.\" Hey Emacs! This file is -*- nroff -*- source.
.\" $Id$
.\" Copyright (c) Andrew G. Morgan 1996-7 <morgan@parc.power.net>
.TH PAM_AUTHENTICATE 3 "1996 Dec 9" "Linux-PAM 0.55" "App. Programmers' Manual"
.SH NAME

pam_authenticate \- authenticate a user

.SH SYNOPSIS
.B #include <security/pam_appl.h>
.sp
.BI "int pam_authenticate(pam_handle_t " *pamh ", int  " flags ");"
.sp 2
.SH DESCRIPTION
.B pam_authenticate

.br
Use this function to authenticate an applicant user.  It is linked
.I dynamically
to the authentication modules by
.BR Linux-PAM ". "
It is the task of these module to perform such an authentication.  The
specific nature of the authentication is not the concern of the
application.

.br
Following successful completion, the
.BR name
of the authenticated user will be present in the
.BR Linux-PAM
item
.BR PAM_USER ". "
This item may be recovered with a call to
.BR pam_get_item "(3)."

.br
The application developer should note that the modules may request
that the user enter their username via the conversation mechanism (see
.BR pam_start "(3))."
Should this be the case, the user-prompt string can be set via
the
.BR PAM_USER_PROMPT
item (see
.BR pam_set_item "(3))."

.SH "RETURN VALUE"
On success
.BR PAM_SUCCESS
is returned.  All other returns should be considered
authentication failures and will be
.I delayed
by an amount specified with prior calls to
.BR pam_fail_delay "(3). "
Specific failures that demand special attention are the following:
.TP
.B PAM_ABORT
the application should exit immediately. Of course,
.BR pam_end "(3)"
should be called first.

.TP
.B PAM_MAXTRIES
the application has tried too many times to authenticate the
user, authentication should not be attempted again.

.SH ERRORS
May be translated to text with
.BR pam_strerror "(3). "

.SH "CONFORMING TO"
DCE-RFC 86.0, October 1995.

.SH BUGS
.sp 2
none known.

.SH "SEE ALSO"

.BR pam_start "(3), "
.BR pam_get_item "(3) "
.BR pam_fail_delay "(3) "
and
.BR pam_strerror "(3). "

Also, see the three
.BR Linux-PAM
Guides, for
.BR "System administrators" ", "
.BR "module developers" ", "
and
.BR "application developers" ". "