< draft-ietf-oauth-v2-05.txt		draft-ietf-oauth-v2-06.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		Intended status: Standards Track D. Recordon
	Expires: November 14, 2010 Facebook		Expires: December 11, 2010 Facebook
	D. Hardt		D. Hardt
	May 13, 2010		Microsoft
			June 9, 2010
	The OAuth 2.0 Protocol		The OAuth 2.0 Protocol
	draft-ietf-oauth-v2-05		draft-ietf-oauth-v2-06
	Abstract		Abstract
	This specification describes the OAuth 2.0 protocol. OAuth provides		This specification describes the OAuth 2.0 protocol. OAuth provides
	a method for making authenticated HTTP requests using a token - an		a method for making authenticated HTTP requests using a token - an
	identifier used to denote an access grant with specific scope,		string used to denote an access grant with specific scope, duration,
	duration, and other attributes. Tokens are issued to third-party		and other attributes. Tokens are issued to third-party clients by an
	clients by an authorization server with the approval of the resource		authorization server with the approval of the resource owner. OAuth
	owner. OAuth defines multiple flows for obtaining a token to support		defines multiple flows for obtaining a token to support a wide range
	a wide range of client types and user experience.		of client types and user experience.
	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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	Copyright Notice		Copyright Notice
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	Table of Contents		Table of Contents
	1. Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . 4		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
	2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4		1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
	2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5		1.2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 6
	2.2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 6		1.3. Example . . . . . . . . . . . . . . . . . . . . . . . . . 8
	2.3. Example . . . . . . . . . . . . . . . . . . . . . . . . . 8		1.4. Notational Conventions . . . . . . . . . . . . . . . . . . 8
	2.4. Notational Conventions . . . . . . . . . . . . . . . . . . 8		2. Obtaining an Access Token . . . . . . . . . . . . . . . . . . 8
	2.5. Conformance . . . . . . . . . . . . . . . . . . . . . . . 8		2.1. Client Credentials . . . . . . . . . . . . . . . . . . . . 9
	3. Obtaining an Access Token . . . . . . . . . . . . . . . . . . 9		2.2. End-User Endpoint . . . . . . . . . . . . . . . . . . . . 9
	3.1. Client Credentials . . . . . . . . . . . . . . . . . . . . 9		2.3. Token Endpoint . . . . . . . . . . . . . . . . . . . . . . 10
	3.2. End-User Endpoint . . . . . . . . . . . . . . . . . . . . 9		2.3.1. Client Authentication . . . . . . . . . . . . . . . . 10
	3.3. Token Endpoint . . . . . . . . . . . . . . . . . . . . . . 10		2.3.2. Response Format . . . . . . . . . . . . . . . . . . . 11
	3.3.1. Client Authentication . . . . . . . . . . . . . . . . 11		2.4. Flow Parameters . . . . . . . . . . . . . . . . . . . . . 14
	3.3.2. Response Format . . . . . . . . . . . . . . . . . . . 12		2.5. Web Server Flow . . . . . . . . . . . . . . . . . . . . . 14
	3.4. Flow Parameters . . . . . . . . . . . . . . . . . . . . . 14		2.5.1. Client Requests Authorization . . . . . . . . . . . . 16
	3.5. User-Agent Flow . . . . . . . . . . . . . . . . . . . . . 15		2.5.2. Client Requests Access Token . . . . . . . . . . . . . 18
	3.5.1. Client Requests Authorization . . . . . . . . . . . . 16		2.6. User-Agent Flow . . . . . . . . . . . . . . . . . . . . . 20
	3.5.2. Client Extracts Access Token . . . . . . . . . . . . . 19		2.6.1. Client Requests Authorization . . . . . . . . . . . . 22
	3.6. Web Server Flow . . . . . . . . . . . . . . . . . . . . . 20		2.6.2. Client Extracts Access Token . . . . . . . . . . . . . 25
	3.6.1. Client Requests Authorization . . . . . . . . . . . . 21		2.7. Device Flow . . . . . . . . . . . . . . . . . . . . . . . 25
	3.6.2. Client Requests Access Token . . . . . . . . . . . . . 24		2.7.1. Client Requests Authorization . . . . . . . . . . . . 27
	3.7. Device Flow . . . . . . . . . . . . . . . . . . . . . . . 25		2.7.2. Client Requests Access Token . . . . . . . . . . . . . 29
	3.7.1. Client Requests Authorization . . . . . . . . . . . . 27		2.8. Username and Password Flow . . . . . . . . . . . . . . . . 31
	3.7.2. Client Requests Access Token . . . . . . . . . . . . . 29		2.8.1. Client Requests Access Token . . . . . . . . . . . . . 32
	3.8. Username and Password Flow . . . . . . . . . . . . . . . . 31		2.9. Client Credentials Flow . . . . . . . . . . . . . . . . . 34
	3.8.1. Client Requests Access Token . . . . . . . . . . . . . 33		2.9.1. Client Requests Access Token . . . . . . . . . . . . . 35
	3.9. Client Credentials Flow . . . . . . . . . . . . . . . . . 35		2.10. Assertion Flow . . . . . . . . . . . . . . . . . . . . . . 36
	3.9.1. Client Requests Access Token . . . . . . . . . . . . . 35		2.10.1. Client Requests Access Token . . . . . . . . . . . . . 37
	3.10. Assertion Flow . . . . . . . . . . . . . . . . . . . . . . 37		2.11. Native Application Considerations . . . . . . . . . . . . 39
	3.10.1. Client Requests Access Token . . . . . . . . . . . . . 38		3. Refreshing an Access Token . . . . . . . . . . . . . . . . . . 40
	4. Refreshing an Access Token . . . . . . . . . . . . . . . . . . 40		4. Accessing a Protected Resource . . . . . . . . . . . . . . . . 42
	5. Accessing a Protected Resource . . . . . . . . . . . . . . . . 42		4.1. The Authorization Request Header . . . . . . . . . . . . . 43
	5.1. The Authorization Request Header . . . . . . . . . . . . . 43		4.2. URI Query Parameter . . . . . . . . . . . . . . . . . . . 44
	5.2. Bearer Token Requests . . . . . . . . . . . . . . . . . . 44		4.3. Form-Encoded Body Parameter . . . . . . . . . . . . . . . 44
	5.2.1. URI Query Parameter . . . . . . . . . . . . . . . . . 45		5. Identifying a Protected Resource . . . . . . . . . . . . . . . 45
	5.2.2. Form-Encoded Body Parameter . . . . . . . . . . . . . 45		5.1. The WWW-Authenticate Response Header . . . . . . . . . . . 45
	5.3. Cryptographic Tokens Requests . . . . . . . . . . . . . . 46		6. Security Considerations . . . . . . . . . . . . . . . . . . . 46
	5.3.1. The 'hmac-sha256' Algorithm . . . . . . . . . . . . . 47		7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 46
	6. Identifying a Protected Resource . . . . . . . . . . . . . . . 50		Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 46
	6.1. The WWW-Authenticate Response Header . . . . . . . . . . . 50		Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 47
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 51		Appendix C. Differences from OAuth 1.0a . . . . . . . . . . . . . 47
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 51		Appendix D. Document History . . . . . . . . . . . . . . . . . . 47
	9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 52		8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 49
	Appendix A. Differences from OAuth 1.0a . . . . . . . . . . . . . 52		8.1. Normative References . . . . . . . . . . . . . . . . . . . 49
	Appendix B. Document History . . . . . . . . . . . . . . . . . . 52		8.2. Informative References . . . . . . . . . . . . . . . . . . 50
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 53		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 51
	10.1. Normative References . . . . . . . . . . . . . . . . . . . 53
	10.2. Informative References . . . . . . . . . . . . . . . . . . 55
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 55
	1. Authors
	This specification was authored with the participation and based on
	the work of Allen Tom (Yahoo!), Brian Eaton (Google), Brent Goldman
	(Facebook), Luke Shepard (Facebook), Raffi Krikorian (Twitter), and
	Yaron Goland (Microsoft).
	2. 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). In the traditional client-server		username and password). In the traditional client-server
	authentication model, a client accessing a protected resource on a		authentication model, a client accessing a protected resource on a
	server presents the resource owner's credentials in order to		server presents the resource owner's credentials in order to
	authenticate and gain access.		authenticate and gain access.
	skipping to change at page 4, line 37 ¶		skipping to change at page 4, line 30 ¶
	duration, or to limit access to the HTTP methods supported by these		duration, or to limit access to the HTTP methods supported by these
	resources.		resources.
	OAuth provides a method for making authenticated HTTP requests using		OAuth provides a method for making authenticated HTTP requests using
	a token - an identifier used to denote an access grant with specific		a token - an identifier used to denote an access grant with specific
	scope, duration, and other attributes. Tokens are issued to third-		scope, duration, and other attributes. Tokens are issued to third-
	party clients by an authorization server with the approval of the		party clients by an authorization server with the approval of the
	resource owner. Instead of sharing their credentials with the		resource owner. Instead of sharing their credentials with the
	client, resource owners grant access by authenticating directly with		client, resource owners grant access by authenticating directly with
	the authorization server which in turn issues a token to the client.		the authorization server which in turn issues a token to the client.
	The client uses the token (and optional secret) to authenticate with		The client uses the token to authenticate with the resource server
	the resource server and gain access.		and gain access.
	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		the photo sharing service (authorization server) which issues the
	printing service delegation-specific credentials (token).		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 1.0 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.
	2.1. Terminology		1.1. Terminology
	resource server		resource server
	An HTTP [RFC2616] server capable of accepting authenticated		An HTTP [RFC2616] server capable of accepting authenticated
	resource requests using the OAuth protocol.		resource requests using the OAuth protocol.
	protected resource		protected resource
	An access-restricted resource which can be obtained from a		An access-restricted resource which can be obtained from a
	resource server using an OAuth-authenticated request.		resource server using an OAuth-authenticated request.
	client		client
	An HTTP client capable of making authenticated requests for		An HTTP client capable of making authenticated requests for
	protected resources using the OAuth protocol.		protected resources using the OAuth protocol.
	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
			A string representing an access grant issued to the client.
			The string is usually opaque to the client and can self-contain
			the authorization information in a verifiable manner (i.e.
			signed), or denotes an identifier used to retrieve the
			authorization information.
	access token		access token
	A unique identifier used by the client to make authenticated		A token used by the client to make authenticated requests on
	requests on behalf of the resource owner. Access tokens may		behalf of the resource owner.
	have a matching secret.
	bearer token An access token without a matching secret, used to		refresh token
	obtain access to a protected resource by simply presenting the		A token used by the client to replace an expired access token
	access token as-is to the resource server.		with a new access token without having to involve the resource
			owner. A refresh token is used when the access token is valid
			for a shorter time period than the duration of the access grant
			approved by the resource owner.
	authorization server		authorization server
	An HTTP server capable of issuing tokens after successfully		An HTTP 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 endpoint		end-user endpoint
	The authorization server's HTTP endpoint capable of		The authorization server's HTTP endpoint capable of
	authenticating the end-user and obtaining authorization.		authenticating the end-user and obtaining authorization.
	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.		tokens and refreshing expired tokens.
	client identifier		client identifier
	An unique identifier issued to the client to identify itself to		An 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.		matching secret.
	refresh token		1.2. Overview
	A unique identifier used by the client to replace an expired
	access token with a new access token without having to involve
	the resource owner. A refresh token is used when the access
	token is valid for a shorter time period than the duration of
	the access grant approved by the resource owner.
	2.2. Overview
	Clients interact with a protected resource, first by requesting		Clients interact with a protected resource, first by requesting
	access (which is granted in the form of an access token) from the		access (which is granted in the form of an access token) from the
	authorization server, and then by authenticating with the resource		authorization server, and then by authenticating with the resource
	server by presenting the access token. Figure 1 demonstrates the		server by presenting the access token. Figure 1 demonstrates the
	flow between the client and authorization server (A, B), and the flow		flow between the client and authorization server (A, B), and the flow
	between the client and resource server (C, D), when the client is		between the client and resource server (C, D), when the client is
	acting autonomously (the client is also the resource owner).		acting autonomously (the client is also the resource owner).
