PAM_ACCESS(8) Linux-PAM Manual PAM_ACCESS(8)NAME
pam_access - PAM module for logdaemon style login access control
SYNOPSIS
pam_access.so [debug] [nodefgroup] [noaudit] [accessfile=file] [fieldsep=sep] [listsep=sep]
DESCRIPTION
The pam_access PAM module is mainly for access management. It provides logdaemon style login access control based on login names, host or
domain names, internet addresses or network numbers, or on terminal line names in case of non-networked logins.
By default rules for access management are taken from config file /etc/security/access.conf if you don't specify another file.
If Linux PAM is compiled with audit support the module will report when it denies access based on origin (host or tty).
OPTIONS
accessfile=/path/to/access.conf
Indicate an alternative access.conf style configuration file to override the default. This can be useful when different services need
different access lists.
debug
A lot of debug information is printed with syslog(3).
noaudit
Do not report logins from disallowed hosts and ttys to the audit subsystem.
fieldsep=separators
This option modifies the field separator character that pam_access will recognize when parsing the access configuration file. For
example: fieldsep=| will cause the default `:' character to be treated as part of a field value and `|' becomes the field separator.
Doing this may be useful in conjunction with a system that wants to use pam_access with X based applications, since the PAM_TTY item is
likely to be of the form "hostname:0" which includes a `:' character in its value. But you should not need this.
listsep=separators
This option modifies the list separator character that pam_access will recognize when parsing the access configuration file. For
example: listsep=, will cause the default ` ' (space) and ` ' (tab) characters to be treated as part of a list element value and `,'
becomes the only list element separator. Doing this may be useful on a system with group information obtained from a Windows domain,
where the default built-in groups "Domain Users", "Domain Admins" contain a space.
nodefgroup
User tokens which are not enclosed in parentheses will not be matched against the group database. The backwards compatible default is
to try the group database match even for tokens not enclosed in parentheses.
MODULE TYPES PROVIDED
All module types (auth, account, password and session) are provided.
RETURN VALUES
PAM_SUCCESS
Access was granted.
PAM_PERM_DENIED
Access was not granted.
PAM_IGNORE
pam_setcred was called which does nothing.
PAM_ABORT
Not all relevant data or options could be gotten.
PAM_USER_UNKNOWN
The user is not known to the system.
FILES
/etc/security/access.conf
Default configuration file
SEE ALSO access.conf(5), pam.d(5), pam(7).
AUTHORS
The logdaemon style login access control scheme was designed and implemented by Wietse Venema. The pam_access PAM module was developed by
Alexei Nogin <alexei@nogin.dnttm.ru>. The IPv6 support and the network(address) / netmask feature was developed and provided by Mike Becher
<mike.becher@lrz-muenchen.de>.
Linux-PAM Manual 06/04/2011 PAM_ACCESS(8)
Check Out this Related Man Page
ACCESS.CONF(5) Linux-PAM Manual ACCESS.CONF(5)NAME
access.conf - the login access control table file
DESCRIPTION
The /etc/security/access.conf file specifies (user/group, host), (user/group, network/netmask) or (user/group, tty) combinations for which
a login will be either accepted or refused.
When someone logs in, the file access.conf is scanned for the first entry that matches the (user/group, host) or (user/group,
network/netmask) combination, or, in case of non-networked logins, the first entry that matches the (user/group, tty) combination. The
permissions field of that table entry determines whether the login will be accepted or refused.
Each line of the login access control table has three fields separated by a ":" character (colon):
permission:users/groups:origins
The first field, the permission field, can be either a "+" character (plus) for access granted or a "-" character (minus) for access
denied.
The second field, the users/group field, should be a list of one or more login names, group names, or ALL (which always matches). To
differentiate user entries from group entries, group entries should be written with brackets, e.g. (group).
The third field, the origins field, should be a list of one or more tty names (for non-networked logins), host names, domain names (begin
with "."), host addresses, internet network numbers (end with "."), internet network addresses with network mask (where network mask can be
a decimal number or an internet address also), ALL (which always matches) or LOCAL. LOCAL keyword matches if and only if the PAM_RHOST is
not set and <origin> field is thus set from PAM_TTY or PAM_SERVICE". If supported by the system you can use @netgroupname in host or user
patterns. The @@netgroupname syntax is supported in the user pattern only and it makes the local system hostname to be passed to the
netgroup match call in addition to the user name. This might not work correctly on some libc implementations causing the match to always
fail.
The EXCEPT operator makes it possible to write very compact rules.
If the nodefgroup is not set, the group file is searched when a name does not match that of the logged-in user. Only groups are matched in
which users are explicitly listed. However the PAM module does not look at the primary group id of a user.
The "#" character at start of line (no space at front) can be used to mark this line as a comment line.
EXAMPLES
These are some example lines which might be specified in /etc/security/access.conf.
User root should be allowed to get access via cron, X11 terminal :0, tty1, ..., tty5, tty6.
+ : root : crond :0 tty1 tty2 tty3 tty4 tty5 tty6
User root should be allowed to get access from hosts which own the IPv4 addresses. This does not mean that the connection have to be a IPv4
one, a IPv6 connection from a host with one of this IPv4 addresses does work, too.
+ : root : 192.168.200.1 192.168.200.4 192.168.200.9
+ : root : 127.0.0.1
User root should get access from network 192.168.201. where the term will be evaluated by string matching. But it might be better to use
network/netmask instead. The same meaning of 192.168.201. is 192.168.201.0/24 or 192.168.201.0/255.255.255.0.
+ : root : 192.168.201.
User root should be able to have access from hosts foo1.bar.org and foo2.bar.org (uses string matching also).
+ : root : foo1.bar.org foo2.bar.org
User root should be able to have access from domain foo.bar.org (uses string matching also).
+ : root : .foo.bar.org
User root should be denied to get access from all other sources.
- : root : ALL
User foo and members of netgroup admins should be allowed to get access from all sources. This will only work if netgroup service is
available.
+ : @admins foo : ALL
User john and foo should get access from IPv6 host address.
+ : john foo : 2001:db8:0:101::1
User john should get access from IPv6 net/mask.
+ : john : 2001:db8:0:101::/64
Disallow console logins to all but the shutdown, sync and all other accounts, which are a member of the wheel group.
-:ALL EXCEPT (wheel) shutdown sync:LOCAL
All other users should be denied to get access from all sources.
- : ALL : ALL
SEE ALSO pam_access(8), pam.d(5), pam(7)AUTHORS
Original login.access(5) manual was provided by Guido van Rooij which was renamed to access.conf(5) to reflect relation to default config
file.
Network address / netmask description and example text was introduced by Mike Becher <mike.becher@lrz-muenchen.de>.
Linux-PAM Manual 06/04/2011 ACCESS.CONF(5)