illumos: manual page: pam

PAM_LDAP(7) Standards, Environments, and Macros PAM_LDAP(7)

NAME

pam_ldap - authentication and account management PAM module for LDAP

SYNOPSIS

pam_ldap.so.1

DESCRIPTION

The pam_ldap module implements pam_sm_authenticate(3PAM) and
pam_sm_acct_mgmt(3PAM), the functions that provide functionality for the
PAM authentication and account management stacks. The pam_ldap module
ties the authentication and account management functionality to the
functionality of the supporting LDAP server. For authentication, pam_ldap
can authenticate the user directly to any LDAP directory server by using
any supported authentication mechanism, such as DIGEST-MD5. However, the
account management component of pam_ldap will work only with the Sun Java
System Directory Server. The server's user account management must be
properly configured before it can be used by pam_ldap. Refer to the Sun
Java System Directory Server Administration Guide for information on how
to configure user account management, including password and account
lockout policy.

pam_ldap must be used in conjunction with the modules that support the
UNIX authentication, password, and account management, which are
pam_authtok_get(7), pam_passwd_auth(7), pam_unix_account(7), and
pam_unix_auth(7). pam_ldap is designed to be stacked directly below these
modules. If other modules are designed to be stacked in this manner, the
modules can be stacked below the pam_ldap module. The Examples section
shows how the UNIX modules are stacked with pam_ldap. When stacked
together, the UNIX modules are used to control local accounts, such as
root. pam_ldap is used to control network accounts, that is, LDAP users.
For the stacks to work, pam_unix_auth, pam_unix_account, and
pam_passwd_auth must be configured with the binding control flag and the
server_policy option. This configuration allows local account override of
a network account.

LDAP Authentication Module

The LDAP authentication module verifies the identity of a user. The
pam_sm_authenticate(3PAM) function uses the password entered by the user
to attempt to authenticate to the LDAP server. If successful, the user is
authenticated. See NOTES for information on password prompting.

The authentication method used is either defined in the client profile,
or the authentication method is configured by using the ldapclient(8)
command. To determine the authentication method to use, this module
first attempts to use the authentication method that is defined, for
service pam_ldap, for example,
serviceAuthenticationMethod:pam_ldap:sasl/DIGEST-MD5. If no
authentication method is defined, pam_ldap uses the default
authentication method. If neither are set, the authentication fails. This
module skips the configured authentication method if the authentication
method is set to none.

The following options can be passed to the LDAP service module:

debug
syslog(3C) debugging information at LOG_DEBUG level.

nowarn
Turn off warning messages.

These options are case sensitive and must be used exactly as presented
here.

LDAP Account Management Module

The LDAP account management module validates the user's account. The
pam_sm_acct_mgmt(3PAM) function authenticates to the LDAP server to
verify that the user's password has not expired, or that the user's
account has not been locked. In the event that there is no user
authentication token (PAM_AUTHTOK) available, the pam_sm_acct_mgmt(3PAM)
function attempts to retrieve the user's account status without
authenticating to the LDAP server as the user logging in. This procedure
will succeed only if the LDAP server is Sun Java System Directory server
5.2 patch 4 or newer. The following options can be passed to the LDAP
service module:

debug
syslog(3C) debugging information at LOG_DEBUG level.

nowarn
Turn off warning messages.

These options are case sensitive, and the options must be used exactly as
presented here.

LDAP Password Management Module

LDAP password management is no longer supported by pam_ldap. Use
pam_authtok_store(7) instead of pam_ldap for password change.
pam_authtok_store(7) handles both the local and LDAP accounts and updates
the passwords in all the repositories configured by nsswitch.conf(5).

ERRORS

The authentication service returns the following error codes:

PAM_SUCCESS
The authentication was successful.

PAM_MAXTRIES
The maximum number of authentication attempts was
exceeded.

PAM_AUTH_ERR
The authentication failed.

PAM_USER_UNKNOWN
No account is present for the user.

PAM_BUF_ERR
A memory buffer error occurred.

PAM_SYSTEM_ERR
A system error occurred.

