pam_access — PAM module for logdaemon style login access control

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

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, X
$DISPLAY values, or PAM service 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. Then individual *.conf files
from the /etc/security/access.d/ directory are read. The files are parsed one
after another in the order of the system locale. The effect of the individual
files is the same as if all the files were concatenated together in the order
of parsing. This means that once a pattern is matched in some file no further
files are parsed. If a config file is explicitly specified with the accessfile
option the files in the above directory are not parsed.

By default rules for access management are taken from config file /etc/security
/access.conf or, if that one is not present, the file %vendordir%/security/
access.conf. These settings can be overruled by setting in a config file
explicitly specified with the accessfile option. Then individual *.conf files
from the /etc/security/access.d/ and %vendordir%/security/access.d directories
are read. If /etc/security/access.d/@filename@.conf exists, then %vendordir%/
security/access.d/@filename@.conf will not be used. All access.d/*.conf files
are sorted by their @filename@.conf in lexicographic order regardless of which
of the directories they reside in. The effect of the individual files is the
same as if all the files were concatenated together in the order of parsing.
This means that once a pattern is matched in some file no further files are
parsed. If a config file is explicitly specified with the accessfile option the
files in the above directories are not parsed.

If Linux PAM is compiled with audit support the module will report when it
denies access based on origin (host, tty, etc.).

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.

quiet_log

    Do not log denials with syslog(3).

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 `\t' (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.

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 and foo should get access from IPv6 link local host address.

+:john foo:fe80::de95:818c:1b55:7e42%eth1

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

