Question: google-authenticator PAM module is not returning valid error codes

[raviteja-b]

pam_google_authenticator identifies different error cases but returns generic PAM_AUTH_ERR

when totp token is not passed then I noticed this trace and I see PAM_AUTH_ERR
pam_google_authenticator: Did not receive verification code from user

when invalid totp token is passed, I noticed this trace which says invalid token but still PAM_AUTH_ERR error returned.
pam_google_authenticator: Invalid verification code for testmfaadmin

pam_authenticate() should return PAM_CRED_INSUFFICIENT, If there is no token is provided

[ThomasHabets]

That sounds correct. I'll accept well written PRs.