< draft-ietf-oauth-v2-09.txt		draft-ietf-oauth-v2-10.txt >
	Network Working Group E. Hammer-Lahav, Ed.		Network Working Group E. Hammer-Lahav, Ed.
	Internet-Draft Yahoo!		Internet-Draft Yahoo!
	Intended status: Standards Track D. Recordon		Obsoletes: 5849 (if approved) D. Recordon
	Expires: December 31, 2010 Facebook		Intended status: Standards Track Facebook
	D. Hardt		Expires: January 12, 2011 D. Hardt
	Microsoft		Microsoft
	June 29, 2010		July 11, 2010
	The OAuth 2.0 Protocol		The OAuth 2.0 Protocol
	draft-ietf-oauth-v2-09		draft-ietf-oauth-v2-10
	Abstract		Abstract
	This specification describes the OAuth 2.0 protocol.		This specification describes the OAuth 2.0 protocol.
	Status of this Memo		Status of this Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
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	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
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	This Internet-Draft will expire on December 31, 2010.		This Internet-Draft will expire on January 12, 2011.
	Copyright Notice		Copyright Notice
	Copyright (c) 2010 IETF Trust and the persons identified as the		Copyright (c) 2010 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	skipping to change at page 2, line 10 ¶		skipping to change at page 2, line 10 ¶
	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
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	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
	1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 5		1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 5
	1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5		1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
	1.3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 6		1.3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 7
	1.4. Client Profiles . . . . . . . . . . . . . . . . . . . . . 9		1.4. Client Profiles . . . . . . . . . . . . . . . . . . . . . 10
	1.4.1. Web Server . . . . . . . . . . . . . . . . . . . . . . 10		1.4.1. Web Server . . . . . . . . . . . . . . . . . . . . . . 10
	1.4.2. User-Agent . . . . . . . . . . . . . . . . . . . . . . 11		1.4.2. User-Agent . . . . . . . . . . . . . . . . . . . . . . 11
	1.4.3. Native Application . . . . . . . . . . . . . . . . . . 13		1.4.3. Native Application . . . . . . . . . . . . . . . . . . 13
	1.4.4. Autonomous . . . . . . . . . . . . . . . . . . . . . . 14		1.4.4. Autonomous . . . . . . . . . . . . . . . . . . . . . . 14
	2. Client Credentials . . . . . . . . . . . . . . . . . . . . . . 14		2. Client Credentials . . . . . . . . . . . . . . . . . . . . . . 14
	2.1. Basic Client Credentials . . . . . . . . . . . . . . . . . 15		2.1. Client Password Credentials . . . . . . . . . . . . . . . 15
	3. Obtaining End-User Authorization . . . . . . . . . . . . . . . 16		3. Obtaining End-User Authorization . . . . . . . . . . . . . . . 16
	3.1. Authorization Response . . . . . . . . . . . . . . . . . . 18		3.1. Authorization Response . . . . . . . . . . . . . . . . . . 18
	3.2. Error Response . . . . . . . . . . . . . . . . . . . . . . 20		3.2. Error Response . . . . . . . . . . . . . . . . . . . . . . 20
	3.2.1. Error Codes . . . . . . . . . . . . . . . . . . . . . 21		3.2.1. Error Codes . . . . . . . . . . . . . . . . . . . . . 21
	4. Obtaining an Access Token . . . . . . . . . . . . . . . . . . 21		4. Obtaining an Access Token . . . . . . . . . . . . . . . . . . 21
	4.1. Access Grant Types . . . . . . . . . . . . . . . . . . . . 22		4.1. Access Grant Types . . . . . . . . . . . . . . . . . . . . 23
	4.1.1. Authorization Code . . . . . . . . . . . . . . . . . . 23		4.1.1. Authorization Code . . . . . . . . . . . . . . . . . . 23
	4.1.2. Resource Owner Basic Credentials . . . . . . . . . . . 23		4.1.2. Resource Owner Password Credentials . . . . . . . . . 24
	4.1.3. Assertion . . . . . . . . . . . . . . . . . . . . . . 24		4.1.3. Assertion . . . . . . . . . . . . . . . . . . . . . . 24
	4.1.4. Refresh Token . . . . . . . . . . . . . . . . . . . . 25		4.1.4. Refresh Token . . . . . . . . . . . . . . . . . . . . 25
	4.2. Access Token Response . . . . . . . . . . . . . . . . . . 25		4.2. Access Token Response . . . . . . . . . . . . . . . . . . 26
	4.3. Error Response . . . . . . . . . . . . . . . . . . . . . . 27		4.3. Error Response . . . . . . . . . . . . . . . . . . . . . . 27
	4.3.1. Error Codes . . . . . . . . . . . . . . . . . . . . . 27		4.3.1. Error Codes . . . . . . . . . . . . . . . . . . . . . 28
	5. Accessing a Protected Resource . . . . . . . . . . . . . . . . 28		5. Accessing a Protected Resource . . . . . . . . . . . . . . . . 29
	5.1. Authenticated Requests . . . . . . . . . . . . . . . . . . 29		5.1. Authenticated Requests . . . . . . . . . . . . . . . . . . 29
	5.1.1. The Authorization Request Header Field . . . . . . . . 29		5.1.1. The Authorization Request Header Field . . . . . . . . 30
	5.1.2. URI Query Parameter . . . . . . . . . . . . . . . . . 29		5.1.2. URI Query Parameter . . . . . . . . . . . . . . . . . 30
	5.1.3. Form-Encoded Body Parameter . . . . . . . . . . . . . 30		5.1.3. Form-Encoded Body Parameter . . . . . . . . . . . . . 31
	5.2. The WWW-Authenticate Response Header Field . . . . . . . . 31		5.2. The WWW-Authenticate Response Header Field . . . . . . . . 32
	5.2.1. Error Codes . . . . . . . . . . . . . . . . . . . . . 32		5.2.1. Error Codes . . . . . . . . . . . . . . . . . . . . . 33
	6. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 33		6. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 34
	6.1. Defining New Client Credentials Types . . . . . . . . . . 33		6.1. Defining New Client Credentials Types . . . . . . . . . . 34
	6.2. Defining New Endpoint Parameters . . . . . . . . . . . . . 33		6.2. Defining New Endpoint Parameters . . . . . . . . . . . . . 34
	6.3. Defining New Header Field Parameters . . . . . . . . . . . 34		6.3. Defining New Header Field Parameters . . . . . . . . . . . 35
	6.4. Defining New Access Grant Types . . . . . . . . . . . . . 34		6.4. Defining New Access Grant Types . . . . . . . . . . . . . 35
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 34		7. Security Considerations . . . . . . . . . . . . . . . . . . . 35
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 34		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35
	8.1. The OAuth Parameters Registry . . . . . . . . . . . . . . 34		8.1. The OAuth Parameters Registry . . . . . . . . . . . . . . 35
	8.1.1. Registration Template . . . . . . . . . . . . . . . . 35		8.1.1. Registration Template . . . . . . . . . . . . . . . . 36
	8.1.2. Example . . . . . . . . . . . . . . . . . . . . . . . 35		8.1.2. Example . . . . . . . . . . . . . . . . . . . . . . . 36
	Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 36		Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 37
	Appendix B. Contributors . . . . . . . . . . . . . . . . . . . . 36		Appendix B. Contributors . . . . . . . . . . . . . . . . . . . . 37
	Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 36		Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 37
	Appendix D. Document History . . . . . . . . . . . . . . . . . . 36		Appendix D. Document History . . . . . . . . . . . . . . . . . . 38
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 40		9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 42
	9.1. Normative References . . . . . . . . . . . . . . . . . . . 40		9.1. Normative References . . . . . . . . . . . . . . . . . . . 42
	9.2. Informative References . . . . . . . . . . . . . . . . . . 41		9.2. Informative References . . . . . . . . . . . . . . . . . . 43
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 42		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 43
	1. Introduction		1. Introduction
	With the increasing use of distributed web services and cloud		With the increasing use of distributed web services and cloud
	computing, third-party applications require access to server-hosted		computing, third-party applications require access to server-hosted
	resources. These resources are usually protected and require		resources. These resources are usually protected and require
	authentication using the resource owner's credentials (typically a		authentication using the resource owner's credentials (typically a
	username and password).		username and password).
	In the traditional client-server authentication model, the client		In the traditional client-server authentication model, the client
	accesses a protected resource on the server by presenting the		accesses a protected resource on the server by authenticating with
	resource owner's credentials in order to authenticate and gain		the server using the resource owner's credentials. In order to
	access. OAuth introduces a third role to the traditional model: the		provide third-party applications access to protected resources, the
	resource owner. In OAuth, the client (which is usually not the		resource owner shares its credentials with the third-party. This
	resource owner, but is acting on its behalf) requests access to		creates several problems and limitations:
	resources controlled by the resource owner and hosted by the resource
	server.
	In addition to removing the need for resource owners to share their		o Third-party applications are required to store the resource-
	credentials, resource owners require the ability to restrict access		owner's credentials for future use, typically a password in clear-
	to a limited subset of the resources they control, to limit access		text.
	duration, or to limit access to the methods supported by these
	resources.		o Servers are required to support password (symmetric)
			authentication, despite the security weaknesses created by
			passwords.
			o Third-party applications gain overly broad access to the resource-
			owner's protected resources, leaving resource owners without any
			ability to restrict access to a limited subset of resources, to
			limit access duration, or to limit access to the methods supported
			by these resources.
			o Resource owners cannot revoke access to an individual third-party
			without revoking access to all third-parties, and must do so by
			changing their password.
			OAuth address these issues by separating the role of the client from
			that of the resource owner. In OAuth, the client (which is usually
			not the resource owner, but is acting on the resource owner's behalf)
			requests access to resources controlled by the resource owner and
			hosted by the resource server, and is issued a different set of
			credentials than those of the resource owner.
