code: function sshKeyToPEM(key) {
      assert.equal('string', typeof key, 'typeof ssh_key');
  
      /* JSSTYLED */
      if (/^ssh-rsa.*/.test(key))
        return rsaToPEM(key);
  
      /* JSSTYLED */
      if (/^ssh-ds[as].*/.test(key))
        return dsaToPEM(key);
  
      throw new Error('Only RSA and DSA public keys are allowed');
    }
docs: /--- API 
  Converts an OpenSSH public key (rsa only) to a PKCS#8 PEM file.
  
  The intent of this module is to interoperate with OpenSSL only,
  specifically the node crypto module's `verify` method.
  
  @param {String} key an OpenSSH public key.
  @return {String} PEM encoded form of the RSA public key.
  @throws {TypeError} on bad input.
  @throws {Error} on invalid ssh key formatted data.