One document matched: draft-hammer-oauth-00.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd">
<?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>
<rfc category="std" ipr="full3978" docName="draft-hammer-oauth-00" ipr="full3978">
<?rfc strict="yes" ?>
<?rfc toc="yes"?>
<?rfc tocdepth="3"?>
<?rfc symrefs="yes"?>
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<?rfc subcompact="no" ?>
<front>
<title abbrev="OAuth Authorization Protocol">OAuth: HTTP Authorization Delegation Protocol</title>
<author initials="E" surname="Hammer-Lahav" fullname="Eran Hammer-Lahav" role="editor">
<organization/>
<address>
<email>eran@hueniverse.com</email>
<uri>http://hueniverse.com</uri>
</address>
</author>
<author initials="B" surname="Cook" fullname="Blaine Cook">
<organization/>
<address>
<email>romeda@gmail.com</email>
<uri>http://romeda.org/</uri>
</address>
</author>
<date year="2008"/>
<abstract>
<t>
This document specifies OAuth, an HTTP authorization delegation protocol for accessing
protected resources.
</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>
The OAuth protocol enables websites or applications (Consumers) to
access Protected Resources from a web service (Service Provider) via an
API, without requiring Users to disclose their Service Provider
credentials to the Consumers. More generally, OAuth creates a
freely-implementable and generic methodology for API authentication.
</t>
<t>
An example use case is allowing printing service printer.example.com
(the Consumer), to access private photos stored on photos.example.net
(the Service Provider) without requiring Users to provide their
photos.example.net credentials to printer.example.com.
</t>
<t>
OAuth does not require a specific user interface or interaction
pattern, nor does it specify how Service Providers authenticate Users,
making the protocol ideally suited for cases where authentication
credentials are unavailable to the Consumer, such as with OpenID.
</t>
<t>
OAuth aims to unify the experience and implementation of delegated web
service authentication into a single, community-driven protocol. OAuth
builds on existing protocols and best practices that have been
independently implemented by various websites. An open standard,
supported by large and small providers alike, promotes a consistent and
trusted experience for both application developers and the users of
those applications.
</t>
<t>
Discussion of this draft should take place on the OAuth mailing list located
at oauth@googlegroups.com. To join the list, visit http://groups.google.com/group/oauth
(you will be asked to provide a reason to join solely as a spam filter).
</t>
</section>
<section title="Requirements Language">
<t>
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in <xref target="RFC2119" />.
</t>
</section>
<section title="Definitions">
<t>
<list style="hanging">
<t hangText="Service Provider:">
A web application that allows access via OAuth.
</t>
<t hangText="User:">
An individual who has an account with the Service Provider.
</t>
<t hangText="Consumer:">
A website or application that uses OAuth to access the Service
Provider on behalf of the User.
</t>
<t hangText="Protected Resource(s):">
Data controlled by the Service Provider, which the Consumer can
access through authentication.
</t>
<t hangText="Consumer Developer:">
An individual or organization that implements a Consumer.
</t>
<t hangText="Consumer Key:">
A value used by the Consumer to identify itself to the Service
Provider.
</t>
<t hangText="Consumer Secret:">
A secret used by the Consumer to establish ownership of the
Consumer Key.
</t>
<t hangText="Request Token:">
A value used by the Consumer to obtain authorization from the User,
and exchanged for an Access Token.
</t>
<t hangText="Access Token:">
A value used by the Consumer to gain access to the Protected
Resources on behalf of the User, instead of using the User's
Service Provider credentials.
</t>
<t hangText="Token Secret:">
A secret used by the Consumer to establish ownership of a given
Token.
</t>
<t hangText="OAuth Protocol Parameters:">
Parameters with names beginning with <spanx style="verb">oauth_</spanx>.
</t>
</list>
</t>
</section>
<section title="Documentation and Registration">
<t>
OAuth includes a Consumer Key and matching Consumer Secret that
together authenticate the Consumer (as opposed to the User) with the
Service Provider. Consumer-specific identification allows the Service
Provider to vary access levels to Consumers (such as un-throttled access
to resources).
</t>
<t>
Service Providers SHOULD NOT rely on the Consumer Secret as a method to
verify the Consumer identity, unless the Consumer Secret is known to be
inaccessible to anyone other than the Consumer and the Service
Provider. The Consumer Secret MAY be an empty string (for example when
no Consumer verification is needed, or when verification is achieved
through other means such as RSA).
</t>
<section title="Request URLs" anchor="request_urls">
<t>
OAuth defines three request URLs:
<list style="hanging">
<t hangText="Request Token URL:">
The URL used to obtain an unauthorized Request Token, described
in <xref target="auth_step1" />.
</t>
<t hangText="User Authorization URL:">
The URL used to obtain User authorization for Consumer access,
described in <xref target="auth_step2" />.
</t>
<t hangText="Access Token URL:">
The URL used to exchange the User-authorized Request Token for
an Access Token, described in <xref target="auth_step3" />.
</t>
</list>
</t>
<t>
The three URLs MUST include scheme, authority, and path, and MAY
include query and fragment as defined by <xref target="RFC3986" />
section 3. The request URL query MUST NOT contain any OAuth Protocol
Parameters. For example:
<figure>
<artwork>
http://sp.example.com/authorize
</artwork>
</figure>
</t>
</section>
<section title="Service Providers">
<t>
The Service Provider's responsibility is to enable Consumer Developers
to establish a Consumer Key and Consumer Secret. The process and
requirements for provisioning these are entirely up to the Service
Providers.
</t>
<t>
The Service Provider's documentation includes:
<list style="numbers">
<t>
The <xref target="request_urls">URLs</xref> the Consumer will
use when making OAuth requests, and the HTTP methods (i.e. GET,
POST, etc.) used in the Request Token URL and Access Token URL.
</t>
<t>
Signature methods supported by the Service Provider.
</t>
<t>
Any additional request parameters that the Service Provider
requires in order to obtain a Token. Service Provider specific
parameters MUST NOT begin with <spanx style="verb">oauth_</spanx>.
</t>
</list>
</t>
</section>
<section title="Consumers">
<t>
The Consumer Developer MUST establish a Consumer Key and a Consumer
Secret with the Service Provider. The Consumer Developer MAY also be
required to provide additional information to the Service Provider
upon registration.
</t>
</section>
</section>
<section title="Parameters">
<t>
OAuth Protocol Parameter names and values are case sensitive. Each
OAuth Protocol Parameters MUST NOT appear more than once per request,
and are REQUIRED unless otherwise noted.
</t>
<section title="Consumer Request Parameters" anchor="consumer_req_param">
<t>
OAuth Protocol Parameters are sent from the Consumer to the Service
Provider in one of three methods, in order of decreasing preference:
<list style="numbers">
<t>
In the HTTP <spanx style="verb">Authorization</spanx> header as defined in
<xref target="auth_header">OAuth HTTP Authorization Scheme</xref>.
</t>
<t>
As the HTTP request body with a <spanx style="verb">
content-type
</spanx> of
<spanx style="verb">application/x-www-form-urlencoded</spanx> as defined by <xref target="W3C.REC-html40-19980424" />.