	Instead of using the resource owner's credentials to access protected		Instead of using the resource owner's credentials to access protected
	resources, clients obtain an access token (a string which denotes a		resources, clients obtain an access token (a string which denotes a
	specific scope, duration, and other attributes). The format and		specific scope, duration, and other attributes). The format and
	structure of access tokens is beyond the scope of this specification.		structure of access tokens is beyond the scope of this specification.
	Tokens are issued to third-party clients by an authorization server		Tokens are issued to third-party clients by an authorization server
	with the approval of the resource owner. The client uses the access		with the approval of the resource owner. The client uses the access
	token to access the protected resources hosted by the resource		token to access the protected resources hosted by the resource
	server. The interaction between the authorization server and		server. The interaction between the authorization server and
	resource server is beyond the scope of this specification.		resource server is beyond the scope of this specification.
	For example, a web user (resource owner) can grant a printing service		For example, a web user (resource owner) can grant a printing service
	(client) access to her protected photos stored at a photo sharing		(client) access to her protected photos stored at a photo sharing
	service (resource server), without sharing her username and password		service (resource server), without sharing her username and password
	with the printing service. Instead, she authenticates directly with		with the printing service. Instead, she authenticates directly with
	the photo sharing service (authorization server) which issues the		an authentication service trusted by the photo sharing service
	printing service delegation-specific credentials (token).		(authorization server) which issues the printing service delegation-
			specific credentials (token).
	This specification defines the use of OAuth over HTTP [RFC2616] (or		This specification defines the use of OAuth over HTTP [RFC2616] (or
	HTTP over TLS as defined by [RFC2818]). Other specifications may		HTTP over TLS as defined by [RFC2818]). Other specifications may
	extend it for use with other transport protocols.		extend it for use with other transport protocols.
	1.1. Notational Conventions		1.1. 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
	document are to be interpreted as described in [RFC2119].		document are to be interpreted as described in [RFC2119].
	skipping to change at page 5, line 37 ¶		skipping to change at page 6, line 5 ¶
	A server capable of accepting and responding to protected		A server capable of accepting and responding to protected
	resource requests.		resource requests.
	client		client
	An application obtaining authorization and making protected		An application obtaining authorization and making protected
	resource requests.		resource requests.
	resource owner		resource owner
	An entity capable of granting access to a protected resource.		An entity capable of granting access to a protected resource.
	end-user		end-user
	A human resource owner.		A human resource owner.
	token		token
	A string representing an access authorization issued to the		A string representing an access authorization issued to the
	client. The string is usually opaque to the client and can		client. The string is usually opaque to the client. Tokens
	self-contain the authorization information in a verifiable		represent specific scopes and durations of access, granted by
	manner (i.e. signed), or denotes an identifier used to retrieve		the resource owner, and enforced by the resource server and
	the information. Tokens represent a specific scope, duration,		authorization servers. The token may denote an identifier used
	and other authorization attributes granted by the resource		to retrieve the authorization information, or self-contain the
	owner and enforced by the resource server and authorization		authorization information in a verifiable manner (i.e. a token
	servers.		string consisting of some data and a signature). Tokens may be
			pure capabilities. Specific additional authentication
			credentials may be required in order for a client to use a
			token.
	access token		access token
	A token used by the client to make authenticated requests		A token used by the client to make authenticated requests on
	on behalf of the resource owner.		behalf of the resource owner.
	refresh token		refresh token
	A token used by the client to obtain a new access token		A token used by the client to obtain a new access token without
	without having to involve the resource owner.		having to involve the resource owner.
	authorization code A short-lived token representing the access		authorization code A short-lived token representing the access grant
	grant provided by the end-user. The authorization code		provided by the end-user. The authorization code is used to
	is used to obtain an access token and a refresh token.		obtain an access token and a refresh token.
	authorization server		authorization server
	A server capable of issuing tokens after successfully		A server capable of issuing tokens after successfully
	authenticating the resource owner and obtaining authorization.		authenticating the resource owner and obtaining authorization.
	The authorization server may be the same server as the resource		The authorization server may be the same server as the resource
	server, or a separate entity.		server, or a separate entity.
	end-user authorization endpoint		end-user authorization endpoint
	The authorization server's HTTP endpoint capable of		The authorization server's HTTP endpoint capable of
	authenticating the end-user and obtaining authorization. The		authenticating the end-user and obtaining authorization. The
	end-user authorization endpoint is described in Section 3.		end-user authorization endpoint is described in Section 3.
	token endpoint		token endpoint
	The authorization server's HTTP endpoint capable of issuing		The authorization server's HTTP endpoint capable of issuing
	tokens and refreshing expired tokens. The token endpoint is		tokens and refreshing expired tokens. The token endpoint is
	described in Section 4.		described in Section 4.
	client identifier		client identifier
	An unique identifier issued to the client to identify itself to		A unique identifier issued to the client to identify itself to
	the authorization server. Client identifiers may have a		the authorization server. Client identifiers may have a
	matching secret. The client identifier is described in		matching secret. The client identifier is described in
	Section 2.		Section 2.
	1.3. Overview		1.3. Overview
	OAuth provides a method for clients to access a protected resource on		OAuth provides a method for clients to access a protected resource on
	behalf of a resource owner. Before a client can access a protected		behalf of a resource owner. Before a client can access a protected
	resource, it must first obtain authorization from the resource owner,		resource, it must first obtain authorization from the resource owner,
	then exchange the access grant for an access token (representing the		then exchange the access grant for an access token (representing the
	skipping to change at page 7, line 29 ¶		skipping to change at page 7, line 40 ¶
	| | | Server |		| | | Server |
	| |<-(F)---- Protected Resource -----| |		| |<-(F)---- Protected Resource -----| |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 1: Abstract Protocol Flow		Figure 1: Abstract Protocol Flow
	The abstract flow illustrated in Figure 1 includes the following		The abstract flow illustrated in Figure 1 includes the following
	steps:		steps:
	(A) The client requests authorization from the resource owner. The		(A) The client requests authorization from the resource owner. The
	client should not interact directly with the resource owner		client should not request the resource owner's credentials
	(since that would expose the resource owner's credentials to the		directly. Instead, it should request authorization via an
	client), but instead request authorization via an authorization		authorization server or other entities. For example, the client
	server or other entities. For example, the client directs the		directs the resource owner to the authorization server which in
	resource owner to the authorization server which in turn issues		turn issues it an access grant. When unavoidable, the client
	it an access grant. When unavoidable, the client interacts		interacts directly with the end-user, asking for the end-user's
	directly with the end-user, asking for the end-user's username		username and password. If the client is acting autonomously,
	and password. If the client is acting autonomously, the		the authorization request is beyond the scope of this
	authorization request is beyond the scope of this specification.		specification.
	(B) The client is issued an access grant which represents the		(B) The client is issued an access grant which represents the
	authorization provided by the resource owner. The access grant		authorization provided by the resource owner. The access grant
	can be expressed as:		can be expressed as:
	* Authorization code - an access grant obtained via an		* Authorization code - an access grant obtained via an
	authorization server. The process used to obtain an		authorization server. Section 3 describes how to obtain an
	authorization code utilized the end-user's user-agent and is		authorization code when the end-user is present and using a
	described in Section 3.		user-agent.
	* Assertion - an access grant obtained using a different trust		* Assertion - an access grant obtained using a different trust
	framework. Assertions enable the client to utilize existing		framework. Assertions enable the client to utilize existing
	trust relationships to obtain an access token. They provide		trust relationships to obtain an access token. They provide
	a bridge between OAuth and other trust frameworks. The		a bridge between OAuth and other trust frameworks. The
	access grant represented by an assertion depends on the		access grant represented by an assertion depends on the
	assertion type, its content, and how it was issued, which are		assertion type, its content, and how it was issued, which are
	beyond the scope of this specification.		beyond the scope of this specification.
	* Resource owner basic credentials - obtained when interacting		* Resource owner password credentials - obtained when
	directly with a resource-owner. Resource owner basic		interacting directly with a resource-owner. Resource owner
	credentials (i.e. a username and password) should only be		password credentials (i.e. a username and password) should
	used when there is a high degree of trust between the		only be used when there is a high degree of trust between the
	resource owner and the client (e.g. its computer operating		resource owner and the client (e.g. its computer operating
	system or a highly privileged application). However, unlike		system or a highly privileged application). However, unlike
	the HTTP Basic authentication scheme defined in [RFC2617],		the HTTP Basic authentication scheme defined in [RFC2617],
	the resource owner's credentials are used for a single		the resource owner's credentials are used for a single
	request and are exchanged for an access token and refresh		request and are exchanged for an access token and refresh
	token. This eliminates the need for the client to store the		token. This eliminates the need for the client to store the
	resource-owner's credentials for future use.		resource-owner's credentials for future use.
	(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 access grant. The		authorization server, and presenting the access grant. The
	skipping to change at page 9, line 9 ¶		skipping to change at page 9, line 16 ¶
	serves the request.		serves the request.