	+--------+ +---------------+		+--------+ +---------------+
	skipping to change at page 6, line 34 ¶		skipping to change at page 6, line 32 ¶
	| | | Server |		| | | Server |
	| |<-(B)------ Access Token ---------| |		| |<-(B)------ Access Token ---------| |
	| | (w/ Optional Refresh Token) +---------------+		| | (w/ Optional Refresh Token) +---------------+
	| Client |		| Client |
	| | HTTP Request +---------------+		| | HTTP Request +---------------+
	| |--(C)--- with Access Token ------>| Resource |		| |--(C)--- with Access Token ------>| Resource |
	| | | Server |		| | | Server |
	| |<-(D)------ HTTP Response --------| |		| |<-(D)------ HTTP Response --------| |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 1		Figure 1: Generic Client-Server Flow
	Access token strings can use any internal structure agreed upon		Access token strings can use any internal structure agreed upon
	between the authorization server and the resource server, but their		between the authorization server and the resource server, but their
	structure is opaque to the client. Since the access token provides		structure is opaque to the client. Since the access token provides
	the client access to the protected resource for the life of the		the client access to the protected resource for the life of the
	access token (or until revoked), the authorization server should		access token (or until revoked), the authorization server should
	issue access tokens which expire within an appropriate time, usually		issue access tokens which expire within an appropriate time, usually
	much shorter than the duration of the access grant.		much shorter than the duration of the access grant.
	When an access token expires, the client can request a new access		When an access token expires, the client can request a new access
	token from the authorization server by presenting its credentials		token from the authorization server by presenting its credentials
	again (Figure 1), or by using the refresh token (if issued with the		again (Figure 1), or by using the refresh token (if issued with the
	access token) as shown in Figure 2. Once an expired access token has		access token) as shown in Figure 2. Once an expired access token has
	been replaced with a new access token (A, B), the client uses the new		been replaced with a new access token (A, B), the client uses the new
	access token as before (C, D).		access token as before (C, D).
	+--------+ +---------------+		+--------+ +---------------+
	| |--(A)------ Refresh Token ------->| Authorization |		| |--(A)------ Refresh Token ------->| Authorization |
	| | | Server |		| | | Server |
	| |<-(B)------ Access Token ---------| |		| |<-(B)------ Access Token ---------| |
	| | (with Optional Secret) +---------------+		| | +---------------+
	| Client |		| Client |
	| | HTTP Request +---------------+		| | HTTP Request +---------------+
	| |--(C)--- with Access Token ------>| Resource |		| |--(C)--- with Access Token ------>| Resource |
	| | | Server |		| | | Server |
	| |<-(D)----- HTTP Response ---------| |		| |<-(D)----- HTTP Response ---------| |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 2		Figure 2: Refreshing an Access Token
	This specification defines a number of authorization flows to support		This specification defines a number of authorization flows to support
	different client types and scenarios. These authorization flows can		different client types and scenarios. These authorization flows can
	be separated into three groups: user delegation flows, direct		be separated into three groups: user delegation flows, direct
	credentials flows, and autonomous flows.		credentials flows, and autonomous flows.
	Additional authorization flows may be defined by other specifications		Additional authorization flows may be defined by other specifications
	to cover different scenarios and client types.		to cover different scenarios and client types.
	User delegation flows are used to grant client access to protected		User delegation flows are used to grant client access to protected
	resources by the end-user without sharing the end-user credentials		resources by the end-user without sharing the end-user credentials
	(e.g. a username and password) with the client. Instead, the end-		(e.g. a username and password) with the client. Instead, the end-
	user authenticates directly with the authorization server, and grants		user authenticates directly with the authorization server, and grants
	client access to its protected resources. The user delegation flows		client access to its protected resources. The user delegation flows
	defined by this specifications are:		defined by this specifications are:
	o User-Agent Flow - This flow is designed for clients running inside
	a user-agent (typically a web browser). This flow is described in
	Section 3.5.
	o Web Server Flow - This flow is optimized for clients that are part		o Web Server Flow - This flow is optimized for clients that are part
	of a web server application, accessible via HTTP requests. This		of a web server application, accessible via HTTP requests. This
	flow is described in Section 3.6.		flow is described in Section 2.5.
			o User-Agent Flow - This flow is designed for clients running inside
			a user-agent (typically a web browser). This flow is described in
			Section 2.6.
	o Device Flow - This flow is suitable for clients executing on		o Device Flow - This flow is suitable for clients executing on
	limited devices, but where the end-user has separate access to a		limited devices, but where the end-user has separate access to a
	user-agent on another computer or device. This flow is described		user-agent on another computer or device. This flow is described
	in Section 3.7.		in Section 2.7.
	Direct credentials flows enable clients to obtain an access token		Direct credentials flows enable clients to obtain an access token
	with a single request using the client credentials or end-user		with a single request using the client credentials or end-user
	credentials without seeking additional resource owner authorization.		credentials without seeking additional resource owner authorization.
	The direct credentials flows defined by this specification are:		The direct credentials flows defined by this specification are:
	o Username and Password Flow - This flow is used in cases where the		o Username and Password Flow - This flow is used in cases where the
	end-user trusts the client to handle its credentials but it is		end-user trusts the client to handle its credentials but it is
	still undesirable for the client to store the end-user's username		still undesirable for the client to store the end-user's username
	and password. This flow is only suitable when there is a high		and password. This flow is only suitable when there is a high
	degree of trust between the end-user and the client. This flow is		degree of trust between the end-user and the client. This flow is
	described in Section 3.8.		described in Section 2.8.
	o Client Credentials Flow - The client uses its credentials to		o Client Credentials Flow - The client uses its credentials to
	obtain an access token. This flow is described in Section 3.9.		obtain an access token. This flow is described in Section 2.9.
	Autonomous flows enable clients to use utilize existing trust		Autonomous flows enable clients to use utilize existing trust
	relationships or different authorization constructs to obtain an		relationships or different authorization constructs to obtain an
	access token. They provide a bridge between OAuth and other trust		access token. They provide a bridge between OAuth and other trust
	frameworks. The autonomous authorization flow defined by this		frameworks. The autonomous authorization flow defined by this
	specifications is:		specifications is:
	o Assertion Flow - The client presents an assertion such as a SAML		o Assertion Flow - The client presents an assertion such as a SAML
	[OASIS.saml-core-2.0-os] assertion to the authorization server in		[OASIS.saml-core-2.0-os] assertion to the authorization server in
	exchange for an access token. This flow is described in		exchange for an access token. This flow is described in
	Section 3.10.		Section 2.10.
	2.3. Example		1.3. Example
	[[ Todo ]]		[[ Todo ]]
	2.4. Notational Conventions		1.4. 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].
	This document uses the Augmented Backus-Naur Form (ABNF) notation of		This document uses the Augmented Backus-Naur Form (ABNF) notation of
	[I-D.ietf-httpbis-p1-messaging]. Additionally, the realm and auth-		[I-D.ietf-httpbis-p1-messaging]. Additionally, the realm and auth-
	param rules are included from [RFC2617], and the URI-Reference rule		param rules are included from [RFC2617], and the URI-Reference rule
	from [RFC3986].		from [RFC3986].
	2.5. Conformance		2. Obtaining an Access Token
	An implementation is not compliant if it fails to satisfy one or more
	of the MUST or REQUIRED level requirements for the flows it
	implements. An implementation that satisfies all the MUST or
	REQUIRED level and all the SHOULD level requirements for its flows is
	said to be "unconditionally compliant"; one that satisfies all the
	MUST level requirements but not all the SHOULD level requirements for
	its flows is said to be "conditionally compliant."
	3. Obtaining an Access Token
	The client obtains an access token by using one of the authorization		The client obtains an access token by using one of the authorization
	flows supported by the authorization server. The authorization flows		flows supported by the authorization server. The authorization flows
	all use the same authorization and token endpoints, each with a		all use the same authorization and token endpoints, each with a
	different set of request parameters and values.		different set of request parameters and values.
	Access tokens have a scope, duration, and other access attributes		Access tokens have a scope, duration, and other access attributes
	granted by the resource owner. These attributes MUST be enforced by		granted by the resource owner. These attributes MUST be enforced by
	the resource server when receiving a protected resource request, and		the resource server when receiving a protected resource request, and
	by the authorization server when receiving a token refresh request.		by the authorization server when receiving a token refresh request.
	In many cases it is desirable to issue access tokens with a shorter		In many cases it is desirable to issue access tokens with a shorter
	lifetime than the duration of the authorization grant. However, it		lifetime than the duration of the authorization grant. However, it
	may be undesirable to require the resource owner to authorize the		may be undesirable to require the resource owner to authorize the
	request again. Instead, the authorization server issues a refresh		request again. Instead, the authorization server issues a refresh
	token in addition to the access token. When the access token		token in addition to the access token. When the access token
	expires, the client can request a new access token without involving		expires, the client can request a new access token without involving
	the resource owner as long as the authorization grant is still valid.		the resource owner as long as the authorization grant is still valid.
	The token refresh method is described in Section 4.		The token refresh method is described in Section 3.
	3.1. Client Credentials		2.1. Client Credentials
	When requesting access from the authorization server, the client		When requesting access from the authorization server, the client
	identifies itself using a set of client credentials. The client		identifies itself using a set of client credentials. The client
	credentials include a client identifier and an OPTIONAL symmetric		credentials include a client identifier and an OPTIONAL symmetric
	shared secret. The means through which the client obtains these		shared secret. The means through which the client obtains these
	credentials are beyond the scope of this specification, but usually		credentials are beyond the scope of this specification, but usually
	involve registration with the authorization server.		involve registration with the authorization server.
	The client identifier is used by the authorization server to		The client identifier is used by the authorization server to
	establish the identity of the client for the purpose of presenting		establish the identity of the client for the purpose of presenting
	skipping to change at page 9, line 48 ¶		skipping to change at page 9, line 36 ¶
	as for providing different service levels to different clients. They		as for providing different service levels to different clients. They
	can also be used to block unauthorized clients from requesting		can also be used to block unauthorized clients from requesting
	access.		access.
	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 credentials
	without establishing trust with the client operator. Authorization		without establishing trust with the client operator. Authorization
	servers SHOULD NOT issue client secrets to clients incapable of		servers SHOULD NOT issue client secrets to clients incapable of
	keeping their secrets confidential.		keeping their secrets confidential.
	3.2. End-User Endpoint		2.2. End-User Endpoint
	In flows that involved an end-user, clients direct the end-user to		In flows that involved an end-user, clients direct the end-user to
	the end-user endpoint to approve their access request. When		the end-user endpoint to approve their access request. When
	accessing the end-user endpoint, the end-user first authenticates		accessing the end-user endpoint, the end-user first authenticates
	with the authorization server, and then approves or denies the access		with the authorization server, and then approves or denies the access
	request.		request.
	The way in which the authorization server authenticates the end-user		The way in which the authorization server authenticates the end-user
	(e.g. username and password login, OpenID, session cookies) and in		(e.g. username and password login, OpenID, session cookies) and in
	which the authorization server obtains the end-user's authorization,		which the authorization server obtains the end-user's authorization,
	including whether it uses a secure channel such as TLS/SSL, is beyond		including whether it uses a secure channel such as TLS, is beyond the
	the scope of this specification. However, the authorization server		scope of this specification. However, the authorization server MUST
	MUST first verify the identity of the end-user.		first verify the identity of the end-user.
	The URI of the end-user endpoint can be found in the service		The URI of the end-user endpoint can be found in the service
	documentation, or can be obtained by the client by making an		documentation, or can be obtained by using [[ OAuth Discovery ]].
	unauthorized protected resource request (from the "WWW-Authenticate"
	response header "user-uri" attribute as described by Section 5.1).
	The end-user endpoint advertised by the resource server MAY include a		The end-user endpoint advertised by the resource server MAY include a
	query component as defined by [RFC3986] section 3, which must be		query component as defined by [RFC3986] section 3, which must be
	retained when adding additional query parameters.		retained when adding additional query parameters.
	Since requests to the end-user endpoint result in user authentication		Since requests to the end-user endpoint result in user authentication
	and the transmission of sensitive values, the authorization server		and the transmission of sensitive values, the authorization server
	SHOULD require the use of a transport-layer mechanism such as TLS/SSL		SHOULD require the use of a transport-layer mechanism such as TLS
	(or a secure channel with equivalent protections) when sending		when sending requests to the end-user endpoint.
	requests to the end-user endpoint.
	3.3. Token Endpoint		2.3. Token Endpoint
	After obtaining authorization from the resource owner, clients		After obtaining authorization from the resource owner, clients
	request an access token from the authorization server's token		request an access token from the authorization server's token
	endpoint.		endpoint.
	The URI of the token endpoint can be found in the service		The URI of the token endpoint can be found in the service
	documentation, or can be obtained by the client by making an		documentation, or can be obtained by using [[ OAuth Discovery ]].
	unauthorized protected resource request (from the "WWW-Authenticate"
	response header "token-uri" attribute as described by Section 5.1).
	The token endpoint advertised by the resource server MAY include a		The token endpoint advertised by the resource server MAY include a
	query component as defined by [RFC3986] section 3.		query component as defined by [RFC3986] section 3.
