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PAM_AUTHENTICATE

Section: Linux-PAM Manual (3)
Updated: 04/01/2016
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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.