OAuth 2.0 Dance (Authorize) Fails With Error "redirect_uri_mismatch"

SYMPTOM

You are using OAuth 2.0 authentication in your Mule application and performing OAuth dance by invoking Authorize URL configured in the OAuth 2.0 configuration in your application.
In this example, the authorization URL is invoked from the browser:

error while authorizing:: error=redirect_uri_mismatch&error_description=redirect_uri%20must%20match%20configuration

e.g., Salesforce OAuth 2.0 dance throwing "redirect_uri_mismatch" error.

CAUSE

[2021-10-15 10:54:55.111] DEBUG   org.mule.service.http.impl.service.HttpMessageLogger.HTTP_Listener_config [http.listener.01 SelectorRunner]: LISTENER
HTTP/1.1 302 Moved Temporarily
Content-Length: 0
location: https://test.my.salesforce.com/services/oauth2/authorize?response_type=code&client_id=.....&redirect_uri=https%3A%2F%2Ftest-salesforce.us-e2.cloudhub.io%2Fapi%2FcompositeCallback

However, in this case, the callback URL configured in the server is different from the URL configured in your Mule application resulting in the Redirect URI Mismatch error.

SOLUTION

In order to resolve this issue, you need to ensure that the OAuth 2.0 callback URL configured in your server should match with the URL where your application is configured. Once configured in your "oauthCallbackConfig", callback URL will implicitly create an endpoint listening to this URL. Based on the type of deployment, you need to ensure that the whole URL should be configured in the server's OAuth 2.0 client application config, e.g.,