	When the client is acting on its own behalf (the client is also the		When the client is acting on its own behalf (the client is also the
	resource owner), the client does not obtain an access grant. The		resource owner), the client does not obtain an access grant. The
	simplified protocol flow is illustrated in Figure 2:		simplified protocol flow is illustrated in Figure 2:
	+--------+ +---------------+		+--------+ +---------------+
	| |--(C)--- Client Credentials ----->| Authorization |		| |--(C)--- Client Credentials ----->| Authorization |
	| | | Server |		| | | Server |
	| |<-(D)------ Access Token ---------| |		| |<-(D)------ Access Token ---------| |
	| | (w/ Optional Refresh Token) +---------------+		| | +---------------+
	| Client |		| Client |
	| | +---------------+		| | +---------------+
	| |--(E)------ Access Token -------->| Resource |		| |--(E)------ Access Token -------->| Resource |
	| | | Server |		| | | Server |
	| |<-(F)---- Protected Resource -----| |		| |<-(F)---- Protected Resource -----| |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 2: Protocol Flow for Client Acting On Its Own Behalf		Figure 2: Protocol Flow for Client Acting On Its Own Behalf
	When the client uses the user-agent profile (described in		When the client uses the user-agent profile (described in
	skipping to change at page 10, line 38 ¶		skipping to change at page 10, line 48 ¶
	| |<---(E)----- Access Token -------------------'		| |<---(E)----- Access Token -------------------'
	+---------+ (w/ Optional Refresh Token)		+---------+ (w/ Optional Refresh Token)
	Figure 4: Web Server Flow		Figure 4: Web Server Flow
	The web server flow illustrated in Figure 4 includes the following		The web server flow illustrated in Figure 4 includes the following
	steps:		steps:
	(A) The web client initiates the flow by redirecting the end-user's		(A) The web client initiates the flow by redirecting the end-user's
	user-agent to the end-user authorization endpoint as described		user-agent to the end-user authorization endpoint as described
	in Section 3 The client includes its client identifier,		in Section 3. The client includes its client identifier,
	requested scope, local state, and a redirect URI to which the		requested scope, local state, and a redirect URI to which the
	authorization server will send the end-user back once access is		authorization server will send the end-user back once access is
	granted (or denied).		granted (or denied).
	(B) The authorization server authenticates the end-user (via the		(B) The authorization server authenticates the end-user (via the
	user-agent) and establishes whether the end-user grants or		user-agent) and establishes whether the end-user grants or
	denies the client's access request.		denies the client's access request.
	(C) Assuming the end-user granted access, the authorization server		(C) Assuming the end-user granted access, the authorization server
	redirects the user-agent back to the client to the redirection		redirects the user-agent back to the client to the redirection
	skipping to change at page 11, line 21 ¶		skipping to change at page 11, line 31 ¶
	the authorization code and responds back with the access token.		the authorization code and responds back with the access token.
	1.4.2. User-Agent		1.4.2. User-Agent
	The user-agent profile is suitable for client applications residing		The user-agent profile is suitable for client applications residing
	in a user-agent, typically implemented in a browser using a scripting		in a user-agent, typically implemented in a browser using a scripting
	language such as JavaScript. These clients cannot keep client		language such as JavaScript. These clients cannot keep client
	secrets confidential and the authentication of the client is based on		secrets confidential and the authentication of the client is based on
	the user-agent's same-origin policy.		the user-agent's same-origin policy.
	Unlike other profiles in which the client makes a separate end-user		Unlike other profiles in which the client makes separate requests for
	authorization request and an access token requests, the client		end-user authorization and access token, the client receives the
	receives the access token as a result of the end-user authorization		access token as a result of the end-user authorization request in the
	request in the form of an HTTP redirection. The client requests the		form of an HTTP redirection. The client requests the authorization
	authorization server to redirect the user-agent to another web server		server to redirect the user-agent to another web server or local
	or local resource accessible to the user-agent which is capable of		resource accessible to the user-agent which is capable of extracting
	extracting the access token from the response and passing it to the		the access token from the response and passing it to the client.
	client.
	This user-agent profile does not utilize the client secret since the		This user-agent profile does not utilize the client secret since the
	client executables reside on the end-user's computer or device which		client executables reside on the end-user's computer or device which
	makes the client secret accessible and exploitable. Because the		makes the client secret accessible and exploitable. Because the
	access token is encoded into the redirection URI, it may be exposed		access token is encoded into the redirection URI, it may be exposed
	to the end-user and other applications residing on the computer or		to the end-user and other applications residing on the computer or
	device.		device.
	+----------+ Client Identifier +----------------+		+----------+ Client Identifier +----------------+
	| |>---(A)-- & Redirection URI --->| |		| |>---(A)-- & Redirection URI --->| |
	skipping to change at page 13, line 37 ¶		skipping to change at page 13, line 37 ¶
	URI scheme (registered with the operating system to invoke the		URI scheme (registered with the operating system to invoke the
	client application), or by providing a redirection URI pointing to		client application), or by providing a redirection URI pointing to
	a server-hosted resource under the client's control which makes		a server-hosted resource under the client's control which makes
	the response available to the client (e.g. using the window title		the response available to the client (e.g. using the window title
	or other locations accessible from outside the user-agent).		or other locations accessible from outside the user-agent).
	o Utilize the end-user authorization endpoint as described in		o Utilize the end-user authorization endpoint as described in
	Section 3 by using an embedded user-agent. The client obtains the		Section 3 by using an embedded user-agent. The client obtains the
	response by directly communicating with the embedded user-agent.		response by directly communicating with the embedded user-agent.
	o Prompt end-users for their basic credentials (username and		o Prompt end-users for their password and use them directly to
	password) and use them directly to obtain an access token. This		obtain an access token. This is generally discouraged, as it
	is generally discouraged as it hands the end-user's password		hands the end-user's password directly to the third-party client
	directly to the 3rd party and is limited to basic credentials.		which in turn has to store it in clear-text. It also requires the
			server to support password-based authentication.
	When choosing between launching an external browser and an embedded		When choosing between launching an external browser and an embedded
	user-agent, developers should consider the following:		user-agent, developers should consider the following:
	o External user-agents may improve completion rate as the end-user		o External user-agents may improve completion rate as the end-user
	may already be logged-in and not have to re-authenticate.		may already be logged-in and not have to re-authenticate.
	o Embedded user-agents often offer a better end-user flow, as they		o Embedded user-agents often offer a better end-user flow, as they
	remove the need to switch context and open new windows.		remove the need to switch context and open new windows.
	skipping to change at page 14, line 32 ¶		skipping to change at page 14, line 35 ¶
	SAML [OASIS.saml-core-2.0-os] assertion) from an assertion issuer		SAML [OASIS.saml-core-2.0-os] assertion) from an assertion issuer
	or to self-issue an assertion. The assertion format, the process		or to self-issue an assertion. The assertion format, the process
	by which the assertion is obtained, and the method of validating		by which the assertion is obtained, and the method of validating
	the assertion are defined by the assertion issuer and the		the assertion are defined by the assertion issuer and the
	authorization server, and are beyond the scope of this		authorization server, and are beyond the scope of this
	specification.		specification.
	2. Client Credentials		2. Client Credentials
	When interacting with the authorization server, the client identifies		When interacting with the authorization server, the client identifies
	itself using a set of client credentials. The client credentials		itself using a client identifier and authenticates using a set of
	include a client identifier and MAY include a secret or other means		client credentials. This specification provides one mechanism for
	for the authorization server to authenticate the client.		authenticating the client using password credentials.
	The means through which the client obtains its credentials are beyond		The means through which the client obtains its credentials are beyond
	the scope of this specification, but usually involve registration		the scope of this specification, but usually involve registration
	with the authorization server. [[ OAuth Discovery provides one way of		with the authorization server. [[ OAuth Discovery provides one way of
	obtaining basic client credentials ]]		obtaining a client password ]]
	Due to the nature of some clients, authorization servers SHOULD NOT		Due to the nature of some clients, authorization servers SHOULD NOT
	make assumptions about the confidentiality of client credentials		make assumptions about the confidentiality of client secrets without
	without establishing trust with the client operator. Authorization		establishing trust with the client operator. Authorization servers
	servers SHOULD NOT issue client secrets to clients incapable of		SHOULD NOT issue client secrets to clients incapable of keeping their
	keeping their secrets confidential.		secrets confidential.
	This specification provides one mechanism for authenticating the
	client using a set of basic client credentials. The authorization
	server MAY authenticate the client using any desired authentication
	scheme.
	The client MUST NOT include more than one set of client credentials		The authorization server MAY authenticate the client using any
	with each request, and MUST NOT utilize more than one mechanism to		appropriate set of credentials and authentication scheme. The client
	authenticate each request (regardless whether the credentials are		MUST NOT utilize more than one set of credentials or authentication
	identical).		mechanism with each request.
	2.1. Basic Client Credentials		2.1. Client Password Credentials
	The basic client credentials include a client identifier and an		The client password credentials use a shared symmetric secret to
	OPTIONAL matching shared symmetric secret. The client identifier and		authenticate the client. The client identifier and password are
	secret are included in the request using the HTTP Basic		included in the request using the HTTP Basic authentication scheme as
	authentication scheme as defined in [RFC2617] by including the client		defined in [RFC2617] by including the client identifier as the
	identifier as the username and secret as the password.		username and client password as the password.
	For example (line breaks are for display purposes only):		For example (line breaks are for display purposes only):
	POST /token HTTP/1.1		POST /token HTTP/1.1
	Host: server.example.com		Host: server.example.com
	Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW		Authorization: Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
	Content-Type: application/x-www-form-urlencoded		Content-Type: application/x-www-form-urlencoded
	type=web-server&code=i1WsRn1uB1&		grant_type=authorization_code&client_id=s6BhdRkqt3&code=i1WsRn1uB1&
	redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb		redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb
	Alternatively, the client MAY include the credentials using the		Alternatively, the client MAY include the password in the request
	following request parameters:		body using the following parameter:
	client_id
	REQUIRED. The client identifier.
	client_secret REQUIRED if the client identifier has a matching		client_secret REQUIRED. The client password.
	secret.
	For example (line breaks are for display purposes only):		For example (line breaks are 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
	type=web-server&client_id=s6BhdRkqt3&		grant_type=authorization_code&client_id=s6BhdRkqt3&
	client_secret=gX1fBat3bV&code=i1WsRn1uB1&		client_secret=gX1fBat3bV&code=i1WsRn1uB1&
	redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb		redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb
	The authorization server MUST accept the client credentials using		The authorization server MUST accept the client credentials using
	both the request parameters, and the HTTP Basic authentication		both the request parameter, and the HTTP Basic authentication scheme.
	scheme. The authorization server MAY support additional		The authorization server MAY support additional authentication
	authentication schemes suitable for the transmission of a username		schemes suitable for the transmission of a password.
	and password.