</t>
<t>
Added to the URLs in the query part (as defined by
<xref target="RFC3986" /> section 3).
</t>
</list>
</t>
<t>
In addition to these defined methods, future extensions may describe
alternate methods for sending the OAuth Protocol Parameters.
The methods for sending other request parameters are left
undefined, but SHOULD NOT use the
<xref target="auth_header">OAuth HTTP Authorization Scheme</xref> header.
</t>
</section>
<section title="Service Provider Response Parameters" anchor="response_parameters">
<t>
Response parameters such as Tokens and Token Secrets are sent by the Service Provider
to the Consumer in the HTTP response body using the <spanx style="verb">application/x-www-form-urlencoded</spanx>
content type as defined by <xref target="W3C.REC-html40-19980424" />. For example:
</t>
<figure>
<artwork>
oauth_token=ab3cd9j4ks73hf7g&oauth_token_secret=xyz4992k83j47x0b
</artwork>
</figure>
</section>
<section title="OAuth HTTP Authorization Scheme" anchor="auth_header">
<t>
This section defines an <xref target="RFC2617" /> extension to
support OAuth. It uses the standard HTTP <spanx style="verb">Authorization</spanx> and
<spanx style="verb">WWW-Authenticate</spanx> headers to pass OAuth Protocol Parameters.
</t>
<t>
It is RECOMMENDED that Service Providers accept the HTTP
<spanx style="verb">Authorization</spanx> header. Consumers SHOULD be able to send OAuth
Protocol Parameters in the OAuth <spanx style="verb">Authorization</spanx> header.
</t>
<t>
The extension auth-scheme (as defined by
<xref target="RFC2617" />) is <spanx style="verb">OAuth</spanx> and is case-insensitive.
</t>
<section title="Authorization Header" anchor="auth_header_authorization">
<t>
The OAuth Protocol Parameters are sent in the <spanx style="verb">Authorization</spanx>
header the following way:
<list style="numbers">
<t>
Parameter names and values are encoded per
<xref target="encoding_parameters">Parameter Encoding</xref>.
</t>
<t>
For each parameter, the name is immediately followed by an '='
character (ASCII code 61), a '"' character (ASCII code 34), the
parameter value (MAY be empty), and another '"' character
(ASCII code 34).
</t>
<t>
Parameters are separated by a comma character (ASCII code 44)
and OPTIONAL linear whitespace per <xref target="RFC2617" />.
</t>
<t>
The OPTIONAL <spanx style="verb">realm</spanx> parameter is added and interpreted per
<xref target="RFC2617" />, section 1.2.
</t>
</list>
</t>
<t>
For example:
<figure>
<artwork>
Authorization: OAuth realm="http://sp.example.com/",
oauth_consumer_key="0685bd9184jfhq22",
oauth_token="ad180jjd733klru7",
oauth_signature_method="HMAC-SHA1",
oauth_signature="wOJIO9A2W5mFwDgiDvZbTSMK%2FPY%3D",
oauth_timestamp="137131200",
oauth_nonce="4572616e48616d6d65724c61686176",
oauth_version="1.0"
</artwork>
</figure>
</t>
</section>
<section title="WWW-Authenticate Header">
<t>
Service Providers MAY indicate their support for the extension by
returning the OAuth HTTP <spanx style="verb">WWW-Authenticate</spanx>
header upon Consumer requests for Protected Resources. As per
<xref target="RFC2617" /> such a response MAY include additional
HTTP <spanx style="verb">WWW-Authenticate</spanx> headers:
</t>
<t>
For example:
<figure>
<artwork>
WWW-Authenticate: OAuth realm="http://sp.example.com/"
</artwork>
</figure>
</t>
<t>
The realm parameter defines a protection realm per
<xref target="RFC2617" />, section 1.2.
</t>
</section>
</section>
</section>
<section title="Authenticating with OAuth">
<t>
OAuth authentication is the process in which Users grant access to
their Protected Resources without sharing their credentials with the
Consumer. OAuth uses Tokens generated by the Service Provider instead
of the User's credentials in Protected Resources requests. The process
uses two Token types:
<list style="hanging">
<t hangText="Request Token:">
Used by the Consumer to ask the User to authorize access to the
Protected Resources. The User-authorized Request Token is exchanged
for an Access Token, MUST only be used once, and MUST NOT be used
for any other purpose. It is RECOMMENDED that Request Tokens have
a limited lifetime.
</t>
<t hangText="Access Token:">
Used by the Consumer to access the Protected Resources on behalf of
the User. Access Tokens MAY limit access to certain Protected
Resources, and MAY have a limited lifetime. Service Providers
SHOULD allow Users to revoke Access Tokens. Only the Access Token
SHALL be used to access the Protect Resources.
</t>
</list>
</t>
<t>
OAuth Authentication is done in three steps:
<list style="numbers">
<t>
The Consumer obtains an unauthorized Request Token.
</t>
<t>
The User authorizes the Request Token.
</t>
<t>
The Consumer exchanges the Request Token for an Access Token.
</t>
</list>
</t>
<section title="Obtaining an Unauthorized Request Token" anchor="auth_step1">
<t>
The Consumer obtains an unauthorized Request Token by asking the
Service Provider to issue a Token. The Request Token's sole purpose
is to receive User approval and can only be used to obtain an Access
Token. The Request Token process goes as follows:
</t>
<section title="Consumer Obtains a Request Token" anchor="obtain_request_token">
<t>
To obtain a Request Token, the Consumer sends an HTTP request to
the Service Provider's Request Token URL. The Service Provider
documentation specifies the HTTP method for this request, and HTTP POST
is RECOMMENDED. The request MUST be signed and contains the following parameters:
<list style="hanging">
<t hangText="oauth_consumer_key:">
The Consumer Key.
</t>
<t hangText="oauth_signature_method:">
The signature method the Consumer used to sign the request.
</t>
<t hangText="oauth_signature:">
The signature as defined in
<xref target="signing_process">Signing Requests</xref>.
</t>
<t hangText="oauth_timestamp:">
As defined in <xref target="nonce">Nonce and Timestamp</xref>.
</t>
<t hangText="oauth_nonce:">
As defined in <xref target="nonce">Nonce and Timestamp</xref>.
</t>
<t hangText="oauth_version:">
OPTIONAL. If present, value MUST be <spanx style="verb">
1.0
</spanx>. Service Providers
MUST assume the protocol version to be <spanx style="verb">1.0</spanx> if this parameter
is not present. Service Providers' response to non-<spanx style="verb">1.0</spanx> value
is left undefined.
</t>
<t hangText="Additional parameters:">
Any additional parameters, as defined by the Service Provider.
</t>
</list>
</t>
</section>
<section title="Service Provider Issues an Unauthorized Request Token" anchor="request_grant">
<t>
The Service Provider verifies the signature and Consumer Key. If
successful, it generates a Request Token and Token Secret and
returns them to the Consumer in the HTTP response body as defined
in <xref target="response_parameters">Service Provider Response Parameters</xref>.
The Service Provider MUST ensure the Request
Token cannot be exchanged for an Access Token until the User
successfully grants access in <xref target="auth_step2">
Obtaining
User Authorization
</xref>.
