title: Converting rsa.PublicKey to ssh.PublicKey
body: <p>I have an <code>rsa.PublicKey</code> which consists of a modulus and a public exponenet in a struct. I want to verify an <code>ssh.Signature</code> which is signed with that key, and I figure if I have an <code>ssh.PublicKey</code> I can call the <code>Verify</code> method on that interface. However, I can't find any classes that implement <code>ssh.PublicKey</code> and support converting from <code>rsa.PublicKey</code>. Do I need to write a proprietary method to do this, or is there some class I'm not finding, or a better way to go about solving my problem?</p>
  
  <p>For context, I got the <code>rsa.PublicKey</code> from an <code>x509.Certificate</code> which came from a yubikey attesting a key in one of its PIV slots.</p>