centos man page for pam_authenticate

PAM_AUTHENTICATE(3)						 Linux-PAM Manual					       PAM_AUTHENTICATE(3)

NAME
       pam_authenticate - account authentication

SYNOPSIS
       #include <security/pam_appl.h>

       int pam_authenticate(pam_handle_t *pamh, int flags);

DESCRIPTION
       The pam_authenticate function is used to authenticate the user. The user is required to provide an authentication token depending upon the
       authentication service, usually this is a password, but could also be a finger print.

       The PAM service module may request that the user enter their username vio the the conversation mechanism (see pam_start(3) and
       pam_conv(3)). The name of the authenticated user will be present in the PAM item PAM_USER. This item may be recovered with a call to
       pam_get_item(3).

       The pamh argument is an authentication handle obtained by a prior call to pam_start(). The flags argument is the binary or of zero or more
       of the following values:

       PAM_SILENT
	   Do not emit any messages.

       PAM_DISALLOW_NULL_AUTHTOK
	   The PAM module service should return PAM_AUTH_ERR if the user does not have a registered authentication token.

RETURN VALUES
       PAM_ABORT
	   The application should exit immediately after calling pam_end(3) first.

       PAM_AUTH_ERR
	   The user was not authenticated.

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

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

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

       PAM_SUCCESS
	   The user was successfully authenticated.

       PAM_USER_UNKNOWN
	   User unknown to authentication service.

SEE ALSO
       pam_start(3), pam_setcred(3), pam_chauthtok(3), pam_strerror(3), pam(8)

Linux-PAM Manual						    09/19/2013						       PAM_AUTHENTICATE(3)