</t>
<t>
The response contains the following parameters:
<list style="hanging">
<t hangText="oauth_token:">
The Request Token.
</t>
<t hangText="oauth_token_secret:">
The Token Secret.
</t>
<t hangText="Additional parameters:">
Any additional parameters, as defined by the Service Provider.
</t>
</list>
</t>
<t>
If the request fails verification or is rejected for other reasons,
the Service Provider SHOULD respond with the appropriate response
code as defined in <xref target="http_codes">HTTP Response Codes</xref>.
The Service Provider MAY include some further details about why the
request was rejected in the HTTP response body as defined in
<xref target="response_parameters">Service Provider Response Parameters</xref>.
</t>
</section>
</section>
<section title="Obtaining User Authorization" anchor="auth_step2">
<t>
The Consumer cannot use the Request Token until it has been
authorized by the User. Obtaining User authorization includes
the following steps:
</t>
<section title="Consumer Directs the User to the Service Provider" anchor="user_auth_redirected">
<t>
In order for the Consumer to be able to exchange the Request Token
for an Access Token, the Consumer MUST obtain approval from the
User by directing the User to the Service Provider. The Consumer
constructs an HTTP GET request to the Service Provider's
User Authorization URL with the following parameter:
<list style="hanging">
<t hangText="oauth_token:">
OPTIONAL. The Request Token obtained in the previous step. The
Service Provider MAY declare this parameter as REQUIRED, or
accept requests to the User Authorization URL without it, in
which case it will prompt the User to enter it manually.
</t>
<t hangText="oauth_callback:">
OPTIONAL. The Consumer MAY specify a URL the Service Provider
will use to redirect the User back to the Consumer when
<xref target="auth_step2">Obtaining User Authorization</xref>
is complete.
</t>
<t hangText="Additional parameters:">
Any additional parameters, as defined by the Service Provider.
</t>
</list>
</t>
<t>
Once the request URL has been constructed the Consumer redirects
the User to the URL via the User's web browser. If the Consumer is
incapable of automatic HTTP redirection, the Consumer SHALL notify
the User how to manually go to the constructed request URL.
</t>
<t>
Note: If a Service Provider knows a Consumer to be running on a
mobile device or set-top box, the Service Provider SHOULD ensure
that the User Authorization URL and Request Token are suitable
for manual entry.
</t>
</section>
<section title="Service Provider Authenticates the User and Obtains Consent">
<t>
The Service Provider verifies the User's identity and asks for
consent as detailed. OAuth does not specify how the Service Provider
authenticates the User. However, it does define a set of REQUIRED
steps:
<list style="symbols">
<t>
The Service Provider MUST first verify the User's identity
before asking for consent. It MAY prompt the User to sign
in if the User has not already done so.
</t>
<t>
The Service Provider presents to the User information about the
Consumer requesting access (as registered by the Consumer
Developer). The information includes the duration of the
access and the Protected Resources provided. The information
MAY include other details specific to the Service Provider.
</t>
<t>
The User MUST grant or deny permission for the Service Provider
to give the Consumer access to the Protected Resources on
behalf of the User. If the User denies the Consumer access, the
Service Provider MUST NOT allow access to the Protected
Resources.
</t>
</list>
</t>
<t>
When displaying any identifying information about the Consumer to
the User based on the Consumer Key, the Service Provider MUST
inform the User if it is unable to assure the Consumer's true
identity. The method in which the Service Provider informs the User
and the quality of the identity assurance is beyond the scope of
this specification.
</t>
</section>
<section title="Service Provider Directs the User Back to the Consumer">
<t>
After the User authenticates with the Service Provider and grants
permission for Consumer access, the Consumer MUST be notified that
the Request Token has been authorized and ready to be exchanged for
an Access Token. If the User denies access, the Consumer MAY be
notified that the Request Token has been revoked.
</t>
<t>
If the Consumer provided a callback URL in <spanx style="verb">oauth_callback</spanx> (as
described in <xref target="user_auth_redirected">Consumer Directs the User to the Service Provider</xref>),
the Service Provider constructs an HTTP GET request URL, and
redirects the User's web browser to that URL with the following
parameters:
<list style="hanging">
<t hangText="oauth_token:">
The Request Token the User authorized or denied.
</t>
</list>
</t>
<t>
The callback URL MAY include Consumer provided query parameters.
The Service Provider MUST retain them unmodified and append the
<spanx style="verb">oauth_token</spanx> parameter to the existing query.
</t>
<t>
If no callback URL was provided, the Service Provider instructs
the User to manually inform the Consumer that authorization has
completed.
</t>
</section>
</section>
<section title="Obtaining an Access Token" anchor="auth_step3">
<t>
The Consumer exchanges the Request Token for an Access Token capable
of accessing the Protected Resources. Obtaining an Access Token
includes the following steps:
</t>
<section title="Consumer Requests an Access Token">
<t>
The Request Token and Token Secret MUST be exchanged for an Access
Token and Token Secret.
</t>
<t>
To request an Access Token, the Consumer makes an HTTP request to
the Service Provider's Access Token URL. The Service Provider
documentation specifies the HTTP method for this request, and HTTP POST
is RECOMMENDED. The request MUST be signed per
<xref target="signing_process">Signing Requests</xref>,
and contains the following parameters:
<list style="hanging">
<t hangText="oauth_consumer_key:">
The Consumer Key.
</t>
<t hangText="oauth_token:">
The Request Token obtained previously.
</t>
<t hangText="oauth_signature_method:">
The signature method the Consumer used to sign the request.
</t>
<t hangText="oauth_signature:">
The signature as defined in <xref target="signing_process">Signing Requests</xref>.
</t>
<t hangText="oauth_timestamp:">
As defined in <xref target="nonce">Nonce and Timestamp</xref>.
</t>
<t hangText="oauth_nonce:">
As defined in <xref target="nonce">Nonce and Timestamp</xref>.
</t>
<t hangText="oauth_version:">
OPTIONAL. If present, value MUST be <spanx style="verb">
1.0
</spanx>. Service Providers
MUST assume the protocol version to be <spanx style="verb">1.0</spanx> if this parameter
is not present. Service Providers' response to non-<spanx style="verb">1.0</spanx> value
is left undefined.
</t>
</list>
</t>
<t>
No additional Service Provider specific parameters are allowed when
requesting an Access Token to ensure all Token related information
is present prior to seeking User approval.
</t>
</section>
<section title="Service Provider Grants an Access Token" anchor="access_grant">
<t>
The Service Provider MUST ensure that:
<list style="symbols">
<t>
The request signature has been successfully verified.
</t>
<t>
The Request Token has never been exchanged for an Access Token.
</t>
<t>
The Request Token matches the Consumer Key.
</t>
</list>
</t>
<t>
If successful, the Service Provider generates an Access Token and
Token Secret and returns them in the HTTP response body as defined
in <xref target="response_parameters">Service Provider Response Parameters</xref>.
The Access Token and Token Secret are stored by the Consumer and
used when signing Protected Resources requests. The response
contains the following parameters:
<list style="hanging">
<t hangText="oauth_token:">
The Access Token.
