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libtacplus_map v1.0.0
June 22, 2016

This library supports local mapping of users authenticated via TACACS with
the pam_tacplus module.

The TACACS+ users do not need entries in /etc/passwd to supply home directory, uid,
and gid information.

This is done by creating local users called tacacs0 ... tacacs15 (at least
one, but up to all 16).   The tacacs user's privilege level is used to select
the local tacacsN user, starting with an exact match, and working down to 0.

A new libtacplus_map library (map_tacplus_user.c) writes the mappings into
a local file in /run, and cleans up on exit (for unexpected exits without
cleanups, the file is validated and cleaned up whenever a new entry is added
or an old entry removed).

audit_[gs]etloginuid() is used to set a stable uid identifier as well as
triggering the /proc/$$/sessionid in the process.  These are both recorded
in the mapping file, along with tty, rhost, etc.

Also see the comments about immutable loginuid in Pam.d.common-example
in the libpam-tacplus package.

A separate package libnss_tacplus uses the mapping library to do lookups by
both name and uid.  uid lookups are only possible while a tacacs user is
logged in.

If multiple tacacs users at the same privilege level are logged in, the
current behavior is that is that if a call is done from within the login
session, the correct (login) name will be returned.   If from outside the
session (audit uid and/or session don't match in the mapping file), the name
from first map entry is used, much like normal systems where multiple users
have the same UID.

Enabled -Werror to catch errors early (and fixed a few related items).

This code is based in the pam_tacplus plugin, written by
Pawel Krawczyk <[email protected]> and Jeroen Nijhof
<[email protected]>, as well as others.   It is based
on version pam_tacplus version 1.3.9.  It uses the libtac
as found in pam_tacplus.  A few minor changes have been made,
and libtac is built as a static archive library.


Author:
~~~~~~~

Dave Olson <[email protected]>