Configuring OAuth2-OpenID Connect Single-Sign-On

OAuth 2.0 has three main phases. They are; requesting an Authorization Grant, exchanging the Authorization Grant for an Access Token and accessing the resources using this Access Token. OpenID Connect is another identity layer on top of OAuth 2.0. OAuth applications can get authentication event information over the IDToken and can get the extra claims of the authenticated user from the OpenID Connect UserInfo endpoint.

To enable OAuth support for your client application, you must first register your application by providing an application name. For code and implicit grant types, you have to provide a callback URL. Follow the instructions below to add a new application.

Let's get started to configure the service provider you created!

1. Expand the OAuth/OpenID Connect Configuration and click Configure.

2. Fill in the form that appears. For the Allowed Grant Types you can disable the ones you do not require or wish to block.

   Note: The grant type highlighted below is a custom grant type. This will only appear on the UI if you have configured the JWT grant type. The value specified in the <GrantTypeName> property of the identity.xml file when creating the custom grant type is the value that will appear on the UI. For more information on writing a custom grant type, see Writing a Custom OAuth 2.0 Grant Type.

   

   When filling out the New Application form, the following details should be taken into consideration.

   Field	Notes
   OAuth Version	Selecting OAuth Version as 1.0a removes all the configurable Allowed Grant Types. This is because this version of OAuth does not support grant types.
   Callback Url	This is the exact location in the service provider's application where an access token would be sent. This is a required field (if the grant type is anything other than 'Code' or 'Implicit') and it is important to configure, as it is imperative that the service provider receives the access token. This is necessary for security purposes to ensure that the token is not compromised. Configure multiple callback URLs From IS 5.2.0 onwards, regex-based consumer URLs are supported when defining the callback URL. This enables you to configure multiple callback URLs for one application by entering a regex pattern as the value for the callback URL field. For example, if you have two service providers that use the same application, you can now define a regex pattern which will work for both callback URLs instead of having to configure two different applications for the two service providers. Assume the two callback URLs for your two service providers are as follows: https://myapp.com/callback https://testapp:8000/callback To configure the callback URL to work for both of these URLs, set it using a regex pattern as follows: regexp=(https://myapp.com/callback|https://testapp:8000/callback) You must have the prefix 'regexp=' before your regex pattern. To define a normal URL, you can specify the callback URL without this prefix.
   Allowed Grant Types - The following are the grant types that are used to get the access token:
   Code	Entering the username and password required at the service provider will result in a code being generated. This code can be used to obtain the access token. For more information on this grant type, see this Authorization Code specification.
   Implicit	This is similar to the code grant type, but instead of generating a code, this directly provides the access token. For more information on this grant type, see this Implicit Grant specification.
   Password	This authenticates the user using the password provided and the access token is provided. For more information on this grant type, see this Resource Owner Password Credentials Grant specification.
   Client Credential	This is the grant type for the client key and client secret. If these two items are provided correctly by the service provider, the access token is sent. For more information on this grant type, see this Client Credentials specification.
   Refresh Token	This will enable the user to obtain an access token by using the refresh token once the originally provided access token is used up. For more information on this grant type, see this Refresh Token specification.
   SAML	This uses SAML assertion to obtain the access token. For more information on this grant type, see this SAML2 Bearer specification.
   IWA-NTLM	This is similar to the password grant type, but it is specific to Microsoft Windows users.
   urn:ietf:params:oauth:grant-type:jwt-bearer	This is a custom grant type. It uses a JWT token to obtain the access token. For more information about this grant type, see this JWT specification.
   PKCE Mandatory	Select this if you are using the Code grant type. PKCE is a recommended security measure used to mitigate a code interception attack. See Mitigating Authorization Code Interception Attacks for more information.
   Support PKCE 'Plain' Transform Algorithm	Select this if you are using PKCE.
   User Access Token Expiry Time, Application Access Token Expiry Time, Refresh Token Expiry Time	Set the validity period (in seconds) for User Access Token, Application Access Token, and Refresh Token.

3. Click Add. The following information is added for your service provider.
   
   • OAuth Client Key - This is the client key of the service provider, which will be checked for authentication by the Identity Server before providing the access token.
   • OAuth Client Secret - This is the client secret of the service provider, which will be checked for authentication by the Identity Server before providing the access token. Click the Show button to view the exact value of this.
   • Actions - 

     • Edit: Click to edit the OAuth/OpenID Connect Configurations

     • Revoke: Click to revoke (deactivate) the OAuth application. This action revokes all tokens issued for this application. In order to activate the application, you have to regenerate the consumer secret. 

     • Regenerate Secret: Click to regenerate the secret key of the OAuth application. 

     • Delete: Click to delete the OAuth/OpenID Connect Configurations

   Tip: The OAuth client key and client secret are stored in plain text. To encrypt the client secret, access token and refresh token, do the following:

   Open the identity.xml file found in the <IS_HOME>/repository/conf/identity directory and change the <TokenPersistenceProcessor> property as follows:

   <TokenPersistenceProcessor>org.wso2.carbon.identity.oauth.tokenprocessor.EncryptionDecryptionPersistenceProcessor</TokenPersistenceProcessor>

   After updating the configuration, make sure to restart the server for the changes to be applied on WSO2 IS.