PAM_TACPLUS(8) BSD System Manager's Manual PAM_TACPLUS(8)NAME
pam_tacplus -- TACACS+ authentication PAM module
SYNOPSIS
[service-name] module-type control-flag pam_tacplus [options]
DESCRIPTION
The pam_tacplus module provides authentication services based upon the TACACS+ protocol for the PAM (Pluggable Authentication Module) frame-
work.
The pam_tacplus module accepts these optional parameters:
use_first_pass causes pam_tacplus to use a previously entered password instead of prompting for a new one. If no password has been entered
then authentication fails.
try_first_pass causes pam_tacplus to use a previously entered password, if one is available. If no password has been entered, pam_tacplus
prompts for one as usual.
echo_pass causes echoing to be left on if pam_tacplus prompts for a password.
conf=pathname specifies a non-standard location for the TACACS+ client configuration file (normally located in /etc/tacplus.conf).
template_user=username
specifies a user whose passwd(5) entry will be used as a template to create the session environment if the supplied username
does not exist in local password database. The user will be authenticated with the supplied username and password, but his
credentials to the system will be presented as the ones for username, i.e., his login class, home directory, resource limits,
etc. will be set to ones defined for username.
If this option is omitted, and there is no username in the system databases equal to the supplied one (as determined by call
to getpwnam(3)), the authentication will fail.
FILES
/etc/tacplus.conf The standard TACACS+ client configuration file for pam_tacplus
SEE ALSO passwd(5), tacplus.conf(5), pam(8)HISTORY
The pam_tacplus module first appeared in FreeBSD 3.1.
AUTHORS
The pam_tacplus manual page was written by Andrzej Bialecki <abial@FreeBSD.org> and adapted to TACACS+ from RADIUS by Mark R V Murray
<markm@FreeBSD.org>.
The pam_tacplus module was written by John D. Polstra <jdp@FreeBSD.org>.
BSD August 2, 1999 BSD
Check Out this Related Man Page
PAM_KRB5(8) BSD System Manager's Manual PAM_KRB5(8)NAME
pam_krb5 -- Kerberos 5 PAM module
SYNOPSIS
[service-name] module-type control-flag pam_krb5 [arguments]
DESCRIPTION
The Kerberos 5 service module for PAM provides functionality for three PAM categories: authentication, account management, and password man-
agement. It also provides null functions for session management.
Kerberos 5 Authentication Module
The Kerberos 5 authentication component provides functions to verify the identity of a user (pam_sm_authenticate()) and to set user specific
credentials (pam_sm_setcred()). pam_sm_authenticate() converts the supplied username into a Kerberos principal, by appending the default
local realm name. It also supports usernames with explicit realm names. If a realm name is supplied, then upon a successful return, it
changes the username by mapping the principal name into a local username (calling krb5_aname_to_localname()). This typically just means the
realm name is stripped.
It prompts the user for a password and obtains a new Kerberos TGT for the principal. The TGT is verified by obtaining a service ticket for
the local host.
When prompting for the current password, the authentication module will use the prompt ``Password for <principal>:''.
The pam_sm_setcred() function stores the newly acquired credentials in a credentials cache, and sets the environment variable KRB5CCNAME
appropriately. The credentials cache should be destroyed by the user at logout with kdestroy(1).
The following options may be passed to the authentication module:
debug syslog(3) debugging information at LOG_DEBUG level.
no_warn suppress warning messages to the user. These messages include reasons why the user's authentication attempt was declined.
use_first_pass If the authentication module is not the first in the stack, and a previous module obtained the user's password, that password
is used to authenticate the user. If this fails, the authentication module returns failure without prompting the user for a
password. This option has no effect if the authentication module is the first in the stack, or if no previous modules
obtained the user's password.
try_first_pass This option is similar to the use_first_pass option, except that if the previously obtained password fails, the user is
prompted for another password.
renewable=timeperiod
Obtain renewable Kerberos credentials for the user. The renewable time can be specified, or it defaults to one month. Since
spaces are not allowed in the pam configuration time, underscores are used to form parseable times (e.g., 1_month).
forwardable Obtain forwardable Kerberos credentials for the user.
no_ccache Do not save the obtained credentials in a credentials cache. This is a useful option if the authentication module is used
for services such as ftp or pop, where the user would not be able to destroy them. [This is not a recommendation to use the
module for those services.]
ccache=name Use name as the credentials cache. name must be in the form type:residual. The special tokens '%u', to designate the deci-
mal UID of the user; and '%p', to designate the current process ID; can be used in name.
Kerberos 5 Account Management Module
The Kerberos 5 account management component provides a function to perform account management, pam_sm_acct_mgmt(). The function verifies
that the authenticated principal is allowed to login to the local user account by calling krb5_kuserok() (which checks the user's .k5login
file).
Kerberos 5 Password Management Module
The Kerberos 5 password management component provides a function to change passwords (pam_sm_chauthtok()). The username supplied (the user
running the passwd(1) command, or the username given as an argument) is mapped into a Kerberos principal name, using the same technique as in
the authentication module. Note that if a realm name was explicitly supplied during authentication, but not during a password change, the
mapping done by the password management module may not result in the same principal as was used for authentication.
Unlike when changing a UNIX password, the password management module will allow any user to change any principal's password (if the user
knows the principal's old password, of course). Also unlike UNIX, root is always prompted for the principal's old password.
The password management module uses the same heuristics as kpasswd(1) to determine how to contact the Kerberos password server.
The following options may be passed to the password management module:
debug syslog(3) debugging information at LOG_DEBUG level.
use_first_pass If the password management module is not the first in the stack, and a previous module obtained the user's old password, that
password is used to authenticate the user. If this fails, the password management module returns failure without prompting
the user for the old password. If successful, the new password entered to the previous module is also used as the new Ker-
beros password. If the new password fails, the password management module returns failure without prompting the user for a
new password.
try_first_pass This option is similar to the use_first_pass option, except that if the previously obtained old or new passwords fail, the
user is prompted for them.
Kerberos 5 Session Management Module
The Kerberos 5 session management component provides functions to initiate (pam_sm_open_session()) and terminate (pam_sm_close_session())
sessions. Since session management is not defined under Kerberos 5, both of these functions simply return success. They are provided only
because of the naming conventions for PAM modules.
ENVIRONMENT
KRB5CCNAME Location of the credentials cache.
FILES
/tmp/krb5cc_uid default credentials cache (uid is the decimal UID of the user).
$HOME/.k5login file containing Kerberos principals that are allowed access.
SEE ALSO kdestroy(1), passwd(1), syslog(3), pam.conf(5), pam(8)NOTES
Applications should not call pam_authenticate() more than once between calls to pam_start() and pam_end() when using the Kerberos 5 PAM mod-
ule.
SECURITY CONSIDERATIONS
The pam_krb5 module implements what is fundamentally a password authentication scheme. It does not use a Kerberos 5 exchange between client
and server, but rather authenticates the password provided by the client against the Kerberos KDC. Therefore, care should be taken to only
use this module over a secure session (secure TTY, encrypted session, etc.), otherwise the user's Kerberos 5 password could be compromised.
BSD March 10, 2007 BSD