title: Password-less login for SSH via SSH
body: <p>I am writing a script which needs to be able to access a server with limited access. I wish to do this by going through another unix server which I do have access to and also has access to the other computer.</p>
  
  <p>I can SSH into the second machine from home an not be prompted for a password, since I generated an SSH key and using ssh-copy-id. When I am physically at the second machine, I can SSH into the <strong>third</strong> in the same manner, with out being prompted for a password.</p>
  
  <p>However, when I SSH into the second and then try to SSH into the third, I am prompted to the pass-pharse for the key and the password for the third computer.</p>
  
  <p>Why does this happen, and how can I stop this prompt?</p>
  
  <p>EDIT: To clarity some points.</p>
  
  <ul>
  <li>I do not have root permission on either machine I am SSHing into, only my machine at home</li>
  <li>I missed typed above (now fixed). While physically at the second machine I can SSH into the <strong>third</strong> server.</li>
  </ul>
  
  <p><strong>Diagram</strong></p>
  
  <pre><code>Machine A : Home machine, root access
  |           SSH (passwordless)
  v
  Machine B : Publicly accessible server, no root permissions
  |           SSH (passwordless while physically logged in,
  |           password prompted while at machine A SSHed into machine B)
  v
  Machine C : Only accessable on campus 
              (which B is and A is not), no root permissions
  </code></pre>