	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
	mechanism such as TLS/SSL (or a secure channel with equivalent		mechanism when sending requests to the token endpoints. Servers MUST
	protections) when sending requests to the token endpoints.		support TLS 1.2 as defined in [RFC5246] and MAY support addition
			mechanisms with equivalent protections.
	3.3.1. Client Authentication		2.3.1. Client Authentication
	The token endpoint requires the client to authenticate itself to the		The token endpoint requires the client to authenticate itself to the
	authorization server. This is done by including the client		authorization server. This is done by including the client
	identifier (and optional secret) in the request. The client		identifier (and optional secret) in the request. The client
	identifier and secret are included in the request using two request		identifier and secret are included in the request using two request
	parameters: "client_id" and "client_secret".		parameters: "client_id" and "client_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&		type=web_server&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 client MAY include the client credentials using an HTTP		The client MAY include the client credentials using an HTTP
	authentication scheme instead of using the "client_id" and		authentication scheme which supports authenticating using a username
	"client_secret" request parameters. Including the client credentials		and password, instead of using the "client_id" and "client_secret"
	using an HTTP authentication scheme fullfills the requirements of		request parameters. Including the client credentials using an HTTP
	including the parameters as defined by the various flows. The client		authentication scheme fulfills the requirements of including the
	MUST NOT include the client credentials using more than one		parameters as defined by the various flows.
	mechanism.
			The client MUST NOT include the client credentials using more than
			one mechanism. If more than one mechanism is used, regardless if the
			credentials are identical, the server MUST reply with an HTTP 400
			status code (Bad Request) and include the "multiple-credentials"
			error message.
	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 scheme		both the request parameters, and the HTTP Basic authentication scheme
	as defined in [RFC2617]. The authorization server MAY support		as defined in [RFC2617]. The authorization server MAY support
	additional HTTP authentication schemes.		additional HTTP authentication schemes.
	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&		type=web_server&code=i1WsRn1uB1&
	redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb		redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb
	3.3.2. Response Format		2.3.2. Response Format
	Authorization servers respond to client requests by including a set		Authorization servers respond to client requests by including a set
	of response parameters in the entity body of the HTTP response. The		of response parameters in the entity body of the HTTP response. The
	response uses one of three formats based on the format requested by		response uses one of three formats based on the format requested by
	the client (using the "format" request parameter):		the client (using the "format" request parameter or the HTTP "Accept"
			header field):
	o The "application/json" media type as defined by [RFC4627]. The		o 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		parameter at the highest structure level. Parameter names and
	string values are included as JSON strings. Numerical values are		string values are included as JSON strings. Numerical values are
	included as JSON numbers.		included as JSON numbers.
	For example:		For example:
	{		{
	skipping to change at page 12, line 41 ¶		skipping to change at page 12, line 28 ¶
	For example:		For example:
	<?xml version='1.0' encoding="utf-8"?>		<?xml version='1.0' encoding="utf-8"?>
	<OAuth>		<OAuth>
	<access_token>SlAV32hkKG</access_token>		<access_token>SlAV32hkKG</access_token>
	<expires_in>3600</expires_in>		<expires_in>3600</expires_in>
	<refresh_token>8xLOxBtZp8</refresh_token>		<refresh_token>8xLOxBtZp8</refresh_token>
	</OAuth>		</OAuth>
	o The "application/x-www-form-urlencoded" media type as defined by		o The "application/x-www-form-urlencoded" media type as defined by
	[W3C.REC-html40-19980424].		[W3C.REC-html401-19991224].
	For example (line breaks are for display purposes only):		For example (line breaks are for display purposes only):
	access_token=SlAV32hkKG&expires_in=3600&		access_token=SlAV32hkKG&expires_in=3600&
	refresh_token=8xLOxBtZp8		refresh_token=8xLOxBtZp8
	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
	containing tokens, secrets, or other sensitive information.		containing tokens, secrets, or other sensitive information.
	3.3.2.1. Access Token Response		2.3.2.1. 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 (as described in each of the flows below),		request from the client (as described in each of the flows below),
	the authorization server constructs the response using the format		the authorization server constructs the response using the format
	requested by the client, which includes the common parameters set as		requested by the client, which includes the parameters listed below,
	well as additional flow-specific parameters. The formatted		as well as additional flow-specific parameters. The formatted
	parameters are sent to the client in the entity body of the HTTP		parameters are sent to the client in the entity body of the HTTP
	response with a 200 status code (OK).		response with a 200 status code (OK).
	The token response contains the following common parameters:		The token response contains the following common parameters:
	access_token		access_token
	REQUIRED. The access token issued by the authorization server.		REQUIRED. The access token issued by the authorization server.
	expires_in		expires_in
	OPTIONAL. The duration in seconds of the access token		OPTIONAL. The duration in seconds of the access token
	lifetime.		lifetime.
	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 Section 4.		using the same end-user access grant as described in Section 3.
	access_token_secret
	REQUIRED if requested by the client. The corresponding access
	token secret as requested by the client.
	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.
	For example:		For example:
	skipping to change at page 14, line 17 ¶		skipping to change at page 13, line 39 ¶
	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"
	}		}
	3.3.2.2. Error Response		2.3.2.2. Error Response
	If the token request is invalid or unauthorized, the authorization		If the token request is invalid or unauthorized, the authorization
	server constructs a JSON-formatted response which includes the common		server constructs the response using the format requested by the
	parameters set as well as additional flow-specific parameters. The		client which includes the parameters listed below, as well as
	formatted parameters are sent to the client in the entity body of the		additional flow-specific parameters. The formatted parameters are
	HTTP response with a 400 status code (Bad Request).		sent to the client in the entity body of the HTTP response with a 400
			status code (Bad Request).
	The response contains the following common parameter:		The response contains the following common parameter:
	error		error
	REQUIRED. The parameter value MUST be set to one of the values		REQUIRED. The parameter value MUST be set to one of the values
	specified by each flow.		specified by each flow.
	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":"incorrect_client_credentials"		"error":"incorrect_client_credentials"
	}		}
	3.4. Flow Parameters		2.4. Flow Parameters
	The sizes of tokens and other values received from the authorization		The sizes of tokens and other values received from the authorization
	server, are left undefined by this specification. Clients should		server, are left undefined by this specification. Clients should
	avoid making assumptions about value sizes. Servers should document		avoid making assumptions about value sizes. Servers should document
	the expected size of any value they issue.		the expected size of any value they issue.
	Unless otherwise noted, all the protocol parameter names and values		Unless otherwise noted, all the protocol parameter names and values
	are case sensitive.		are case sensitive.
	3.5. User-Agent Flow		2.5. Web Server Flow
	The user-agent flow is a user delegation flow suitable for client
	applications residing in a user-agent, typically implemented in a
	browser using a scripting language such as JavaScript. These clients
	cannot keep client secrets confidential and the authentication of the
	client is based on the user-agent's same-origin policy.
	Unlike other flows in which the client makes separate authorization
	and access token requests, the client received the access token as a
	result of the authorization request in the form of an HTTP
	redirection. The client requests the authorization server to
	redirect the user-agent to another web server or local resource
	accessible to the browser which is capable of extracting the access
	token from the response and passing it to the client.
	This user-agent flow does not utilize the client secret since the
	client executables reside on the end-user's computer or device which
	makes the client secret accessible and exploitable. Because the
	access token is encoded into the redirection URI, it may be exposed
	to the end-user and other applications residing on the computer or
	device.
	+----------+ Client Identifier +----------------+
	| |>---(A)-- & Redirection URI --->| |
	| | | |
	End <--+ - - - +----(B)-- User authenticates -->| Authorization |
	User | | | Server |
	| |<---(C)-- Redirect URI --------<| |
	| Client | with Access Token | |
	| in | (w/ Optional Refresh Token) +----------------+
	| Browser | in Fragment
	| | +----------------+
	| |>---(D)-- Redirect URI -------->| |
	| | without Fragment | Web Server |
	| | | with Client |
	| (F) |<---(E)-- Web Page with -------<| Resource |
	| Access | Script | |
	| Token | +----------------+
	+----------+
	Figure 3
	The user-agent flow illustrated in Figure 3 includes the following
	steps:
	(A) The client sends the user-agent to the authorization server and
	includes its client identifier and redirection URI in the
	request.
	(B) The authorization server authenticates the end-user (via the
	user-agent) and establishes whether the end-user grants or
	denies the client's access request.
	(C) Assuming the end-user granted access, the authorization server
	redirects the user-agent to the redirection URI provided
	earlier. The redirection URI includes the access token in the
	URI fragment.
	(D) The user-agent follows the redirection instructions by making a
	request to the web server which does not include the fragment.
	The user-agent retains the fragment information locally.
	(E) The web server returns a web page containing a script capable of
	extracting the access token from the URI fragment retained by
	the user-agent.
	(F) The user-agent executes the script provided by the web server
	which extracts the access token and passes it to the client.
	3.5.1. Client Requests Authorization
	In order for the end-user to grant the client access, the client
	sends the end-user to the authorization server. The client
	constructs the request URI by adding the following URI query
	parameters to the end-user endpoint URI:
	type
	REQUIRED. The parameter value MUST be set to "user_agent".
	client_id
	REQUIRED. The client identifier as described in Section 3.1.
	redirect_uri
	REQUIRED unless a redirection URI has been established between
	the client and authorization server via other means. An
	absolute URI to which the authorization server will redirect
	the user-agent to when the end-user authorization step is
	completed. The authorization server SHOULD require the client
	to pre-register their redirection URI. Authorization servers
	MAY restrict the redirection URI to not include a query
	component as defined by [RFC3986] section 3.
	state
	OPTIONAL. An opaque value used by the client to maintain state
	between the request and callback. The authorization server
	includes this value when redirecting the user-agent back to the
	client.
	scope
	OPTIONAL. The scope of the access request expressed as a list
	of space-delimited strings. The value of the "scope" parameter
	is defined by the authorization server. If the value contains
	multiple space-delimited strings, their order does not matter,
	and each string adds an additional access range to the
	requested scope.
	immediate
	OPTIONAL. The parameter value must be set to "true" or
	"false". If set to "true", the authorization server MUST NOT
	prompt the end-user to authenticate or approve access.
	Instead, the authorization server attempts to establish the
	end-user's identity via other means (e.g. browser cookies) and
	checks if the end-user has previously approved an identical
	access request by the same client and if that access grant is
	still active. If the authorization server does not support an
	immediate check or if it is unable to establish the end-user's
	identity or approval status, it MUST deny the request without
	prompting the end-user. Defaults to "false" if omitted.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	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-
	user's user-agent. The request MUST use the HTTP "GET" method.
	For example, the client directs the end-user's user-agent to make the
	following HTTPS request (line breaks are for display purposes only):
	GET /authorize?type=user_agent&client_id=s6BhdRkqt3&
	redirect_uri=https%3A%2F%2FEexample%2Ecom%2Frd HTTP/1.1
	Host: server.example.com
	If the client has previously registered a redirection URI with the
	authorization server, the authorization server MUST verify that the
	redirection URI received matches the registered URI associated with
	the client identifier.
	The authorization server authenticates the end-user and obtains an
	authorization decision (by asking the end-user or establishing
	approval via other means). The authorization server sends the end-
	user's user-agent to the provided client redirection URI using an
	HTTP redirection response.
	3.5.1.1. End-user Grants Authorization
	If the end-user authorizes the access request, the authorization
	server issues an access token and delivers it to the client by adding
	the following parameters, using the
	"application/x-www-form-urlencoded" format as defined by
	[W3C.REC-html40-19980424], to the redirection URI fragment:
	access_token
	REQUIRED. The access token.
	expires_in
	OPTIONAL. The duration in seconds of the access token
	lifetime.
	refresh_token
	OPTIONAL. The refresh token.
	state
	REQUIRED if the "state" parameter was present in the client
	authorization request. Set to the exact value received from
	the client.
	access_token_secret
	REQUIRED if requested by the client. The corresponding access
	token secret as requested by the client.
	For example, the authorization server redirects the end-user's user-
	agent by sending the following HTTP response:
	HTTP/1.1 302 Found
	Location: http://example.com/rd#access_token=FJQbwq9&expires_in=3600
	3.5.1.2. End-user Denies Authorization
	If the end-user denied the access request, the authorization server
	responds to the client by adding the following parameters, using the
	"application/x-www-form-urlencoded" format as defined by
	[W3C.REC-html40-19980424], to the redirection URI fragment:
	error
	REQUIRED. The parameter value MUST be set to "user_denied".
	state
	REQUIRED if the "state" parameter was present in the client
	authorization request. Set to the exact value received from
	the client.