</t>
<t hangText="oauth_token_secret:">
The Token Secret.
</t>
<t hangText="Additional parameters:">
Any additional parameters, as defined by the Service Provider.
</t>
</list>
</t>
<t>
If the request fails verification or is rejected for other reasons,
the Service Provider SHOULD respond with the appropriate response
code as defined in <xref target="http_codes">HTTP Response Codes</xref>.
The Service Provider MAY include some further details about why the
request was rejected in the HTTP response body as defined in
<xref target="response_parameters">Service Provider Response Parameters</xref>.
</t>
</section>
</section>
</section>
<section title="Accessing Protected Resources">
<t>
After successfully receiving the Access Token and Token Secret, the
Consumer is able to access the Protected Resources on behalf of the
User. The request MUST be signed per
<xref target="signing_process">Signing Requests</xref>, and
contains the following parameters:
<list style="hanging">
<t hangText="oauth_consumer_key:">
The Consumer Key.
</t>
<t hangText="oauth_token:">
The Access Token.
</t>
<t hangText="oauth_signature_method:">
The signature method the Consumer used to sign the request.
</t>
<t hangText="oauth_signature:">
The signature as defined in
<xref target="signing_process">Signing Requests</xref>.
</t>
<t hangText="oauth_timestamp:">
As defined in <xref target="nonce">Nonce and Timestamp</xref>.
</t>
<t hangText="oauth_nonce:">
As defined in <xref target="nonce">Nonce and Timestamp</xref>.
</t>
<t hangText="oauth_version:">
OPTIONAL. If present, value MUST be <spanx style="verb">1.0</spanx>. Service Providers
MUST assume the protocol version to be <spanx style="verb">1.0</spanx> if this parameter
is not present. Service Providers' response to non-<spanx style="verb">1.0</spanx> value
is left undefined.
</t>
<t hangText="Additional parameters:">
Any additional parameters, as defined by the Service Provider.
</t>
</list>
</t>
</section>
<section title="Nonce and Timestamp" anchor="nonce">
<t>
Unless otherwise specified by the Service Provider, the timestamp is
expressed in the number of seconds since January 1, 1970 00:00:00 GMT.
The timestamp value MUST be a positive integer and MUST be equal or
greater than the timestamp used in previous requests.
</t>
<t>
The Consumer SHALL then generate a Nonce value that is unique for all
requests with that timestamp, Consumer Key, and Token combination.
A nonce is a random string, uniquely
generated for each request. The nonce allows the Service Provider to
verify that a request has never been made before and helps prevent
replay attacks when requests are made over a non-secure channel
(such as HTTP).
</t>
</section>
<section title="Signing Requests" anchor="signing_process">
<t>
All Token requests and Protected Resources requests MUST be
signed by the Consumer and verified by the Service Provider.
The purpose of signing requests is to prevent unauthorized parties
from using the Consumer Key and Tokens when making Token requests or
Protected Resources requests. The signature process encodes
the Consumer Secret and Token Secret into a verifiable value which is
included with the request.
</t>
<t>
OAuth does not mandate a particular signature method, as each
implementation can have its own unique requirements. The protocol
defines three signature methods: <spanx style="verb">HMAC-SHA1</spanx>,
<spanx style="verb">RSA-SHA1</spanx>, and
<spanx style="verb">PLAINTEXT</spanx>, but Service Providers
are free to implement and document their own methods.
Recommending any particular method is beyond the scope of this specification.
</t>
<t>
The Consumer declares a signature method in the <spanx style="verb">oauth_signature_method</spanx>
parameter, generates a signature, and stores it in the <spanx style="verb">oauth_signature</spanx>
parameter. The Service Provider verifies the signature as specified in
each method. When verifying a Consumer signature, the Service Provider
SHOULD check the request nonce to ensure it has not been used in a
previous Consumer request.
</t>
<t>
The signature process MUST NOT change the request parameter names or
values, with the exception of the <spanx style="verb">oauth_signature</spanx> parameter.
</t>
<section title="Signature Base String">
<t>
The Signature Base String is a consistent reproducible concatenation
of the request elements into a single string. The string is used as an
input in hashing or signing algorithms. The <spanx style="verb">HMAC-SHA1</spanx> signature
method provides both a standard and an example of using the Signature
Base String with a signing algorithm to generate signatures.
</t>
<section title="Parameter Encoding" anchor="encoding_parameters">
<t>
All parameter names and values MUST be encoded prior to
constructing the Signature Base String. The encoding process uses the parameters in their original
decoded form. It is essential that parameters are encoded in a certain way and need to be processed
without any prior encoding.
</t>
<t>
Text names and values are first encoded as UTF-8 octets per <xref target="RFC3629" />. All parameter names
and values are then escaped using the <xref target="RFC3986" /> percent-encoding (%XX) mechanism as follows:
<list style="symbols">
<t>
Characters not in the unreserved character set
(<xref target="RFC3986" /> section 2.3) MUST be encoded.
</t>
<t>
Characters in the unreserved character set MUST NOT be encoded.
</t>
<t>
Hexadecimal characters in encodings MUST be upper case.
</t>
</list>
</t>
<figure>
<artwork>
unreserved = ALPHA, DIGIT, '-', '.', '_', '~'
</artwork>
</figure>
</section>
<section title="Normalize Request Parameters" anchor="sig_norm_param">
<t>
The request parameters are collected, sorted and concatenated into
a normalized string:
<list style="symbols">
<t>
Parameters in the <xref target="auth_header_authorization">
OAuth HTTP Authorization header
</xref> excluding the <spanx style="verb">realm</spanx>
parameter.
</t>
<t>
Parameters in the HTTP POST request body (with a
<spanx style="verb">content-type</spanx> of
<spanx style="verb">application/x-www-form-urlencoded</spanx>).
</t>
<t>
Added to the URLs in the query part (as defined by
<xref target="RFC3986" /> section 3).
</t>
</list>
</t>
<t>
The <spanx style="verb">oauth_signature</spanx> parameter MUST be
excluded.
</t>
<t>
The parameters are normalized into a single string as follows:
<list style="numbers">
<t>
Parameters are sorted by name, using lexicographical byte value
ordering. If two or more parameters share the same name, they
are sorted by their value. For example:
<figure>
<artwork>
a=1, c=hi%20there, f=25, f=50, f=a, z=p, z=t
</artwork>
</figure>
</t>
<t>
Parameters are concatenated in their sorted order into a single
string. For each parameter, the name is separated from the
corresponding value by an '=' character (ASCII code 61), even
if the value is empty. Each name-value pair is separated by an
'&' character (ASCII code 38). For example:
<figure>
<artwork>
a=1&c=hi%20there&f=25&f=50&f=a&z=p&z=t
</artwork>
</figure>
</t>
</list>
</t>
</section>
<section title="Construct Request URL" anchor="sig_url">
<t>
The Signature Base String includes the request absolute URL, tying
the signature to a specific endpoint. The URL used in the Signature
Base String MUST include the scheme, authority, and path, and MUST
exclude the query and fragment as defined by <xref target="RFC3986" />
section 3.