	3. Obtaining End-User Authorization		3. Obtaining End-User Authorization
	When the client interacts with an end-user, the end-user MUST first		When the client interacts with an end-user, the end-user MUST first
	grant the client authorization to access its protected resources.		grant the client authorization to access its protected resources.
	Once obtained, the end-user access grant is expressed as an		Once obtained, the end-user access grant is expressed as an
	authorization code which the client uses to obtain an access token.		authorization code which the client uses to obtain an access token.
	To obtain an end-user authorization, the client sends the end-user to		To obtain an end-user authorization, the client sends the end-user to
	the end-user authorization endpoint.		the end-user authorization endpoint.
	skipping to change at page 16, line 48 ¶		skipping to change at page 16, line 45 ¶
	In order to direct the end-user's user-agent to the authorization		In order to direct the end-user's user-agent to the authorization
	server, the client constructs the request URI by adding the following		server, the client constructs the request URI by adding the following
	parameters to the end-user authorization endpoint URI query component		parameters to the end-user authorization endpoint URI query component
	using the "application/x-www-form-urlencoded" format as defined by		using the "application/x-www-form-urlencoded" format as defined by
	[W3C.REC-html401-19991224]:		[W3C.REC-html401-19991224]:
	response_type		response_type
	REQUIRED. The requested response: an access token, an		REQUIRED. The requested response: an access token, an
	authorization code, or both. The parameter value MUST be set		authorization code, or both. The parameter value MUST be set
	to "token" for requesting an access token, "code" for		to "token" for requesting an access token, "code" for
	requesting an authorization code, or "code-and-token" to		requesting an authorization code, or "code_and_token" to
	request both. The authorization server MAY decline to provide		request both. The authorization server MAY decline to provide
	one or more of these response types. [[ The 'code-and-token'		one or more of these response types. [[ The 'code_and_token'
	type is pending use cases and may be removed for the		type is pending use cases and may be removed for the
	specification ]]		specification ]]
	client_id		client_id
	REQUIRED. The client identifier as described in Section 2.		REQUIRED. The client identifier as described in Section 2.
	redirect_uri		redirect_uri
	REQUIRED, unless a redirection URI has been established between		REQUIRED, unless a redirection URI has been established between
	the client and authorization server via other means. An		the client and authorization server via other means. An
	absolute URI to which the authorization server will redirect		absolute URI to which the authorization server will redirect
	skipping to change at page 17, line 34 ¶		skipping to change at page 17, line 32 ¶
	requested scope.		requested scope.
	state		state
	OPTIONAL. An opaque value used by the client to maintain state		OPTIONAL. An opaque value used by the client to maintain state
	between the request and callback. The authorization server		between the request and callback. The authorization server
	includes this value when redirecting the user-agent back to the		includes this value when redirecting the user-agent back to the
	client.		client.
	The client directs the end-user to the constructed URI using an HTTP		The client directs the end-user to the constructed URI using an HTTP
	redirection response, or by other means available to it via the end-		redirection response, or by other means available to it via the end-
	user's user-agent. The request MUST use the HTTP "GET" method.		user's user-agent. The authorization server MUST support the use of
			the HTTP "GET" method for the end-user authorization endpoint, and
			MAY support the use of the "POST" method as well.
	For example, the client directs the end-user's user-agent to make the		For example, the client directs the end-user's user-agent to make the
	following HTTP request using transport-layer security (line breaks		following HTTP request using transport-layer security (line breaks
	are for display purposes only):		are for display purposes only):
	GET /authorize?response_type=code&client_id=s6BhdRkqt3&		GET /authorize?response_type=code&client_id=s6BhdRkqt3&
	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
	If the client has previously registered a redirection URI with the		If the client has previously registered a redirection URI with the
	skipping to change at page 18, line 4 ¶		skipping to change at page 17, line 49 ¶
	GET /authorize?response_type=code&client_id=s6BhdRkqt3&		GET /authorize?response_type=code&client_id=s6BhdRkqt3&
	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
	If the client has previously registered a redirection URI with the		If the client has previously registered a redirection URI with the
	authorization server, the authorization server MUST verify that the		authorization server, the authorization server MUST verify that the
	redirection URI received matches the registered URI associated with		redirection URI received matches the registered URI associated with
	the client identifier. [[ provide guidance on how to perform matching		the client identifier. [[ provide guidance on how to perform matching
	]]		]]
	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.		omitted from the request. The authorization server SHOULD ignore
			unrecognized request parameters.
	The authorization server validates the request to ensure all required		The authorization server validates the request to ensure all required
	parameters are present and valid. If the request is invalid, the		parameters are present and valid. If the request is invalid, the
	authorization server immediately redirects the user-agent back to the		authorization server immediately redirects the user-agent back to the
	client using the redirection URI provided with the appropriate error		client using the redirection URI provided with the appropriate error
	code as described in Section 3.2.		code as described in Section 3.2.
	The authorization server authenticates the end-user and obtains an		The authorization server authenticates the end-user and obtains an
	authorization decision (by asking the end-user or by establishing		authorization decision (by asking the end-user or by establishing
	approval via other means). When a decision has been established, the		approval via other means). When a decision has been established, the
	skipping to change at page 18, line 28 ¶		skipping to change at page 18, line 28 ¶
	or by other means available to it via the end-user's user-agent.		or by other means available to it via the end-user's user-agent.
	3.1. Authorization Response		3.1. Authorization Response
	If the end-user grants the access request, the authorization server		If the end-user grants the access request, the authorization server
	issues an access token, an authorization code, or both, and delivers		issues an access token, an authorization code, or both, and delivers
	them to the client by adding the following parameters to the		them to the client by adding the following parameters to the
	redirection URI (as described below):		redirection URI (as described below):
	code		code
	REQUIRED if the response type is "token" or "code-and-token",		REQUIRED if the response type is "code" or "code_and_token",
	otherwise MUST NOT be included. The authorization code		otherwise MUST NOT be included. The authorization code
	generated by the authorization server. The authorization code		generated by the authorization server. The authorization code
	SHOULD expire shortly after it is issued. The authorization		SHOULD expire shortly after it is issued. The authorization
	server MUST invalidate the authorization code after a single		server MUST invalidate the authorization code after a single
	usage. The authorization code is bound to the client		usage. The authorization code is bound to the client
	identifier and redirection URI.		identifier and redirection URI.
	access_token		access_token
	REQUIRED if the response type is "token" or "code-and-token",		REQUIRED if the response type is "token" or "code_and_token",
	otherwise MUST NOT be included. The access token.		otherwise MUST NOT be included. The access token issued by the
			authorization server. The access token string MUST comply with
			the access-token rule defined in Section 5.1.1.
	expires_in		expires_in
	OPTIONAL. The duration in seconds of the access token lifetime		OPTIONAL. The duration in seconds of the access token lifetime
	if an access token is included. For example, the value "3600"		if an access token is included. For example, the value "3600"
	denotes that the access token will expire in one hour from the		denotes that the access token will expire in one hour from the
	time the response was generated by the authorization server.		time the response was generated by the authorization server.
	scope		scope
	OPTIONAL. The scope of the access token as a list of space-		OPTIONAL. The scope of the access token as a list of space-
	delimited strings if an access token is included. The value of		delimited strings if an access token is included. The value of
	skipping to change at page 18, line 50 ¶		skipping to change at page 19, line 4 ¶
	expires_in		expires_in
	OPTIONAL. The duration in seconds of the access token lifetime		OPTIONAL. The duration in seconds of the access token lifetime
	if an access token is included. For example, the value "3600"		if an access token is included. For example, the value "3600"
	denotes that the access token will expire in one hour from the		denotes that the access token will expire in one hour from the
	time the response was generated by the authorization server.		time the response was generated by the authorization server.
	scope		scope
	OPTIONAL. The scope of the access token as a list of space-		OPTIONAL. The scope of the access token as a list of space-
	delimited strings if an access token is included. The value of		delimited strings if an access token is included. The value of
	the "scope" parameter is defined by the authorization server.		the "scope" parameter is defined by the authorization server.
	If the value contains multiple space-delimited strings, their		If the value contains multiple space-delimited strings, their
	order does not matter, and each string adds an additional		order does not matter, and each string adds an additional
	access range to the requested scope.		access range to the requested scope. The authorization server
			SHOULD include the parameter if the requested scope is
			different from the one requested by the client.
	state		state
	REQUIRED if the "state" parameter was present in the client		REQUIRED if the "state" parameter was present in the client
	authorization request. Set to the exact value received from		authorization request. Set to the exact value received from
	the client.		the client.
	The method in which the authorization server adds the parameter to		The method in which the authorization server adds the parameter to
	the redirection URI is determined by the response type requested by		the redirection URI is determined by the response type requested by
	the client in the authorization request using the "response_type"		the client in the authorization request using the "response_type"
	parameter.		parameter.
	skipping to change at page 19, line 38 ¶		skipping to change at page 19, line 43 ¶
	parameters to the redirection URI fragment component using the		parameters to the redirection URI fragment component using the
	"application/x-www-form-urlencoded" format as defined by		"application/x-www-form-urlencoded" format as defined by
	[W3C.REC-html401-19991224].		[W3C.REC-html401-19991224].