	For example, the authorization server responds with the following:
	HTTP/1.1 302 Found
	Location: http://example.com/rd#error=user_denied
	The authorization flow concludes unsuccessfully. To extract the
	error message, the client follows the steps described in
	Section 3.5.2.
	3.5.2. Client Extracts Access Token
	The user-agent follows the authorization server redirection response
	by making an HTTP "GET" request to the URI received in the "Location"
	HTTP response header. The user-agent SHALL NOT include the fragment
	component with the request.
	For example, the user-agent makes the following HTTP "GET" request in
	response to the redirection directive received from the authorization
	server:
	GET /rd HTTP/1.1
	Host: example.com
	The HTTP response to the redirection request returns a web page
	(typically an HTML page with an embedded script) capable of accessing
	the full redirection URI including the fragment retained by the user-
	agent, and extracting the access token (and other parameters)
	contained in the fragment.
	3.6. Web Server Flow
	The web server flow is a user delegation flow suitable for clients		The web server flow is a user delegation flow suitable for clients
	capable of interacting with the end-user's user-agent (typically a		capable of interacting with the end-user's user-agent (typically a
	web browser) and capable of receiving incoming requests from the		web browser) and capable of receiving incoming requests from the
	authorization server (capable of acting as an HTTP server).		authorization server (capable of acting as an HTTP server).
	+----------+ Client Identifier +---------------+		+----------+ Client Identifier +---------------+
	| -+----(A)-- & Redirect URI ------->| |		| -+----(A)-- & Redirect URI ------->| |
	| End-user | | Authorization |		| End-user | | Authorization |
	| at |<---(B)-- User authenticates --->| Server |		| at |<---(B)-- User authenticates --->| Server |
	skipping to change at page 20, line 31 ¶		skipping to change at page 15, line 24 ¶
	| | | |		| | | |
	^ v | |		^ v | |
	+---------+ | |		+---------+ | |
	| |>---(D)-- Client Credentials, --------' |		| |>---(D)-- Client Credentials, --------' |
	| Web | Verification Code, |		| Web | Verification Code, |
	| Client | & Redirect URI |		| Client | & Redirect URI |
	| | |		| | |
	| |<---(E)------- Access Token -----------------'		| |<---(E)------- Access Token -----------------'
	+---------+ (w/ Optional Refresh Token)		+---------+ (w/ Optional Refresh Token)
	Figure 4		Figure 3: Web Server Flow
	The web server flow illustrated in Figure 4 includes the following		The web server flow illustrated in Figure 3 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 endpoint with its client identifier		user-agent to the end-user endpoint with its client identifier
	and a redirect URI to which the authorization server will send		and a redirect URI to which the authorization server will send
	the end-user back once authorization is received (or denied).		the end-user back once authorization is received (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.
	skipping to change at page 21, line 13 ¶		skipping to change at page 16, line 5 ¶
	code for the client to use to obtain an access token.		code for the client to use to obtain an access token.
	(D) The client requests an access token from the authorization		(D) The client requests an access token from the authorization
	server by including its client credentials (identifier and		server by including its client credentials (identifier and
	secret), as well as the verification code received in the		secret), as well as the verification code received in the
	previous step.		previous step.
	(E) The authorization server validates the client credentials and		(E) The authorization server validates the client credentials and
	the verification code and responds back with the access token.		the verification code and responds back with the access token.
	3.6.1. Client Requests Authorization		2.5.1. Client Requests Authorization
	In order for the end-user to grant the client access, the client		In order for the end-user to grant the client access, the client
	sends the end-user to the authorization server. The client		sends the end-user to the authorization server. The client
	constructs the request URI by adding the following URI query		constructs the request URI by adding the following URI query
	parameters to the end-user endpoint URI:		parameters to the end-user endpoint URI:
	type		type
	REQUIRED. The parameter value MUST be set to "web_server".		REQUIRED. The parameter value MUST be set to "web_server".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	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
	the user-agent to when the end-user authorization step is		the user-agent to when the end-user authorization step is
	completed. The authorization server MAY require the client to		completed. The authorization server MAY require the client to
	pre-register their redirection URI. Authorization servers MAY		pre-register their redirection URI. Authorization servers MAY
	restrict the redirection URI to not include a query component		restrict the redirection URI to not include a query component
	as defined by [RFC3986] section 3.		as defined by [RFC3986] section 3.
	skipping to change at page 22, line 41 ¶		skipping to change at page 17, line 29 ¶
	redirection URI received matches the registered URI associated with		redirection URI received matches the registered URI associated with
	the client identifier.		the client identifier.
	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 establishing		authorization decision (by asking the end-user or establishing
	approval via other means). The authorization server sends the end-		approval via other means). The authorization server sends the end-
	user's user-agent to the provided client redirection URI using an		user's user-agent to the provided client redirection URI using an
	HTTP redirection response, or by other means available to it via the		HTTP redirection response, or by other means available to it via the
	end-user's user-agent.		end-user's user-agent.
	3.6.1.1. End-user Grants Authorization		2.5.1.1. End-user Grants Authorization
	If the end-user authorizes the access request, the authorization		If the end-user authorizes the access request, the authorization
	server generates a verification code and associates it with the		server generates a verification code and associates it with the
	client identifier and redirection URI. The authorization server		client identifier and redirection URI. The authorization server
	constructs the request URI by adding the following parameters to the		constructs the request URI by adding the following parameters to the
	query component of redirection URI provided by the client:		query component of redirection URI provided by the client:
	code		code
	REQUIRED. The verification code generated by the authorization		REQUIRED. The verification code generated by the authorization
	server.		server.
	skipping to change at page 23, line 29 ¶		skipping to change at page 18, line 17 ¶
	HTTP/1.1 302 Found		HTTP/1.1 302 Found
	Location: https://client.example.com/cb?code=i1WsRn1uB1		Location: https://client.example.com/cb?code=i1WsRn1uB1
	In turn, the end-user's user-agent makes the following HTTPS "GET"		In turn, the end-user's user-agent makes the following HTTPS "GET"
	request:		request:
	GET /cb?code=i1WsRn1uB1 HTTP/1.1		GET /cb?code=i1WsRn1uB1 HTTP/1.1
	Host: client.example.com		Host: client.example.com
	3.6.1.2. End-user Denies Authorization		2.5.1.2. End-user Denies Authorization
	If the end-user denied the access request, the authorization server		If the end-user denied the access request, the authorization server
	constructs the request URI by adding the following parameters to the		constructs the request URI by adding the following parameters to the
	query component of the redirection URI provided by the client:		query component of the redirection URI provided by the client:
	error		error
	REQUIRED. The parameter value MUST be set to "user_denied".		REQUIRED. The parameter value MUST be set to "user_denied".
	state		state
	REQUIRED if the "state" parameter was present in the client		REQUIRED if the "state" parameter was present in the client
	skipping to change at page 24, line 7 ¶		skipping to change at page 18, line 39 ¶
	the client.		the client.
	For example, the authorization server directs the client to make the		For example, the authorization server directs the client to make the
	following HTTP request:		following HTTP request:
	GET /cb?error=user_denied HTTP/1.1		GET /cb?error=user_denied HTTP/1.1
	Host: client.example.com		Host: client.example.com
	The authorization flow concludes unsuccessfully.		The authorization flow concludes unsuccessfully.
	3.6.2. Client Requests Access Token		2.5.2. Client Requests Access Token
	The client obtains an access token from the authorization server by		The client obtains an access token from the authorization server by
	making an HTTP "POST" request to the token endpoint. The client		making an HTTP "POST" request to the token endpoint. The client
	constructs a request URI by adding the following parameters to the		constructs a request URI by adding the following parameters to the
	request:		request:
	type		type
	REQUIRED. The parameter value MUST be set to "web_server".		REQUIRED. The parameter value MUST be set to "web_server".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	client_secret		client_secret
	REQUIRED if the client identifier has a matching secret. The		REQUIRED if the client identifier has a matching secret. The
	client secret as described in Section 3.1.		client secret as described in Section 2.1.
	code		code
	REQUIRED. The verification code received from the		REQUIRED. The verification 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.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request (line		For example, the client makes the following HTTPS request (line
	breaks are for display purposes only):		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&		type=web_server&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 verification code,		The authorization server MUST verify that the verification code,
	client identity, client secret, and redirection URI are all valid and		client identity, client secret, and redirection URI are all valid and
	match its stored association. If the request is valid, the		match its stored association. If the request is valid, the
	authorization server issues a successful response as described in		authorization server issues a successful response as described in
	Section 3.3.2.1.		Section 2.3.2.1.
	For example:		For example:
	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"
	}		}
	If the request is invalid, the authorization server returns an error		If the request is invalid, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "redirect_uri_mismatch"		o "redirect_uri_mismatch"
	o "bad_verification_code"		o "bad_verification_code"
	o "incorrect_client_credentials"		o "incorrect_client_credentials"
	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":"incorrect_client_credentials"		"error":"incorrect_client_credentials"
	}		}
	3.7. Device Flow		2.6. User-Agent Flow
			The user-agent flow is a user delegation flow suitable for client
			applications residing in a user-agent, typically implemented in a
			browser using a scripting language such as JavaScript. These clients
			cannot keep client secrets confidential and the authentication of the
			client is based on the user-agent's same-origin policy.
			Unlike other flows in which the client makes separate authorization
			and access token requests, the client received the access token as a
			result of the authorization request in the form of an HTTP
			redirection. The client requests the authorization server to
			redirect the user-agent to another web server or local resource
			accessible to the browser which is capable of extracting the access
			token from the response and passing it to the client.
			This user-agent flow does not utilize the client secret since the
			client executables reside on the end-user's computer or device which
			makes the client secret accessible and exploitable. Because the
			access token is encoded into the redirection URI, it may be exposed
			to the end-user and other applications residing on the computer or
			device.
			+----------+ Client Identifier +----------------+
			| |>---(A)-- & Redirection URI --->| |
			| | | |
			End <--+ - - - +----(B)-- User authenticates -->| Authorization |
			User | | | Server |
			| |<---(C)-- Redirect URI --------<| |
			| Client | with Access Token | |
			| in | (w/ Optional Refresh Token) +----------------+
			| Browser | in Fragment
			| | +----------------+
			| |>---(D)-- Redirect URI -------->| |
			| | without Fragment | Web Server |
			| | | with Client |
			| (F) |<---(E)-- Web Page with -------<| Resource |
			| Access | Script | |
			| Token | +----------------+
			+----------+
			Figure 4: User-Agent Flow
			The user-agent flow illustrated in Figure 4 includes the following
			steps:
			(A) The client sends the user-agent to the authorization server and
			includes its client identifier and redirection URI in the
			request.
			(B) The authorization server authenticates the end-user (via the
			user-agent) and establishes whether the end-user grants or
			denies the client's access request.
			(C) Assuming the end-user granted access, the authorization server
			redirects the user-agent to the redirection URI provided
			earlier. The redirection URI includes the access token in the
			URI fragment.
			(D) The user-agent follows the redirection instructions by making a
			request to the web server which does not include the fragment.
			The user-agent retains the fragment information locally.
			(E) The web server returns a web page containing a script capable of
			extracting the access token from the URI fragment retained by
			the user-agent.
			(F) The user-agent executes the script provided by the web server
			which extracts the access token and passes it to the client.
			2.6.1. Client Requests Authorization
			In order for the end-user to grant the client access, the client
			sends the end-user to the authorization server. The client
			constructs the request URI by adding the following URI query
			parameters to the end-user endpoint URI:
			type
			REQUIRED. The parameter value MUST be set to "user_agent".
			client_id
			REQUIRED. The client identifier as described in Section 2.1.
			redirect_uri
			REQUIRED unless a redirection URI has been established between
			the client and authorization server via other means. An
			absolute URI to which the authorization server will redirect
			the user-agent to when the end-user authorization step is
			completed. The authorization server SHOULD require the client
			to pre-register their redirection URI. Authorization servers
			MAY restrict the redirection URI to not include a query
			component as defined by [RFC3986] section 3.
			state
			OPTIONAL. An opaque value used by the client to maintain state
			between the request and callback. The authorization server
			includes this value when redirecting the user-agent back to the
			client.
			scope
			OPTIONAL. The scope of the access request expressed as a list
			of space-delimited strings. The value of the "scope" parameter
			is defined by the authorization server. If the value contains
			multiple space-delimited strings, their order does not matter,
			and each string adds an additional access range to the
			requested scope.
			immediate
			OPTIONAL. The parameter value must be set to "true" or
			"false". If set to "true", the authorization server MUST NOT
			prompt the end-user to authenticate or approve access.
			Instead, the authorization server attempts to establish the
			end-user's identity via other means (e.g. browser cookies) and
			checks if the end-user has previously approved an identical
			access request by the same client and if that access grant is
			still active. If the authorization server does not support an
			immediate check or if it is unable to establish the end-user's
			identity or approval status, it MUST deny the request without
			prompting the end-user. Defaults to "false" if omitted.
