anchor.diff:  %% return {ok, Key(s)} or {error, not_found}
   %%
   
  -lookup_host_key(Host, Alg, Opts) ->
  +lookup_host_key(KeyToMatch, Host, Alg, Opts) ->
       Host1 = replace_localhost(Host),
  -    do_lookup_host_key(Host1, Alg, Opts).
  +    do_lookup_host_key(KeyToMatch, Host1, Alg, Opts).
   	    
   
   add_host_key(Host, Key, Opts) ->
  
positive.code: 
  %% Used by client
  is_host_key(Key, PeerName, Algorithm, Opts) ->
      case lookup_host_key(PeerName, Algorithm, Opts) of
  	{ok, Key} ->
  	    true;
  	_ ->
  
negative.code: identity_pass_phrase("ssh-rsa") ->
      rsa_pass_phrase.
  
  lookup_host_key_fd(Fd, KeyToMatch, Host, KeyType) ->
      case io:get_line(Fd, '') of
  	eof ->
  	    {error, not_found};
  	Line ->
  	    case ssh_decode_line(Line, known_hosts) of
  		[{Key, Attributes}] ->
  		    handle_host(Fd, KeyToMatch, Host, proplists:get_value(hostnames, Attributes), Key, KeyType);
  		[] ->
  		    lookup_host_key_fd(Fd, KeyToMatch, Host, KeyType)
  	    end
      end.
  
  