I have a server (lets assume its ip be a.b.c.d) which allows users to login via ssh. Now I want to change the physical machine keeping the ip same. So that the new machine is still accessed by a user like this
$ssh a.b.c.d
Problem is, every time one user tries to login, she gets the following ssh-key mismatch error.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is 02:dc:c6:18:1b:34:b7:1d:fa:90:ab:e1:95:48:69:84. Please contact your system administrator. Add correct host key in /home/user/.ssh/known_hosts to get rid of this message. Offending key in /home/user/.ssh/known_hosts:37 RSA host key for alumni has changed and you have requested strict checking. Host key verification failed.
I know that user can delete line # 37 from the file ~/.ssh/known_hosts and next time she would get a yes/no prompt. What I want is that user should be kept unaware of this whole machine replacement thing and just get a prompt for password.
How to do that?
ssh
's only protection against man in the middle attacks and could result in you sending your password right to the attacker instead of the intended machine? Unless you know for a fact that you are invulnerable to active attacks (for example, you are on the same secure internal network as the target machine) this destroysssh
's security model.