NAME

       access.conf - the login access control table file

DESCRIPTION

       The /etc/security/access.conf file specifies (user/group, host), (user/group,
       network/netmask), (user/group, tty), (user/group, X-$DISPLAY-value), or (user/group,
       pam-service-name) 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, or
       in the case of non-networked logins without a tty, the first entry that matches the
       (user/group, X-$DISPLAY-value) or (user/group, pam-service-name/) 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), X $DISPLAY values or PAM service names (for non-networked logins
       without a tty), 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. The LOCAL keyword matches if and only if pam_get_item(3), when called
       with an item_type of PAM_RHOST, returns NULL or an empty string (and therefore the origins
       field is compared against the return value of pam_get_item(3) called with an item_type of
       PAM_TTY or, absent that, 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

       Members of group wheel should be allowed to get access from all sources.

       +:(wheel):ALL

       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

NOTES

       The default separators of list items in a field are space, ',', and tabulator characters.
       Thus conveniently if spaces are put at the beginning and the end of the fields they are
       ignored. However if the list separator is changed with the listsep option, the spaces will
       become part of the actual item and the line will be most probably ignored. For this
       reason, it is not recommended to put spaces around the ':' characters.

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>.

[FIXME: source]                             05/07/2023                             ACCESS.CONF(5)