</t>
<t>
If the absolute request URL is not available to the Service Provider
(it is always available to the Consumer), it can be constructed by
combining the scheme being used, the HTTP <spanx style="verb">Host</spanx>
header, and the relative HTTP request URL. If the
<spanx style="verb">Host</spanx> header is not available, the Service
Provider SHOULD use the host name communicated to the Consumer in the
documentation or other means.
</t>
<t>
The Service Provider SHOULD document the form of URL used in the
Signature Base String to avoid ambiguity due to URL normalization.
Unless specified, URL scheme and authority MUST be lowercase and
include the port number; <spanx style="verb">http</spanx> default
port 80 and <spanx style="verb">https</spanx> default port 443 MUST
be excluded.
</t>
<t>
For example, the request:
<figure>
<artwork>
HTTP://Example.com:80/resource?id=123
</artwork>
</figure>
Is included in the Signature Base String as:
<figure>
<artwork>
http://example.com/resource
</artwork>
</figure>
</t>
</section>
<section title="Concatenate Request Elements">
<t>
The following items MUST be concatenated in order into a single
string. Each item is <xref target="encoding_parameters">encoded</xref>
and separated by an '&' character (ASCII code 38), even if empty.
<list style="numbers">
<t>
The HTTP request method used to send the request. Value MUST be
uppercase, for example: <spanx style="verb">HEAD</spanx>, <spanx style="verb">
GET
</spanx>, <spanx style="verb">POST</spanx>, etc.
</t>
<t>
The request URL from <xref target="sig_url" />.
</t>
<t>
The normalized request parameters string from <xref target="sig_norm_param" />.
</t>
</list>
</t>
<t>
See Signature Base String example in <xref target="sig_base_example" />.
</t>
</section>
</section>
<section title="HMAC-SHA1">
<t>
The <spanx style="verb">HMAC-SHA1</spanx> signature method uses the HMAC-SHA1 signature
algorithm as defined in <xref target="RFC2104" /> where the Signature
Base String is the <spanx style="verb">text</spanx> and the
<spanx style="verb">key</spanx> is the concatenated values
(each first encoded per <xref target="encoding_parameters">Parameter Encoding</xref>)
of the Consumer Secret and Token Secret, separated by an '&'
character (ASCII code 38) even if empty.
</t>
<section title="Generating Signature">
<t>
<spanx style="verb">oauth_signature</spanx> is set
to the calculated <spanx style="verb">digest</spanx> octet string, first base64-encoded per
<xref target="RFC2045" /> section 6.8, then URL-encoded per
<xref target="encoding_parameters">Parameter Encoding</xref>.
</t>
</section>
<section title="Verifying Signature">
<t>
The Service Provider verifies the request by generating a new request
signature octet string, and comparing it to the signature provided by the Consumer,
first URL-decoded per <xref target="encoding_parameters">Parameter Encoding</xref>,
then base64-decoded per <xref target="RFC2045" /> section 6.8.
The signature is generated using the request parameters as provided
by the Consumer, and the Consumer Secret and Token Secret as stored
by the Service Provider.
</t>
</section>
</section>
<section title="RSA-SHA1">
<t>
The <spanx style="verb">RSA-SHA1</spanx> signature method uses the
RSASSA-PKCS1-v1_5 signature algorithm as defined in
<xref target="RFC3447" /> section 8.2 (more simply known as PKCS#1),
using SHA-1 as the hash function for EMSA-PKCS1-v1_5. It is assumed
that the Consumer has provided its RSA public key in a verified way
to the Service Provider, in a manner which is beyond the scope of
this specification.
</t>
<section title="Generating Signature">
<t>
The Signature Base String is signed using the Consumer's RSA private
key per <xref target="RFC3447" /> section 8.2.1, where <spanx style="verb">K</spanx> is the
Consumer's RSA private key, <spanx style="verb">M</spanx> the Signature Base String, and <spanx style="verb">S</spanx> is
the result signature octet string:
<figure>
<artwork>
S = RSASSA-PKCS1-V1_5-SIGN (K, M)
</artwork>
</figure>
</t>
<t>
<spanx style="verb">oauth_signature</spanx> is set to <spanx style="verb">S</spanx>, first base64-encoded per
<xref target="RFC2045" /> section 6.8, then URL-encoded per
<xref target="encoding_parameters">Parameter Encoding</xref>.
</t>
</section>
<section title="Verifying Signature">
<t>
The Service Provider verifies the signature per <xref target="RFC3447" />
section 8.2.2, where <spanx style="verb">
(n, e)
</spanx> is the Consumer's RSA public key, <spanx style="verb">M</spanx>
is the Signature Base String, and <spanx style="verb">S</spanx> is the octet string
representation of the <spanx style="verb">oauth_signature</spanx> value:
<figure>
<artwork>
RSASSA-PKCS1-V1_5-VERIFY ((n, e), M, S)
</artwork>
</figure>
</t>
</section>
</section>
<section title="PLAINTEXT">
<t>
The <spanx style="verb">
PLAINTEXT
</spanx> method does not provide any security protection and
SHOULD only be used over a secure channel such as HTTPS. It does not
use the Signature Base String.
</t>
<section title="Generating Signature">
<t>
<spanx style="verb">oauth_signature</spanx> is set to the concatenated encoded values of the
Consumer Secret and Token Secret, separated by a '&' character (ASCII
code 38), even if either secret is empty. The result MUST be encoded again.
</t>
<t>
These examples show the value of <spanx style="verb">oauth_signature</spanx>
for Consumer Secret <spanx style="verb">djr9rjt0jd78jf88</spanx> and
3 different Token Secrets:
<list style="hanging">
<t hangText="jjd999tj88uiths3:">
<spanx style="verb">oauth_signature</spanx>=<spanx style="verb">djr9rjt0jd78jf88%26jjd999tj88uiths3</spanx>
</t>
<t hangText="jjd99$tj88uiths3:">
<spanx style="verb">oauth_signature</spanx>=<spanx style="verb">djr9rjt0jd78jf88%26jjd99%2524tj88uiths3</spanx>
</t>
<t hangText="Empty:">
<spanx style="verb">oauth_signature</spanx>=<spanx style="verb">djr9rjt0jd78jf88%26</spanx>
</t>
</list>
</t>
</section>
<section title="Verifying Signature">
<t>
The Service Provider verifies the request by breaking the signature
value into the Consumer Secret and Token Secret, and ensures they
match the secrets stored locally.
</t>
</section>
</section>
</section>
<section title="HTTP Response Codes" anchor="http_codes">
<t>
This section applies only to the Request Token and Access Token
requests. In general, the Service Provider SHOULD use the
response codes defined in <xref target="RFC2616" /> Section 10. When
the Service Provider rejects a Consumer request, it SHOULD respond with
HTTP 400 Bad Request or HTTP 401 Unauthorized.
