Linux man pages

Section (3) pam_authenticate

Linux manual pages	Section 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 via 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_UNAVAIL: 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.