pam_sm_authenticate

3 Linux-PAM Linux-PAM Manual

pam_sm_authenticate

PAM service function for user authentication

          #include <security/pam_modules.h>

            int pam_sm_authenticate
            pam_handle_t *pamh
            int flags
            int argc
            const char **argv

## DESCRIPTION

The `pam_sm_authenticate` function is the service module's implementation of the

pam_authenticate

3 interface.

This function performs the task of authenticating the user.

Valid flags, which may be logically OR'd with PAM_SILENT, are:

PAM_SILENT

- Do not emit any messages.

PAM_DISALLOW_NULL_AUTHTOK

- Return PAM_AUTH_ERR if the database of authentication tokens for this authentication mechanism has a NULL entry for the user. Without this flag, such a NULL token will lead to a success without the user being prompted.

## RETURN VALUES

PAM_AUTH_ERR

- Authentication failure.

PAM_CRED_INSUFFICIENT

- For some reason the application does not have sufficient credentials to authenticate the user.

PAM_AUTHINFO_UNAVAIL

- The modules were not able to access the authentication information. This might be due to a network or hardware failure etc.

PAM_SUCCESS

- The authentication token was successfully updated.

PAM_USER_UNKNOWN

- The supplied username is not known to the authentication service.

PAM_MAXTRIES

- One or more of the authentication modules has reached its limit of tries authenticating the user. Do not try again.

## SEE ALSO

pam

3 ,

pam_authenticate

3 ,

pam_sm_setcred

3 ,

pam_strerror

3 ,

PAM

8