers to exploit this
practice to steal resource owners' passwords. practice to steal resource owners' passwords.
Service providers should attempt to educate end-users about the risks Service providers should attempt to educate end-users about the risks
phishing attacks pose, and should provide mechanisms that make it phishing attacks pose and should provide mechanisms that make it easy
easy for end-users to confirm the authenticity of their sites. for end-users to confirm the authenticity of their sites. Client
Client developers should consider the security implications of how developers should consider the security implications of how they
they interact with the user-agent (e.g., external, embedded), and the interact with the user-agent (e.g., external, embedded), and the
ability of the end-user to verify the authenticity of the ability of the end-user to verify the authenticity of the
authorization server. authorization server.
To reduce the risk of phishing attacks, the authorization servers To reduce the risk of phishing attacks, the authorization servers
MUST require the use of TLS on every endpoint used for end-user MUST require the use of TLS on every endpoint used for end-user
interaction. interaction.
10.12. Cross-Site Request Forgery 10.12. Cross-Site Request Forgery
Cross-site request forgery (CSRF) is an exploit in which an attacker Cross-site request forgery (CSRF) is an exploit in which an attacker
causes the user-agent of a victim end-user to follow a malicious URI causes the user-agent of a victim end-user to follow a malicious URI
(e.g. provided to the user-agent as a misleading link, image, or (e.g., provided to the user-agent as a misleading link, image, or
redirection) to a trusting server (usually established via the redirection) to a trusting server (usually established via the
presence of a valid session cookie). presence of a valid session cookie).
A CSRF attack against the client's redirection URI allows an attacker A CSRF attack against the client's redirection URI allows an attacker
to inject their own authorization code or access token, which can to inject its own authorization code or access token, which can
result in the client using an access token associated with the result in the client using an access token associated with the
attacker's protected resources rather than the victim's (e.g. save attacker's protected resources rather than the victim's (e.g., save
the victim's bank account information to a protected resource the victim's bank account information to a protected resource
controlled by the attacker). controlled by the attacker).
The client MUST implement CSRF protection for its redirection URI. The client MUST implement CSRF protection for its redirection URI.
This is typically accomplished by requiring any request sent to the This is typically accomplished by requiring any request sent to the
redirection URI endpoint to include a value that binds the request to redirection URI endpoint to include a value that binds the request to
the user-agent's authenticated state (e.g. a hash of the session the user-agent's authenticated state (e.g., a hash of the session
cookie used to authenticate the user-agent). The client SHOULD cookie used to authenticate the user-agent). The client SHOULD
utilize the "state" request parameter to deliver this value to the utilize the "state" request parameter to deliver this value to the
authorization server when making an authorization request. authorization server when making an authorization request.
Once authorization has been obtained from the end-user, the Once authorization has been obtained from the end-user, the
authorization server redirects the end-user's user-agent back to the authorization server redirects the end-user's user-agent back to the
client with the required binding value contained in the "state" client with the required binding value contained in the "state"
parameter. The binding value enables the client to verify the parameter. The binding value enables the client to verify the
validity of the request by matching the binding value to the user- validity of the request by matching the binding value to the
agent's authenticated state. The binding value used for CSRF user-agent's authenticated state. The binding value used for CSRF
protection MUST contain a non-guessable value (as described in protection MUST contain a non-guessable value (as described in
Section 10.10), and the user-agent's authenticated state (e.g. Section 10.10), and the user-agent's authenticated state (e.g.,
session cookie, HTML5 local storage) MUST be kept in a location session cookie, HTML5 local storage) MUST be kept in a location
accessible only to the client and the user-agent (i.e., protected by accessible only to the client and the user-agent (i.e., protected by
same-origin policy). same-origin policy).
A CSRF attack against the authorization server's authorization A CSRF attack against the authorization server's authorization
endpoint can result in an attacker obtaining end-user authorization endpoint can result in an attacker obtaining end-user authorization
for a malicious client without involving or alerting the end-user. for a malicious client without involving or alerting the end-user.
The authorization server MUST implement CSRF protection for its The authorization server MUST implement CSRF protection for its
authorization endpoint, and ensure that a malicious client cannot authorization endpoint and ensure that a malicious client cannot
obtain authorization without the awareness and explicit consent of obtain authorization without the awareness and explicit consent of
the resource owner. the resource owner.
10.13. Clickjacking 10.13. Clickjacking
In a clickjacking attack, an attacker registers a legitimate client In a clickjacking attack, an attacker registers a legitimate client
and then constructs a malicious site in which it loads the and then constructs a malicious site in which it loads the
authorization server's authorization endpoint web page in a authorization server's authorization endpoint web page in a
transparent iframe overlaid on top of a set of dummy buttons, which transparent iframe overlaid on top of a set of dummy buttons, which
are carefully constructed to be placed directly under important are carefully constructed to be placed directly under important
buttons on the authorization page. When an end-user clicks a buttons on the authorization page. When an end-user clicks a
misleading visible button, the end-user is actually clicking an misleading visible button, the end-user is actually clicking an
invisible button on the authorization page (such as an "Authorize" invisible button on the authorization page (such as an "Authorize"
button). This allows an attacker to trick a resource owner into button). This allows an attacker to trick a resource owner into
granting its client access without their knowledge. granting its client access without the end-user's knowledge.
To prevent this form of attack, native applications SHOULD use To prevent this form of attack, native applications SHOULD use
external browsers instead of embedding browsers within the external browsers instead of embedding browsers within the
application when requesting end-user authorization. For most newer application when requesting end-user authorization. For most newer
browsers, avoidance of iframes can be enforced by the authorization browsers, avoidance of iframes can be enforced by the authorization
server using the (non-standard) "x-frame-options" header. This server using the (non-standard) "x-frame-options" header. This
header can have two values, "deny" and "sameorigin", which will block header can have two values, "deny" and "sameorigin", which will block
any framing, or framing by sites with a different origin, any framing, or framing by sites with a different origin,
respectively. For older browsers, JavaScript framebusting techniques respectively. For older browsers, JavaScript frame-busting
can be used but may not be effective in all browsers. techniques can be used but may not be effective in all browsers.
