Custom authentication error message

[Paroxizm]

How can i send to SSHClient custom error message from SSH Server if connection not allowed.

For example, my ssh server for each connection checks userName, password and clientIP. How can i send error message to client in case of login/password is correct, but IP is blacklisted?

[Dimon]

SSH protocol doesn't allow to send user's error message in authentication process. Moreover, it forbids to specify such messages, because it reduces security. The more information a violator knows, the easier it is for him to break-in.