	For example, the authorization server redirects the end-user's user-		For example, the authorization server redirects the end-user's user-
	agent by sending the following HTTP response:		agent by sending the following HTTP response:
	HTTP/1.1 302 Found		HTTP/1.1 302 Found
	Location: http://example.com/rd#access_token=FJQbwq9&expires_in=3600		Location: http://example.com/rd#access_token=FJQbwq9&expires_in=3600
	If the response type is "code-and-token", the authorization server		If the response type is "code_and_token", the authorization server
	adds the "code" and "state" parameters to the redirection URI query		adds the "code" and "state" parameters to the redirection URI query
	component and the "access_token", "scope", and "expires_in" to the		component and the "access_token", "scope", and "expires_in" to the
	redirection URI fragment using the		redirection URI fragment using the
	"application/x-www-form-urlencoded" format as defined by		"application/x-www-form-urlencoded" format as defined by
	[W3C.REC-html401-19991224].		[W3C.REC-html401-19991224].
	For example, the authorization server redirects the end-user's user-		For example, the authorization server redirects the end-user's user-
	agent by sending the following HTTP response (line breaks are for		agent by sending the following HTTP response (line breaks are for
	display purposes only):		display purposes only):
	HTTP/1.1 302 Found		HTTP/1.1 302 Found
	Location: http://example.com/rd?code=i1WsRn1uB1		Location: http://example.com/rd?code=i1WsRn1uB1
	#access_token=FJQbwq9&expires_in=3600		#access_token=FJQbwq9&expires_in=3600
	The sizes of tokens and other values received from the authorization		Clients SHOULD ignore unrecognized response parameters. The sizes of
	server, are left undefined by this specification. Clients should		tokens and other values received from the authorization server, are
	avoid making assumptions about value sizes. Servers should document		left undefined by this specification. Clients should avoid making
	the expected size of any value they issue.		assumptions about value sizes. Servers should document the expected
			size of any value they issue.
	3.2. Error Response		3.2. Error Response
	If the end-user denies the access request or if the request is		If the end-user denies the access request or if the request is
	invalid, the authorization server informs the client by adding the		invalid, the authorization server informs the client by adding the
	following parameters to the redirection URI query component using the		following parameters to the redirection URI query component using the
	"application/x-www-form-urlencoded" format as defined by		"application/x-www-form-urlencoded" format as defined by
	[W3C.REC-html401-19991224]:		[W3C.REC-html401-19991224]:
	error		error
	skipping to change at page 21, line 10 ¶		skipping to change at page 21, line 10 ¶
	agent by sending the following HTTP response:		agent by sending the following HTTP response:
	HTTP/1.1 302 Found		HTTP/1.1 302 Found
	Location: https://client.example.com/cb?error=access-denied		Location: https://client.example.com/cb?error=access-denied
	3.2.1. Error Codes		3.2.1. Error Codes
	The authorization server includes one of the following error codes		The authorization server includes one of the following error codes
	with the error response:		with the error response:
	invalid-request		invalid_request
	The request is missing a required parameter, includes an		The request is missing a required parameter, includes an
	unknown parameter or parameter value, or is otherwise		unsupported parameter or parameter value, or is otherwise
	malformed.		malformed.
	invalid-client-id		invalid_client
	The client identifier provided is invalid.		The client identifier provided is invalid.
	unauthorized-client		unauthorized_client
	The client is not authorized to use the requested response		The client is not authorized to use the requested response
	type.		type.
	redirect-uri-mismatch		redirect_uri_mismatch
	The redirection URI provided does not match a pre-registered		The redirection URI provided does not match a pre-registered
	value.		value.
	access-denied		access_denied
	The end-user or authorization server denied the request.		The end-user or authorization server denied the request.
	unsupported-response-type		unsupported_response_type
	The requested response type is not supported by the		The requested response type is not supported by the
	authorization server.		authorization server.
	invalid_scope		invalid_scope
	The requested scope is invalid, unknown, or malformed.		The requested scope is invalid, unknown, or malformed.
	[[ Add mechanism for extending error codes ]]		[[ Add mechanism for extending error codes ]]
	4. Obtaining an Access Token		4. Obtaining an Access Token
	The client obtains an access token by authenticating with the		The client obtains an access token by authenticating with the
	authorization server and presenting its access grant.		authorization server and presenting its access grant (in the form of
			an authorization code, resource owner credentials, an assertion, or a
	After establishing resource owner authorization, clients request an
	access token from the authorization server's token endpoint. When
	requesting an access token, the client authenticates with the
	authorization server and includes the access grant (in the form of an
	authorization code, resource owner credentials, an assertion, or a
	refresh token).		refresh token).
	The location of the token endpoint can be found in the service
	documentation, or can be obtained by using [[ OAuth Discovery ]].
	The token endpoint URI MAY include a query component.
	Since requests to the token endpoint result in the transmission of		Since requests to the token endpoint result in the transmission of
	plain text credentials in the HTTP request and response, the		plain text credentials in the HTTP request and response, the
	authorization server MUST require the use of a transport-layer		authorization server MUST require the use of a transport-layer
	security mechanism when sending requests to the token endpoints.		security mechanism when sending requests to the token endpoints.
	Servers MUST support TLS 1.2 as defined in [RFC5246], and MAY support		Servers MUST support TLS 1.2 as defined in [RFC5246], and MAY support
	additional transport-layer security mechanisms.		additional transport-layer security mechanisms.
	The client requests an access token by constructing a token request		The client requests an access token by making an HTTP "POST" request
	and making an HTTP "POST" request. The client constructs the request		to the token endpoint. The location of the token endpoint can be
	URI by adding its client credentials to the request as described in		found in the service documentation, or can be obtained by using [[
	Section 2, and includes the following parameters using the		OAuth Discovery ]]. The token endpoint URI MAY include a query
	"application/x-www-form-urlencoded" format in the HTTP request		component.
	entity-body:
			The client authenticates with the authorization server by adding its
			client credentials to the request as described in Section 2. The
			authorization server MAY allow unauthenticated access token requests
			when the client identity does not matter (e.g. anonymous client) or
			when the client identity is established via other means (e.g. using
			an assertion access grant).
			The client constructs the request by including the following
			parameters using the "application/x-www-form-urlencoded" format in
			the HTTP request entity-body:
	grant_type		grant_type
	REQUIRED. The access grant type included in the request.		REQUIRED. The access grant type included in the request.
	Value MUST be one of "authorization-code", "basic-credentials",		Value MUST be one of "authorization_code", "password",
	"assertion", "refresh-token", or "none".		"assertion", "refresh_token", or "none".
			client_id
			REQUIRED, unless the client identity can be establish via other
			means (e.g. assertion). The client identifier as described in
			Section 2.
	scope		scope
	OPTIONAL. The scope of the access request expressed as a list		OPTIONAL. The scope of the access request expressed as a list
	of space-delimited strings. The value of the "scope" parameter		of space-delimited strings. The value of the "scope" parameter
	is defined by the authorization server. If the value contains		is defined by the authorization server. If the value contains
	multiple space-delimited strings, their order does not matter,		multiple space-delimited strings, their order does not matter,
	and each string adds an additional access range to the		and each string adds an additional access range to the
	requested scope. If the access grant being used already		requested scope. If the access grant being used already
	represents an approved scope (e.g. authorization code,		represents an approved scope (e.g. authorization code,
	assertion), the requested scope MUST be equal or lesser than		assertion), the requested scope MUST be equal or lesser than
	the scope previously granted.		the scope previously granted.
	In addition, the client MUST include the appropriate parameters		In addition, the client MUST include the appropriate parameters
	listed for the selected access grant type as described in		listed for the selected access grant type as described in
	Section 4.1.		Section 4.1.
	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.		omitted from the request. The authorization server SHOULD ignore
			unrecognized request parameters.
	4.1. Access Grant Types		4.1. Access Grant Types
	The client requests an access token using one of the four types of		The client requests an access token using one of the four types of
	access grants: authorization code, basic credentials, assertion, or		access grants: authorization code, password credentials, assertion,
	refresh token.		or refresh token.
	When requesting an access token using the "none" access grant type		When requesting an access token using the "none" access grant type
	(no access grant is included), the client is requesting access to the		(no access grant is included), the client is requesting access to the
	protected resources under its control, or those of another resource		protected resources under its control, or those of another resource
	owner which has been previously arranged with the authorization		owner which has been previously arranged with the authorization
	server (the method of which is beyond the scope of this		server (the method of which is beyond the scope of this
	specification).		specification).
	4.1.1. Authorization Code		4.1.1. Authorization Code
	The client includes the authorization code using the		The client includes the authorization code using the
	"authorization-code" access grant type and the following parameters:		"authorization_code" access grant type and the following parameters:
	code		code
	REQUIRED. The authorization code received from the		REQUIRED. The authorization code received from the
	authorization server.		authorization server.
	redirect_uri		redirect_uri
	REQUIRED. The redirection URI used in the initial request.		REQUIRED. The redirection URI used in the initial request.
	For example, the client makes the following HTTP request using		For example, the client makes the following HTTP request by including
	transport-layer security (line breaks are for display purposes only):		its client credentials via the "client_secret" parameter described in
			Section 2 and using transport-layer security (line breaks are 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=authorization-code&client_id=s6BhdRkqt3&		grant_type=authorization_code&client_id=s6BhdRkqt3&
	client_secret=gX1fBat3bV&code=i1WsRn1uB1&		client_secret=gX1fBat3bV&code=i1WsRn1uB1&
	redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb		redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb
	The authorization server MUST verify that the authorization code,		The authorization server MUST:
	client identity, client secret, and redirection URI are all valid and
	match its stored association. If the request is valid, the
	authorization server issues a successful response as described in
	Section 4.2.
	4.1.2. Resource Owner Basic Credentials		o Validate the client credentials (if present) and ensure they match
			the authorization code.
			o Verify that the authorization code and redirection URI are all
			valid and match its stored association.
			If the request is valid, the authorization server issues a successful
			response as described in Section 4.2.