10.14. Code Injection and Input Validation 10.14. Code Injection and Input Validation
A code injection attack occurs when an input or otherwise external A code injection attack occurs when an input or otherwise external
variable is used by an application unsanitized and causes variable is used by an application unsanitized and causes
modification to the application logic. This may allow an attacker to modification to the application logic. This may allow an attacker to
gain access to the application device or its data, cause denial of gain access to the application device or its data, cause denial of
service, or a wide range of malicious side-effects. service, or introduce a wide range of malicious side-effects.
The Authorization server and client MUST sanitize (and validate when The authorization server and client MUST sanitize (and validate when
possible) any value received, in particular, the value of the "state" possible) any value received -- in particular, the value of the
and "redirect_uri" parameters. "state" and "redirect_uri" parameters.
10.15. Open Redirectors 10.15. Open Redirectors
The authorization server authorization endpoint and the client The authorization server, authorization endpoint, and client
redirection endpoint can be improperly configured and operate as open redirection endpoint can be improperly configured and operate as open
redirectors. An open redirector is an endpoint using a parameter to redirectors. An open redirector is an endpoint using a parameter to
automatically redirect a user-agent to the location specified by the automatically redirect a user-agent to the location specified by the
parameter value without any validation. parameter value without any validation.
Open redirectors can be used in phishing attacks, or by an attacker Open redirectors can be used in phishing attacks, or by an attacker
to get end-users to visit malicious sites by making the URI's to get end-users to visit malicious sites by using the URI authority
authority look like a familiar and trusted destination. In addition, component of a familiar and trusted destination. In addition, if the
if the authorization server allows the client to register only part authorization server allows the client to register only part of the
of the redirection URI, an attacker can use an open redirector redirection URI, an attacker can use an open redirector operated by
operated by the client to construct a redirection URI that will pass the client to construct a redirection URI that will pass the
the authorization server validation but will send the authorization authorization server validation but will send the authorization code
code or access token to an endpoint under the control of the or access token to an endpoint under the control of the attacker.
attacker.
10.16. Misuse of Access Token to Impersonate Resource Owner in Implicit 10.16. Misuse of Access Token to Impersonate Resource Owner in Implicit
Flow Flow
For public clients using implicit flows, this specification does not For public clients using implicit flows, this specification does not
provide any method for the client to determine what client an access provide any method for the client to determine what client an access
token was issued to. token was issued to.
A Resource Owner may willingly delegate access to a resource by A resource owner may willingly delegate access to a resource by
granting an access token to an attacker's malicious client. This may granting an access token to an attacker's malicious client. This may
be due to Phishing or some other pretext. An attacker may also steal be due to phishing or some other pretext. An attacker may also steal
a token via some other mechanism. An attacker may then attempt to a token via some other mechanism. An attacker may then attempt to
impersonate the resource owner by providing the access token to a impersonate the resource owner by providing the access token to a
legitimate public client. legitimate public client.
In the implicit flow (response_type=token), the attacker can easily In the implicit flow (response_type=token), the attacker can easily
switch the token in the response from the authorization server, switch the token in the response from the authorization server,
replacing the real access_token with the one previously issued to the replacing the real access token with the one previously issued to the
attacker. attacker.
Servers communicating with native applications that rely on being Servers communicating with native applications that rely on being
passed an access token in the back channel to identify the user of passed an access token in the back channel to identify the user of
the client may be similarly compromised by an attacker creating a the client may be similarly compromised by an attacker creating a
compromised application that can inject arbitrary stolen access compromised application that can inject arbitrary stolen access
tokens. tokens.
Any public client that makes the assumption that only the resource Any public client that makes the assumption that only the resource
owner can present them with a valid access token for the resource is owner can present it with a valid access token for the resource is
vulnerable to this attack. vulnerable to this type of attack.
This attack may expose information about the resource owner at the This type of attack may expose information about the resource owner
legitimate client to the attacker (malicious client). This will also at the legitimate client to the attacker (malicious client). This
allow the attacker to perform operations at the legitimate client will also allow the attacker to perform operations at the legitimate
with the same permissions as the resource owner who originally client with the same permissions as the resource owner who originally
granted the access token or authorization code. granted the access token or authorization code.
Authenticating Resource Owners to clients is out of scope for this Authenticating resource owners to clients is out of scope for this
specification. Any specification that uses the authorization process specification. Any specification that uses the authorization process
as a form of delegated end-user authentication to the client (e.g. as a form of delegated end-user authentication to the client (e.g.,
third-party sign-in service) MUST NOT use the implicit flow without third-party sign-in service) MUST NOT use the implicit flow without
additional security mechanisms such as audience restricting the additional security mechanisms that would enable the client to
access token that enable the client to determine if the access token determine if the access token was issued for its use (e.g., audience-
was issued for its use. restricting the access token).
11. IANA Considerations 11. IANA Considerations
11.1. OAuth Access Token Type Registry 11.1. OAuth Access Token Types Registry
This specification establishes the OAuth access token type registry. This specification establishes the OAuth Access Token Types registry.
Access token types are registered with a Specification Required Access token types are registered with a Specification Required
([RFC5226]) after a two week review period on the [TBD]@ietf.org ([RFC5226]) after a two-week review period on the
mailing list, on the advice of one or more Designated Experts. oauth-ext-review@ietf.org mailing list, on the advice of one or more
However, to allow for the allocation of values prior to publication, Designated Experts. However, to allow for the allocation of values
the Designated Expert(s) may approve registration once they are prior to publication, the Designated Expert(s) may approve
satisfied that such a specification will be published. registration once they are satisfied that such a specification will
be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list Registration requests must be sent to the oauth-ext-review@ietf.org
for review and comment, with an appropriate subject (e.g., "Request mailing list for review and comment, with an appropriate subject
for access token type: example"). [[ Note to RFC-EDITOR: The name of (e.g., "Request for access token type: example").
the mailing list should be determined in consultation with the IESG
and IANA. Suggested name: oauth-ext-review. ]]
Within the review period, the Designated Expert(s) will either Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request and, if applicable, suggestions as to how to make the request
successful. successful.
