Missed nonce, code_challenge, code_challenge_method for OIDC integration

We are implementing ability for users to login by external service using button “Login with …” on universal login page.

We also have successfully placed mentioned button on Universal login page and pressing it successfully redirects to Consent page of the external authentication service, however no other following action is possible due to the following.

This service requires set of request parameters:
state (provided by Auth0)
scope (provided by Auth0, set in Dashboard)
response_type (provided by Auth0)
redirect_uri (provided by Auth0)
client_id (provided by Auth0, set in Dashboard)
nonce (missed)
code_challenge (missed)
code_challenge_method (missed, but should be fixed as “S256”)
response_mode (provided by Auth0).

As a result, servers responds with notification “required parameter code_challenge missed”

Please advice, where we can add missed request parameters in order to complete login procedure?

Hi @artiukhov.external,

Welcome to the Auth0 Community!

I understand that you have encountered some issues with the authentication flow, specifically with the required parameter code_challenge missing error.

First, have you taken a look at our Add Login Using the Authorization Code Flow with PKCE documentation?

To create the code_challenge, you’ll first need to create a code verifier and then use the code verifier to generate the code_challenge.

Once that is done, you’ll be able to pass the code_challenge along with the request.

Please let me know if you have any further questions. I’d be happy to clarify.

Thank you.

May you please please provide the exact place, where I could add mentioned “code_verifier”?

Please, do not mark “as solved” before I can confirm, if it was really “solved”.

Hi @artiukhov.external,

Thank you for your response, and my apologies for marking it solved.

The code verifier and code challenge will need to be implemented directly before calling the /authorize request in your application.

If you have a moment, please look at this code example for exact code placements.

Please let me know how this works for you and if you require further clarifications.

Thank you.