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xmpp.chapril.org-ejabberd/src/ejabberd_captcha.erl
Badlop 659d546897 Fix warnings detected by Dialyzer
2010-11-04 01:00:18 +01:00

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%%%-------------------------------------------------------------------
%%% File : ejabberd_captcha.erl
%%% Author : Evgeniy Khramtsov <xramtsov@gmail.com>
%%% Purpose : CAPTCHA processing.
%%% Created : 26 Apr 2008 by Evgeniy Khramtsov <xramtsov@gmail.com>
%%%
%%%
%%% 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
%%%
%%%-------------------------------------------------------------------
%%% Database schema (version / storage / table)
%%%
%%% 2.1.x / mnesia / captcha
%%% id = string()
%%% pid = pid()
%%% key = string()
%%% tref = any()
%%% args = any()
%%%
%%% 3.0.0-alpha / ets / captcha
%%% id = string()
%%% pid = pid()
%%% key = string()
%%% tref = any()
%%% args = any()
-module(ejabberd_captcha).
-behaviour(gen_server).
%% API
-export([start_link/0]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-export([create_captcha/5, build_captcha_html/2, check_captcha/2,
process_reply/1, process/2, is_feature_available/0,
create_captcha_x/4, create_captcha_x/5]).
-include_lib("exmpp/include/exmpp.hrl").
-include("jlib.hrl").
-include("ejabberd.hrl").
-include("web/ejabberd_http.hrl").
-define(VFIELD(Type, Var, Value),
#xmlel{name = 'field',
attrs = [
#xmlattr{name = 'type',
value = Type
},
#xmlattr{name = 'var',
value = Var
}
],
children = [
#xmlel{name = 'value',
children = [Value]
}
]}).
-define(CAPTCHA_TEXT(Lang), list_to_binary(translate:translate(Lang, "Enter the text you see"))).
-define(CAPTCHA_LIFETIME, 120000). % two minutes
-define(RPC_TIMEOUT, 5000).
-record(state, {}).
-record(captcha, {id, pid, key, tref, args}).
%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
create_captcha(SID, From, To, Lang, Args)
when is_binary(Lang), is_binary(SID) ->
case create_image() of
{ok, Type, Key, Image} ->
Id = randoms:get_string() ++ "-" ++ ejabberd_cluster:node_id(),
B64Image = list_to_binary(jlib:encode_base64(binary_to_list(Image))),
JID = exmpp_jid:to_list(From),
CID = list_to_binary(["sha1+", sha:sha(Image), "@bob.xmpp.org"]),
% Data = {xmlelement, "data",
% [{"xmlns", ?NS_BOB}, {"cid", CID},
% {"max-age", "0"}, {"type", Type}],
% [{xmlcdata, B64Image}]},
Data =
#xmlel{
name = 'data',
ns = ?NS_BOB,
attrs = [
#xmlattr{name = 'cid',
value = CID
},
#xmlattr{name = 'max-age',
value = <<"0">>
},
#xmlattr{name = 'type',
value = Type
}
],
children = [#xmlcdata{cdata = B64Image}]},
% {xmlelement, "captcha", [{"xmlns", ?NS_CAPTCHA}],
% %% ?NS_DATA_FORMS is 'jabber:x:data'
% [{xmlelement, "x", [{"xmlns", "jabber:x:data"}, {"type", "form"}],
% [?VFIELD("hidden", "FORM_TYPE", {xmlcdata, ?NS_CAPTCHA}),
% ?VFIELD("hidden", "from", {xmlcdata, exmpp_jid:to_list(To)}),
% ?VFIELD("hidden", "challenge", {xmlcdata, Id}),
% ?VFIELD("hidden", "sid", {xmlcdata, SID}),
% {xmlelement, "field", [{"var", "ocr"}, {"label", ?CAPTCHA_TEXT(Lang)}],
% [{xmlelement, "media", [{"xmlns", ?NS_DATA_FORMS_MEDIA_s}],
% [{xmlelement, "uri", [{"type", Type}],
% [{xmlcdata, "cid:" ++ CID}]}]}]}]}]},
%% TODO : kael : write exmpp_captcha.erl
Captcha =
#xmlel{
name = 'captcha',
ns = ?NS_CAPTCHA,
children = [
#xmlel{name = 'x',
ns = ?NS_DATA_FORMS_s,
attrs = [
#xmlattr{name = 'type',
value = <<"form">>
}
],
children = [
?VFIELD(<<"hidden">>, <<"FORM_TYPE">>, #xmlcdata{cdata = ?NS_CAPTCHA_b}),
?VFIELD(<<"hidden">>, <<"from">>, #xmlcdata{cdata = exmpp_jid:to_binary(To)}),
?VFIELD(<<"hidden">>, <<"challenge">>, #xmlcdata{cdata = list_to_binary(Id)}),
?VFIELD(<<"hidden">>, <<"sid">>, #xmlcdata{cdata = SID}),
#xmlel{name = 'field',
attrs = [
#xmlattr{name = 'var',
value = <<"ocr">>
},
#xmlattr{name = 'label',
value = ?CAPTCHA_TEXT(Lang)
}
],
children = [
#xmlel{ns = ?NS_DATA_FORMS, name = 'required'},
#xmlel{name = 'media',
ns = ?NS_DATA_FORMS_MEDIA_s,
children = [
#xmlel{name = 'uri',
attrs = [
#xmlattr{name = 'type',
value = Type
}
],
children = [
#xmlcdata{cdata = list_to_binary(["cid:", CID])}
]
}
]
}
]
}
]
}
]
},
BodyString1 = translate:translate(Lang, "Your messages to ~s are being blocked. To unblock them, visit ~s"),
BodyString = io_lib:format(BodyString1, [JID, get_url(Id)]),
Body =
#xmlel{name = 'body',
children = [
#xmlcdata{cdata = list_to_binary(BodyString)
}
]
},
OOB =
#xmlel{name = 'x',
ns = ?NS_OOBD_X_s,
children = [
#xmlel{name = 'url',
children = [
#xmlcdata{cdata = list_to_binary(get_url(Id))}
]
}
]
},
%Body = {xmlelement, "body", [],
% [{xmlcdata, BodyString}]},
%OOB = {xmlelement, "x", [{"xmlns", ?NS_OOBD_X_s}],
% [{xmlelement, "url", [], [{xmlcdata, get_url(Id)}]}]},
Tref = erlang:send_after(?CAPTCHA_LIFETIME, ?MODULE, {remove_id, Id}),
ets:insert(captcha, #captcha{id=Id, pid=self(), key=Key,
tref=Tref, args=Args}),
{ok, Id, [Body, OOB, Captcha, Data]};
_Err ->
error
end.