IANA must only accept registry updates from the Designated Expert(s), IANA must only accept registry updates from the Designated Expert(s)
and should direct all requests for registration to the review mailing and should direct all requests for registration to the review mailing
list. list.
11.1.1. Registration Template 11.1.1. Registration Template
Type name: Type name:
The name requested (e.g., "example"). The name requested (e.g., "example").
Additional Token Endpoint Response Parameters: Additional Token Endpoint Response Parameters:
Additional response parameters returned together with the Additional response parameters returned together with the
"access_token" parameter. New parameters MUST be separately "access_token" parameter. New parameters MUST be separately
registered in the OAuth parameters registry as described by registered in the OAuth Parameters registry as described by
Section 11.2. Section 11.2.
HTTP Authentication Scheme(s): HTTP Authentication Scheme(s):
The HTTP authentication scheme name(s), if any, used to The HTTP authentication scheme name(s), if any, used to
authenticate protected resources requests using access tokens of authenticate protected resource requests using access tokens of
this type. this type.
Change controller: Change controller:
For standards-track RFCs, state "IETF". For others, give the name For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address, of the responsible party. Other details (e.g., postal address,
e-mail address, home page URI) may also be included. email address, home page URI) may also be included.
Specification document(s): Specification document(s):
Reference to the document that specifies the parameter, preferably Reference to the document(s) that specify the parameter,
including a URI that can be used to retrieve a copy of the preferably including a URI that can be used to retrieve a copy of
document. An indication of the relevant sections may also be the document(s). An indication of the relevant sections may also
included, but is not required. be included but is not required.
11.2. OAuth Parameters Registry 11.2. OAuth Parameters Registry
This specification establishes the OAuth parameters registry. This specification establishes the OAuth Parameters registry.
Additional parameters for inclusion in the authorization endpoint Additional parameters for inclusion in the authorization endpoint
request, the authorization endpoint response, the token endpoint request, the authorization endpoint response, the token endpoint
request, or the token endpoint response are registered with a request, or the token endpoint response are registered with a
Specification Required ([RFC5226]) after a two week review period on Specification Required ([RFC5226]) after a two-week review period on
the [TBD]@ietf.org mailing list, on the advice of one or more the oauth-ext-review@ietf.org mailing list, on the advice of one or
Designated Experts. However, to allow for the allocation of values more Designated Experts. However, to allow for the allocation of
prior to publication, the Designated Expert(s) may approve values prior to publication, the Designated Expert(s) may approve
registration once they are satisfied that such a specification will registration once they are satisfied that such a specification will
be published. be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list Registration requests must be sent to the oauth-ext-review@ietf.org
for review and comment, with an appropriate subject (e.g., "Request mailing list for review and comment, with an appropriate subject
for parameter: example"). [[ Note to RFC-EDITOR: The name of the (e.g., "Request for parameter: example").
mailing list should be determined in consultation with the IESG and
IANA. Suggested name: oauth-ext-review. ]]
Within the review period, the Designated Expert(s) will either Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request and, if applicable, suggestions as to how to make the request
successful. successful.
IANA must only accept registry updates from the Designated Expert(s), IANA must only accept registry updates from the Designated Expert(s)
and should direct all requests for registration to the review mailing and should direct all requests for registration to the review mailing
list. list.
11.2.1. Registration Template 11.2.1. Registration Template
Parameter name: Parameter name:
The name requested (e.g., "example"). The name requested (e.g., "example").
Parameter usage location: Parameter usage location:
The location(s) where parameter can be used. The possible The location(s) where parameter can be used. The possible
locations are: authorization request, authorization response, locations are authorization request, authorization response, token
token request, or token response. request, or token response.
Change controller: Change controller:
For standards-track RFCs, state "IETF". For others, give the name For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address, of the responsible party. Other details (e.g., postal address,
e-mail address, home page URI) may also be included. email address, home page URI) may also be included.
Specification document(s): Specification document(s):
Reference to the document that specifies the parameter, preferably Reference to the document(s) that specify the parameter,
including a URI that can be used to retrieve a copy of the preferably including a URI that can be used to retrieve a copy of
document. An indication of the relevant sections may also be the document(s). An indication of the relevant sections may also
included, but is not required. be included but is not required.
11.2.2. Initial Registry Contents 11.2.2. Initial Registry Contents
The OAuth Parameters Registry's initial contents are: The OAuth Parameters registry's initial contents are:
o Parameter name: client_id o Parameter name: client_id
o Parameter usage location: authorization request, token request o Parameter usage location: authorization request, token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: client_secret o Parameter name: client_secret
o Parameter usage location: token request o Parameter usage location: token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: response_type o Parameter name: response_type
o Parameter usage location: authorization request o Parameter usage location: authorization request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: redirect_uri o Parameter name: redirect_uri
o Parameter usage location: authorization request, token request o Parameter usage location: authorization request, token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: scope o Parameter name: scope
o Parameter usage location: authorization request, authorization o Parameter usage location: authorization request, authorization
response, token request, token response response, token request, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: state o Parameter name: state
o Parameter usage location: authorization request, authorization o Parameter usage location: authorization request, authorization
response response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: code o Parameter name: code
o Parameter usage location: authorization response, token request o Parameter usage location: authorization response, token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: error_description o Parameter name: error_description
o Parameter usage location: authorization response, token response o Parameter usage location: authorization response, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: error_uri o Parameter name: error_uri
o Parameter usage location: authorization response, token response o Parameter usage location: authorization response, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: grant_type o Parameter name: grant_type
o Parameter usage location: token request o Parameter usage location: token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: access_token o Parameter name: access_token
o Parameter usage location: authorization response, token response o Parameter usage location: authorization response, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: token_type o Parameter name: token_type
o Parameter usage location: authorization response, token response o Parameter usage location: authorization response, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: expires_in o Parameter name: expires_in
o Parameter usage location: authorization response, token response o Parameter usage location: authorization response, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: username o Parameter name: username
o Parameter usage location: token request o Parameter usage location: token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: password o Parameter name: password
o Parameter usage location: token request o Parameter usage location: token request
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Parameter name: refresh_token o Parameter name: refresh_token
o Parameter usage location: token request, token response o Parameter usage location: token request, token response
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
11.3. OAuth Authorization Endpoint Response Type Registry 11.3. OAuth Authorization Endpoint Response Types Registry
This specification establishes the OAuth authorization endpoint This specification establishes the OAuth Authorization Endpoint
response type registry. Response Types registry.
