Limit who can use OpenSSH based on a list of users

Anonymous Reader writes “The idea is very simple you want to limit who can use sshd based on a list of users. The text file contains a list of users that may not log in (or allowed to log in) using the SSH server. This is use for improving security. So if you want to deny or allow access to large number of users SSH PAM configuration (ideal for ISPs and Web hosting service providers) is right choice for you. Another option is to limit users using sshd’s AllowUser or DenyUser directives.”