Configuring PAM-related parameters on IBM AIX computers

On IBM AIX computers, the PAM configuration parameters described in this chapter apply to the AIX Loadable Authentication Module (LAM) or to the PAM interface. If you have configured the AIX computer to use the PAM interface, the configuration parameters apply to the PAM settings. If the AIX computer is configured to use the LAM interface, the parameters configure LAM settings, as applicable. For more information about AIX-specific configuration parameters, see the Customizing AIX configuration parameters.

Controlling access to AIX computers

On most computers, the predefined login-all PAM access right is required to allow users who are assigned the UNIX Login role to log on and use PAM-enabled applications in the zones they have permission to access. However, if you have AIX computers that are configured to use the Loadable Authentication Module (LAM) instead of PAM in a zone, users will be able to log on even if they have not been assigned the UNIX Login role. In addition, if you define your own custom PAM access rights, those rights will not be applicable on AIX computers that use the LAM interface.

To prevent users from logging on to or using unauthorized applications on AIX computers is a zone, you can explicitly allow or deny access to specific users and groups through configuration parameters or group policies or change the configuration of your AIX computers to use the more commonly supported Pluggable Authentication Module (PAM) interface. For more information about controlling access, see Enforcing access rights on AIX computers.

Explicitly allowing and denying access

If you have AIX computers that use the Loadable Authentication Module (LAM) interface, you cannot use the predefined login-all PAM access right or custom PAM access rights to authorize who can log on and who can use specific applications. Therefore, the default UNIX Login role does not apply on AIX computers that use the LAM interface. If you are primarily concerned with who can log on to those computers, you can use the pam.allow.groups, pam.allow.users, or both parameters to explicitly specify the groups and users who can log on to AIX computers that use the LAM interface. All other groups and users—including those assigned the UNIX Login role—will be denied access. Alternatively, you can use the pam.deny.users, pam.deny.groups, or both parameters to explicitly specify the users and groups who are not allowed to log on.

Changing the configuration of AIX computers

By default, AIX computers are configured to use the Loadable Authentication Module (LAM) instead of the Pluggable Authentication Module (PAM) subsystem. If you want to be able to use the default or custom PAM access rights to authorize access to specific applications, you might want to reconfigure your AIX computers to use the PAM interface instead of the LAM interface. If you choose to reconfigure AIX computers, you should also be sure to replace the OpenSSH package for LAM with the OpenSSH for PAM and thoroughly test your applications.