Additional response type for use with the authorization endpoint are Additional response types for use with the authorization endpoint are
registered with a Specification Required ([RFC5226]) after a two week registered with a Specification Required ([RFC5226]) after a two-week
review period on the [TBD]@ietf.org mailing list, on the advice of review period on the oauth-ext-review@ietf.org mailing list, on the
one or more Designated Experts. However, to allow for the allocation advice of one or more Designated Experts. However, to allow for the
of values prior to publication, the Designated Expert(s) may approve allocation of values prior to publication, the Designated Expert(s)
registration once they are satisfied that such a specification will may approve registration once they are satisfied that such a
be published. specification will be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list Registration requests must be sent to the oauth-ext-review@ietf.org
for review and comment, with an appropriate subject (e.g., "Request mailing list for review and comment, with an appropriate subject
for response type: example"). [[ Note to RFC-EDITOR: The name of the (e.g., "Request for response type: example").
mailing list should be determined in consultation with the IESG and
IANA. Suggested name: oauth-ext-review. ]]
Within the review period, the Designated Expert(s) will either Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request and, if applicable, suggestions as to how to make the request
successful. successful.
IANA must only accept registry updates from the Designated Expert(s), IANA must only accept registry updates from the Designated Expert(s)
and should direct all requests for registration to the review mailing and should direct all requests for registration to the review mailing
list. list.
11.3.1. Registration Template 11.3.1. Registration Template
Response type name: Response type name:
The name requested (e.g., "example"). The name requested (e.g., "example").
Change controller: Change controller:
For standards-track RFCs, state "IETF". For others, give the name For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address, of the responsible party. Other details (e.g., postal address,
e-mail address, home page URI) may also be included. email address, home page URI) may also be included.
Specification document(s): Specification document(s):
Reference to the document that specifies the type, preferably Reference to the document(s) that specify the type, preferably
including a URI that can be used to retrieve a copy of the including a URI that can be used to retrieve a copy of the
document. An indication of the relevant sections may also be document(s). An indication of the relevant sections may also be
included, but is not required. included but is not required.
11.3.2. Initial Registry Contents 11.3.2. Initial Registry Contents
The OAuth Authorization Endpoint Response Type Registry's initial The OAuth Authorization Endpoint Response Types registry's initial
contents are: contents are:
o Response type name: code o Response type name: code
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
o Response type name: token o Response type name: token
o Change controller: IETF o Change controller: IETF
o Specification document(s): [[ this document ]] o Specification document(s): RFC 6749
11.4. OAuth Extensions Error Registry 11.4. OAuth Extensions Error Registry
This specification establishes the OAuth extensions error registry. This specification establishes the OAuth Extensions Error registry.
Additional error codes used together with other protocol extensions Additional error codes used together with other protocol extensions
(i.e. extension grant types, access token types, or extension (i.e., extension grant types, access token types, or extension
parameters) are registered with a Specification Required ([RFC5226]) parameters) are registered with a Specification Required ([RFC5226])
after a two week review period on the [TBD]@ietf.org mailing list, on after a two-week review period on the oauth-ext-review@ietf.org
the advice of one or more Designated Experts. However, to allow for mailing list, on the advice of one or more Designated Experts.
the allocation of values prior to publication, the Designated However, to allow for the allocation of values prior to publication,
Expert(s) may approve registration once they are satisfied that such the Designated Expert(s) may approve registration once they are
a specification will be published. satisfied that such a specification will be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list Registration requests must be sent to the oauth-ext-review@ietf.org
for review and comment, with an appropriate subject (e.g., "Request mailing list for review and comment, with an appropriate subject
for error code: example"). [[ Note to RFC-EDITOR: The name of the (e.g., "Request for error code: example").
mailing list should be determined in consultation with the IESG and
IANA. Suggested name: oauth-ext-review. ]]
Within the review period, the Designated Expert(s) will either Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request and, if applicable, suggestions as to how to make the request
successful. successful.
IANA must only accept registry updates from the Designated Expert(s), IANA must only accept registry updates from the Designated Expert(s)
and should direct all requests for registration to the review mailing and should direct all requests for registration to the review mailing
list. list.
11.4.1. Registration Template 11.4.1. Registration Template
Error name: Error name:
The name requested (e.g., "example"). Values for the error name The name requested (e.g., "example"). Values for the error name
MUST NOT include characters outside the set %x20-21 / %x23-5B / MUST NOT include characters outside the set %x20-21 / %x23-5B /
%x5D-7E. %x5D-7E.
Error usage location: Error usage location:
The location(s) where the error can be used. The possible The location(s) where the error can be used. The possible
locations are: authorization code grant error response locations are authorization code grant error response
(Section 4.1.2.1), implicit grant error response (Section 4.1.2.1), implicit grant error response
(Section 4.2.2.1), token error response (Section 5.2), or resource (Section 4.2.2.1), token error response (Section 5.2), or resource
access error response (Section 7.2). access error response (Section 7.2).
Related protocol extension: Related protocol extension:
The name of the extension grant type, access token type, or The name of the extension grant type, access token type, or
extension parameter, the error code is used in conjunction with. extension parameter that the error code is used in conjunction
with.
Change controller: Change controller:
For standards-track RFCs, state "IETF". For others, give the name For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address, of the responsible party. Other details (e.g., postal address,
e-mail address, home page URI) may also be included. email address, home page URI) may also be included.