PAM_IGNORE
The user's account was inactivated.

The account management service returns the following error codes:

PAM_SUCCESS
The user was allowed access to the account.

PAM_NEW_AUTHTOK_REQD
A new authentication token is required.

PAM_ACCT_EXPIRED
The user account has expired.

PAM_PERM_DENIED
The user was denied access to the account at this
time.

PAM_USER_UNKNOWN
No account is present for the user.

PAM_BUF_ERR
A memory buffer error occurred.

PAM_SYSTEM_ERR
A system error occurred.

EXAMPLES

Example 1: Using pam_ldap With Authentication

The following is a configuration for the login service when using
pam_ldap. The service name login can be substituted for any other
authentication service such as dtlogin or su. Lines that begin with the #
symbol are comments and are ignored.

# Authentication management for login service is stacked.
# If pam_unix_auth succeeds, pam_ldap is not invoked.
# The control flag "binding" provides a local overriding
# remote (LDAP) control. The "server_policy" option is used
# to tell pam_unix_auth.so.1 to ignore the LDAP users.

login auth requisite pam_authtok_get.so.1
login auth required pam_dhkeys.so.1
login auth required pam_unix_cred.so.1
login auth binding pam_unix_auth.so.1 server_policy
login auth required pam_ldap.so.1

Example 2: Using pam_ldap With Account Management

The following is a configuration for account management when using
pam_ldap. Lines that begin with the # symbol are comments and are
ignored.

# Account management for all services is stacked
# If pam_unix_account succeeds, pam_ldap is not invoked.
# The control flag "binding" provides a local overriding
# remote (LDAP) control. The "server_policy" option is used
# to tell pam_unix_account.so.1 to ignore the LDAP users.

other account requisite pam_roles.so.1
other account binding pam_unix_account.so.1 server_policy
other account required pam_ldap.so.1

Example 3: Using pam_authtok_store With Password Management For Both Local

and LDAP Accounts

The following is a configuration for password management when using
pam_authtok_store. Lines that begin with the # symbol are comments and
are ignored.

# Password management (authentication)
# The control flag "binding" provides a local overriding
# remote (LDAP) control. The server_policy option is used
# to tell pam_passwd_auth.so.1 to ignore the LDAP users.

passwd auth binding pam_passwd_auth.so.1 server_policy
passwd auth required pam_ldap.so.1

# Password management (updates)
# This updates passwords stored both in the local /etc
# files and in the LDAP directory. The "server_policy"
# option is used to tell pam_authtok_store to
# follow the LDAP server's policy when updating
# passwords stored in the LDAP directory

other password required pam_dhkeys.so.1
other password requisite pam_authtok_get.so.1
other password requisite pam_authtok_check.so.1
other password required pam_authtok_store.so.1 server_policy

FILES

/var/ldap/ldap_client_file
/var/ldap/ldap_client_cred
The LDAP configuration files of the client.
Do not manually modify these files, as
these files might not be human readable.
Use ldapclient(8) to update these files.

/etc/pam.conf
PAM configuration file.

ATTRIBUTES

NOTES

The interfaces in libpam(3LIB) are MT-Safe only if each thread within the
multi-threaded application uses its own PAM handle.

The previously supported use_first_pass and try_first_pass options are
obsolete in this version, are no longer needed, can safely be removed
from pam.conf(5), and are silently ignored. They might be removed in a
future release. Password prompting must be provided for by stacking
pam_authtok_get(7) before pam_ldap in the auth and password module stacks
and pam_passwd_auth(7) in the passwd service auth stack (as described in
the EXAMPLES section). The previously supported password update function
is replaced in this release by the previously recommended use of
pam_authtok_store with the server_policy option (as described in the
EXAMPLES section).

The functions: pam_sm_setcred(3PAM), pam_sm_chauthtok(3PAM),
pam_sm_open_session(3PAM), and pam_sm_close_session(3PAM) do nothing and
return PAM_IGNORE in pam_ldap.

August 19, 2023 PAM_LDAP(7)