			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-
			user's user-agent. The request MUST use the HTTP "GET" method.
			For example, the client directs the end-user's user-agent to make the
			following HTTPS request (line breaks are for display purposes only):
			GET /authorize?type=user_agent&client_id=s6BhdRkqt3&
			redirect_uri=https%3A%2F%2FEexample%2Ecom%2Frd HTTP/1.1
			Host: server.example.com
			If the client has previously registered a redirection URI with the
			authorization server, the authorization server MUST verify that the
			redirection URI received matches the registered URI associated with
			the client identifier.
			The authorization server authenticates the end-user and obtains an
			authorization decision (by asking the end-user or establishing
			approval via other means). The authorization server sends the end-
			user's user-agent to the provided client redirection URI using an
			HTTP redirection response.
			2.6.1.1. End-user Grants Authorization
			If the end-user authorizes the access request, the authorization
			server issues an access token and delivers it to the client by adding
			the following parameters, using the
			"application/x-www-form-urlencoded" format as defined by
			[W3C.REC-html401-19991224], to the redirection URI fragment:
			access_token
			REQUIRED. The access token.
			expires_in
			OPTIONAL. The duration in seconds of the access token
			lifetime.
			refresh_token
			OPTIONAL. The refresh token.
			state
			REQUIRED if the "state" parameter was present in the client
			authorization request. Set to the exact value received from
			the client.
			For example, the authorization server redirects the end-user's user-
			agent by sending the following HTTP response:
			HTTP/1.1 302 Found
			Location: http://example.com/rd#access_token=FJQbwq9&expires_in=3600
			2.6.1.2. End-user Denies Authorization
			If the end-user denied the access request, the authorization server
			responds to the client by adding the following parameters, using the
			"application/x-www-form-urlencoded" format as defined by
			[W3C.REC-html401-19991224], to the redirection URI fragment:
			error
			REQUIRED. The parameter value MUST be set to "user_denied".
			state
			REQUIRED if the "state" parameter was present in the client
			authorization request. Set to the exact value received from
			the client.
			For example, the authorization server responds with the following:
			HTTP/1.1 302 Found
			Location: http://example.com/rd#error=user_denied
			The authorization flow concludes unsuccessfully. To extract the
			error message, the client follows the steps described in
			Section 2.6.2.
			2.6.2. Client Extracts Access Token
			The user-agent follows the authorization server redirection response
			by making an HTTP "GET" request to the URI received in the "Location"
			HTTP response header. The user-agent SHALL NOT include the fragment
			component with the request.
			For example, the user-agent makes the following HTTP "GET" request in
			response to the redirection directive received from the authorization
			server:
			GET /rd HTTP/1.1
			Host: example.com
			The HTTP response to the redirection request returns a web page
			(typically an HTML page with an embedded script) capable of accessing
			the full redirection URI including the fragment retained by the user-
			agent, and extracting the access token (and other parameters)
			contained in the fragment.
			2.7. Device Flow
	The device flow is a user delegation flow suitable for clients		The device flow is a user delegation flow suitable for clients
	executing on devices which do not have an easy data-entry method		executing on devices which do not have an easy data-entry method
	(e.g. game consoles or media hub), but where the end-user has		(e.g. game consoles or media hub), but where the end-user has
	separate access to a user-agent on another computer or device (e.g.		separate access to a user-agent on another computer or device (e.g.
	home computer, a laptop, or a smart phone). The client is incapable		home computer, a laptop, or a smart phone). The client is incapable
	of receiving incoming requests from the authorization server		of receiving incoming requests from the authorization server
	(incapable of acting as an HTTP server).		(incapable of acting as an HTTP server).
	Instead of interacting with the end-user's user-agent, the client		Instead of interacting with the end-user's user-agent, the client
	instructs the end-user to use another computer or device and connect		instructs the end-user to use another computer or device and connect
	to the authorization server to approve the access request. Since the		to the authorization server to approve the access request. Since the
	client cannot receive incoming requests, it polls the authorization		client cannot receive incoming requests, it polls the authorization
	server repeatedly until the end-user completes the approval process.		server repeatedly until the end-user completes the approval process.
	skipping to change at page 26, line 44 ¶		skipping to change at page 26, line 30 ¶
	: | |		: | |
	(C) User Code & Verification URI | |		(C) User Code & Verification URI | |
	: | |		: | |
	v | |		v | |
	+----------+ | |		+----------+ | |
	| End-user | | |		| End-user | | |
	| at |<---(D)-- User authenticates -->| |		| at |<---(D)-- User authenticates -->| |
	| Browser | | |		| Browser | | |
	+----------+ +----------------+		+----------+ +----------------+
	Figure 5		Figure 5: Device Flow
	The device flow illustrated in Figure 5 includes the following steps:		The device flow illustrated in Figure 5 includes the following steps:
	(A) The client requests access from the authorization server and		(A) The client requests access from the authorization server and
	includes its client identifier in the request.		includes its client identifier in the request.
	(B) The authorization server issues a verification code, an end-user		(B) The authorization server issues a verification code, an end-user
	code, and provides the end-user verification URI.		code, and provides the end-user verification URI.
	(C) The client instructs the end-user to use its user-agent		(C) The client instructs the end-user to use its user-agent
	skipping to change at page 27, line 33 ¶		skipping to change at page 27, line 15 ¶
	(E) While the end-user authorizes (or denies) the client's request		(E) While the end-user authorizes (or denies) the client's request
	(D), the client repeatedly polls the authorization server to		(D), the client repeatedly polls the authorization server to
	find out if the end-user completed the end-user authorization		find out if the end-user completed the end-user authorization
	step. The client includes the verification code and its client		step. The client includes the verification code and its client
	identifier.		identifier.
	(F) Assuming the end-user granted access, the authorization server		(F) Assuming the end-user granted access, the authorization server
	validates the verification code provided by the client and		validates the verification code provided by the client and
	responds back with the access token.		responds back with the access token.
	3.7.1. Client Requests Authorization		2.7.1. Client Requests Authorization
	The client initiates the flow by requesting a set of verification		The client initiates the flow by requesting a set of verification
	codes from the authorization server by making an HTTP "POST" request		codes from the authorization server by making an HTTP "POST" request
	to the token endpoint. The client constructs a request URI by adding		to the token endpoint. The client constructs a request URI by adding
	the following parameters to the request:		the following parameters to the request:
	type		type
	REQUIRED. The parameter value MUST be set to "device_code".		REQUIRED. The parameter value MUST be set to "device_code".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	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.		requested scope.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request (line		For example, the client makes the following HTTPS request (line
	breaks are for display purposes only):		breaks are for display purposes only):
	POST /token?type=device_code&client_id=s6BhdRkqt3		POST /token HTTP/1.1
	HTTP/1.1
	Host: server.example.com		Host: server.example.com
			Content-Type: application/x-www-form-urlencoded
			type=device_code&client_id=s6BhdRkqt3
	In response, the authorization server generates a verification code		In response, the authorization server generates a verification code
	and an end-user code and includes them in the HTTP response body		and an end-user code and includes them in the HTTP response body
	using the "application/json" format as described by Section 3.3.2		using the "application/json" format as described by Section 2.3.2
	with a 200 status code (OK). The response contains the following		with a 200 status code (OK). The response contains the following
	parameters:		parameters:
	code		code
	REQUIRED. The verification code.		REQUIRED. The verification code.
	user_code		user_code
	REQUIRED. The end-user code.		REQUIRED. The end-user code.
	verification_uri		verification_uri
	skipping to change at page 29, line 29 ¶		skipping to change at page 29, line 8 ¶
	URI to the end-user, and instructs the end-user to visit the URI		URI to the end-user, and instructs the end-user to visit the URI
	using a user-agent and enter the end-user code.		using a user-agent and enter the end-user code.
	The end-user manually types the provided verification URI and		The end-user manually types the provided verification URI and
	authenticates with the authorization server. The authorization		authenticates with the authorization server. The authorization
	server prompts the end-user to authorize the client's request by		server prompts the end-user to authorize the client's request by
	entering the end-user code provided by the client. Once the end-user		entering the end-user code provided by the client. Once the end-user
	approves or denies the request, the authorization server informs the		approves or denies the request, the authorization server informs the
	end-user to return to the device for further instructions.		end-user to return to the device for further instructions.
	3.7.2. Client Requests Access Token		2.7.2. Client Requests Access Token
	Since the client is unable to receive incoming requests from the		Since the client is unable to receive incoming requests from the
	authorization server, it polls the authorization server repeatedly		authorization server, it polls the authorization server repeatedly
	until the end-user grants or denies the request, or the verification		until the end-user grants or denies the request, or the verification
	code expires.		code expires.
	The client makes the following request at an arbitrary but reasonable		The client makes the following request at an arbitrary but reasonable
	interval which MUST NOT exceed the minimum interval rate provided by		interval which MUST NOT exceed the minimum interval rate provided by
	the authorization server (if present via the "interval" parameter).		the authorization server (if present via the "interval" parameter).
	Alternatively, the client MAY provide a user interface for the end-		Alternatively, the client MAY provide a user interface for the end-
	user to manually inform it when authorization was granted.		user to manually inform it when authorization was granted.
	The client requests an access token by making an HTTP "POST" request		The client requests an access token by making an HTTP "POST" request
	to the token endpoint. The client constructs a request URI by adding		to the token endpoint. The client constructs a request URI by adding
	the following parameters to the request:		the following parameters to the request:
	type		type
	REQUIRED. The parameter value MUST be set to "device_token".		REQUIRED. The parameter value MUST be set to "device_token".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	code		code
	The verification code received from the authorization server.		REQUIRED. The verification code received from the
			authorization server.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request (line		For example, the client makes the following HTTPS request (line
	breaks are for display purposes only):		breaks are for display purposes only):
	POST /token?type=device_token&client_id=s6BhdRkqt3		POST /token HTTP/1.1
	&code=74tq5miHKB HTTP/1.1
	Host: server.example.com		Host: server.example.com
			Content-Type: application/x-www-form-urlencoded
			type=device_token&client_id=s6BhdRkqt3
			&code=74tq5miHKB
	If the end-user authorized the request, the authorization server		If the end-user authorized the request, the authorization server
	issues an access token response as described in Section 3.3.2.1.		issues an access token response as described in Section 2.3.2.1.
	For example:		For example:
	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"
	}		}
	If the request is invalid, the authorization server returns an error		If the request is invalid, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "authorization_declined"		o "authorization_declined"
	o "bad_verification_code"		o "bad_verification_code"
	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":"authorization_declined"		"error":"authorization_declined"
	}		}
	If the end-user authorization is pending or expired without receiving		If the end-user authorization is pending or expired without receiving
	any response from the end-user, or the client is exceeding the		any response from the end-user, or the client is exceeding the
	allowed polling interval, the authorization server returns an error		allowed polling interval, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "'authorization_pending"		o "'authorization_pending"
	o "slow_down"		o "slow_down"
	o "code_expired"		o "code_expired"
	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":"authorization_pending"		"error":"authorization_pending"
	}		}
	3.8. Username and Password Flow		2.8. Username and Password Flow
	The username and password flow is suitable for clients capable of		The username and password flow is suitable for clients capable of
	asking end-users for their usernames and passwords. It is also used		asking end-users for their usernames and passwords. It is also used
	to migrate existing clients using direct authentication schemes such		to migrate existing clients using direct authentication schemes such
	as HTTP Basic or Digest authentication to OAuth by converting the		as HTTP Basic or Digest authentication to OAuth by converting the
	end-user credentials stored with tokens.		end-user credentials stored with tokens.
	However, unlike the HTTP Basic authentication scheme defined in		However, unlike the HTTP Basic authentication scheme defined in
	[RFC2617], the end-user's credentials are used in a single request		[RFC2617], the end-user's credentials are used in a single request
	and are exchanged for an access token and refresh token which		and are exchanged for an access token and refresh token which
	skipping to change at page 32, line 35 ¶		skipping to change at page 32, line 19 ¶
	:		:
	v		v
	+--------+ +---------------+		+--------+ +---------------+
	| | Client Credentials | |		| | Client Credentials | |
	| |>--(B)--- & User Credentials ---->| Authorization |		| |>--(B)--- & User Credentials ---->| Authorization |
	| Client | | Server |		| Client | | Server |
	| |<--(C)---- Access Token ---------<| |		| |<--(C)---- Access Token ---------<| |
	| | (w/ Optional Refresh Token) | |		| | (w/ Optional Refresh Token) | |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 6		Figure 6: Username and Password Flow
	The username and password flow illustrated in Figure 6 includes the		The username and password flow illustrated in Figure 6 includes the
	following steps:		following steps:
	(A) The end-user provides the client with its username and password.		(A) The end-user provides the client with its username and password.
