'\" t
.\"     Title: pam_get_authtok
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 06/08/2020
.\"    Manual: Linux-PAM Manual
.\"    Source: Linux-PAM Manual
.\"  Language: English
.\"
.TH "PAM_GET_AUTHTOK" "3" "06/08/2020" "Linux-PAM Manual" "Linux-PAM Manual"
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.SH "NAME"
pam_get_authtok, pam_get_authtok_verify, pam_get_authtok_noverify \- get authentication token
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <security/pam_ext\&.h>
.fi
.ft
.HP \w'int\ pam_get_authtok('u
.BI "int pam_get_authtok(pam_handle_t\ *" "pamh" ", int\ " "item" ", const\ char\ **" "authtok" ", const\ char\ *" "prompt" ");"
.HP \w'int\ pam_get_authtok_noverify('u
.BI "int pam_get_authtok_noverify(pam_handle_t\ *" "pamh" ", const\ char\ **" "authtok" ", const\ char\ *" "prompt" ");"
.HP \w'int\ pam_get_authtok_verify('u
.BI "int pam_get_authtok_verify(pam_handle_t\ *" "pamh" ", const\ char\ **" "authtok" ", const\ char\ *" "prompt" ");"
.SH "DESCRIPTION"
.PP
The
\fBpam_get_authtok\fR
function returns the cached authentication token, or prompts the user if no token is currently cached\&. It is intended for internal use by Linux\-PAM and PAM service modules\&. Upon successful return,
\fIauthtok\fR
contains a pointer to the value of the authentication token\&. Note, this is a pointer to the
\fIactual\fR
data and should
\fBnot\fR
be
\fIfree()\fR\*(Aqed or over\-written!
.PP
The
\fIprompt\fR
argument specifies a prompt to use if no token is cached\&. If a NULL pointer is given,
\fBpam_get_authtok\fR
uses pre\-defined prompts\&.
.PP
The following values are supported for
\fIitem\fR:
.PP
PAM_AUTHTOK
.RS 4
Returns the current authentication token\&. Called from
\fBpam_sm_chauthtok\fR(3)
\fBpam_get_authtok\fR
will ask the user to confirm the new token by retyping it\&. If a prompt was specified, "Retype" will be used as prefix\&.
.RE
.PP
PAM_OLDAUTHTOK
.RS 4
Returns the previous authentication token when changing authentication tokens\&.
.RE
.PP
The
\fBpam_get_authtok_noverify\fR
function can only be used for changing the password (from
\fBpam_sm_chauthtok\fR(3))\&. It returns the cached authentication token, or prompts the user if no token is currently cached\&. The difference to
\fBpam_get_authtok\fR
is, that this function does not ask a second time for the password to verify it\&. Upon successful return,
\fIauthtok\fR
contains a pointer to the value of the authentication token\&. Note, this is a pointer to the
\fIactual\fR
data and should
\fBnot\fR
be
\fIfree()\fR\*(Aqed or over\-written!
.PP
The
\fBpam_get_authtok_verify\fR
function can only be used to verify a password for mistypes gotten by
\fBpam_get_authtok_noverify\fR(3)\&. This function asks a second time for the password and verify it with the password provided by
\fIauthtok\fR
argument\&. In case of an error, the value of
\fIauthtok\fR
is undefined\&. Else this argument will point to the
\fIactual\fR
data and should
\fBnot\fR
be
\fIfree()\fR\*(Aqed or over\-written!
.SH "OPTIONS"
.PP
\fBpam_get_authtok\fR
honours the following module options:
.PP
\fBtry_first_pass\fR
.RS 4
Before prompting the user for their password, the module first tries the previous stacked module\*(Aqs password in case that satisfies this module as well\&.
.RE
.PP
\fBuse_first_pass\fR
.RS 4
The argument
\fBuse_first_pass\fR
forces the module to use a previous stacked modules password and will never prompt the user \- if no password is available or the password is not appropriate, the user will be denied access\&.
.RE
.PP
\fBuse_authtok\fR
.RS 4
When password changing enforce the module to set the new token to the one provided by a previously stacked
\fBpassword\fR
module\&. If no token is available token changing will fail\&.
.RE
.PP
\fBauthtok_type=\fR\fB\fIXXX\fR\fR
.RS 4
The default action is for the module to use the following prompts when requesting passwords: "New UNIX password: " and "Retype UNIX password: "\&. The example word
\fIUNIX\fR
can be replaced with this option, by default it is empty\&.
.RE
.SH "RETURN VALUES"
.PP
PAM_AUTH_ERR
.RS 4
Authentication token could not be retrieved\&.
.RE
.PP
PAM_AUTHTOK_ERR
.RS 4
New authentication could not be retrieved\&.
.RE
.PP
PAM_SUCCESS
.RS 4
Authentication token was successfully retrieved\&.
.RE
.PP
PAM_SYSTEM_ERR
.RS 4
No space for an authentication token was provided\&.
.RE
.PP
PAM_TRY_AGAIN
.RS 4
New authentication tokens mismatch\&.
.RE
.SH "SEE ALSO"
.PP
\fBpam\fR(8)
.SH "STANDARDS"
.PP
The
\fBpam_get_authtok\fR
function is a Linux\-PAM extensions\&.