			4.1.2. Resource Owner Password Credentials
	The client includes the resource owner credentials using the		The client includes the resource owner credentials using the
	"basic-credentials" access grant type and the following parameters:		"password" access grant type and the following parameters: [[ add
	[[ add internationalization consideration for username and password		internationalization consideration for username and password ]]
	]]
	username		username
	REQUIRED. The end-user's username.		REQUIRED. The resource owner's username.
	password		password
	REQUIRED. The end-user's password.		REQUIRED. The resource owner's password.
	For example, the client makes the following HTTP request using		For example, the client makes the following HTTP request by including
	transport-layer security (line breaks are for display purposes only):		its client credentials via the "client_secret" parameter described in
			Section 2 and using transport-layer security (line breaks are 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=basic-credentials&client_id=s6BhdRkqt3&		grant_type=password&client_id=s6BhdRkqt3&
	client_secret=47HDu8s&username=johndoe&password=A3ddj3w		client_secret=47HDu8s&username=johndoe&password=A3ddj3w
	The authorization server MUST validate the client credentials and		The authorization server MUST validate the client credentials (if
	end-user credentials and if valid issues an access token response as		present) and end-user credentials and if valid issue an access token
	described in Section 4.2.		response as described in Section 4.2.
	4.1.3. Assertion		4.1.3. Assertion
	The client includes the assertion using the "assertion" access grant		The client includes the assertion using the "assertion" access grant
	type and the following parameters:		type and the following parameters:
	assertion_type		assertion_type
	REQUIRED. The format of the assertion as defined by the		REQUIRED. The format of the assertion as defined by the
	authorization server. The value MUST be an absolute URI.		authorization server. The value MUST be an absolute URI.
	assertion		assertion
	REQUIRED. The assertion.		REQUIRED. The assertion.
	For example, the client makes the following HTTP request using		For example, the client makes the following HTTP request using
	transport-layer security (line breaks are for display purposes only):		transport-layer security, and client authentication is achieved via
			the assertion (line breaks are 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=assertion&client_id=s6BhdRkqt3&client_secret=diejdsks&		grant_type=assertion&
	assertion_type=urn%3Aoasis%3Anames%3Atc%3ASAML%3A2.0%3Aassertion&		assertion_type=urn%3Aoasis%3Anames%3Atc%3ASAML%3A2.0%3Aassertion&
	assertion=PHNhbWxwOl...[omitted for brevity]...ZT4%3D		assertion=PHNhbWxwOl...[omitted for brevity]...ZT4%3D
	The authorization server MUST validate the assertion and if valid		The authorization server MUST validate the client credentials (if
	issues an access token response as described in Section 4.2. The		present) and the assertion and if valid issues an access token
	authorization server SHOULD NOT issue a refresh token.		response as described in Section 4.2. The authorization server
			SHOULD NOT issue a refresh token (instead, require the client to use
			the same or new assertion).
	Authorization servers SHOULD issue access tokens with a limited		Authorization servers SHOULD issue access tokens with a limited
	lifetime and require clients to refresh them by requesting a new		lifetime and require clients to refresh them by requesting a new
	access token using the same assertion if it is still valid.		access token using the same assertion if it is still valid.
	Otherwise the client MUST obtain a new valid assertion.		Otherwise the client MUST obtain a new valid assertion.
	4.1.4. Refresh Token		4.1.4. Refresh Token
	The client includes the refresh token using the "refresh-token"		The client includes the refresh token using the "refresh_token"
	access grant type and the following parameter:		access grant type and the following parameter:
	refresh_token		refresh_token
	REQUIRED. The refresh token associated with the access token		REQUIRED. The refresh token associated with the access token
	to be refreshed.		to be refreshed.
	For example, the client makes the following HTTP request using		For example, the client makes the following HTTP request by including
	transport-layer security (line break are for display purposes only):		its client credentials via the "client_secret" parameter described in
			Section 2 and using transport-layer security (line breaks are 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=refresh-token&client_id=s6BhdRkqt3&		grant_type=refresh_token&client_id=s6BhdRkqt3&
	client_secret=8eSEIpnqmM&refresh_token=n4E9O119d		client_secret=8eSEIpnqmM&refresh_token=n4E9O119d
	The authorization server MUST verify the client credentials, the		The authorization server MUST verify the client credentials (if
	validity of the refresh token, and that the resource owner's		present), the validity of the refresh token, and that the resource
	authorization is still valid. If the request is valid, the		owner's authorization is still valid. If the request is valid, the
	authorization server issues an access token response as described in		authorization server issues an access token response as described in
	Section 4.2. The authorization server MAY issue a new refresh token.		Section 4.2. The authorization server MAY issue a new refresh token.
	4.2. Access Token Response		4.2. Access Token Response
	After receiving and verifying a valid and authorized access token		After receiving and verifying a valid and authorized access token
	request from the client, the authorization server issues the access		request from the client, the authorization server issues the access
	token and optional refresh token, and constructs the response by		token and optional refresh token, and constructs the response by
	adding the following parameters to the entity body of the HTTP		adding the following parameters to the entity body of the HTTP
	response with a 200 (OK) status code:		response with a 200 (OK) status code:
	The token response contains the following parameters:		The token response contains the following parameters:
	access_token		access_token
	REQUIRED. The access token issued by the authorization server.		REQUIRED. The access token issued by the authorization server.
			The access token string MUST comply with the access-token rule
			defined in Section 5.1.1.
	expires_in		expires_in
	OPTIONAL. The duration in seconds of the access token		OPTIONAL. The duration in seconds of the access token
	lifetime. For example, the value "3600" denotes that the		lifetime. For example, the value "3600" denotes that the
	access token will expire in one hour from the time the response		access token will expire in one hour from the time the response
	was generated by the authorization server.		was generated by the authorization server.
	refresh_token		refresh_token
	OPTIONAL. The refresh token used to obtain new access tokens		OPTIONAL. The refresh token used to obtain new access tokens
	using the same end-user access grant as described in		using the same end-user access grant as described in
	Section 4.1.4.		Section 4.1.4. The authorization server SHOULD NOT issue a
			refresh token when the access grant type is set to "none".
	scope		scope
	OPTIONAL. The scope of the access token as a list of space-		OPTIONAL. The scope of the access token as a list of space-
	delimited strings. The value of the "scope" parameter is		delimited strings. The value of the "scope" parameter is
	defined by the authorization server. If the value contains		defined by the authorization server. If the value contains
	multiple space-delimited strings, their order does not matter,		multiple space-delimited strings, their order does not matter,
	and each string adds an additional access range to the		and each string adds an additional access range to the
	requested scope.		requested scope. The authorization server SHOULD include the
			parameter if the requested scope is different from the one
			requested by the client.
	The parameters are including in the entity body of the HTTP response		The parameters are including 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.		as JSON numbers.
	The authorization server MUST include the HTTP "Cache-Control"		The authorization server MUST include the HTTP "Cache-Control"
	response header field with a value of "no-store" in any response		response header field with a value of "no-store" in any response
	skipping to change at page 26, line 47 ¶		skipping to change at page 27, line 22 ¶
	HTTP/1.1 200 OK		HTTP/1.1 200 OK
	Content-Type: application/json		Content-Type: application/json
	Cache-Control: no-store		Cache-Control: no-store
	{		{
	"access_token":"SlAV32hkKG",		"access_token":"SlAV32hkKG",
	"expires_in":3600,		"expires_in":3600,
	"refresh_token":"8xLOxBtZp8"		"refresh_token":"8xLOxBtZp8"
	}		}
	The sizes of tokens and other values received from the authorization		Clients SHOULD ignore unrecognized response parameters. The sizes of
	server, are left undefined by this specification. Clients should		tokens and other values received from the authorization server, are
	avoid making assumptions about value sizes. Servers should document		left undefined by this specification. Clients should avoid making
	the expected size of any value they issue.		assumptions about value sizes. Servers should document the expected
			size of any value they issue.
	4.3. Error Response		4.3. Error Response
	If the token request is invalid or unauthorized, the authorization		If the token request is invalid or unauthorized, the authorization
	server constructs the response by adding the following parameter to		server constructs the response by adding the following parameter to
	the entity body of the HTTP response using the "application/json"		the entity body of the HTTP response using the "application/json"
	media type:		media type:
	error		error
	REQUIRED. A single error code as described in Section 4.3.1.		REQUIRED. A single error code as described in Section 4.3.1.
	skipping to change at page 27, line 30 ¶		skipping to change at page 28, line 12 ¶
	with information about the error, used to provide the end-user		with information about the error, used to provide the end-user
	with additional information about the error.		with additional information about the error.
	For example:		For example:
	HTTP/1.1 400 Bad Request		HTTP/1.1 400 Bad Request
	Content-Type: application/json		Content-Type: application/json
	Cache-Control: no-store		Cache-Control: no-store
	{		{
	"error":"invalid-request"		"error":"invalid_request"
	}		}
	If the client provided invalid credentials using an HTTP		If the client provided invalid credentials using an HTTP
	authentication scheme via the "Authorization" request header field,		authentication scheme via the "Authorization" request header field,
	the authorization server MUST respond with the HTTP 401		the authorization server MUST respond with the HTTP 401
	(Unauthorized) status code. Otherwise, the authorization server		(Unauthorized) status code. Otherwise, the authorization server
	SHALL respond with the HTTP 400 (Bad Request) status code.		SHALL respond with the HTTP 400 (Bad Request) status code.
