[CLUE-Tech] rsa1 logs in w/out password - not rsa(2)

[David Anselmi]

Dave Price wrote:
> cluebies,
> 
> I have genereated rssa1 and rsa keys and moved the .pub (public key)
> components to ann authorized_hosts file on a remote system.
> 
> When I do an ssh -1 user at remote I get in with no password (rsa1)
> 
> However, ssh user at remote (rsa2) always prompts me for a password.
> 
> Any idea why this would happen?

You did not password protect your private key (~/.ssh/identity by 
default).  When you connect with ssh 1, the server asks for rsa 
authentiction and the client provides it.  If the key had been encrypted 
with a password, you would have gotten a message asking for the 
passphrase for the key (it is noticably different than when ssh asks for 
your login password on the server).

When you use ssh 2, a different type of key is used (either an rsa or a 
dsa key pair, I don't know how the rsa keys differ from those used in 
ssh 1).  Since you don't have a public key for ssh 2 on the server, 
public key authentication fails and it tries password authentication 
next.  You can see all the gory details by using the above commands with 
-v (or -vv) and comparing the debugging info.

By ssh 1 and ssh 2 I mean version 1 or 2 of the ssh protocol, regardless 
of implementation.  I assume you're using OpenSSH which uses different 
key file formats for the two versions of the protocol even though the 
underlying encrypt/decrypt algorithms are the same (though their use in 
the two protocols may not be).

Dave