Specification document(s): Specification document(s):
Reference to the document that specifies the error code, Reference to the document(s) that specify the error code,
preferably including a URI that can be used to retrieve a copy of preferably including a URI that can be used to retrieve a copy of
the document. An indication of the relevant sections may also be the document(s). An indication of the relevant sections may also
included, but is not required. be included but is not required.
12. References 12. References
12.1. Normative References 12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", [RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",
RFC 2246, January 1999. RFC 2246, January 1999.
skipping to change at page 64, line 26 skipping to change at page 69, line 7
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A., and L. Stewart, "HTTP Leach, P., Luotonen, A., and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication", Authentication: Basic and Digest Access Authentication",
RFC 2617, June 1999. RFC 2617, June 1999.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO [RFC3629] Yergeau, F., "UTF-8, a transformation format of
10646", STD 63, RFC 3629, November 2003. ISO 10646", STD 63, RFC 3629, November 2003.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005. RFC 3986, January 2005.
[RFC4627] Crockford, D., "The application/json Media Type for [RFC4627] Crockford, D., "The application/json Media Type for
JavaScript Object Notation (JSON)", RFC 4627, July 2006. JavaScript Object Notation (JSON)", RFC 4627, July 2006.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", [RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
RFC 4949, August 2007. RFC 4949, August 2007.
skipping to change at page 65, line 11 skipping to change at page 69, line 41
Verification of Domain-Based Application Service Identity Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509 within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer (PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, March 2011. Security (TLS)", RFC 6125, March 2011.
[USASCII] American National Standards Institute, "Coded Character [USASCII] American National Standards Institute, "Coded Character
Set -- 7-bit American Standard Code for Information Set -- 7-bit American Standard Code for Information
Interchange", ANSI X3.4, 1986. Interchange", ANSI X3.4, 1986.
[W3C.REC-html401-19991224] [W3C.REC-html401-19991224]
Hors, A., Raggett, D., and I. Jacobs, "HTML 4.01 Raggett, D., Le Hors, A., and I. Jacobs, "HTML 4.01
Specification", World Wide Web Consortium Specification", World Wide Web Consortium
Recommendation REC-html401-19991224, December 1999, Recommendation REC-html401-19991224, December 1999,
<http://www.w3.org/TR/1999/REC-html401-19991224>. <http://www.w3.org/TR/1999/REC-html401-19991224>.
[W3C.REC-xml-20081126] [W3C.REC-xml-20081126]
Sperberg-McQueen, C., Yergeau, F., Paoli, J., Bray, T., Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E.,
and E. Maler, "Extensible Markup Language (XML) 1.0 (Fifth and F. Yergeau, "Extensible Markup Language (XML) 1.0
Edition)", World Wide Web Consortium Recommendation REC- (Fifth Edition)", World Wide Web Consortium
xml-20081126, November 2008, Recommendation REC-xml-20081126, November 2008,
<http://www.w3.org/TR/2008/REC-xml-20081126>. <http://www.w3.org/TR/2008/REC-xml-20081126>.
12.2. Informative References 12.2. Informative References
[I-D.draft-hardt-oauth-01] [OAuth-HTTP-MAC]
Hardt, D., Ed., Tom, A., Eaton, B., and Y. Goland, "OAuth Hammer-Lahav, E., Ed., "HTTP Authentication: MAC Access
Web Resource Authorization Profiles", January 2010. Authentication", Work in Progress, February 2012.
[I-D.ietf-oauth-saml2-bearer] [OAuth-SAML2]
Campbell, B. and C. Mortimore, "SAML 2.0 Bearer Assertion Campbell, B. and C. Mortimore, "SAML 2.0 Bearer Assertion
Profiles for OAuth 2.0", draft-ietf-oauth-saml2-bearer-13 Profiles for OAuth 2.0", Work in Progress, September 2012.
(work in progress), July 2012.
[I-D.ietf-oauth-v2-bearer]
Jones, M., Hardt, D., and D. Recordon, "The OAuth 2.0
Authorization Framework: Bearer Token Usage",
draft-ietf-oauth-v2-bearer-22 (work in progress),
July 2012.
[I-D.ietf-oauth-v2-http-mac] [OAuth-THREATMODEL]
Hammer-Lahav, E., "HTTP Authentication: MAC Access Lodderstedt, T., Ed., McGloin, M., and P. Hunt, "OAuth 2.0
Authentication", draft-ietf-oauth-v2-http-mac-01 (work in Threat Model and Security Considerations", Work
progress), February 2012. in Progress, October 2012.
[I-D.ietf-oauth-v2-threatmodel] [OAuth-WRAP]
Lodderstedt, T., McGloin, M., and P. Hunt, "OAuth 2.0 Hardt, D., Ed., Tom, A., Eaton, B., and Y. Goland, "OAuth
Threat Model and Security Considerations", Web Resource Authorization Profiles", Work in Progress,
draft-ietf-oauth-v2-threatmodel-06 (work in progress), January 2010.
June 2012.
[RFC5849] Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849, [RFC5849] Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849,
April 2010. April 2010.
[RFC6750] Jones, M. and D. Hardt, "The OAuth 2.0 Authorization
Framework: Bearer Token Usage", RFC 6750, October 2012.
Appendix A. Augmented Backus-Naur Form (ABNF) Syntax Appendix A. Augmented Backus-Naur Form (ABNF) Syntax
This section provides Augmented Backus-Naur Form (ABNF) syntax This section provides Augmented Backus-Naur Form (ABNF) syntax
descriptions for the elements defined in this specification using the descriptions for the elements defined in this specification using the
notation of [RFC5234]. The ABNF below is defined in terms of Unicode notation of [RFC5234]. The ABNF below is defined in terms of Unicode
code points [W3C.REC-xml-20081126]; these characters are typically code points [W3C.REC-xml-20081126]; these characters are typically
encoded in UTF-8. Elements are presented in the order first defined. encoded in UTF-8. Elements are presented in the order first defined.
