Using ~/.ssh/config and no passwords with Mac OS X

Using ssh to securely connect with servers from the terminal is pretty easy. set up a public key and a private key using

However you may want separate keys for work, for home servers and other services like a webserver or github. the ~/.ssh /config file is a way to specify a list of possible keys to use and associate them with a host name. I when using this initially Mac OS X always prompted me for my identity file password. instead of acting password-less.

For OS X it looks like you have to add a few more options to get the same behaviour as without the .ssh/config :

Host *
  RSAAuthentication yes
  PasswordAuthentication yes
  IdentityFile ~/.ssh/id_rsa

Adding more Identity files the first passing will be used

Host *
  RSAAuthentication yes
  PasswordAuthentication yes
  IdentityFile ~/.ssh/id_rsa
  IdentityFile ~/.ssh/id_rsa_work
  IdentityFile ~/.ssh/id_rsa_github

Multiple Identities, using known identity for known location.

Host *.work.com
  IdentityFile ~/.ssh/id_rsa

Host *.github.com
  IdentityFile ~/.ssh/id_rsa_github

Host *
  RSAAuthentication yes
  PasswordAuthentication yes
  IdentityFile ~/.ssh/id_rsa