How to create a (username/password or certificate) white/black list for ssh?
For example of blacklist, I can use any username/password combination to access the server, except the ones on the blacklist.
The ssh version can be OpenSSH.
And the server is a Linux.
Creating lots of users on Linux for white list is not a nice way.
Any approach can be used, like modifying SSH software itself, or using Linux/SSH features, or using other modules.
Maybe I did not describe the situation clearly. Basically, I simply want any username/password combination to be able to login, except the black list.
For example, if the black list is "admin/admin; root/123". I can simply use "abc/123456" to login. The server is like a VERY VULNERABLE one with almost no credential needed.
For white list, I can give a number of username/password/certificate combinations for the list, not just the username.