Some of the definitions that follow use the "URI-reference" Some of the definitions that follow use the "URI-reference"
definition from [RFC3986]. definition from [RFC3986].
skipping to change at page 66, line 43 skipping to change at page 71, line 42
client-id = *VSCHAR client-id = *VSCHAR
A.2. "client_secret" Syntax A.2. "client_secret" Syntax
The "client_secret" element is defined in Section 2.3.1: The "client_secret" element is defined in Section 2.3.1:
client-secret = *VSCHAR client-secret = *VSCHAR
A.3. "response_type" Syntax A.3. "response_type" Syntax
The "response_type" element is defined in Section 3.1.1 and The "response_type" element is defined in Sections 3.1.1 and 8.4:
Section 8.4:
response-type = response-name *( SP response-name ) response-type = response-name *( SP response-name )
response-name = 1*response-char response-name = 1*response-char
response-char = "_" / DIGIT / ALPHA response-char = "_" / DIGIT / ALPHA
A.4. "scope" Syntax A.4. "scope" Syntax
The "scope" element is defined in Section 3.3: The "scope" element is defined in Section 3.3:
scope = scope-token *( SP scope-token ) scope = scope-token *( SP scope-token )
scope-token = 1*NQCHAR scope-token = 1*NQCHAR
A.5. "state" Syntax A.5. "state" Syntax
The "state" element is defined in Section 4.1.1, Section 4.1.2, The "state" element is defined in Sections 4.1.1, 4.1.2, 4.1.2.1,
Section 4.1.2.1, Section 4.2.1, Section 4.2.2, and Section 4.2.2.1: 4.2.1, 4.2.2, and 4.2.2.1:
state = 1*VSCHAR state = 1*VSCHAR
A.6. "redirect_uri" Syntax A.6. "redirect_uri" Syntax
The "redirect_uri" element is defined in Section 4.1.1, The "redirect_uri" element is defined in Sections 4.1.1, 4.1.3,
Section 4.1.3, and Section 4.2.1: and 4.2.1:
redirect-uri = URI-reference redirect-uri = URI-reference
A.7. "error" Syntax A.7. "error" Syntax
The "error" element is defined in Section 4.1.2.1, Section 4.2.2.1, The "error" element is defined in Sections 4.1.2.1, 4.2.2.1, 5.2,
Section 5.2, Section 7.2, and Section 8.5: 7.2, and 8.5:
error = 1*NQSCHAR error = 1*NQSCHAR
A.8. "error_description" Syntax A.8. "error_description" Syntax
The "error_description" element is defined in Section 4.1.2.1, The "error_description" element is defined in Sections 4.1.2.1,
Section 4.2.2.1, Section 5.2, and Section 7.2: 4.2.2.1, 5.2, and 7.2:
error-description = 1*NQSCHAR error-description = 1*NQSCHAR
A.9. "error_uri" Syntax A.9. "error_uri" Syntax
The "error_uri" element is defined in Section 4.1.2.1, The "error_uri" element is defined in Sections 4.1.2.1, 4.2.2.1, 5.2,
Section 4.2.2.1, Section 5.2, and Section 7.2: and 7.2:
error-uri = URI-reference error-uri = URI-reference
A.10. "grant_type" Syntax A.10. "grant_type" Syntax
The "grant_type" element is defined in Section 4.1.3, Section 4.3.2, The "grant_type" element is defined in Sections 4.1.3, 4.3.2, 4.4.2,
Section 4.4.2, Section 6, and Section 4.5: 4.5, and 6:
grant-type = grant-name / URI-reference grant-type = grant-name / URI-reference
grant-name = 1*name-char grant-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA name-char = "-" / "." / "_" / DIGIT / ALPHA
A.11. "code" Syntax A.11. "code" Syntax
The "code" element is defined in Section 4.1.3: The "code" element is defined in Section 4.1.3:
code = 1*VSCHAR code = 1*VSCHAR
A.12. "access_token" Syntax A.12. "access_token" Syntax
The "access_token" element is defined in Section 4.2.2 and The "access_token" element is defined in Sections 4.2.2 and 5.1:
Section 5.1:
access-token = 1*VSCHAR access-token = 1*VSCHAR
A.13. "token_type" Syntax A.13. "token_type" Syntax
The "token_type" element is defined in Section 4.2.2, Section 5.1, The "token_type" element is defined in Sections 4.2.2, 5.1, and 8.1:
and Section 8.1:
token-type = type-name / URI-reference token-type = type-name / URI-reference
type-name = 1*name-char type-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA name-char = "-" / "." / "_" / DIGIT / ALPHA
A.14. "expires_in" Syntax A.14. "expires_in" Syntax
The "expires_in" element is defined in Section 4.2.2 and Section 5.1: The "expires_in" element is defined in Sections 4.2.2 and 5.1:
expires-in = 1*DIGIT expires-in = 1*DIGIT
A.15. "username" Syntax A.15. "username" Syntax
The "username" element is defined in Section 4.3.2: The "username" element is defined in Section 4.3.2:
username = *UNICODECHARNOCRLF username = *UNICODECHARNOCRLF
A.16. "password" Syntax A.16. "password" Syntax
The "password" element is defined in Section 4.3.2: The "password" element is defined in Section 4.3.2:
password = *UNICODECHARNOCRLF password = *UNICODECHARNOCRLF
A.17. "refresh_token" Syntax A.17. "refresh_token" Syntax
The "refresh_token" element is defined in Section 5.1 and Section 6: The "refresh_token" element is defined in Sections 5.1 and 6:
refresh-token = 1*VSCHAR refresh-token = 1*VSCHAR
A.18. Endpoint Parameter Syntax A.18. Endpoint Parameter Syntax
The syntax for new endpoint parameters is defined in Section 8.2: The syntax for new endpoint parameters is defined in Section 8.2:
param-name = 1*name-char param-name = 1*name-char
name-char = "-" / "." / "_" / DIGIT / ALPHA name-char = "-" / "." / "_" / DIGIT / ALPHA
Appendix B. Use of application/x-www-form-urlencoded Media Type Appendix B. Use of application/x-www-form-urlencoded Media Type
At the time of publication of this specification, the At the time of publication of this specification, the
"application/x-www-form-urlencoded" media type was defined in Section "application/x-www-form-urlencoded" media type was defined in
17.13.4 of [W3C.REC-html401-19991224], but not registered in the IANA Section 17.13.4 of [W3C.REC-html401-19991224] but not registered in
media types registry the IANA MIME Media Types registry
(<http://www.iana.org/assignments/media-types/index.html>). (<http://www.iana.org/assignments/media-types>). Furthermore, that
Furthermore, that definition is incomplete, as it does not consider definition is incomplete, as it does not consider non-US-ASCII
non-US-ASCII characters. characters.
