Ssh with two or more private keys using ~/.ssh/config read the wrong private key

Question

Hi,
I have created a config file in ~/.ssh/ to be able to connect to remote sites using different private keys per site.
The problem is when I try to connect to any of them ssh reads the wrong private key dispite of the configuration in ~/.ssh/config file.
For example:
Host vps
   Hostname x.x.x.x
  User guesswho
   IdentityFile vps.pk
Host home
  Hostname y.y.y.y
  User home
  IdentityFile home.pk
>ssh -v vps ( connects using home.pk)
>ssh -v -i ~/.ssh/vps.pk ( connects using home.pk)
I tried it on a Ubuntu 10.04.3 LTS using same config file and keys (openssh-server 1:5.3p1-3ubuntu7) and it worked as expected.
Any help would be appreciated.
zcookie

Answer 1

My question is do I have to create a separate private key from my imac or can I just copy the private key from my macbook?
Do you have to create separate private keys? No, but there are reasons why you might want to.
The biggest one is the fact that if any key is compromised, they are all compromised (since they are the same). Say, for example, your MacBook is lost or stolen. You really should consider disabling the MacBook's key from authorized_keys to prevent the finder/thief from getting into your server. If that one key is shared by multiple hosts, though, you're going to lock out all the other hosts as well, even though they haven't been affected.
Having separate keys per client lets you nix just the key for the MacBook (or whichever machine) without impacting the other machines' ability to connect.
Other than the trivial amount of work it takes to create a private key there's really no overhead in having unique keys per client machine. If, however, you really want them to be the same, knock yourself out