.\" Copyright (c) 2001 Mark R V Murray
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.\" $FreeBSD$
.\"
.Dd July 7, 2001
.Dt PAM_UNIX 8
.Os
.Sh NAME
.Nm pam_unix
.Nd UNIX PAM module
.Sh SYNOPSIS
.Op Ar service-name
.Ar module-type
.Ar control-flag
.Pa pam_unix
.Op Ar options
.Sh DESCRIPTION
The
.Ux
authentication service module for PAM,
.Nm
provides functionality for two PAM categories:
authentication
and account management.
In terms of the
.Ar module-type
parameter, they are the
.Dq Li auth
and
.Dq Li account
features.
It also provides a null function for session management.
.Ss Ux Ss Authentication Module
The
.Ux
authentication component
provides functions to verify the identity of a user
.Pq Fn pam_sm_authenticate ,
which obtains the relevant
.Xr passwd 5
entry.
It prompts the user for a password
and verifies that this is correct with
.Xr crypt 3 .
.Pp
The following options may be passed to the authentication module:
.Bl -tag -width ".Cm use_first_pass"
.It Cm debug
.Xr syslog 3
debugging information at
.Dv LOG_DEBUG
level.
.It Cm use_first_pass
If the authentication module
is not the first in the stack,
and a previous module
obtained the user's password,
that password is used
to authenticate the user.
If this fails,
the authentication module returns failure
without prompting the user for a password.
This option has no effect
if the authentication module
is the first in the stack,
or if no previous modules
obtained the user's password.
.It Cm try_first_pass
This option is similar to the
.Cm use_first_pass
option,
except that if the previously obtained password fails,
the user is prompted for another password.
.It Cm auth_as_self
This option will require the user
to authenticate themself as the user
given by
.Xr getlogin 2 ,
not as the account they are attempting to access.
This is primarily for services like
.Xr su 1 ,
where the user's ability to retype
their own password
might be deemed sufficient.
.It Cm nullok
If the password database
has no password
for the entity being authenticated,
then this option
will forgo password prompting,
and silently allow authentication to succeed.
.El
.Ss Ux Ss Account Management Module
The
.Ux
account management component
provides a function to perform account management,
.Fn pam_sm_acct_mgmt .
The function verifies
that the authenticated user
is allowed to login to the local user account
by checking the password expiry date.
.Pp
The following options may be passed to the management module:
.Bl -tag -width ".Cm use_first_pass"
.It Cm debug
.Xr syslog 3
debugging information at
.Dv LOG_DEBUG
level.
.El
.Ss Ux Ss Password Management Module
The
.Ux
password management component
provides a function to perform account management,
.Fn pam_sm_chauthtok .
The function changes
the user's password.
.Pp
The following options may be passed to the password module:
.Bl -tag -width ".Cm use_first_pass"
.It Cm debug
.Xr syslog 3
debugging information at
.Dv LOG_DEBUG
level.
.It Cm no_warn
suppress warning messages to the user.
These messages include
reasons why the user's
authentication attempt was declined.
.It Cm local_pass
forces the password module
to change a local password
in favour of a NIS one.
.It Cm nis_pass
forces the password module
to change a NIS password
in favour of a local one.
.El
.Sh FILES
.Bl -tag -width ".Pa /etc/master.passwd" -compact
.It Pa /etc/master.passwd
default
.Ux
password database.
.El
.Sh SEE ALSO
.Xr passwd 1 ,
.Xr getlogin 2 ,
.Xr crypt 3 ,
.Xr syslog 3 ,
.Xr pam.conf 5 ,
.Xr passwd 5 ,
.Xr pam 8