	(B) The client sends an access token request to the authorization		(B) The client sends an access token request to the authorization
	server and includes its client identifier and client secret, and		server and includes its client identifier and client secret, and
	the end-user's username and password.		the end-user's username and password.
	(C) The authorization server validates the end-user credentials and		(C) The authorization server validates the end-user credentials and
	the client credentials and issues an access token.		the client credentials and issues an access token.
	3.8.1. Client Requests Access Token		2.8.1. Client Requests Access Token
	The client requests an access token by making an HTTP "POST" request		The client requests an access token by making an HTTP "POST" request
	to the token endpoint. The client constructs a request URI by adding		to the token endpoint. The client constructs a request URI by adding
	the following parameters to the request:		the following parameters to the request:
	type		type
	REQUIRED. The parameter value MUST be set to "username".		REQUIRED. The parameter value MUST be set to "username".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	client_secret		client_secret
	REQUIRED. The client secret as described in Section 3.1.		REQUIRED. The client secret as described in Section 2.1.
	OPTIONAL if no client secret was issued.		OPTIONAL if no client secret was issued.
	username		username
	REQUIRED. The end-user's username.		REQUIRED. The end-user's username.
	password		password
	REQUIRED. The end-user's password.		REQUIRED. The end-user's password.
	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.		requested scope.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request (line		For example, the client makes the following HTTPS request (line
	breaks are for display purposes only):		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
	type=username&client_id=s6BhdRkqt3&client_secret=		type=username&client_id=s6BhdRkqt3&client_secret=
	47HDu8s&username=johndoe&password=A3ddj3w		47HDu8s&username=johndoe&password=A3ddj3w
	The authorization server MUST validate the client credentials and		The authorization server MUST validate the client credentials and
	end-user credentials and if valid issues an access token response as		end-user credentials and if valid issues an access token response as
	described in Section 3.3.2.1.		described in Section 2.3.2.1.
	For example:		For example:
	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,
	skipping to change at page 34, line 28 ¶		skipping to change at page 34, line 4 ¶
	For example:		For example:
	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"
	}		}
	If the request is invalid, the authorization server returns an error		If the request is invalid, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "incorrect_client_credentials"		o "incorrect_client_credentials"
	o "unauthorized_client'" - The client is not permitted to use this		o "unauthorized_client'" - The client is not permitted to use this
	flow.		flow.
	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":"incorrect_client_credentials"		"error":"incorrect_client_credentials"
	}		}
	3.9. Client Credentials Flow		2.9. Client Credentials Flow
	The client credentials flow is used when the client acts on behalf of		The client credentials flow is used when the client acts on behalf of
	itself (the client is the resource owner), or when the client		itself (the client is the resource owner), or when the client
	credentials are used to obtain an access token representing a		credentials are used to obtain an access token representing a
	previously established access authorization. The client secret is		previously established access authorization. The client secret is
	assumed to be high-entropy since it is not designed to be memorized		assumed to be high-entropy since it is not designed to be memorized
	by an end-user.		by an end-user.
	+--------+ +---------------+		+--------+ +---------------+
	| | | |		| | | |
	| |>--(A)--- Client Credentials ---->| Authorization |		| |>--(A)--- Client Credentials ---->| Authorization |
	| Client | | Server |		| Client | | Server |
	| |<--(B)---- Access Token ---------<| |		| |<--(B)---- Access Token ---------<| |
	| | (w/ Optional Refresh Token) | |		| | (w/ Optional Refresh Token) | |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 7		Figure 7: Client Credentials Flow
	The client credential flow illustrated in Figure 7 includes the		The client credential flow illustrated in Figure 7 includes the
	following steps:		following steps:
	(A) The client sends an access token request to the authorization		(A) The client sends an access token request to the authorization
	server and includes its client identifier and client secret.		server and includes its client identifier and client secret.
	(B) The authorization server validates the client credentials and		(B) The authorization server validates the client credentials and
	issues an access token.		issues an access token.
	3.9.1. Client Requests Access Token		2.9.1. Client Requests Access Token
	The client requests an access token by making an HTTP "POST" request		The client requests an access token by making an HTTP "POST" request
	to the token endpoint. The client constructs a request URI by adding		to the token endpoint. The client constructs a request URI by adding
	the following parameters to the request:		the following parameters to the request:
	type		type
	REQUIRED. The parameter value MUST be set to		REQUIRED. The parameter value MUST be set to
	"client_credentials".		"client_credentials".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	client_secret		client_secret
	REQUIRED. The client secret as described in Section 3.1.		REQUIRED. The client secret as described in Section 2.1.
	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.		requested scope.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request:		For example, the client makes the following HTTPS request:
	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
	type=client_credentials&client_id=s6BhdRkqt3&client_secret=47HDu8s		type=client_credentials&client_id=s6BhdRkqt3&client_secret=47HDu8s
	The authorization server MUST validate the client credentials and if		The authorization server MUST validate the client credentials and if
	valid issues an access token response as described in		valid issues an access token response as described in
	Section 3.3.2.1.		Section 2.3.2.1.
	For example:		For example:
	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"
	}		}
	If the request is invalid, the authorization server returns an error		If the request is invalid, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "incorrect_client_credentials"		o "incorrect_client_credentials"
	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":"incorrect_client_credentials"		"error":"incorrect_client_credentials"
	}		}
	3.10. Assertion Flow		2.10. Assertion Flow
	The assertion flow is used when a client wishes to exchange an		The assertion flow is used when a client wishes to exchange an
	existing security token or assertion for an access token. This flow		existing security token or assertion for an access token. This flow
	is suitable when the client is the resource owner or is acting on		is suitable when the client is the resource owner or is acting on
	behalf of the resource owner (based on the content of the assertion		behalf of the resource owner (based on the content of the assertion
	used).		used).
	The assertion flow requires the client to obtain a assertion (such as		The assertion flow requires the client to obtain a assertion (such as
	a SAML [OASIS.saml-core-2.0-os] assertion) from an assertion issuer		a SAML [OASIS.saml-core-2.0-os] assertion) from an assertion issuer
	or to self-issue an assertion prior to initiating the flow. The		or to self-issue an assertion prior to initiating the flow. The
	skipping to change at page 37, line 42 ¶		skipping to change at page 37, line 15 ¶
	specification.		specification.
	+--------+ +---------------+		+--------+ +---------------+
	| | | |		| | | |
	| |>--(A)------ Assertion ---------->| Authorization |		| |>--(A)------ Assertion ---------->| Authorization |
	| Client | | Server |		| Client | | Server |
	| |<--(B)---- Access Token ---------<| |		| |<--(B)---- Access Token ---------<| |
	| | | |		| | | |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 8		Figure 8: Assertion Flow
	The assertion flow illustrated in Figure 8 includes the following		The assertion flow illustrated in Figure 8 includes the following
	steps:		steps:
	(A) The client sends an access token request to the authorization		(A) The client sends an access token request to the authorization
	server and includes an assertion.		server and includes an assertion.
	(B) The authorization server validates the assertion and issues an		(B) The authorization server validates the assertion and issues an
	access token.		access token.
	3.10.1. Client Requests Access Token		2.10.1. Client Requests Access Token
	The client requests an access token by making an HTTP "POST" request		The client requests an access token by making an HTTP "POST" request
	to the token endpoint. The client constructs a request URI by adding		to the token endpoint. The client constructs a request URI by adding
	the following parameters to the request:		the following parameters to the request:
	type		type
	REQUIRED. The parameter value MUST be set to "assertion".		REQUIRED. The parameter value MUST be set to "assertion".
	format		assertion_format
	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.
	client_id		client_id
	OPTIONAL. The client identifier as described in Section 3.1.		OPTIONAL. The client identifier as described in Section 2.1.
	The authorization server MAY require including the client		The authorization server MAY require including the client
	credentials with the request based on the assertion properties.		credentials with the request based on the assertion properties.
	client_secret		client_secret
	OPTIONAL. The client secret as described in Section 3.1. MUST		OPTIONAL. The client secret as described in Section 2.1. MUST
	NOT be included if the "client_id" parameter is omitted.		NOT be included if the "client_id" parameter is omitted.
	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.		requested scope.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request (line		For example, the client makes the following HTTPS request (line
	breaks are for display purposes only):		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
	type=assertion&format=_______&assertion=_______		type=assertion&assertion_format=_______&assertion=_______
	The authorization server MUST validate the assertion and if valid		The authorization server MUST validate the assertion and if valid
	issues an access token response as described in Section 3.3.2.1. The		issues an access token response as described in Section 2.3.2.1. The
	authorization server SHOULD NOT issue a refresh token.		authorization server SHOULD NOT issue a refresh token.
	For example:		For example:
	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
	}		}
	If the request is invalid, the authorization server returns an error		If the request is invalid, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "invalid_assertion"		o "invalid_assertion"
	o "unknown_format"		o "unknown_format"
	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_assertion"		"error":"invalid_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. Refreshing an Access Token		2.11. Native Application Considerations
			Native application are clients running as native code on the end-
			user's computer or device (i.e. executing outside a browser or as a
			desktop program). These clients are often capable of interacting
			with (or embedding) the end-user's user-agent but are incapable of
			receiving callback requests from the server (incapable of acting as
			an HTTP server).
			Native application clients can utilize many of the flows defined in
			this specification with little or no changes. For example:
			o Launch an external user-agent and have it redirect back to the
			client using a custom URI scheme. This works with the web server
			flow and user-agent flow.
			o Launch an external user-agent and poll for changes to the window
			title. This works with the web server flow with a server-hosted
			custom redirect result page that puts the verification code in the
			title.
			o Use an embedded user-agent and obtain the redirection URI. This
			works with the web server flow and user-agent flow.
			o Use the device profile with an external or embedded user-agent.
			The application will open a user-agent and then poll the
			authorization server for results.
			o Use the username and password flow and prompt the end-users for
			their credentials. This is generally discouraged as it hands the
			end-user's password directly to the 3rd party and may not work
			with some authentication schemes.
			When choosing between launching an external browser and an embedded
			user-agent, developers should consider the following:
			o External user-agents may improve completion rate as the end-user
			may already be logged-in and not have to re-authenticate.
			o Embedded user-agents often offer a better end-user flow, as they
			remove the need to switch context and open new windows.
			o Embedded user-agents are less secure because users are
			authenticating in unidentified window without access to the
			protections offered by many user-agents.
			3. Refreshing an Access Token
	Token refresh is used when the lifetime of an access token is shorter		Token refresh is used when the lifetime of an access token is shorter
	than the lifetime of the authorization grant. It allows clients to		than the lifetime of the authorization grant. It allows clients to
	obtain a new access token without having to go through the		obtain a new access token without having to go through the
	authorization flow again or involve the resource owner. It is also		authorization flow again or involve the resource owner.
	used to obtain a new token with different security properties (e.g.
	bearer token, token with shared symmetric secret).
	+--------+ Client Credentials, +---------------+		+--------+ +---------------+
	| | Refresh Token, | |		| | Client Credentials, | |
	| |>--(A)----- & Secret Type ------->| Authorization |		| |>--(A)----- Refresh Token ------->| Authorization |
	| Client | | Server |		| Client | | Server |
	| |<--(B)----- Access Token --------<| |		| |<--(B)----- Access Token --------<| |
	| | & Optional Secret | |		| | | |
	+--------+ +---------------+		+--------+ +---------------+
	Figure 9		Figure 9: Refreshing an Access Token
	To refresh a token, the client constructs an HTTP "POST" request to		To refresh a token, the client constructs an HTTP "POST" request to
	the token endpoint and includes the following parameters in the HTTP		the token endpoint and includes the following parameters in the HTTP
	request body using the "application/x-www-form-urlencoded" content		request body using the "application/x-www-form-urlencoded" content
	type as defined by [W3C.REC-html40-19980424]:		type as defined by [W3C.REC-html401-19991224]:
	type		type
	REQUIRED. The parameter value MUST be set to "refresh".		REQUIRED. The parameter value MUST be set to "refresh".
	client_id		client_id
	REQUIRED. The client identifier as described in Section 3.1.		REQUIRED. The client identifier as described in Section 2.1.
	client_secret		client_secret
	REQUIRED if the client was issued a secret. The client secret.		REQUIRED if the client was issued a secret. The client secret.
