The LDAP authentication component provides functions to verify the identity of a user and to set user specific credentials. See pam_sm_authenticate(3PAM) and pam_sm_setcred(3PAM)). The pam_sm_authenticate() function uses the password entered by the user to attempt to authenticate to the LDAP server. If successful, the user is authenticated.

The authentication method used is defined in the client profile or is configured by using the ldapclient(1M) command. To determine the authentication method to use, this module first attempts to use the authentication method defined for service pam_ldap. If no authentication method is defined, it will then use the default authentication method. If neither are set, the authentication will fail. This module will skip the configured authentication method if it is set to none.

At present, the pam_sm_setcred() function succeeds all the time without setting any credentials.

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

debug

syslog(3C) debugging information at LOG_DEBUG level.

nowarn

Turn off warning messages.

use_first_pass

Authenticate to the directory by using the password that the user initially entered when the user authenticated to the first authentication module in the stack. If the authentication fails, or if no password has been entered, it quits. The user is not prompted for another password.

try_first_pass

Authenticate to the directory by using the password the user initially entered when the user authenticated to the first authentication module in the stack. If the authentication fails, or if no password has been entered, the user is prompted for another password.

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

The LDAP password management component provides the pam_sm_chauthtok(3PAM) function to change passwords in the LDAP password database. The following options may be passed in to the LDAP service module:

debug

syslog(3C) debugging information at LOG_DEBUG level.

nowarn

Turn off warning messages.

use_first_pass

Compare the password in the password database with the user's old password, which was entered to the first password module in the stack. If the passwords do not match, or if no password has been entered, pam_ldap quits. It does not prompt the user for the old password. It also attempts to use the new password, which was entered to the first password module in the stack, as the new password for this module. If the new password fails, pam_ldap quits and does not prompt the user for a new password.

try_first_pass

Compare the password in the password database with the user's old password, which was entered to the first password module in the stack. If the passwords do not match, or if no password has been entered, it prompts the user for the old password. It also attempts to use the new password, which was entered to the first password module in the stack, as the new password for this module. If the new password fails, it prompts the user for a new password.

The following is a configuration for the login service when using pam_ldap.so.1. 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 succeeds, pam_ldap is not invoked.
login   auth sufficient /usr/lib/security/pam_unix.so.1
login   auth required   /usr/lib/security/pam_ldap.so.1 try_first_pass

Note that the pam_unix.so.1 is qualified with the sufficient control flag.

The following is a configuration for password management when using pam_ldap.so.1. Lines that begin with the # symbol are ignored.

# Password management
#
other   password sufficient     /usr/lib/security/pam_unix.so.1
other   password required       /usr/lib/security/pam_ldap.so.1