pam_handle_t() is used to indicate that an authenticated session has begun. It is used to inform the module that the user is currently in a session. It should be possible for the PAM library to open a session and close the same session from different applications.
flags may have the value
PAM_SILENT to indicate that no output be
generated as a rsult of this function call.
One of the loaded modules was unable to open a session for the user.