NAME

pam.conf — PAM policy file format

DESCRIPTION

The PAM library searches for policies in the following files, in decreasing order of preference:

1. /etc/pam.d/service-name
2. /etc/pam.conf
3. /usr/local/etc/pam.d/service-name
4. /usr/local/etc/pam.conf

If none of these locations contains a policy for the given service, the “other” policy is used instead, if it exists.

Entries in per-service policy files must be of one of the two forms below:

facility control-flag module-path [arguments ...]
facility include other-service-name

Entries in pam.conf-style policy files are of the same form, but are prefixed by an additional field specifying the name of the service they apply to.

In both cases, blank lines and comments introduced by a ‘#’ sign are ignored, and the normal shell quoting rules apply. The precise details of how the file is tokenized are described in openpam_readword(3).

The facility field specifies the facility the entry applies to, and is one of:

auth

Authentication functions (pam_authenticate(3), pam_setcred(3))

account

Account management functions (pam_acct_mgmt(3))

session

Session handling functions (pam_open_session(3), pam_close_session(3))

password

Password management functions (pam_chauthtok(3))

The control-flag field determines how the result returned by the module affects the flow of control through (and the final result of) the rest of the chain, and is one of:

required

If this module succeeds, the result of the chain will be success unless a later module fails. If it fails, the rest of the chain still runs, but the final result will be failure regardless of the success of later modules.

requisite

If this module succeeds, the result of the chain will be success unless a later module fails. If the module fails, the chain is broken and the result is failure.

sufficient

If this module succeeds, the chain is broken and the result is success. If it fails, the rest of the chain still runs, but the final result will be failure unless a later module succeeds.

binding

If this module succeeds, the chain is broken and the result is success. If it fails, the rest of the chain still runs, but the final result will be failure regardless of the success of later modules.

optional

If this module succeeds, the result of the chain will be success unless a later module fails. If this module fails, the result of the chain will be failure unless a later module succeeds.

There are two exceptions to the above: sufficient and binding modules are treated as optional by pam_setcred(3), and in the PAM_PRELIM_CHECK phase of pam_chauthtok(3).

The module-path field specifies the name or full path of the module to call. If only the name is specified, the PAM library will search for it in the following locations:

1. /usr/lib
2. /usr/local/lib

The remaining fields, if any, are passed unmodified to the module if and when it is invoked.

The include form of entry causes entries from a different chain (specified by other-system-name) to be included in the current one. This allows one to define system-wide policies which are then included into service-specific policies. The system-wide policy can then be modified without having to also modify each and every service-specific policy.

MODULE OPTIONS

Some PAM library functions may alter their behavior when called by a service module if certain module options were specified, regardless of whether the module itself accords them any importance. One such option is debug, which causes the dispatcher to enable debugging messages before calling each service function, and disable them afterwards (unless they were already enabled). Other special options include:

authtok_prompt=prompt, oldauthtok_prompt=prompt, user_prompt=prompt

These options can be used to override the prompts used by pam_get_authtok(3) and pam_get_user(3).

echo_pass

This option controls whether pam_get_authtok(3) will allow the user to see what they are typing.

try_first_pass, use_first_pass

These options control pam_get_authtok(3)'s use of cached authentication tokens.

SEE ALSO

pam(3)

STANDARDS

X/Open Single Sign-On Service (XSSO) - Pluggable Authentication Modules, June 1997.

AUTHORS

The OpenPAM library was developed for the FreeBSD Project by ThinkSec AS and Network Associates Laboratories, the Security Research Division of Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 (“CBOSS”), as part of the DARPA CHATS research program.

The OpenPAM library is maintained by Dag-Erling Smørgrav <des@des.no>.