	4.3.1. Error Codes		4.3.1. Error Codes
	The authorization server includes one of the following error codes		The authorization server includes one of the following error codes
	with the error response:		with the error response:
	invalid-request		invalid_request
	The request is missing a required parameter, includes an		The request is missing a required parameter, includes an
	unknown parameter or parameter value, repeats a parameter,		unsupported parameter or parameter value, repeats a parameter,
	includes multiple credentials, utilizes more than one mechanism		includes multiple credentials, utilizes more than one mechanism
	for authenticating the client, or is otherwise malformed.		for authenticating the client, or is otherwise malformed.
	invalid-client-credentials		invalid_client
	The client identifier provided is invalid, the client failed to		The client identifier provided is invalid, the client failed to
	authenticate, or the client provided multiple client		authenticate, the client did not include its credentials,
	credentials.		provided multiple client credentials, or used unsupported
			credentials type.
	unauthorized-client		unauthorized_client
	The client is not authorized to use the access grant type		The authenticated client is not authorized to use the access
	provided.		grant type provided.
	invalid-grant		invalid_grant
	The provided access grant is invalid, expired, or revoked (e.g.		The provided access grant is invalid, expired, or revoked (e.g.
	invalid assertion, expired authorization token, bad end-user		invalid assertion, expired authorization token, bad end-user
	basic credentials, or mismatching authorization code and		password credentials, or mismatching authorization code and
	redirection URI).		redirection URI).
	unsupported-grant-type		unsupported_grant_type
	The access grant included - its type or another attribute - is		The access grant included - its type or another attribute - is
	not supported by the authorization server.		not supported by the authorization server.
	invalid-scope		invalid_scope
	The requested scope is invalid, unknown, malformed, or exceeds		The requested scope is invalid, unknown, malformed, or exceeds
	the previously granted scope.		the previously granted scope.
	[[ Add mechanism for extending error codes ]]		[[ Add mechanism for extending error codes ]]
	5. Accessing a Protected Resource		5. Accessing a Protected Resource
	Clients access protected resources by presenting an access token to		Clients access protected resources by presenting an access token to
	the resource server. Access tokens act as bearer tokens, where the		the resource server. Access tokens act as bearer tokens, where the
	token string acts as a shared symmetric secret. This requires		token string acts as a shared symmetric secret. This requires
	skipping to change at page 29, line 10 ¶		skipping to change at page 29, line 43 ¶
	The resource server MUST validate the access token and ensure it has		The resource server MUST validate the access token and ensure it has
	not expired and that its scope covers the requested resource. The		not expired and that its scope covers the requested resource. The
	methods used by the resource server to validate the access token are		methods used by the resource server to validate the access token are
	beyond the scope of this specification, but generally involve an		beyond the scope of this specification, but generally involve an
	interaction or coordination between the resource server and		interaction or coordination between the resource server and
	authorization server.		authorization server.
	5.1. Authenticated Requests		5.1. Authenticated Requests
	Clients make authenticated token requests using the "Authorization"		Clients make authenticated token requests using the "Authorization"
	request header field as described in Section 5.1.1. Alternatively,		request header field. Resource servers MUST accept authenticated
	clients MAY include the access token using the HTTP request URI in		requests using the "OAuth" HTTP authentication scheme as described in
	the query component as described in Section 5.1.2, or in the HTTP		Section 5.1.1, and MAY support additional methods.
	body when using the "application/x-www-form-urlencoded" content type
	as described in Section 5.1.3.		Alternatively, clients MAY attempt to include the access token using
			the HTTP request URI in the query component as described in
			Section 5.1.2, or in the HTTP body when using the
			"application/x-www-form-urlencoded" content type as described in
			Section 5.1.3. Resource server MAY support these alternative
			methods.
	Clients SHOULD only use the request URI or body when the		Clients SHOULD only use the request URI or body when the
	"Authorization" request header field is not available, and MUST NOT		"Authorization" request header field is not available, and MUST NOT
	use more than one method in each request.		use more than one method in each request.
	5.1.1. The Authorization Request Header Field		5.1.1. The Authorization Request Header Field
	The "Authorization" request header field is used by clients to make		The "Authorization" request header field is used by clients to make
	authenticated token requests. The client uses the "token" attribute		authenticated token requests. The client uses the "OAuth"
	to include the access token in the request.		authentication scheme to include the access token in the request.
	For example:		For example:
	GET /resource HTTP/1.1		GET /resource HTTP/1.1
	Host: server.example.com		Host: server.example.com
	Authorization: Token token="vF9dft4qmT"		Authorization: OAuth vF9dft4qmT
	The "Authorization" header field uses the framework defined by		The "Authorization" header field uses the framework defined by
	[RFC2617] as follows:		[RFC2617] as follows:
	credentials = "Token" RWS access-token [ CS 1#auth-param ]		credentials = "OAuth" RWS access-token [ CS 1#auth-param ]
	access-token = "token" "=" <"> token <">		access-token = 1*( quoted-char / <"> )
	CS = OWS "," OWS		CS = OWS "," OWS
			quoted-char = "!" / "#" / "$" / "%" / "&" / "'" / "("
			/ ")" / "*" / "+" / "-" / "." / "/" / DIGIT
			/ ":" / "<" / "=" / ">" / "?" / "@" / ALPHA
			/ "[" / "]" / "^" / "_" / "`" / "{" / "|"
			/ "}" / "~" / "\" / "," / ";"
			NOTE: [RFC5849] defines a different format for the "OAuth"
			authentication scheme. Resource servers can differentiate between
			the two protocol versions based on the presence of the
			"oauth_signature_method" which is REQUIRED in the previous version
			and is not supported by this specification.
	5.1.2. URI Query Parameter		5.1.2. URI Query Parameter
	When including the access token in the HTTP request URI, the client		When including the access token in the HTTP request URI, the client
	adds the access token to the request URI query component as defined		adds the access token to the request URI query component as defined
	by [RFC3986] using the "oauth_token" parameter.		by [RFC3986] using the "oauth_token" parameter.
	For example, the client makes the following HTTP request using		For example, the client makes the following HTTP request using
	transport-layer security:		transport-layer security:
	GET /resource?oauth_token=vF9dft4qmT HTTP/1.1		GET /resource?oauth_token=vF9dft4qmT HTTP/1.1
	skipping to change at page 30, line 20 ¶		skipping to change at page 31, line 20 ¶
	The HTTP request URI query can include other request-specific		The HTTP request URI query can include other request-specific
	parameters, in which case, the "oauth_token" parameters SHOULD be		parameters, in which case, the "oauth_token" parameters SHOULD be
	appended following the request-specific parameters, properly		appended following the request-specific parameters, properly
	separated by an "&" character (ASCII code 38).		separated by an "&" character (ASCII code 38).
	For example:		For example:
	http://example.com/resource?x=y&oauth_token=vF9dft4qmT		http://example.com/resource?x=y&oauth_token=vF9dft4qmT
			NOTE: The "oauth_token" parameter is used by the previous version
			of the OAuth protocol as described in [RFC5849]. Resource servers
			can differentiate between the two protocol versions based on the
			presence of the "oauth_signature_method" which is REQUIRED in the
			previous version and is not supported by this specification.
	5.1.3. Form-Encoded Body Parameter		5.1.3. Form-Encoded Body Parameter
	When including the access token in the HTTP request entity-body, the		When including the access token in the HTTP request entity-body, the
	client adds the access token to the request body using the		client adds the access token to the request body using the
	"oauth_token" parameter. The client can use this method only if the		"oauth_token" parameter. The client can use this method only if the
	following REQUIRED conditions are met:		following REQUIRED conditions are met:
	o The entity-body is single-part.		o The entity-body is single-part.
	o The entity-body follows the encoding requirements of the		o The entity-body follows the encoding requirements of the
	skipping to change at page 31, line 14 ¶		skipping to change at page 32, line 14 ¶
	For example, the client makes the following HTTP request using		For example, the client makes the following HTTP request using
	transport-layer security:		transport-layer security:
	POST /resource HTTP/1.1		POST /resource 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
	oauth_token=vF9dft4qmT		oauth_token=vF9dft4qmT
			NOTE: The "oauth_token" parameter is used by the previous version
			of the OAuth protocol as described in [RFC5849]. Resource servers
			can differentiate between the two protocol versions based on the
			presence of the "oauth_signature_method" which is REQUIRED in the
			previous version and is not supported by this specification.
	5.2. The WWW-Authenticate Response Header Field		5.2. The WWW-Authenticate Response Header Field
	If the protected resource request contains an invalid access token or		If the protected resource request contains an invalid access token or
	is malformed, the resource server MUST include the HTTP		is malformed, the resource server MUST include the HTTP
	"WWW-Authenticate" response header field. The "WWW-Authenticate"		"WWW-Authenticate" response header field. The "WWW-Authenticate"
	header field uses the framework defined by [RFC2617] as follows:		header field uses the framework defined by [RFC2617] as follows:
	challenge = "Token" RWS token-challenge		challenge = "OAuth" RWS token-challenge
	token-challenge = realm		token-challenge = realm
	[ CS error ]		[ CS error ]
	[ CS error-desc ]		[ CS error-desc ]
	[ CS error-uri ]		[ CS error-uri ]
	[ CS scope ]		[ CS scope ]
	[ CS 1#auth-param ]		[ CS 1#auth-param ]
	error = "error" "=" <"> token <">		error = "error" "=" <"> token <">
	error-desc = "error-description" "=" quoted-string		error-desc = "error_description" "=" quoted-string
	error-uri = "error-uri" = <"> URI-Reference <">		error-uri = "error_uri" = <"> URI-Reference <">
	scope = ptoken / <"> ptoken *( 1*SP ptoken ) <">		scope = quoted-value /
			<"> quoted-value *( 1*SP quoted-value ) <">
	ptoken = 1*ptokenchar		quoted-value = 1*quoted-char
	ptokenchar = "!" / "#" / "$" / "%" / "&" / "'" / "("
	/ ")" / "*" / "+" / "-" / "." / "/" / DIGIT
	/ ":" / "<" / "=" / ">" / "?" / "@" / ALPHA
	/ "[" / "]" / "^" / "_" / "`" / "{" / "|"
	/ "}" / "~"
	For example:		For example:
	HTTP/1.1 401 Unauthorized		HTTP/1.1 401 Unauthorized
	WWW-Authenticate: Token realm='Example Service', error='expired-token'		WWW-Authenticate: OAuth realm='Example Service', error='expired-token'
	The "realm" attribute is used to provide the protected resources		The "realm" attribute is used to provide the protected resources
	partition as defined by [RFC2617]. [[ add explanation ]]		partition as defined by [RFC2617]. [[ add explanation ]]
	The "error" attribute is used to provide the client with the reason		The "error" attribute is used to provide the client with the reason
	why the access request was declined. The parameter values are		why the access request was declined. The parameter values are
	described in Section 5.2.1.		described in Section 5.2.1.
