[Oauth2-Proxy] Oauth2-Proxy encounters issue with Cognito

Hiện tại thì Oauth2-Proxy incounter issue with Cognito.
https://github.com/oauth2-proxy/oauth2-proxy/pull/2265

oauth2-proxy encodes the redirect-URL as part of the state parameter to the authorization endpoint. AWS doesn’t give a full documentation on valid characters, but it hints that URL-encoding data will not work and advice to do a base64 encoding instead.

https://docs.aws.amazon.com/cognito/latest/developerguide/authorization-endpoint.html

This patch will do a base64-encoding of the redirect URL in the state variable.

Chúng ta cùng mổ sẻ vấn đề.

Problem: AWS Cognito doesn’t like the way OAuth2-proxy is encoding the redirect URL in the state parameter. It prefers base64 encoding instead of the current method.

Solution: Use base64 encoding for the redirect URL before putting it in the state parameter.

Steps:

1. Before Sending to AWS Cognito:
   • Take the redirect URL.
   • Convert it to a base64 format.
   • Use this base64 string as the state parameter.
2. After Getting Response from AWS Cognito:
   • Take the state parameter (which is in base64 format).
   • Convert it back from base64 to get the original redirect URL.
   • Use this URL to redirect the user.
3. If Something Goes Wrong:
   • Check if there’s an error during the conversion process.
   • Handle the error (like showing a message to the user).