To address this shortcoming when generating payloads using this media To address this shortcoming when generating payloads using this media
type, names and values MUST be encoded using the UTF-8 character type, names and values MUST be encoded using the UTF-8 character
encoding scheme [RFC3629] first; the resulting octet sequence then encoding scheme [RFC3629] first; the resulting octet sequence then
needs to be further encoded using the escaping rules defined in needs to be further encoded using the escaping rules defined in
[W3C.REC-html401-19991224]. [W3C.REC-html401-19991224].
When parsing data from a payload using this media type, the names and When parsing data from a payload using this media type, the names and
values resulting from reversing the name/value encoding consequently values resulting from reversing the name/value encoding consequently
need to be treated as octet sequences, to be decoded using the UTF-8 need to be treated as octet sequences, to be decoded using the UTF-8
character encoding scheme. character encoding scheme.
For example, the value consisting of the six Unicode code points (1) For example, the value consisting of the six Unicode code points
U+0020 (SPACE), (2) U+0025 (PERCENT SIGN), (3) U+0026 (AMPERSAND), (1) U+0020 (SPACE), (2) U+0025 (PERCENT SIGN),
(4) U+002B (PLUS SIGN), (5) U+00A3 (POUND SIGN), and (6) U+20AC (EURO (3) U+0026 (AMPERSAND), (4) U+002B (PLUS SIGN),
SIGN) would be encoded into the octet sequence below (using (5) U+00A3 (POUND SIGN), and (6) U+20AC (EURO SIGN) would be encoded
hexadecimal notation): into the octet sequence below (using hexadecimal notation):
20 25 26 2B C2 A3 E2 82 AC 20 25 26 2B C2 A3 E2 82 AC
and then represented in the payload as: and then represented in the payload as:
+%25%26%2B%C2%A3%E2%82%AC +%25%26%2B%C2%A3%E2%82%AC
Appendix C. Acknowledgements Appendix C. Acknowledgements
The initial OAuth 2.0 protocol specification was edited by David The initial OAuth 2.0 protocol specification was edited by David
Recordon, based on two previous publications: the OAuth 1.0 community Recordon, based on two previous publications: the OAuth 1.0 community
specification [RFC5849], and OAuth WRAP (OAuth Web Resource specification [RFC5849], and OAuth WRAP (OAuth Web Resource
Authorization Profiles) [I-D.draft-hardt-oauth-01]. Eran Hammer then Authorization Profiles) [OAuth-WRAP]. Eran Hammer then edited many
edited the drafts through draft -26. The Security Considerations of the intermediate drafts that evolved into this RFC. The Security
section was drafted by Torsten Lodderstedt, Mark McGloin, Phil Hunt, Considerations section was drafted by Torsten Lodderstedt, Mark
Anthony Nadalin, and John Bradley. The section on use of the McGloin, Phil Hunt, Anthony Nadalin, and John Bradley. The section
application/x-www-form-urlencoded media type was drafted by Julian on use of the "application/x-www-form-urlencoded" media type was
Reschke. The ABNF section was drafted by Michael B. Jones. drafted by Julian Reschke. The ABNF section was drafted by Michael
B. Jones.
The OAuth 1.0 community specification was edited by Eran Hammer and The OAuth 1.0 community specification was edited by Eran Hammer and
authored by Mark Atwood, Dirk Balfanz, Darren Bounds, Richard M. authored by Mark Atwood, Dirk Balfanz, Darren Bounds, Richard M.
Conlan, Blaine Cook, Leah Culver, Breno de Medeiros, Brian Eaton, Conlan, Blaine Cook, Leah Culver, Breno de Medeiros, Brian Eaton,
Kellan Elliott-McCrea, Larry Halff, Eran Hammer, Ben Laurie, Chris Kellan Elliott-McCrea, Larry Halff, Eran Hammer, Ben Laurie, Chris
Messina, John Panzer, Sam Quigley, David Recordon, Eran Sandler, Messina, John Panzer, Sam Quigley, David Recordon, Eran Sandler,
Jonathan Sergent, Todd Sieling, Brian Slesinsky, and Andy Smith. Jonathan Sergent, Todd Sieling, Brian Slesinsky, and Andy Smith.
The OAuth WRAP specification was edited by Dick Hardt and authored by The OAuth WRAP specification was edited by Dick Hardt and authored by
Brian Eaton, Yaron Y. Goland, Dick Hardt, and Allen Tom. Brian Eaton, Yaron Y. Goland, Dick Hardt, and Allen Tom.
