Forced per-user ssh port

Question

I want to allow access to each user on a server through a different port. For example; user1 can only be accessed by ssh through port 2201, user 2 can only be accessed through port 2202. I have already allowed access through ports 2201 and 2202 by editing "/etc/ssh/sshd_config" and adding two lines:

Port 2201
Port 2202

Both users can now access ssh through both ports (and 22).

• How would I restrict them to only their own ports?

(Also), the users [except root] don't have any automatically created "~/.ssh/" directory so I made one and tried adding a config file and an authorized_keys file - these don't seem to make any difference.

OS is debian squeeze and thanks in advance.

Answer 1

You'll have to create a separate sshd_config for each user/port combo containing (along with the usual configuration options) the ListenAddress and AllowUsers keywords.

sshd_config_2201

ListenAddress 0:2201
AllowUsers user1

sshd_config_2202

ListenAddress 0:2202
AllowUsers user2

etc.

You'll need to run sshd once for each user with the -f switch to specify the individual configuration files.