<list style="symbols">
<t>
HTTP 400 Bad Request
<list style="symbols">
<t>
Unsupported parameter
</t>
<t>
Unsupported signature method
</t>
<t>
Missing required parameter
</t>
<t>
Duplicated OAuth Protocol Parameter
</t>
</list>
</t>
<t>
HTTP 401 Unauthorized
<list style="symbols">
<t>
Invalid Consumer Key
</t>
<t>
Invalid / expired Token
</t>
<t>
Invalid signature
</t>
<t>
Invalid / used nonce
</t>
</list>
</t>
</list>
</t>
</section>
<section anchor="IANA" title="IANA Considerations">
<t>
This memo includes no request to IANA.
</t>
</section>
<section anchor="Security" title="Security Considerations">
<section title="Credentials and Token Exchange">
<t>
The OAuth specification does not describe any mechanism for protecting
Tokens and secrets from eavesdroppers when they are transmitted from
the Service Provider to the Consumer in <xref target="request_grant" />
and <xref target="access_grant" />. Service Providers should ensure
that these transmissions are protected using transport-layer mechanisms
such as TLS or SSL.
</t>
</section>
<section title="RSA-SHA1 Signature Method">
<t>
When used with <spanx style="verb">RSA-SHA1</spanx> signatures, the
OAuth protocol does not use the Consumer Secret and Token Secret. This means
the protocol relies completely on the secrecy of the Private Key used by
the Consumer to sign requests.
</t>
</section>
<section title="PLAINTEXT Signature Method">
<t>
When used with <spanx style="verb">PLAINTEXT</spanx> signatures, the
OAuth protocol makes no attempts to protect User credentials from
eavesdroppers or man-in-the-middle attacks.
The <spanx style="verb">PLAINTEXT</spanx> signature algorithm is only
intended to be used in conjunction with a transport-layer security
mechanism such as TLS or SSL which does provide such protection.
If transport-layer protection is unavailable, the
<spanx style="verb">PLAINTEXT</spanx> signature method should not be
used.
</t>
</section>
<section title="Confidentiality of Requests">
<t>
While OAuth provides a mechanism for verifying the integrity of
requests, it provides no guarantee of request confidentiality.
Unless further precautions are taken, eavesdroppers will have full
access to request content. Service Providers should carefully
consider the kinds of data likely to be sent as part of such requests,
and should employ transport-layer security mechanisms to protect
sensitive resources.
</t>
</section>
<section title="Spoofing by Counterfeit Servers">
<t>
OAuth makes no attempt to verify the authenticity of the Service
Provider. A hostile party could take advantage of this by intercepting
the Consumer's requests and returning misleading or otherwise incorrect
responses. Service providers should consider such attacks when
developing services based on OAuth, and should require transport-layer
security for any requests where the authenticity of the Service
Provider or of request responses is an issue.
</t>
</section>
<section title="Proxying and Caching of Authenticated Content">
<t>
The <xref target="auth_header">HTTP Authorization scheme</xref> is
optional. However, <xref target="RFC2616" /> relies on the
<spanx style="verb">Authorization</spanx> and
<spanx style="verb">WWW-Authenticate</spanx> headers to distinguish
authenticated content so that it can be protected. Proxies and
caches, in particular, may fail to adequately protect requests not
using these headers.
</t>
<t>
For example, private authenticated content may be stored in (and thus
retrievable from) publicly-accessible caches. Service Providers not
using the <xref target="auth_header">HTTP Authorization scheme</xref>
should take care to use other mechanisms, such as the
<spanx style="verb">Cache-Control</spanx> header, to ensure that
authenticated content is protected.
</t>
</section>
<section title="Plaintext Storage of Credentials">
<t>
The Consumer Secret and Token Secret function the same way passwords
do in traditional authentication systems. In order to compute the
signatures used in the non-<spanx style="verb">PLAINTEXT</spanx>
methods, the Service Provider must have access to these secrets in
plaintext form. This is in contrast, for example, to modern operating
systems, which store only a one-way hash of user credentials.
</t>
<t>
If an attacker were to gain access to these secrets - or worse, to
the Service Provider's database of all such secrets - he or she would
be able to perform any action on behalf of any User. Accordingly, it
is critical that Service Providers protect these secrets from
unauthorized access.
</t>
</section>
<section title="Secrecy of the Consumer Secret">
<t>
In many applications, the Consumer application will be under the
control of potentially untrusted parties. For example, if the
Consumer is a freely available desktop application, an attacker may
be able to download a copy for analysis. In such cases, attackers
will be able to recover the Consumer Secret used to authenticate the
Consumer to the Service Provider.
</t>
<t>
Accordingly, Service Providers should not use the Consumer Secret
alone to verify the identity of the Consumer. Where possible, other
factors such as IP address should be used as well.
</t>
</section>
<section title="Phishing Attacks">
<t>
Wide deployment of OAuth and similar protocols may cause
Users to become inured to the practice of being redirected to
websites where they are asked to enter their passwords. If Users are
not careful to verify the authenticity of these websites before
entering their credentials, it will be possible for attackers to
exploit this practice to steal Users' passwords.
</t>
<t>
Service Providers should attempt to educate Users about the risks
phishing attacks pose, and should provide mechanisms that make it
easy for Users to confirm the authenticity of their sites.
</t>
</section>
<section title="Scoping of Access Requests">
<t>
By itself, OAuth does not provide any method for scoping the access
rights granted to a Consumer. A Consumer either has access to
Protected Resources or it doesn't. Many applications will, however,
require greater granularity of access rights. For example, Service
Providers may wish to make it possible to grant access to some
Protected Resources but not others, or to grant only limited access
(such as read-only access) to those Protected Resources.
</t>
<t>
When implementing OAuth, Service Providers should consider the types
of access Users may wish to grant Consumers, and should provide
mechanisms to do so. Service Providers should also take care to
ensure that Users understand the access they are granting, as well as
any risks that may be involved.
</t>
</section>
<section title="Entropy of Secrets">
<t>
Unless a transport-layer security protocol is used, eavesdroppers will
have full access to OAuth requests and signatures, and will thus be
able to mount offline brute-force attacks to recover the Consumer's
credentials used. Service Providers should be careful to assign Token
Secrets and Consumer Secrets which are long enough - and random enough
- to resist such attacks for at least the length of time that the
secrets are valid.
</t>
<t>
For example, if Token Secrets are valid for two weeks, Service
Providers should ensure that it is not possible to mount a brute force
attack that recovers the Token Secret in less than two weeks. Of
course, Service Providers are urged to err on the side of caution,
and use the longest secrets reasonable.
</t>
<t>
It is equally important that the pseudo-random number generator (PRNG)
used to generate these secrets be of sufficiently high quality. Many
PRNG implementations generate number sequences that may appear to be
random, but which nevertheless exhibit patterns or other weaknesses
which make cryptanalysis or brute force attacks easier. Implementors
should be careful to use cryptographically secure PRNGs to avoid these
problems.
</t>
</section>
<section title="Denial of Service / Resource Exhaustion Attacks">
<t>
The OAuth protocol has a number of features which may make resource
exhaustion attacks against Service Providers possible. For example,
if a Service Provider includes a nontrivial amount of entropy in Token
Secrets as recommended above, then an attacker may be able to exhaust
the Service Provider's entropy pool very quickly by repeatedly
obtaining Request Tokens from the Service Provider.
