If you select the “Multi-factor authentication required” system right in a role definition, the PAM applications you add to the role will require users to select a secondary form of authentication to log on successfully. You define the forms of authentication available and presented to the user in the authentication profile you have configured using the administrative portal for the Centrify identity platform. For example, you might configure an authentication profile that require users to answer a phone call, click a link in an email message, or respond to a text message.
Note that some applications do not support multi-factor authentication and users might be denied access to applications that they would otherwise be able to use. For example, if a specific version of an application that you want to use only supports a single layer of authentication—such as a password challenge—users would be prevented from logging on and using the service even if they are assigned to a role with the predefined login-all PAM application right.
If you want to grant access to applications that only support one layer of authentication in roles where you are generally using the “Multi-factor authentication required” system right, you must add those applications to the list of applications for which you want to skip multi‑factor authentication. You can update the list of applications for which to skip multi‑factor authentication by enabling and modifying the “Specify programs for which multi-factor authentication is ignored” group policy or setting the pam.mfa.program.ignore configuration parameter in the centrifydc.conf file.
Before assigning roles with multi-factor authentication required to users, you should test access to all of the applications you expect users to access to verify they won’t be unexpectedly denied access simply because multi-factor authentication isn’t supported. Because the applications that don’t support multi-factor authentication will depend on the platforms and the versions of the applications you plan to support, testing in your own environment is the only way to determine which applications to add to the pam.mfa.program.ignore configuration parameter.
The most common applications that are known to only support a single password challenge and response for authentication are ignored for multi-factor authentication by default. For example, some versions of java and vsftpd do not support multi-factor authentication and are ignored by default.
Additionally, while some platforms support multi-factor authentication for all PAM applications, they may not allow you to require multi-factor authentication for GUI log in. For example, for users running AIX, Solaris, and HP-UX, multi-factor authentication for GUI login is not supported.