anchor.diff:  replace_localhost(Host) ->
       Host.
   
  -do_lookup_host_key(Host, Alg, Opts) ->
  +do_lookup_host_key(KeyToMatch, Host, Alg, Opts) ->
       case file:open(file_name(user, "known_hosts", Opts), [read, binary]) of
   	{ok, Fd} ->
  -	    Res = lookup_host_key_fd(Fd, Host, Alg),
  +	    Res = lookup_host_key_fd(Fd, KeyToMatch, Host, Alg),
   	    file:close(Fd),
   	    {ok, Res};
   	{error, enoent} -> {error, not_found};
  
positive.code: identity_pass_phrase("ssh-rsa") ->
      rsa_pass_phrase.
  
  lookup_host_key_fd(Fd, 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, Host, proplists:get_value(hostnames, Attributes), Key, KeyType);
  		[] ->
  		    lookup_host_key_fd(Fd, Host, KeyType)
  	    end
      end.
  
  
negative.code: %% return {ok, Key(s)} or {error, not_found}
  %%
  
  lookup_host_key(KeyToMatch, Host, Alg, Opts) ->
      Host1 = replace_localhost(Host),
      do_lookup_host_key(KeyToMatch, Host1, Alg, Opts).
  	    
  
  add_host_key(Host, Key, Opts) ->
  