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You You use the Token API to generate and renew user and application access tokens programmatically. The tokens , which are required to invoke APIs subscribed under an application. Let's see how to generate/renew access tokens and authorize them. We support the four most common authorization grant types and you can also define additional types such as SAML. :

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  1. Combine the consumer key and consumer secret keys in the format consumer-key:consumer-secret and encode the combined string using base64 using the URL: http://base64encode.org.
    Here's an example consumer key and secret combination : wU62DjlyDBnq87GlBwplfqvmAbAa:ksdSdoefDDP7wpaElfqvmjDue.
  2. Invoke the Token API by using a REST client such as the WSO2 REST Client or cURL, with the following parameters.
    • Assuming that both the client and the API Gateway are run on the same server, the token API URL is https://localhost:8243/token
    • payload - "grant_type=password&username=<username>&password=<password>&scope=<scope>". Replace the <username> and <password> values as appropriate. <scope> is optional, you can leave it off if necessary
    • headers - Authorization: Basic <base64 encoded string>, Content-Type: application/x-www-form-urlencoded. Replace the <base64 encoded string> as appropriate.          

    For example, use the following cURL command to access the Token API. It generates two tokens as an access token and a refresh token. You can use the refresh token at the time a token is renewed.

    Code Block
    curl -k -d "grant_type=password&username=<username>&password=<password>" -H "Authorization: Basic SVpzSWk2SERiQjVlOFZLZFpBblVpX2ZaM2Y4YTpHbTBiSjZvV1Y4ZkM1T1FMTGxDNmpzbEFDVzhh, Content-Type: application/x-www-form-urlencoded" https://localhost:8243/token
    Code Block
    titleCuRL command with Scopes
    curl -k -d "grant_type=password&username=<username>&password=<password>&scope<scope1> <scope2>" -H "Authorization: Basic SVpzSWk2SERiQjVlOFZLZFpBblVpX2ZaM2Y4YTpHbTBiSjZvV1Y4ZkM1T1FMTGxDNmpzbEFDVzhh, Content-Type: application/x-www-form-urlencoded" https://localhost:8243/token
    Info
    titleA note about scopes

    When defining an API, the API creator is able to specify a scope for an API resourceits resources. The resource resources can only be accessed through a token that has been issued for at least the scope belonging to the API resource. For example, if a resource has been defined for a scope named 'update' and if the token had been issued for the scopes 'read' and 'update', the token will be allowed to access the resource. If the token had been issued for a scope named 'read', the request bearing the particular token will be blocked.

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  1. for a scope named 'read', the request bearing the particular token will be blocked.

Generating access tokens with authorization code (authorization code grant type)

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Invoking the Token API to generate tokens

Assuming that both the client and the API Gateway are run on the same server, the Authorization API url The Authorization AP'sI URL is https:///localhost:8243/authorize.localhost:8243/authorize. The HTTP request can have the following parameters:

  • query component - : response_type=code&client_id=<consumer_key>&scope=PRODUCTION&redirect_uri=<application_callback_url>
  • headers - : Content-Type: application/x-www-form-urlencoded

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Code Block
HTTP/1.1 302 Found 
Location:
https://client.example.com/cb?code=SplxlOBeZQQYbYS6WxSbIA

Now the The client makes the following HTTP request using TLS to the /token endpoint.

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Exchanging SAML2 bearer tokens with OAuth2 (SAML extension grant type)

SAML 2.0 is an XML-based protocol. It uses security tokens containing assertions to pass information about an enduser end user between a SAML authority and a SAML consumer. A SAML authority is an identity provider (IDP) and a SAML consumer is a service provider (SP).

A lot of enterprise applications use SAML2 to engage a third-party identity provider to grant access to systems that are only authenticated against the enterprise application. These enterprise applications might need to consume OAuth-protected resources through APIs, after validating them against an OAuth2.0 authentication server. However, an enterprise application that already has a working SAML2.0 based SSO infrastructure between itself and the IDP prefers to use the existing trust relationship, even if the OAuth authorization server is entirely different from the IDP. The SAML2 Bearer Assertion Profile for OAuth2.0 helps leverage this existing trust relationship by presenting the SAML2.0 token to the authorization server and exchanging it to an OAuth2.0 access token.WSO2 API Manager provides SAML2 Bearer Assertion Profile Support with the OAuth 2.0 feature. WSO2 Identity Server (version 5.0.0 is used here but you can use any version from 4.5.0 onwards) or any other SAML2 Identity provider can act as an identity service provider for the systems enabled with SSO. WSO2 API Manager acts as the OAuth authorization server. This way, an and exchanging it to an OAuth2.0 access token.

WSO2 API Cloud acts as an authorization server and provides SAML2 Bearer Assertion Profile Support with the OAuth 2.0 feature. An enterprise application can exchange the SAML2.0 bearer token that it retrieves when authenticating against an IDP (e.g., WSO2 Identity Server) with an OAuth2.0 access token from an OAuth authorization server (e.g., WSO2 API ManagerCloud). It can then use the OAuth2 token in API invocations.

The diagram below depicts this scenario:

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The scenarios of the above diagram are explained below:

Scenario [1]: User initiates login call to an enterprise application .

Scenario [2]:

  • As the application is a SAML SP, it redirects the user to the SAML2.0 IDP to log in.
  • The user provides credentials at the IDP and is redirected back to the SP with a SAML2.0 token signed by the IDP.
  • The SP verifies the token and logs the user to the application.
  • The SAML 2.0 token is stored in the user's session by the SP.  

Scenario [3]:

  • The enterprise application (SP) wants to access an OAuth2 protected API resource through WSO2 the API ManagerCloud.
  • The application makes a request to the API Manager Cloud to exchange the SAML2 bearer token for an OAuth2.0 access token.
  • The API Manager Cloud validates the assertion and returns the access token.