	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.
	secret_type
	OPTIONAL. The access token secret type as described by
	Section 5.3. If omitted, the authorization server will issue a
	bearer token (an access token without a matching secret) as
	described by Section 5.2.
	format		format
	OPTIONAL. The response format requested by the client. Value		OPTIONAL. The response format requested by the client. Value
	MUST be one of "json", "xml", or "form". Defaults to "json" if		MUST be one of "json", "xml", or "form". Alternatively, the
	no omitted.		client MAY use the HTTP "Accept" header field with the desired
			media type. Defaults to "json" if omitted and no "Accept"
			header field is present.
	For example, the client makes the following HTTPS request (line break		For example, the client makes the following HTTPS request (line break
	are for display purposes only):		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=refresh_token&client_id=s6BhdRkqt3&client_secret=8eSEIpnqmM		type=refresh_token&client_id=s6BhdRkqt3&client_secret=8eSEIpnqmM
	&refresh_token=n4E9O119d&secret_type=hmac-sha256		&refresh_token=n4E9O119d
	verify the client credential, the validity of the refresh token, and		verify the client credential, the validity of the refresh token, and
	that the resource owner's authorization is still valid. If the		that the resource owner's authorization is still valid. If the
	request is valid, the authorization server issues an access token		request is valid, the authorization server issues an access token
	response as described in Section 3.3.2.1. The authorization server		response as described in Section 2.3.2.1. The authorization server
	MAY issue a new refresh token in which case the client MUST NOT use		MAY issue a new refresh token in which case the client MUST NOT use
	the previous refresh token and replace it with the newly issued		the previous refresh token and replace it with the newly issued
	refresh token.		refresh token.
	For example:		For example:
	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
	}		}
	If the request is invalid, the authorization server returns an error		If the request is invalid, the authorization server returns an error
	response as described in Section 3.3.2.2 with one of the following		response as described in Section 2.3.2.2 with one of the following
	error codes:		error codes:
	o "incorrect_client_credentials"		o "incorrect_client_credentials"
	o "authorization_expired"		o "authorization_expired"
	o "unsupported_secret_type"
	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":"incorrect_client_credentials"		"error":"incorrect_client_credentials"
	}		}
	5. Accessing a Protected Resource		4. 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. The methods used by the resource server to		the resource server.
	validate the access token are beyond the scope of this specification,
	but generally involve an interaction or coordination between the
	resource server and authorization server.
	The method in which a client uses an access token depends on the		For example:
	security properties of the access tokens. By default, access tokens
	are issued without a matching secret. Clients MAY request an access
	token with a matching secret by specifying the desired secret type
	using the "secret_type" token request parameter.
	When an access token does not include a matching secret, the access		GET /resource HTTP/1.1
	token acts as a bearer token, where the token string is a shared		Host: server.example.com
	symmetric secret. This requires treating the access token with the		Authorization: Token token="vF9dft4qmT"
	same care as other secrets (e.g. user passwords). Access tokens
	SHOULD NOT be sent in the clear over an insecure channel.		Access tokens act as bearer tokens, where the token string acts as a
			shared symmetric secret. This requires treating the access token
			with the same care as other secrets (e.g. end-user passwords).
			Access tokens SHOULD NOT be sent in the clear over an insecure
			channel.
	However, when it is necessary to transmit bearer tokens in the clear		However, when it is necessary to transmit bearer tokens in the clear
	without a secure channel, authorization servers SHOULD issue access		without a secure channel, authorization servers SHOULD issue access
	tokens with limited scope and lifetime to reduce the potential risk		tokens with limited scope and lifetime to reduce the potential risk
	from a compromised access token. Clients SHOULD request and utilize		from a compromised access token.
	an access token with a matching secret when making protected resource
	requests over an insecure channel (e.g. an HTTP request without using
	TLS/SSL).
	When an access token includes a matching secret, the secret is not
	included directly in the request but is used instead to generate a
	cryptographic signature of the request. The signature can only be
	generated and verified by entities with access to the secret.
	Clients SHOULD NOT make authenticated requests with an access token		Clients SHOULD NOT make authenticated requests with an access token
	to unfamiliar resource servers, especially when using bearer tokens,		to unfamiliar resource servers, especially when using bearer tokens,
	regardless of the presence of a secure channel.		regardless of the presence of a secure channel.
	5.1. The Authorization Request Header		The methods used by the resource server to validate the access token
			are beyond the scope of this specification, but generally involve an
	The "Authorization" request header field is used by clients to make		interaction or coordination between the resource server and
	both bearer token and cryptographic token requests. When making		authorization server.
	bearer token requests, the client uses the "token" attribute to
	include the access token in the request without any of the other
	attributes. Additional methods for making bearer token requests are
	described in Section 5.2.
	For example:
	GET /resource HTTP/1.1
	Host: server.example.com
	Authorization: Token token="vF9dft4qmT"
	When making a cryptographic token request (using an access token with
	a matching secret) the client uses the "token" attribute to include
	the access token in the request, and uses the "nonce", "timestamp",
	"algorithm", and "signature" attributes to apply the matching secret.
	For example:
	GET /resource HTTP/1.1
	Host: server.example.com
	Authorization: Token token="vF9dft4qmT",
	nonce="s8djwd",
	timestamp="137131200",
	algorithm="hmac-sha256",
	signature="wOJIO9A2W5mFwDgiDvZbTSMK/PY="
	The "Authorization" header field uses the framework defined by
	[RFC2617] as follows:
	credentials = "Token" RWS token-response
	token-response = token-id
	[ CS nonce ]
	[ CS timestamp ]
	[ CS algorithm ]
	[ CS signature ]
	token-id = "token" "=" <"> token <">
	timestamp = "timestamp" "=" <"> 1*DIGIT <">
	nonce = "nonce" "=" <"> token <">
	algorithm = "algorithm" "=" algorithm-name
	algorithm-name = "hmac-sha256" /
	token
	signature = "signature" "=" <"> token <">
	5.2. Bearer Token Requests
	Clients make bearer token requests by including the access token
	using the HTTP "Authorization" request header with the "Token"
	authentication scheme as described in Section 5.1. The access token
	is included using the "token" parameter.
	For example, the client makes the following HTTPS request:
	GET /resource HTTP/1.1
	Host: server.example.com
	Authorization: Token token="vF9dft4qmT"
	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. If the		not expired and that its scope covers the requested resource. If the
	token expired or is invalid, the resource server MUST reply with an		token expired or is invalid, the resource server MUST reply with an
	HTTP 401 status code (Unauthorized) and include the HTTP		HTTP 401 status code (Unauthorized) and include the HTTP
	"WWW-Authenticate" response header as described in Section 6.1.		"WWW-Authenticate" response header as described in Section 5.1.
	For example:		For example:
	HTTP/1.1 401 Unauthorized		HTTP/1.1 401 Unauthorized
	WWW-Authenticate: Token realm='Service', error='token_expired'		WWW-Authenticate: Token realm='Service', error='token_expired'
	Alternatively, the client MAY include the access token using the HTTP		Clients make authenticated token requests using the "Authorization"
	request URI in the query component as described in Section 5.2.1, or		request header field as described in Section 4.1. Alternatively,
	in the HTTP body when using the "application/x-www-form-urlencoded"		clients MAY include the access token using the HTTP request URI in
	content type as described in Section 5.2.2. Clients SHOULD only use		the query component as described in Section 4.2, or in the HTTP body
	the request URI or body when the "Authorization" request header is		when using the "application/x-www-form-urlencoded" content type as
	not available, and MUST NOT use more than one method in each request.		described in Section 4.3.
	5.2.1. URI Query Parameter		Clients SHOULD only use the request URI or body when the
			"Authorization" request header field is not available, and MUST NOT
			use more than one method in each request. [[ specify error ]]
			4.1. The Authorization Request Header
			The "Authorization" request header field is used by clients to make
			authenticated token requests. The client uses the "token" attribute
			to include the access token in the request.
			The "Authorization" header field uses the framework defined by
			[RFC2617] as follows:
			credentials = "Token" RWS access-token [ CS 1#auth-param ]
			access-token = "token" "=" <"> token <">
			CS = OWS "," OWS
			4.2. 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 HTTPS request:		For example, the client makes the following HTTPS request:
	GET /resource?oauth_token=vF9dft4qmT HTTP/1.1		GET /resource?oauth_token=vF9dft4qmT HTTP/1.1
	Host: server.example.com		Host: server.example.com
	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).
	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 its scope includes the requested resource. If the		not expired and its scope includes the requested resource. If the
	resource expired or is not valid, the resource server MUST reply with		resource expired or is not valid, the resource server MUST reply with
	an HTTP 401 status code (Unauthorized) and include the HTTP		an HTTP 401 status code (Unauthorized) and include the HTTP
	"WWW-Authenticate" response header as described in Section 6.1.		"WWW-Authenticate" response header as described in Section 5.1.
	5.2.2. Form-Encoded Body Parameter		4.3. 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
	"application/x-www-form-urlencoded" content-type as defined by		"application/x-www-form-urlencoded" content-type as defined by
	[W3C.REC-html40-19980424].		[W3C.REC-html401-19991224].
	o The HTTP request entity-header includes the "Content-Type" header		o The HTTP request entity-header includes the "Content-Type" header
	field set to "application/x-www-form-urlencoded".		field set to "application/x-www-form-urlencoded".
	o The HTTP request method is "POST", "PUT", or "DELETE".		o The HTTP request method is "POST", "PUT", or "DELETE".
	The entity-body can include other request-specific parameters, in		The entity-body can include other request-specific parameters, in
	which case, the "oauth_token" parameters SHOULD be appended following		which case, the "oauth_token" parameters SHOULD be appended following
	the request-specific parameters, properly separated by an "&"		the request-specific parameters, properly separated by an "&"
	character (ASCII code 38).		character (ASCII code 38).
	skipping to change at page 46, line 35 ¶		skipping to change at page 45, line 24 ¶
	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
	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 its scope includes the requested resource. If the		not expired and its scope includes the requested resource. If the
	resource expired or is not valid, the resource server MUST reply with		resource expired or is not valid, the resource server MUST reply with
	an HTTP 401 status code (Unauthorized) and include the HTTP		an HTTP 401 status code (Unauthorized) and include the HTTP
	"WWW-Authenticate" response header as described in Section 6.1.		"WWW-Authenticate" response header as described in Section 5.1.
	5.3. Cryptographic Tokens Requests
	Clients make authenticated protected resource requests using an
	access token with a matching secret by calculating a set of values
	and including them in the request using the "Authorization" header
	field. The way clients calculate these values depends on the access
	token secret type as issued by the authorization server.
	This specification defines the "hmac-sha256" algorithm, and
	establishes a registry for providing additional algorithms. Clients
	obtain an access token with a matching "hmac-sha256" secret by using
	the "secret_type" parameter when requesting an access token.
	5.3.1. The 'hmac-sha256' Algorithm
	The "hmac-sha256" algorithm uses the HMAC method as defined in
	[RFC2104] together with the SHA-256 hash function defined in [NIST
	FIPS-180-3] to apply the access token secret to the request and
	generate a signature value that is included in the request instead of
	transmitting the secret in the clear.
	To use the "hmac-sha256" algorithm, clients:
	1. Calculate the request timestamp and generate a request nonce as
	described in Section 5.3.1.1.
	2. Construct the normalized request string as described in
	Section 5.3.1.2.
	3. Calculate the request signature as described in Section 5.3.1.3.
	4. Include the timestamp, nonce, algorithm name, and calculated
	signature in the request using the "Authorization" header field.
	For example:
	GET /resource HTTP/1.1
	Host: server.example.com
	Authorization: Token token="vF9dft4qmT",
	nonce="s8djwd",
	timestamp="137131200",
	algorithm="hmac-sha256",
	signature="wOJIO9A2W5mFwDgiDvZbTSMK/PY="
	The resource server MUST validate the access token and ensure it has
	not expired and that its scope covers the requested resource. The
	resource server MUST also recalculate the request signature using the
	attributes provided by the client and compare it to the signature
	provided. If the token expired or is invalid, or if the signature is
	incorrect, the resource server MUST reply with an HTTP 401 status
	code (Unauthorized) and include the HTTP "WWW-Authenticate" response
	header as described in Section 6.1.
	For example:
	HTTP/1.1 401 Unauthorized
	Date: Tue, 15 Nov 2010 08:12:31 GMT
	WWW-Authenticate: Token realm='Service',
	algorithms='hmac-sha256',
	error='invalid_signature'
	[[ Errors list ]]
	5.3.1.1. Nonce and Timestamp
	A timestamp in combination with unique nonce values is used to
	protect against replay attacks when transmitted over an insecure
	channel.
	The nonce is a random string, uniquely generated by the client to
	allow the resource server to verify that a request has never been
	made before and helps prevent replay attacks when requests are made
	over a non-secure channel. The nonce value MUST be unique across all
	requests with the same timestamp and token combinations.
