Tribblix: manual page: pam

PAM_LIST(7) Standards, Environments, and Macros PAM_LIST(7)

NAME

pam_list - PAM account management module for UNIX

SYNOPSIS

pam_list.so.1

DESCRIPTION

The pam_list module implements pam_sm_acct_mgmt(3PAM), which provides
functionality to the PAM account management stack. The module
provides functions to validate that the user's account is valid
on this host based on a list of users, groups, and/or netgroups in
the given file. The users, groups, and netgroups are separated by
newline character. Groups are specified with character '%' and
netgroups are specified with character '@' as prefix before name of
the group/netgroup in the list. The maximum line length is 1023
characters.

The username is the value of PAM_USER. The host is the value of
PAM_RHOST or, if PAM_RHOST is not set, the value of the localhost as
returned by gethostname(3C) is used.

If neither of the allow, deny, or compat options are specified, the
module will look for +/- entries in the local /etc/passwd file. If
this style is used, nsswitch.conf(5) must not be configured with
compat for the passwd database. If no relevant +/- entry exists for
the user, pam_list is not participating in result.

If compat option is specified then the module will look for +/-
entries in the local /etc/passwd file. Other entries in this file
will be counted as + entries. If no relevant entry exits for the
user, pam_list will deny the access.

The following options can be passed to the module:

allow=
The full pathname to a file of allowed users,
groups, and/or netgroups. Only one of allow= or
deny= can be specified.

compat
Activate compat mode.

deny=
The full pathname to a file of denied users,
groups, and/or netgroups. Only one of deny= or
allow= can be specified.

debug
Provide syslog(3C) debugging information at the
LOG_AUTH | LOG_DEBUG level.

group
The module should perform group membership matches
for the username.

user
The module should only perform netgroup matches on
the username. This is the default option.

nouser
The username should not be used in the netgroup
match.

host
Only the host should be used in netgroup matches.

nohost
The hostname should not be used in netgroup
matches.

user_host_exact
The user and hostname must be in the same
netgroup.

ERRORS

The following error values are returned:

PAM_SERVICE_ERR
An invalid set of module options was given in the
pam.conf(5) for this module, or the user/netgroup
file could not be opened.

PAM_BUF_ERR
A memory buffer error occurred.

PAM_IGNORE
The module is ignored, as it is not participating
in the result.

PAM_PERM_DENIED
The user is not on the allow list or is on the
deny list.

PAM_SUCCESS
The account is valid for use at this time.

PAM_USER_UNKNOWN
No account is present for the user

EXAMPLES

Example 1: Using pam_list in default mode

/etc/pam.conf modification looks like:

other account requisite pam_roles.so.1
other account required pam_unix_account.so.1
other account required pam_list.so.1

In the case of default mode or compat mode, the important lines in
/etc/passwd appear as follows:

+loginname - user is approved
-loginname - user is disapproved
+@netgroup - netgroup members are approved
-@netgroup - netgroup members are disapproved

Example 2: Using pam_list with allow file

/etc/pam.conf modification looks like:

other account requisite pam_roles.so.1
other account required pam_unix_account.so.1
other account required pam_list.so.1 allow=/etc/users.allow

/etc/users.allow contains:

root
localloginname
remoteloginname
@netgroup

Example 3: Using pam_list with allow file to allow members of the

'admins' group access.

/etc/pam.conf modification looks like:

other account requisite pam_roles.so.1
other account required pam_unix_account.so.1
other account required pam_list.so.1 group allow=/etc/users.allow

/etc/users.allow contains:

root
%admins

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

+--------------------+-------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------------+
|Interface Stability | Committed |
+--------------------+-------------------------+
|MT-Level | MT-Safe with exceptions |
+--------------------+-------------------------+

The interfaces in libpam(3LIB) are MT-Safe only if each thread within
the multithreaded application uses its own PAM handle.