Scenario [4]: User does API invocations through the API Manager Cloud by setting it as an Authorization header with the returned OAuth2 access token.

Let's see how to configure the token exchange.

Prerequisites

  • A signed SAML2 token (encoded assertion value), which you retrieve when authenticating against a SAML2 IDP. With the authentication request, you must pass attributes such as SAML2 issuer name, token endpoint and the restricted audience. To specify those attributes,
    If you have multiple Carbon servers (such as WSO2 API Manager and WSO2 Application Server) running on the same machine, you must change the port offset and update the token API endpoint. Additionally, if the key server is on a different server from the API Gateway, you must update the token API endpoint to use the correct host and port. For more information, see this prerequisite in the previous section
    1. Log in to the management console (https://localhost:9443/carbon) using admin/admin credentials and select Add under Identity Providers menu in the Main menu.

    2. Provide the following values in the page that opens:
      • Under Basic Information
        • Identity Provider Name: Enter a unique name for IDP
        • Identity Provider Public Certificate: Upload Identity Provider public certificate
        • Alias: Give the name of the alias if the Identity Provider identifies this token endpoint by an alias
      • Under Federated Authenticators -> SAML2 Web SSO Configuration

        • Identity Provider Entity Id: The SAML2 issuer name specified when generating assertion token, which contains the unique identifier of the IDP 

        • Service Provider Entity Id
        • SSO URL: Enter the IDP's SAML2 Web SSO URL value
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  • A valid user account in the API Store. See Signing up to API Store.
  • A valid consumer key and consumer secret. Initially, these keys must be generated through the management console by clicking the Generate link on My Subscriptions page. For more information, see Generate Access Tokens to Authenticate APIs.
  • A running API Gateway instance. See information on API Gateway in Architecture.
        • SAML2 issuer name specified when generating assertion token, which contains the unique identifier of the IDP 

        • Service Provider Entity Id
        • SSO URL: Enter the IDP's SAML2 Web SSO URL value
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  • A valid user account in the API Store.
  • A valid consumer key and consumer secret. Initially, these keys must be generated through the management console by clicking the Generate link on My Subscriptions page.

Invoking Token API to generate tokens
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GenerateToken
GenerateToken
  

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  1. Combine the consumer key and consumer secret keys as consumer-key:consumer-secret and encode the combined string using base64 using http://base64encode.org. Here's an example consumer key and secret combination: wU62DjlyDBnq87GlBwplfqvmAbAa:ksdSdoefDDP7wpaElfqvmjDue.
  2. Access the Token API using a REST client such as the  WSO2 REST Client or Curl. The parameters are explained below:

    • Assuming that both the client and the API Gateway run on the same server, the The Token API URL is https://localhost:8243/token. It can take the following parameters:
      • payload
      -
      • : Authorization :Basic <base64 encoded string>, Content-Type: application/x-www-form-urlencoded. Replace the <base64 encoded string> as appropriate.

    For example, use the following cURL command used to access the Token API generates an access token and a refresh token. You can use the refresh token at the time a token is renewed.

    Code Block
    curl -k -d "grant_type=urn:ietf:params:oauth:grant-type:saml2-bearer&assertion=<SAML2_Encoded Assertion>&scope=PRODUCTION" -H "Authorization: Basic SVpzSWk2SERiQjVlOFZLZFpBblVpX2ZaM2Y4YTpHbTBiSjZvV1Y4ZkM1T1FMTGxDNmpzbEFDVzhh, Content-Type: application/x-www-form-urlencoded" https://localhost:8243/token
    Warning
    The Token API endpoint is specified in <APIM_HOME>/repository/deployment/server/synapse-configs/default/api/_TokenAPI_.xml file. When running the server on a different port from the default (i.e., 9443), or if your Key Manager is running on a different server from your API Gateway, you must update the endpoint inside the _TokenAPI_.xml file as described here.
    ://localhost:8243/token

Renewing access tokens
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Renewing
Renewing

After an access token is generated, sometimes you might have to refresh or renew the old token due to expiration or security concerns. This can be done by issuing a REST call to the Token API through a REST client such as the WSO2 REST Client or Curl, with the following parameters.

  • Assuming that both the client and the API Gateway are run on the same server, the The Token API URL is https://localhost:8243/token. It can take the following parameters:
    • payload
    -
    • : "grant_type=refresh_token&refresh_token=<retoken>&scope=PRODUCTION". Replace the <retoken> value with the refresh token generated in the previous section .
    • headers
    -
    • : Authorization :Basic <base64 encoded string>, Content-Type: application/x-www-form-urlencoded. Replace <base64 encoded string> as appropriate.          

For example, the following cURL command can be used to access the Token API.

Code Block
curl -k -d "grant_type=refresh_token&refresh_token=<retoken>&scope=PRODUCTION" -H "Authorization: Basic SVpzSWk2SERiQjVlOFZLZFpBblVpX2ZaM2Y4YTpHbTBiSjZvV1Y4ZkM1T1FMTGxDNmpzbEFDVzhh, Content-Type: application/x-www-form-urlencoded" https://localhost:8243/token

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After issuing an access token, a user or an admin can revoke it in case of theft or a security violation. You can do this by calling Revoke API using a utility client like cURL.

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  • It can take the following parameters:
    • The token to be revoked
    • Consumer key and consumer secret key. Must be encoded using Base64 algorithm

For example, curl -k -d "token=<ACCESS_TOKEN_TO_BE_REVOKED>" -H "Authorization: Basic Base64Encoded(Consumer key:consumer secret)" http://localhost:8280/revoke.