This specification is the work of the OAuth Working Group, which This specification is the work of the OAuth Working Group, which
includes dozens of active and dedicated participants. In particular, includes dozens of active and dedicated participants. In particular,
the following individuals contributed ideas, feedback, and wording the following individuals contributed ideas, feedback, and wording
that shaped and formed the final specification: that shaped and formed the final specification:
Michael Adams, Amanda Anganes, Andrew Arnott, Dirk Balfanz, Aiden Michael Adams, Amanda Anganes, Andrew Arnott, Dirk Balfanz, Aiden
Bell, John Bradley, Brian Campbell, Scott Cantor, Marcos Caceres, Bell, John Bradley, Marcos Caceres, Brian Campbell, Scott Cantor,
Blaine Cook, Roger Crew, Brian Eaton, Wesley Eddy, Leah Culver, Bill Blaine Cook, Roger Crew, Leah Culver, Bill de hOra, Andre DeMarre,
de hOra, Andre DeMarre, Brian Eaton, Wolter Eldering, Brian Ellin, Brian Eaton, Wesley Eddy, Wolter Eldering, Brian Ellin, Igor
Igor Faynberg, George Fletcher, Tim Freeman, Luca Frosini, Evan Faynberg, George Fletcher, Tim Freeman, Luca Frosini, Evan Gilbert,
Gilbert, Yaron Y. Goland, Brent Goldman, Kristoffer Gronowski, Eran Yaron Y. Goland, Brent Goldman, Kristoffer Gronowski, Eran Hammer,
Hammer, Justin Hart, Dick Hardt, Craig Heath, Phil Hunt, Michael B. Dick Hardt, Justin Hart, Craig Heath, Phil Hunt, Michael B. Jones,
Jones, Terry Jones, John Kemp, Mark Kent, Raffi Krikorian, Chasen Le Terry Jones, John Kemp, Mark Kent, Raffi Krikorian, Chasen Le Hara,
Hara, Rasmus Lerdorf, Torsten Lodderstedt, Hui-Lan Lu, Casey Lucas, Rasmus Lerdorf, Torsten Lodderstedt, Hui-Lan Lu, Casey Lucas, Paul
Paul Madsen, Alastair Mair, Eve Maler, James Manger, Mark McGloin, Madsen, Alastair Mair, Eve Maler, James Manger, Mark McGloin,
Laurence Miao, William Mills, Chuck Mortimore, Anthony Nadalin, Laurence Miao, William Mills, Chuck Mortimore, Anthony Nadalin,
Julian Reschke, Justin Richer, Peter Saint-Andre, Nat Sakimura, Rob Julian Reschke, Justin Richer, Peter Saint-Andre, Nat Sakimura, Rob
Sayre, Marius Scurtescu, Naitik Shah, Luke Shepard, Vlad Skvortsov, Sayre, Marius Scurtescu, Naitik Shah, Luke Shepard, Vlad Skvortsov,
Justin Smith, Haibin Song, Niv Steingarten, Christian Stuebner, Justin Smith, Haibin Song, Niv Steingarten, Christian Stuebner,
Jeremy Suriel, Paul Tarjan, Christopher Thomas, Henry S. Thompson, Jeremy Suriel, Paul Tarjan, Christopher Thomas, Henry S. Thompson,
Allen Tom, Franklin Tse, Nick Walker, Shane Weeden, and Skylar Allen Tom, Franklin Tse, Nick Walker, Shane Weeden, and Skylar
Woodward. Woodward.
This document was produced under the chairmanship of Blaine Cook, This document was produced under the chairmanship of Blaine Cook,
Peter Saint-Andre, Hannes Tschofenig, Barry Leiba, and Derek Atkins. Peter Saint-Andre, Hannes Tschofenig, Barry Leiba, and Derek Atkins.
The area directors included Lisa Dusseault, Peter Saint-Andre, and The area directors included Lisa Dusseault, Peter Saint-Andre, and
Stephen Farrell. Stephen Farrell.
Appendix D. Document History
[[ to be removed by the RFC editor before publication as an RFC ]]
-31
o Clarify that any client can send "client_id" but that sending it
is only required when using the code flow if the client is not
otherwise authenticated.
o Removed David Recordon's name from the author list, at his
request.
-30
o Added text explaining why the "server_error" and
"temporarily_unavailable" error codes are needed.
-29
o Added "MUST" to "A public client that was not issued a client
password MUST use the "client_id" request parameter to identify
itself when sending requests to the token endpoint" and added text
explaining why this must be so.
o Added that the authorization server MUST "ensure the authorization
code was issued to the authenticated confidential client or to the
public client identified by the "client_id" in the request".
o Added Security Considerations section "Misuse of Access Token to
Impersonate Resource Owner in Implicit Flow".
o Added references in the "Implicit" and "Implicit Grant" sections
to particularly pertinent security considerations.
o Added appendix "Use of application/x-www-form-urlencoded Media
Type" and referenced it in places that this encoding is used.
o Deleted ";charset=UTF-8" from examples formerly using "Content-
Type: application/x-www-form-urlencoded;charset=UTF-8".
o Added the phrase "with a character encoding of UTF-8" when
describing how to send requests using the HTTP request entity-
body.
o For symmetry when using HTTP Basic authentication, also apply the
"application/x-www-form-urlencoded" encoding to the client
password, just as was already done for the client identifier.
o Added "The ABNF below is defined in terms of Unicode code points
[W3C.REC-xml-20081126]; these characters are typically encoded in
UTF-8".
o Replaced UNICODENOCTRLCHAR in ABNF with UNICODECHARNOCRLF = %x09 /
%x20-7E / %x80-D7FF / %xE000-FFFD / %x10000-10FFFF.
o Corrected incorrect uses of "which".
o Reduced multiple blank lines around artwork elements to single
blank lines.
o Removed Eran Hammer's name from the author list, at his request.
Dick Hardt is now listed as the editor.
-28
o Updated the ABNF in the manner discussed by the working group,
allowing "username" and "password" to be Unicode and restricting
"client_id" and "client_secret" to ASCII.
o Specified the use of the application/x-www-form-urlencoded
content-type encoding method to encode the "client_id" when used
as the password for HTTP Basic.
-27
o Added character set restrictions for error, error_description, and
error_uri parameters consistent with the OAuth Bearer spec.
o Added "resource access error response" as an error usage location
in the OAuth Extensions Error Registry.
o Added an ABNF for all message elements.
o Corrected editorial issues identified during review.
Author's Address Author's Address
Dick Hardt (editor) Dick Hardt (editor)
Microsoft Microsoft
Email: dick.hardt@gmail.com EMail: dick.hardt@gmail.com
URI: http://dickhardt.org/ URI: http://dickhardt.org/
 End of changes. 351 change blocks. 
701 lines changed or deleted 730 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/