%%%----------------------------------------------------------------------
%%% File : ejabberd_idna.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : Support for IDNA (RFC3490)
%%% Created : 10 Apr 2004 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2016 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License along
%%% with this program; if not, write to the Free Software Foundation, Inc.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%----------------------------------------------------------------------
-module(ejabberd_idna).
-author('alexey@process-one.net').
-export([domain_utf8_to_ascii/1,
domain_ucs2_to_ascii/1,
utf8_to_ucs2/1]).
-ifdef(TEST).
-include_lib("eunit/include/eunit.hrl").
-endif.
-spec domain_utf8_to_ascii(binary()) -> false | binary().
domain_utf8_to_ascii(Domain) ->
domain_ucs2_to_ascii(utf8_to_ucs2(Domain)).
utf8_to_ucs2(S) ->
utf8_to_ucs2(binary_to_list(S), "").
utf8_to_ucs2([], R) -> lists:reverse(R);
utf8_to_ucs2([C | S], R) when C < 128 ->
utf8_to_ucs2(S, [C | R]);
utf8_to_ucs2([C1, C2 | S], R) when C1 < 224 ->
utf8_to_ucs2(S, [C1 band 31 bsl 6 bor C2 band 63 | R]);
utf8_to_ucs2([C1, C2, C3 | S], R) when C1 < 240 ->
utf8_to_ucs2(S,
[C1 band 15 bsl 12 bor (C2 band 63 bsl 6) bor C3 band 63
| R]).
-spec domain_ucs2_to_ascii(list()) -> false | binary().
domain_ucs2_to_ascii(Domain) ->
case catch domain_ucs2_to_ascii1(Domain) of
{'EXIT', _Reason} -> false;
Res -> iolist_to_binary(Res)
end.
domain_ucs2_to_ascii1(Domain) ->
Parts = string:tokens(Domain,
[46, 12290, 65294, 65377]),
ASCIIParts = lists:map(fun (P) -> to_ascii(P) end,
Parts),
string:strip(lists:flatmap(fun (P) -> [$. | P] end,
ASCIIParts),
left, $.).
%% Domain names are already nameprep'ed in ejabberd, so we skiping this step
to_ascii(Name) ->
false = lists:any(fun (C)
when (0 =< C) and (C =< 44) or
(46 =< C) and (C =< 47)
or (58 =< C) and (C =< 64)
or (91 =< C) and (C =< 96)
or (123 =< C) and (C =< 127) ->
true;
(_) -> false
end,
Name),
case Name of
[H | _] when H /= $- -> true = lists:last(Name) /= $-
end,
ASCIIName = case lists:any(fun (C) -> C > 127 end, Name)
of
true ->
true = case Name of
"xn--" ++ _ -> false;
_ -> true
end,
"xn--" ++ punycode_encode(Name);
false -> Name
end,
L = length(ASCIIName),
true = (1 =< L) and (L =< 63),
ASCIIName.
%%% PUNYCODE (RFC3492)
-define(BASE, 36).
-define(TMIN, 1).
-define(TMAX, 26).
-define(SKEW, 38).
-define(DAMP, 700).
-define(INITIAL_BIAS, 72).
-define(INITIAL_N, 128).
punycode_encode(Input) ->
N = (?INITIAL_N),
Delta = 0,
Bias = (?INITIAL_BIAS),
Basic = lists:filter(fun (C) -> C =< 127 end, Input),
NonBasic = lists:filter(fun (C) -> C > 127 end, Input),
L = length(Input),
B = length(Basic),
SNonBasic = lists:usort(NonBasic),
Output1 = if B > 0 -> Basic ++ "-";
true -> ""
end,
Output2 = punycode_encode1(Input, SNonBasic, B, B, L, N,
Delta, Bias, ""),
Output1 ++ Output2.
punycode_encode1(Input, [M | SNonBasic], B, H, L, N,
Delta, Bias, Out)
when H < L ->
Delta1 = Delta + (M - N) * (H + 1),
% let n = m
{NewDelta, NewBias, NewH, NewOut} = lists:foldl(fun (C,
{ADelta, ABias, AH,
AOut}) ->
if C < M ->
{ADelta + 1,
ABias, AH,
AOut};
C == M ->
NewOut =
punycode_encode_delta(ADelta,
ABias,
AOut),
NewBias =
adapt(ADelta,
H +
1,
H
==
B),
{0, NewBias,
AH + 1,
NewOut};
true ->
{ADelta,
ABias, AH,
AOut}
end
end,
{Delta1, Bias, H, Out},
Input),
punycode_encode1(Input, SNonBasic, B, NewH, L, M + 1,
NewDelta + 1, NewBias, NewOut);
punycode_encode1(_Input, _SNonBasic, _B, _H, _L, _N,
_Delta, _Bias, Out) ->
lists:reverse(Out).
punycode_encode_delta(Delta, Bias, Out) ->
punycode_encode_delta(Delta, Bias, Out, ?BASE).
punycode_encode_delta(Delta, Bias, Out, K) ->
T = if K =< Bias -> ?TMIN;
K >= Bias + (?TMAX) -> ?TMAX;
true -> K - Bias
end,
if Delta < T -> [codepoint(Delta) | Out];
true ->
C = T + (Delta - T) rem ((?BASE) - T),
punycode_encode_delta((Delta - T) div ((?BASE) - T),
Bias, [codepoint(C) | Out], K + (?BASE))
end.
adapt(Delta, NumPoints, FirstTime) ->
Delta1 = if FirstTime -> Delta div (?DAMP);
true -> Delta div 2
end,
Delta2 = Delta1 + Delta1 div NumPoints,
adapt1(Delta2, 0).
adapt1(Delta, K) ->
if Delta > ((?BASE) - (?TMIN)) * (?TMAX) div 2 ->
adapt1(Delta div ((?BASE) - (?TMIN)), K + (?BASE));
true ->
K +
((?BASE) - (?TMIN) + 1) * Delta div (Delta + (?SKEW))
end.
codepoint(C) ->
if (0 =< C) and (C =< 25) -> C + 97;
(26 =< C) and (C =< 35) -> C + 22
end.
%%%===================================================================
%%% Unit tests
%%%===================================================================
-ifdef(TEST).
acsii_test() ->
?assertEqual(<<"test.org">>, domain_utf8_to_ascii(<<"test.org">>)).
utf8_test() ->
?assertEqual(
<<"xn--d1acufc.xn--p1ai">>,
domain_utf8_to_ascii(
<<208,180,208,190,208,188,208,181,208,189,46,209,128,209,132>>)).
-endif.