</t>
<t>
Similarly, OAuth requires Service Providers to track used nonces. If
an attacker is able to use many nonces quickly, the resources required
to track them may exhaust available capacity. And again, OAuth can
require Service Providers to perform potentially expensive computations
in order to verify the signature on incoming requests. An attacker may
exploit this to perform a denial of service attack by sending a large
number of invalid requests to the Service Provider.
</t>
<t>
Resource Exhaustion attacks are by no means specific to OAuth. However,
OAuth implementors should be careful to consider the additional
avenues of attack that OAuth exposes, and design their implementations
accordingly. For example, entropy starvation typically results in
either a complete denial of service while the system waits for new
entropy or else in weak (easily guessable) secrets. When implementing
OAuth, Service Providers should consider which of these presents a
more serious risk for their application and design accordingly.
</t>
</section>
<section title="Cryptographic Attacks">
<t>
SHA-1, the hash algorithm used in <spanx style="verb">HMAC-SHA1</spanx>
signatures, has been <xref target="SHA1-CHARACTERISTICS">shown</xref> to have a number
of cryptographic weaknesses that significantly reduce its resistance to
collision attacks. Practically speaking, these weaknesses are difficult
to exploit, and by themselves do not pose a significant risk to users
of OAuth. They may, however, make more efficient attacks possible, and
NIST has <xref target="SHA-COMMENTS">announced</xref> that it will phase out
use of SHA-1 by 2010. Service Providers should take this into account
when considering whether SHA-1 provides an adequate level of security
for their applications.
</t>
</section>
<section title="Signature Base String Compatibility">
<t>
The Signature Base String has been designed to support the signature
methods defined in this specification. When designing additional
signature methods, the Signature Base String should be evaluated to
ensure compatibility with the algorithms used.
</t>
<t>
The Signature Base String cannot guarantee the order in which parameters
are sent. If parameter ordering is important and affects the result of a
request, the Signature Base String will not protect against request
manipulation.
</t>
</section>
</section>
<appendix title="Appendix A - Protocol Example">
<t>
In this example, the Service Provider photos.example.net is a photo
sharing website, and the Consumer printer.example.com is a photo
printing website. Jane, the User, would like printer.example.com to
print the private photo <spanx style="verb">
vacation.jpg
</spanx> stored at photos.example.net.
</t>
<t>
When Jane signs-into photos.example.net using her username and
password, she can access the photo by going to the URL
<spanx style="verb">http://photos.example.net/photo?file=vacation.jpg</spanx>. Other Users
cannot access that photo, and Jane does not want to share her
username and password with printer.example.com.
</t>
<t>
The requests in this example use the URL query method when sending
parameters. This is done to simplify the example and should not be
taken as an endorsement of one method over the others.
</t>
<appendix title="Documentation and Registration">
<t>
The Service Provider documentation explains how to register for a
Consumer Key and Consumer Secret, and declares the following URLs:
<list style="hanging">
<t hangText="Request Token URL:">
https://photos.example.net/request_token, using HTTP POST
</t>
<t hangText="User Authorization URL:">
http://photos.example.net/authorize, using HTTP GET
</t>
<t hangText="Access Token URL:">
https://photos.example.net/access_token, using HTTP POST
</t>
<t hangText="Photo (Protected Resource) URL:">
http://photos.example.net/photo with required parameter
<spanx style="verb">file</spanx> and optional parameter <spanx style="verb">size</spanx>
</t>
</list>
</t>
<t>
The Service Provider declares support for the <spanx style="verb">
HMAC-SHA1
</spanx> signature
method for all requests, and <spanx style="verb">PLAINTEXT</spanx> only for secure (HTTPS)
requests.
</t>
<t>
The Consumer printer.example.com already established a Consumer Key
and Consumer Secret with photos.example.net and advertizes its
printing services for photos stored on photos.example.net. The
Consumer registration is:
<list style="hanging">
<t hangText="Consumer Key:">
<spanx style="verb">
dpf43f3p2l4k3l03
</spanx>
</t>
<t hangText="Consumer Secret:">
<spanx style="verb">kd94hf93k423kf44</spanx>
</t>
</list>
</t>
</appendix>
<appendix title="Obtaining a Request Token">
<t>
After Jane informs printer.example.com that she would like to print
her vacation photo stored at photos.example.net, the printer website
tries to access the photo and receives HTTP 401 Unauthorized
indicating it is private. The Service Provider includes the following
header with the response:
<figure>
<artwork>
WWW-Authenticate: OAuth realm="http://photos.example.net/"
</artwork>
</figure>
</t>
<t>
The Consumer sends the following HTTP POST request to the Service
Provider:
<figure>
<artwork>
https://photos.example.net/request_token?
oauth_consumer_key=dpf43f3p2l4k3l03&oauth_signature_method=PLAINTEXT&
oauth_signature=kd94hf93k423kf44%26&oauth_timestamp=1191242090&
oauth_nonce=hsu94j3884jdopsl&oauth_version=1.0
</artwork>
</figure>
</t>
<t>
The Service Provider checks the signature and replies with an
unauthorized Request Token in the body of the HTTP response:
<figure>
<artwork>
oauth_token=hh5s93j4hdidpola&oauth_token_secret=hdhd0244k9j7ao03
</artwork>
</figure>
</t>
</appendix>
<appendix title="Requesting User Authorization">
<t>
The Consumer redirects Jane's browser to the Service Provider
User Authorization URL to obtain Jane's approval for accessing
her private photos.
<figure>
<artwork>
http://photos.example.net/authorize?oauth_token=hh5s93j4hdidpola&
oauth_callback=http%3A%2F%2Fprinter.example.com%2Frequest_token_ready
</artwork>
</figure>
</t>
<t>
The Service Provider asks Jane to sign-in using her username and
password and, if successful, asks her if she approves granting
printer.example.com access to her private photos. If Jane approves
the request, the Service Provider redirects her back to the
Consumer's callback URL:
<figure>
<artwork>
http://printer.example.com/request_token_ready?
oauth_token=hh5s93j4hdidpola
</artwork>
</figure>
</t>
</appendix>
<appendix title="Obtaining an Access Token">
<t>
Now that the Consumer knows Jane approved the Request Token, it
asks the Service Provider to exchange it for an Access Token:
<figure>
<artwork>
https://photos.example.net/access_token?
oauth_consumer_key=dpf43f3p2l4k3l03&
oauth_token=hh5s93j4hdidpola&oauth_signature_method=PLAINTEXT&
oauth_signature=kd94hf93k423kf44%26hdhd0244k9j7ao03&
oauth_timestamp=1191242092&
oauth_nonce=dji430splmx33448&oauth_version=1.0
</artwork>
</figure>
</t>
<t>
The Service Provider checks the signature and replies with an
Access Token in the body of the HTTP response:
<figure>
<artwork>
oauth_token=nnch734d00sl2jdk&oauth_token_secret=pfkkdhi9sl3r4s00
</artwork>
</figure>
</t>
</appendix>
<appendix title="Accessing Protected Resources">
<t>
The Consumer is now ready to request the private photo. Since the
photo URL is not secure (HTTP), it must use <spanx style="verb">HMAC-SHA1</spanx>.
