%%%----------------------------------------------------------------------
%%% File : 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) 2002-2010 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., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------
-module(idna).
-author('alexey@process-one.net').
%%-compile(export_all).
-export([domain_utf8_to_ascii/1,
domain_ucs2_to_ascii/1]).
domain_utf8_to_ascii(Domain) ->
domain_ucs2_to_ascii(utf8_to_ucs2(Domain)).
utf8_to_ucs2(S) ->
utf8_to_ucs2(S, "").
utf8_to_ucs2([], R) ->
lists:reverse(R);
utf8_to_ucs2([C | S], R) when C < 16#80 ->
utf8_to_ucs2(S, [C | R]);
utf8_to_ucs2([C1, C2 | S], R) when C1 < 16#E0 ->
utf8_to_ucs2(S, [((C1 band 16#1F) bsl 6) bor
(C2 band 16#3F) | R]);
utf8_to_ucs2([C1, C2, C3 | S], R) when C1 < 16#F0 ->
utf8_to_ucs2(S, [((C1 band 16#0F) bsl 12) bor
((C2 band 16#3F) bsl 6) bor
(C3 band 16#3F) | R]).
domain_ucs2_to_ascii(Domain) ->
case catch domain_ucs2_to_ascii1(Domain) of
{'EXIT', _Reason} ->
false;
Res ->
Res
end.
domain_ucs2_to_ascii1(Domain) ->
Parts = string:tokens(Domain, [16#002E, 16#3002, 16#FF0E, 16#FF61]),
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 =< 16#2C) or
(16#2E =< C) and (C =< 16#2F) or
(16#3A =< C) and (C =< 16#40) or
(16#5B =< C) and (C =< 16#60) or
(16#7B =< C) and (C =< 16#7F) ->
true;
(_) ->
false
end, Name),
case Name of
[H | _] when H /= $- ->
true = lists:last(Name) /= $-
end,
ASCIIName = case lists:any(fun(C) -> C > 16#7F 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 =< 16#7f end, Input),
NonBasic = lists:filter(fun(C) -> C > 16#7f 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.
