Get access token using SAML assertion


The OAuth 2.0 Access Token using SAML Assertion filter enables an OAuth client to request an access token using a SAML assertion. This supports the OAuth 2.0 SAML flow, which is used when a client wishes to utilize an existing trust relationship, expressed through the semantics of the SAML assertion, without a direct user approval step at the authorization server. For more details on supported OAuth flows, see API Gateway OAuth 2.0 authentication flows.

For more information on SAML, see the IETF draft document:
SAML 2.0 Profile for OAuth 2.0

OAuth access tokens are used to grant access to specific resources in an HTTP service for a specific period of time (for example, photos on a photo sharing website). This enables users to grant third-party applications access to their resources without sharing all of their data and access permissions. An OAuth access token can be sent to the resource server to access the protected resources of the resource owner (user). This token is a string that denotes a specific scope, lifetime, and other access attributes.

SAML assertion validation settings

Configure the following fields on this tab:

Audience and Recipient within SAML Assertion must contain the following URI:
Enter a URI that must be contained in the SAML assertion's intended audience and recipient. The SAML assertion must contain a URI that identifies the authorization server as an intended audience, and that identifies the token endpoint URL of the authorization server as a recipient. Defaults to http://apigateway/api/oauth/token.

Drift time (seconds):
Enter a drift time in seconds to allow for clock skew.

Call the following policy to verify SAML Assertion signature:
Click the browse button to select a policy to verify the SAML assertion signature.

To guarantee the integrity of an XML signature in a message, the Access Token using SAML Assertion filter should use the XML Signature Verification filter. For more information, see the XML Signature Verification filter in the API Gateway Policy Developer Filter Reference. When API Gateway receives the assertion, it converts the assertion into a W3C DOM document and stores this value in a message attribute named oauth.saml.doc. This message attribute is used by the XML Signature Verification filter. A sample SAML bearer policy flow is available after you have completed setting up OAuth (see Set up API Gateway as an OAuth 2.0 server).

Access token settings

Configure the following fields on this tab:

Access Token will be stored here:

Click the browse button to select where to store the access token (for example, in the default OAuth Access Token Store). To add an access token store, right-click Access Token Stores, and select Add Access Token Store. You can store tokens in a cache, in a relational database, or in an Apache Cassandra database. For more details, see Manage access tokens and authorization codes.

Access Token Expiry (in secs):

Enter the number of seconds before the access token expires. Defaults to 3600 (one hour).

Access Token Length:

Enter the number of characters in the access token. Defaults to 54.

Access Token Type:

Enter the access token type. This provides the client with information required to use the access token to make a protected resource request. The client cannot use an access token if it does not understand the token type. Defaults to Bearer.

Refresh Token Details:

Select one of the following options:

  • Generate a new refresh token:
  • Select this option to generate a new access token and refresh token pair. The old refresh token passed in the request is removed. This option is selected by default.
  • Enter the number of seconds before the refresh token expires in the Refresh Token Expiry (in secs) field, and enter the number of characters in the refresh token in the Refresh Token Length field. The expiry defaults to 43200 (12 hours), and the length defaults to 46.
  • Do not generate a refresh token:
  • Select this option to generate a new access token only. The old refresh token passed in the request is removed.

Store additional meta data with the access token which can subsequently be retrieved:

Click Add to store additional access token parameters, and enter the Name and Value in the dialog (for example, Department and Engineering).

Generate Token Scopes:

When requesting a token from the authorization server, you can specify a parameter for the OAuth scopes that you wish to access. When scopes are sent in the request, you can select whether the access token is generated only if the scopes in the request match all or any scopes registered for the application. Alternatively, for extra flexibility, you can get the scopes by calling out to a policy.

Select one of the following options to configure how access tokens are generated based on specified scopes:

  • Get scopes from a registered application:
  • Select whether the scopes must match Any or All of the scopes registered for the application in the Client Application Registry. Defaults to Any. If no scopes are sent in the request, the token is generated with the scopes registered for the application.
  • Get scopes by calling policy:
  • Select a preconfigured policy to get the scopes, and enter the attribute that stores the scopes in the Scopes approved for token are stored in the attribute field. Defaults to scopes.for.token. The configured filter requires the scopes as a set of strings on the message whiteboard.

Monitoring settings

The real-time monitoring options enable you to view service usage in API Gateway Manager. For more information on real-time monitoring, see the API Gateway Administrator Guide.

Enable monitoring

Select this option to enable real-time monitoring. If this is enabled you can view service usage in the web-based API Gateway Manager tool.

Which attribute is used to identify the client

Enter the message attribute to use to identify authenticated clients. The default is, which stores the identifier of the authenticated user (for example, the user name or user's X.509 Distinguished Name).

Composite Context

This setting enables you to select a service context as a composite context in which multiple service contexts are monitored during the processing of a message. This setting is not selected by default.

For example, the API Gateway receives a message and sends it to serviceA first, and then to serviceB. Monitoring is performed separately for each service by default. However, you can set a composite service context before serviceA and serviceB that includes both services. This composite service passes if both services complete successfully, and monitoring is also performed on the composite service context.

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