	The timestamp value is the current time expressed in the number of
	seconds since January 1, 1970 00:00:00 GMT, and MUST be a positive
	integer.
	To avoid the need to retain an infinite number of nonce values for
	future checks, resource servers MAY choose to restrict the time
	period after which a request with an old timestamp is rejected. When
	resource servers apply such a restriction, clients SHOULD synchronize
	their clocks by using the resource server's time as indicated by the
	HTTP "Date" response header field as defined in [RFC2616].
	5.3.1.2. Normalized String Construction
	The normalized request string is a consistent, reproducible
	concatenation of several of the HTTP request elements into a single
	string. The string is used as an input to the selected cryptographic
	method and includes the HTTP request method (e.g. "GET", "POST",
	etc.), the authority as declared by the HTTP "Host" request header,
	and the request resource URI.
	The normalized request string does not cover the entire HTTP request.
	Most notably, it does not include the entity-body or most HTTP
	entity-headers. It is important to note that the resource server
	cannot verify the authenticity of the excluded request elements
	without using additional protections such as TLS/SSL.
	The normalized request string is constructed by concatenating
	together, in order, the following HTTP request elements, separated by
	the "," character (ASCII code 44):
	1. The request timestamp as described in Section 5.3.1.1.
	2. The request nonce as described in Section 5.3.1.1.
	3. The cryptographic algorithm used.
	4. The HTTP request method in uppercase. For example: "HEAD",
	"GET", "POST", etc.
	5. The hostname, colon-separated (ASCII code 58) from the TCP port
	used to make the request as included in the HTTP request "Host"
	header field. The port MUST be included even if it is not
	included in the "Host" header field (i.e. the default port for
	the scheme).
	6. The request resource URI.
	For example, the normalized request string for the "GET" request URI
	"http://example.com/resource", request timestamp "137131200", request
	nonce "s8djwd", and "hmac-sha256" algorithm (line breaks are for
	display purposes only):
	137131200,s8djwd,hmac-sha256,GET,example.com:80,
	http://example.com/resource
	5.3.1.3. Signature Calculation
	Clients calculate the request signature using the HMAC-SHA256
	function:
	digest = HMAC-SHA256 (key, text)
	by setting the function variables are follows:
	text
	is set to the value of the normalize request string as
	described in Section 5.3.1.2.
	key
	is set to the access token secret.
	The request signature is the calculated value of the "digest"
	variable after the result octet string is base64-encoded per
	[RFC2045] section 6.8.
	6. Identifying a Protected Resource		5. Identifying a Protected Resource
	Clients access protected resources after locating the appropriate		Clients access protected resources after locating the appropriate
	end-user and token endpoints and obtaining an access token. In many		end-user and token endpoints and obtaining an access token. In many
	cases, interacting with a protected resource requires prior knowledge		cases, interacting with a protected resource requires prior knowledge
	of the protected resource properties and methods, as well as its		of the protected resource properties and methods, as well as its
	authentication requirements (i.e. establishing client identity,		authentication requirements (i.e. establishing client identity,
	locating the end-user and token endpoints).		locating the end-user and token endpoints).
	However, there are cases in which clients are unfamiliar with the		However, there are cases in which clients are unfamiliar with the
	protected resource, including whether the resource requires		protected resource, including whether the resource requires
	authentication. When clients attempt to access an unfamiliar		authentication. When clients attempt to access an unfamiliar
	protected resource without an access token, the resource server		protected resource without an access token, the resource server
	denies the request and informs the client of the required credentials		denies the request and informs the client of the required credentials
	using an HTTP authentication challenge.		using an HTTP authentication challenge.
	In addition, when receiving an invalid authenticated request, the		In addition, when receiving an invalid authenticated request, the
	resource server issues an authentication challenge including the		resource server issues an authentication challenge including the
	error type and message.		error type and message.
	6.1. The WWW-Authenticate Response Header		5.1. The WWW-Authenticate Response Header
	A resource server receiving a request for a protected resource		A resource server receiving a request for a protected resource
	without a valid access token MUST respond with a 401 (Unauthorized)		without a valid access token MUST respond with a 401 (Unauthorized)
	or 403 (Forbidden) HTTP status code, and include at least one "Token"		or 403 (Forbidden) HTTP status code, and include at least one "Token"
	"WWW-Authenticate" response header field challenge.		"WWW-Authenticate" response header field challenge.
	The "WWW-Authenticate" header field uses the framework defined by		The "WWW-Authenticate" header field uses the framework defined by
	[RFC2617] as follows:		[RFC2617] as follows:
	challenge = "Token" RWS token-challenge		challenge = "Token" RWS token-challenge
	token-challenge = realm		token-challenge = realm
	[ CS user-uri ]
	[ CS token-uri ]
	[ CS algorithms ]
	[ CS scope ]
	[ CS error ]		[ CS error ]
			[ CS 1#auth-param ]
	user-uri = "user-uri" "=" URI-Reference
	token-uri = "token-uri" "=" URI-Reference
	algorithms = "algorithms" "=" <"> 1#algorithm-name <">
	scope = "scope" "=" <"> 1#URI-Reference <">
	error = "error" "=" <"> token <">		error = "error" "=" <"> token <">
	CS = OWS "," OWS
	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].		partition as defined by [RFC2617].
	The "user-uri" and "token-uri" attributes provide a way for the
	resource server to advertise the URIs of the end-user and token
	endpoints capable of issuing an access token suitable for accessing
	the requested resource.
	The "algorithms" attribute is a space-delimited list of the
	cryptographic algorithms supported by the resource server. The
	client MAY request an access token with a suitable matching secret by
	using the "secret_type" request parameter as described in
	Section 5.3.
	The "scope" attribute is a space-delimited list of URIs (relative or
	absolute) indicating the required scope of the access token for
	accessing the requested resource.
	The "error" attribute is used to inform the client the reason why an		The "error" attribute is used to inform the client the reason why an
	access request was declined. [[ Add list of error codes ]]		access request was declined. [[ Add list of error codes ]]
	7. Security Considerations		6. Security Considerations
	[[ Todo ]]		[[ Todo ]]
	8. IANA Considerations		7. IANA Considerations
	[[ Not Yet ]]		[[ Not Yet ]]
	9. Acknowledgements		Appendix A. Contributors
			The following people contributed to preliminary versions of this
			document: Blaine Cook (BT), Brian Eaton (Google), Yaron Goland
			(Microsoft), Brent Goldman (Facebook), Raffi Krikorian (Twitter),
			Luke Shepard (Facebook), and Allen Tom (Yahoo!). The content and
			concepts within are a product of the OAuth community, WRAP community,
			and the OAuth Working Group.
			The OAuth Working Group has dozens of very active contributors who
			proposed ideas and wording for this document, including: [[ If your
			name is missing or you think someone should be added here, please
			send Eran a note - don't be shy ]]
			Michael Adams, Andrew Arnott, Dirk Balfanz, Brian Campbell, Leah
			Culver, Igor Faynberg, George Fletcher, Evan Gilbert, Justin Hart,
			John Kemp, Torsten Lodderstedt, Eve Maler, James Manger, Chuck
			Mortimore, Justin Richer, Peter Saint-Andre, Nat Sakimura, Rob Sayre,
			Marius Scurtescu, Justin Smith, and Franklin Tse.
			Appendix B. Acknowledgements
	[[ Add OAuth 1.0a authors + WG contributors ]]		[[ Add OAuth 1.0a authors + WG contributors ]]
	Appendix A. Differences from OAuth 1.0a		Appendix C. Differences from OAuth 1.0a
	[[ Todo ]]		[[ Todo ]]
	Appendix B. 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 ]]
			-06
			o Editorial changes, corrections, clarifications, etc.
			o Removed conformance section.
			o Moved authors section to contributors appendix.
			o Added section on native applications.
			o Changed error response to use the requested format. Added support
			for HTTP "Accept" header.
			o Flipped the order of the web server and user-agent flows.
			o Renamed assertion flow "format" parameter name to
			"assertion_format" to resolve conflict.
			o Removed the term identifier from token definitions. Added a
			cryptographic token definition.
			o Added figure titles.
			o Added server response 401 when client tried to authenticate using
			multiple credentials.
			o Clarified support for TLS alternatives, and added requirement for
			TLS 1.2 support for token endpoint.
			o Removed all signature and cryptography.
			o Removed all discovery.
			o Updated HTML4 reference.
	-05		-05
	o Corrected device example.		o Corrected device example.
	o Added client credentials parameters to the assertion flow as		o Added client credentials parameters to the assertion flow as
	OPTIONAL.		OPTIONAL.
	o Added the ability to send client credentials using an HTTP		o Added the ability to send client credentials using an HTTP
	authentication scheme.		authentication scheme.
	skipping to change at page 53, line 39 ¶		skipping to change at page 49, line 30 ¶
	o Editorial changes based on feedback from Brian Eaton, Bill Keenan,		o Editorial changes based on feedback from Brian Eaton, Bill Keenan,
	and Chuck Mortimore.		and Chuck Mortimore.
	o Changed device flow "type" parameter values and switch to use only		o Changed device flow "type" parameter values and switch to use only
	the token endpoint.		the token endpoint.
	-00		-00
	o Initial draft based on a combination of WRAP and OAuth 1.0a.		o Initial draft based on a combination of WRAP and OAuth 1.0a.
	10. References		8. References
	10.1. Normative References		8.1. Normative References
	[I-D.ietf-httpbis-p1-messaging]		[I-D.ietf-httpbis-p1-messaging]
	Fielding, R., Gettys, J., Mogul, J., Nielsen, H.,		Fielding, R., Gettys, J., Mogul, J., Nielsen, H.,
	Masinter, L., Leach, P., Berners-Lee, T., and J. Reschke,		Masinter, L., Leach, P., Berners-Lee, T., and J. Reschke,
	"HTTP/1.1, part 1: URIs, Connections, and Message		"HTTP/1.1, part 1: URIs, Connections, and Message
	Parsing", draft-ietf-httpbis-p1-messaging-09 (work in		Parsing", draft-ietf-httpbis-p1-messaging-09 (work in
	progress), March 2010.		progress), March 2010.
	[NIST FIPS-180-3]		[NIST FIPS-180-3]
	National Institute of Standards and Technology, "Secure		National Institute of Standards and Technology, "Secure
	skipping to change at page 54, line 45 ¶		skipping to change at page 50, line 37 ¶
	[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO		[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
	10646", STD 63, RFC 3629, November 2003.		10646", STD 63, RFC 3629, November 2003.
	[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66,		Resource Identifier (URI): Generic Syntax", STD 66,
	RFC 3986, January 2005.		RFC 3986, January 2005.
	[RFC4627] Crockford, D., "The application/json Media Type for		[RFC4627] Crockford, D., "The application/json Media Type for
	JavaScript Object Notation (JSON)", RFC 4627, July 2006.		JavaScript Object Notation (JSON)", RFC 4627, July 2006.
	[W3C.REC-html40-19980424]		[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
	Hors, A., Raggett, D., and I. Jacobs, "HTML 4.0		(TLS) Protocol Version 1.2", RFC 5246, August 2008.
			[W3C.REC-html401-19991224]
			Hors, A., Jacobs, I., and D. Raggett, "HTML 4.01
	Specification", World Wide Web Consortium		Specification", World Wide Web Consortium
	Recommendation REC-html40-19980424, April 1998,		Recommendation REC-html401-19991224, December 1999,
	<http://www.w3.org/TR/1998/REC-html40-19980424>.		<http://www.w3.org/TR/1999/REC-html401-19991224>.
	10.2. Informative References		8.2. 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.
	[I-D.hardt-oauth]		[I-D.hardt-oauth]
	Hardt, D., Tom, A., Eaton, B., and Y. Goland, "OAuth Web		Hardt, D., Tom, A., Eaton, B., and Y. Goland, "OAuth Web
	Resource Authorization Profiles", draft-hardt-oauth-01		Resource Authorization Profiles", draft-hardt-oauth-01
	(work in progress), January 2010.		(work in progress), January 2010.
	skipping to change at page 55, line 37 ¶		skipping to change at page 51, line 31 ¶
	Email: eran@hueniverse.com		Email: eran@hueniverse.com
	URI: http://hueniverse.com		URI: http://hueniverse.com
	David Recordon		David Recordon
	Facebook		Facebook
	Email: davidrecordon@facebook.com		Email: davidrecordon@facebook.com
	URI: http://www.davidrecordon.com/		URI: http://www.davidrecordon.com/
	Dick Hardt		Dick Hardt
			Microsoft
	Email: dick.hardt@gmail.com		Email: dick.hardt@gmail.com
	URI: http://dickhardt.org/		URI: http://dickhardt.org/
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