system-auth-ac (5) - Linux Man Pages
system-auth-ac: Common configuration files for
system-auth-ac, password-auth-ac, smartcard-auth-ac, fingerprint-auth-ac, postlogin-ac - Common configuration files for PAMified services written by authconfig(8)
The purpose of this configuration file is to provide common configuration file for all applications and service daemons calling PAM library.
The system-auth configuration file is included from all individual service configuration files with the help of the include directive. When authconfig(8) writes the system PAM configuration file it replaces the default system-auth file with a symlink pointing to system-auth-ac and writes the configuration to this file. The symlink is not changed on subsequent configuration changes even if it points elsewhere. This allows system administrators to override the configuration written by authconfig.
The authconfig now writes the authentication modules also into additional PAM configuration files /etc/pam.d/password-auth-ac, /etc/pam.d/smartcard-auth-ac, and /etc/pam.d/fingerprint-auth-ac. These configuration files contain only modules which perform authentication with the respective kinds of authentication tokens. For example /etc/pam.d/smartcard-auth[-ac] will not contain pam_unix and pam_ldap modules and /etc/pam.d/password-auth[-ac] will not contain pam_pkcs11 and pam_fprintd modules.
The file /etc/pam.d/postlogin-ac contains common services to be invoked after login. An example can be a module that encrypts an user's filesystem or user's keyring and is decrypted by his password.
The PAM configuration files of services which are accessed by remote connections such as sshd or ftpd now include the /etc/pam.d/password-auth configuration file instead of /etc/pam.d/system-auth.
EXAMPLEConfigure system to use pam_tally2 for configuration of maximum number of failed logins. Also call pam_access to verify if access is allowed.
Make system-auth symlink point to system-auth-local which contains:
auth requisite pam_access.so
auth requisite pam_tally2.so deny=3 lock_time=30 \
auth include system-auth-ac
account required pam_tally2.so
account include system-auth-ac
password include system-auth-ac
session include system-auth-ac