</t>
<appendix title="Generating Signature Base String" anchor="sig_base_example">
<t>
To generate the signature, it first needs to generate the Signature
Base String. The request contains the following parameters
(<spanx style="verb">oauth_signature</spanx> excluded) which are ordered and concatenated into
a normalized string:
<list style="hanging">
<t hangText="oauth_consumer_key:">
<spanx style="verb">dpf43f3p2l4k3l03</spanx>
</t>
<t hangText="oauth_token:">
<spanx style="verb">nnch734d00sl2jdk</spanx>
</t>
<t hangText="oauth_signature_method:">
<spanx style="verb">HMAC-SHA1</spanx>
</t>
<t hangText="oauth_timestamp:">
<spanx style="verb">1191242096</spanx>
</t>
<t hangText="oauth_nonce:">
<spanx style="verb">kllo9940pd9333jh</spanx>
</t>
<t hangText="oauth_version:">
<spanx style="verb">1.0</spanx>
</t>
<t hangText="file:">
<spanx style="verb">vacation.jpg</spanx>
</t>
<t hangText="size:">
<spanx style="verb">original</spanx>
</t>
</list>
</t>
<t>
The following inputs are used to generate the Signature Base String:
<list style="numbers">
<t hangText="The HTTP request method:">
<spanx style="verb">GET</spanx>
</t>
<t hangText="The request URL:">
<spanx style="verb">http://photos.example.net/photos</spanx>
</t>
<t hangText="The encoded normalized request parameters string:">
<spanx style="verb">file=vacation.jpg&oauth_consumer_key=dpf43f3p2l4k3l03&oauth_nonce=kllo9940pd9333jh&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1191242096&oauth_token=nnch734d00sl2jdk&oauth_version=1.0&size=original</spanx>
</t>
</list>
</t>
<t>
The Signature Base String is:
<figure>
<artwork>
GET&http%3A%2F%2Fphotos.example.net%2Fphotos&file%3Dvacation.jpg%26
oauth_consumer_key%3Ddpf43f3p2l4k3l03%26
oauth_nonce%3Dkllo9940pd9333jh%26
oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1191242096%26
oauth_token%3Dnnch734d00sl2jdk%26oauth_version%3D1.0%26size%3Doriginal
</artwork>
</figure>
</t>
</appendix>
<appendix title="Calculating Signature Value">
<t>
HMAC-SHA1 produces the following <spanx style="verb">digest</spanx> value as a base64-encoded
string (using the Signature Base String as <spanx style="verb">text</spanx> and
<spanx style="verb">
kd94hf93k423kf44&pfkkdhi9sl3r4s00
</spanx> as <spanx style="verb">key</spanx>):
<figure>
<artwork>
tR3+Ty81lMeYAr/Fid0kMTYa/WM=
</artwork>
</figure>
</t>
</appendix>
<appendix title="Requesting Protected Resource">
<t>
All together, the Consumer request for the photo is:
<figure>
<artwork>
http://photos.example.net/photos?file=vacation.jpg&size=original
Authorization: OAuth realm="http://photos.example.net/",
oauth_consumer_key="dpf43f3p2l4k3l03",
oauth_token="nnch734d00sl2jdk",
oauth_signature_method="HMAC-SHA1",
oauth_signature="tR3%2BTy81lMeYAr%2FFid0kMTYa%2FWM%3D",
oauth_timestamp="1191242096",
oauth_nonce="kllo9940pd9333jh",
oauth_version="1.0"
</artwork>
</figure>
</t>
<t>
And if using query parameters:
<figure>
<artwork>
http://photos.example.net/photos?file=vacation.jpg&size=original&
oauth_consumer_key=dpf43f3p2l4k3l03&oauth_token=nnch734d00sl2jdk&
oauth_signature_method=HMAC-SHA1&
oauth_signature=tR3%2BTy81lMeYAr%2FFid0kMTYa%2FWM%3D&
oauth_timestamp=1191242096&
oauth_nonce=kllo9940pd9333jh&oauth_version=1.0
</artwork>
</figure>
</t>
<t>
photos.example.net checks the signature and responds with the
requested photo.
</t>
</appendix>
</appendix>
</appendix>
<appendix title="Contributors">
<t>
The content and concepts within are a product of the OAuth community. It has been
originally published as the <xref target="OAuth Core 1.0" /> community specification
and was authored by:
<list style='empty'>
<t>Mark Atwood (me@mark.atwood.name)</t>
<t>Richard M. Conlan (zeveck@google.com)</t>
<t>Blaine Cook (romeda@gmail.com)</t>
<t>Leah Culver (leah@pownce.com)</t>
<t>Kellan Elliott-McCrea (kellan@flickr.com)</t>
<t>Larry Halff (larry@ma.gnolia.com)</t>
<t>Eran Hammer-Lahav (eran@hueniverse.com)</t>
<t>Ben Laurie (benl@google.com)</t>
<t>Chris Messina (chris@citizenagency.com)</t>
<t>John Panzer (jpanzer@acm.org)</t>
<t>Sam Quigley (quigley@emerose.com)</t>
<t>David Recordon (david@sixapart.com)</t>
<t>Eran Sandler (eran@yedda.com)</t>
<t>Jonathan Sergent (sergent@google.com)</t>
<t>Todd Sieling (todd@ma.gnolia.com)</t>
<t>Brian Slesinsky (brian-oauth@slesinsky.org)</t>
<t>Andy Smith (andy@jaiku.com)</t>
</list>
</t>
</appendix>
</middle>
<back>
<references title="Normative References">
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2045.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2104.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2616.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2617.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.3447.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.3629.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.3986.xml"?>
<?rfc include="http://xml.resource.org/public/rfc/bibxml4/reference.W3C.REC-html40-19980424.xml"?>
</references>
<references title="Informative References">
<reference anchor="OAuth Core 1.0">
<front>
<title>OAuth Core 1.0</title>
<author initials="OCW" surname="OAuth" fullname="OAuth Core Workgroup">
<organization />
</author>
</front>
<format type="HTML" target="http://oauth.net/core/1.0" />
</reference>
<reference anchor="SHA1-CHARACTERISTICS">
<front>
<title>Finding SHA-1 Characteristics: General Results and Applications</title>
<author initials="C.DC" surname="De Canniere" fullname="Christophe De Canniere">
<organization />
</author>
<author initials="C.R" surname="Rechberger" fullname="Christian Rechberger">
<organization />
</author>
</front>
<format type="HTML" target="http://dx.doi.org/10.1007/11935230_1" />
</reference>
<reference anchor="SHA-COMMENTS">
<front>
<title>NIST Brief Comments on Recent Cryptanalytic Attacks on Secure Hashing Functions and the Continued Security Provided by SHA-1, August, 2004.</title>
<author initials="NIST" surname="National Institute of Standards and Technolog" fullname="National Institute of Standards and Technolog">
<organization />
</author>
</front>
<format type="PDF" target="http://csrc.nist.gov/hash_standards_comments.pdf" />
</reference>
</references>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-24 15:51:28 |