implementing OAuth2 Authentication Flow in a Flask App Using Authlib and Keycloak
I'm getting frustrated with I've been struggling with this for a few days now and could really use some help. I'm experiencing issues with the OAuth2 authentication flow in my Flask application using the Authlib library and Keycloak as the identity provider. After successfully obtaining an authorization code, the subsequent token exchange fails with a 400 Bad Request behavior. Here's the relevant code snippet for my token exchange logic: ```python from authlib.integrations.flask_client import OAuth from flask import Flask, redirect, url_for, session app = Flask(__name__) app.secret_key = 'your_secret_key' oauth = OAuth(app) keycloak = oauth.register( 'keycloak', client_id='your_client_id', client_secret='your_client_secret', access_token_url='http://keycloak-server/auth/realms/your_realm/protocol/openid-connect/token', authorize_url='http://keycloak-server/auth/realms/your_realm/protocol/openid-connect/auth', redirect_uri='http://localhost:5000/auth/callback', scope='openid' ) @app.route('/login') def login(): redirect_uri = url_for('auth', _external=True) return keycloak.authorize(redirect_uri=redirect_uri) @app.route('/auth/callback') def auth(): token = keycloak.authorize_access_token() return 'Logged in!' ``` The behavior appears at the `authorize_access_token()` step, and the response from Keycloak gives me the following message: "Invalid request: Missing or invalid parameters." I have verified that the client ID and secret are correct and have also confirmed that the redirect URI in Keycloak matches the one in the app. I've also checked that the authorization code is being passed correctly from Keycloak back to my application. My Flask app is running in debug mode, and the logs show that the redirect URI matches what I defined in Keycloak. I've tried various combinations of scopes and configurations, but it seems like there might be something I'm missing regarding the token request parameters. Has anyone faced a similar scenario or can suggest what parameters I might need to adjust to resolve this behavior?