	The "error-description" attribute provides a human-readable text		The "error_description" attribute provides a human-readable text
	containing additional information, used to assist in the		containing additional information, used to assist in the
	understanding and resolution of the error occurred.		understanding and resolution of the error occurred.
	The "error-uri" attribute provides a URI identifying a human-readable		The "error_uri" attribute provides a URI identifying a human-readable
	web page with information about the error, used to offer the end-user		web page with information about the error, used to offer the end-user
	with additional information about the error. If the value is not an		with additional information about the error. If the value is not an
	absolute URI, it is relative to the URI of the requested protected		absolute URI, it is relative to the URI of the requested protected
	resource.		resource.
	The "scope" attribute is a space-delimited list of scope values		The "scope" attribute is a space-delimited list of scope values
	indicating the required scope of the access token for accessing the		indicating the required scope of the access token for accessing the
	requested resource.		requested resource.
	5.2.1. Error Codes		5.2.1. Error Codes
	The authorization server includes one of the following error codes		The authorization server includes one of the following error codes
	with the error response:		with the error response:
	invalid-request		invalid_request
	The request is missing a required parameter, includes an		The request is missing a required parameter, includes an
	unknown parameter or parameter value, repeats the same		unsupported parameter or parameter value, repeats the same
	parameter, uses more than one method for including an access		parameter, uses more than one method for including an access
	token, or is otherwise malformed. The resource server MUST		token, or is otherwise malformed. The resource server MUST
	respond with the HTTP 400 (Bad Request) status code.		respond with the HTTP 400 (Bad Request) status code.
	invalid-token		invalid_token
	The access token provided is invalid. Resource servers SHOULD		The access token provided is invalid. Resource servers SHOULD
	use this error code when receiving an expired token which		use this error code when receiving an expired token which
	cannot be refreshed to indicate to the client that a new		cannot be refreshed to indicate to the client that a new
	authorization is necessary. The resource server MUST respond		authorization is necessary. The resource server MUST respond
	with the HTTP 401 (Unauthorized) status code.		with the HTTP 401 (Unauthorized) status code.
	expired-token		expired_token
	The access token provided has expired. Resource servers SHOULD		The access token provided has expired. Resource servers SHOULD
	only use this error code when the client is expected to be able		only use this error code when the client is expected to be able
	to handle the response and request a new access token using the		to handle the response and request a new access token using the
	refresh token issued with the expired access token. The		refresh token issued with the expired access token. The
	resource server MUST respond with the HTTP 401 (Unauthorized)		resource server MUST respond with the HTTP 401 (Unauthorized)
	status code.		status code.
	insufficient-scope		insufficient_scope
	The request requires higher privileges than provided by the		The request requires higher privileges than provided by the
	access token. The resource server SHOULD respond with the HTTP		access token. The resource server SHOULD respond with the HTTP
	403 (Forbidden) status code and MAY include the "scope"		403 (Forbidden) status code and MAY include the "scope"
	attribute with the scope necessary to access the protected		attribute with the scope necessary to access the protected
	resource.		resource.
	[[ Add mechanism for extending error codes ]]		[[ Add mechanism for extending error codes ]]
	If the request lacks any authentication information (i.e. the client		If the request lacks any authentication information (i.e. the client
	was unaware authentication is necessary), the resource server SHOULD		was unaware authentication is necessary or attempted using an
	not include an error code or other error information.		unsupported authentication method), the resource server SHOULD not
			include an error code or other error information.
	For example:		For example:
	HTTP/1.1 401 Unauthorized		HTTP/1.1 401 Unauthorized
	WWW-Authenticate: Token realm='Example Service'		WWW-Authenticate: OAuth realm='Example Service'
	6. Extensibility		6. Extensibility
	6.1. Defining New Client Credentials Types		6.1. Defining New Client Credentials Types
	[[ TBD ]]		[[ TBD ]]
	6.2. Defining New Endpoint Parameters		6.2. Defining New Endpoint Parameters
	Applications that wish to define new request or response parameters		Applications that wish to define new request or response parameters
	skipping to change at page 33, line 47 ¶		skipping to change at page 34, line 48 ¶
	Parameters utilizing the "x_" parameter name prefix MUST be limited		Parameters utilizing the "x_" parameter name prefix MUST be limited
	to vendor-specific extensions that are not commonly applicable, and		to vendor-specific extensions that are not commonly applicable, and
	are specific to the implementation details of the authorization		are specific to the implementation details of the authorization
	server where they are used. All other new parameters MUST be		server where they are used. All other new parameters MUST be
	registered, and MUST NOT use the "x_" parameter name prefix.		registered, and MUST NOT use the "x_" parameter name prefix.
	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*fchar		param-name = 1*name-char
	fchar = "-" / "." / "_" / DIGIT / ALPHA		name-char = "-" / "." / "_" / DIGIT / ALPHA
	6.3. Defining New Header Field Parameters		6.3. Defining New Header Field Parameters
	Applications that wish to define new parameters for use in the OAuth		Applications that wish to define new parameters for use in the OAuth
	"Authorization" or "WWW-Authenticate" header fields MUST register		"Authorization" or "WWW-Authenticate" header fields MUST register
	them in the parameters registry, following the procedures in		them in the parameters registry, following the procedures in
	Section 8.1.		Section 8.1.
	Parameter names MUST conform to the param-name ABNF and MUST NOT		Parameter names MUST conform to the param-name ABNF and MUST NOT
	begin with "x_". Parameter values MUST conform to the param-value		begin with "x_". Parameter values MUST conform to the param-value
	ABNF and their syntax MUST be well-defined (e.g., using ABNF, or a		ABNF and their syntax MUST be well-defined (e.g., using ABNF, or a
	reference to the syntax of an existing parameter).		reference to the syntax of an existing parameter).
	param-value = ptoken | quoted-string		param-value = quoted-value | quoted-string
	6.4. Defining New Access Grant Types		6.4. Defining New Access Grant Types
	The assertion access grant type was designed to allow the		The assertion access grant type was designed to allow the
	authorization server to accept additional access grants not		authorization server to accept additional access grants not
	specified. Applications that wish to define additional access grant		specified. Applications that wish to define additional access grant
	types can do so by utilizing a new or existing assertion type and		types can do so by utilizing a new or existing assertion type and
	format.		format.
	7. Security Considerations		7. Security Considerations
	skipping to change at page 36, line 44 ¶		skipping to change at page 38, line 9 ¶
	Smith, Jeremy Suriel, and Franklin Tse.		Smith, Jeremy Suriel, and Franklin Tse.
	Appendix C. Acknowledgements		Appendix C. Acknowledgements
	[[ Add OAuth 1.0a authors + WG contributors ]]		[[ Add OAuth 1.0a authors + WG contributors ]]
	Appendix D. Document History		Appendix D. Document History
	[[ to be removed by RFC editor before publication as an RFC ]]		[[ to be removed by RFC editor before publication as an RFC ]]
			-10
			o Fixed typos. Many editorial changes. Rewrote introduction.
			removed terminology grouping.
			o Allowed POST for end-user authorization endpoint.
			o Fixed token endpoint to not require client authentication.
			o Made URI query and POST body 'oauth_token' parameter optional.
			o Moved all parameter names and values to use underscores.
			o Changed 'basic_credentials' to 'password',
			'invalid_client_credentials' and 'invalid_client_id' to
			'invalid_client'.
			o Added note that access token requests without an access grant
			should not include a refresh token.
			o Changed scheme name from 'Token' to 'OAuth', simplified request
			format to simple string for token instead of key=value pair (still
			supported for extensions).
			o Defined permitted access token string characters (suitable for
			inclusion in an HTTP header).
			o Added a note about conflicts with previous versions.
			o Moved 'client_id' definition from client authentication to access
			token endpoint.
	-09		-09
	o Fixed typos, editorial changes.		o Fixed typos, editorial changes.
	o Added token expiration example.		o Added token expiration example.
	o Added scope parameter to end-user authorization endpoint response.		o Added scope parameter to end-user authorization endpoint response.
	o Added note about parameters with empty values (same as omitted).		o Added note about parameters with empty values (same as omitted).
	skipping to change at page 41, line 29 ¶		skipping to change at page 43, line 20 ¶
	[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.
	[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an		[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
	IANA Considerations Section in RFCs", BCP 26, RFC 5226,		IANA Considerations Section in RFCs", BCP 26, RFC 5226,
	May 2008.		May 2008.
	[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security		[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
	(TLS) Protocol Version 1.2", RFC 5246, August 2008.		(TLS) Protocol Version 1.2", RFC 5246, August 2008.
			[RFC5849] Hammer-Lahav, E., "The OAuth 1.0 Protocol", RFC 5849,
			April 2010.
	[W3C.REC-html401-19991224]		[W3C.REC-html401-19991224]
	Hors, A., Jacobs, I., and D. Raggett, "HTML 4.01		Raggett, D., 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>.
	9.2. Informative References		9.2. Informative References
	[I-D.hammer-oauth]		[I-D.hammer-oauth]
	Hammer-Lahav, E., "The OAuth 1.0 Protocol",		Hammer-Lahav, E., "The OAuth 1.0 Protocol",
	draft-hammer-oauth-10 (work in progress), February 2010.		draft-hammer-oauth-10 (work in progress), February 2010.
End of changes. 118 change blocks.
	267 lines changed or deleted		375 lines changed or added
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