We have a system that is using its own authentication system and I need to make it use our Google Workspace accounts to integrate with Google SSO so that when the user gives their credentials to the webpage, it will be authenticated in both google account and on our web app account.
Google default workflow redirects the user to its own form, so we have the problem of the password not being passed to our server.
Crossed my mind the fact that this would be too insecure to exist, but remember that all users that would log in to our website would have an account created in a workplace totally managed by us.
how could I auth the user this way?
Why not use "Sign-in with Google" -> OpenID Connect to access to the website. That way it will authenticate with Google.
Or add the website as a custom SAML application in the Admin console, and use Google as the IDP since the users will be provided by your organization.