create_captcha_x(SID, To, Lang, HeadEls) ->
create_captcha_x(SID, To, Lang, HeadEls, []).
create_captcha_x(SID, To, Lang, HeadEls, TailEls) ->
case create_image() of
{ok, Type, Key, Image} ->
Id = randoms:get_string() ++ "-" ++ ejabberd_cluster:node_id(),
B64Image = list_to_binary(jlib:encode_base64(binary_to_list(Image))),
CID = list_to_binary(["sha1+", sha:sha(Image), "@bob.xmpp.org"]),
Data =
#xmlel{
name = 'data',
ns = ?NS_BOB,
attrs = [
#xmlattr{name = 'cid',
value = CID
},
#xmlattr{name = 'max-age',
value = <<"0">>
},
#xmlattr{name = 'type',
value = Type
}
],
children = [#xmlcdata{cdata = B64Image}]},
HelpTxt = translate:translate(
Lang,
"If you don't see the CAPTCHA image here, "
"visit the web page."),
Imageurl = list_to_binary(get_url(Id ++ "/image")),
Captcha =
#xmlel{name = 'x',
ns = ?NS_DATA_FORMS_s,
attrs = [
#xmlattr{name = 'type',
value = <<"form">>
}
],
children = [
?VFIELD(<<"hidden">>, <<"FORM_TYPE">>, #xmlcdata{cdata = ?NS_CAPTCHA_b}) | HeadEls] ++ [
#xmlel{ns = ?NS_DATA_FORMS, name = 'field', attrs =
[?XMLATTR('type', <<"fixed">>), ?XMLATTR('label', HelpTxt)]},
?VFIELD(<<"hidden">>, <<"captchahidden">>, #xmlcdata{cdata = <<"workaround-for-psi">>}),
#xmlel{name = 'field',
attrs = [
#xmlattr{name = 'type',
value = <<"text-single">>
},
#xmlattr{name = 'label',
value = list_to_binary(translate:translate(Lang, "CAPTCHA web page"))
},
#xmlattr{name = 'var',
value = <<"url">>
}
],
children = [
#xmlel{name = 'value',
children = [#xmlcdata{cdata = Imageurl}]
}
]},
?VFIELD(<<"hidden">>, <<"from">>, #xmlcdata{cdata = exmpp_jid:to_binary(To)}),
?VFIELD(<<"hidden">>, <<"challenge">>, #xmlcdata{cdata = list_to_binary(Id)}),
?VFIELD(<<"hidden">>, <<"sid">>, #xmlcdata{cdata = SID}),
#xmlel{name = 'field',
attrs = [
#xmlattr{name = 'var',
value = <<"ocr">>
},
#xmlattr{name = 'label',
value = ?CAPTCHA_TEXT(Lang)
}
],
children = [
#xmlel{ns = ?NS_DATA_FORMS, name = 'required'},
#xmlel{name = 'media',
ns = ?NS_DATA_FORMS_MEDIA_s,
children = [
#xmlel{name = 'uri',
attrs = [
#xmlattr{name = 'type',
value = Type
}
],
children = [
#xmlcdata{cdata = list_to_binary(["cid:", CID])}
]
}
]
}
]
}
] ++ TailEls
},
Tref = erlang:send_after(?CAPTCHA_LIFETIME, ?MODULE, {remove_id, Id}),
ets:insert(captcha, #captcha{id=Id, key=Key, tref=Tref}),
{ok, [Captcha, Data]};
_ ->
error
end.
%% @spec (Id::string(), Lang::string()) -> {FormEl, {ImgEl, TextEl, IdEl, KeyEl}} | captcha_not_found
%% where FormEl = xmlelement()
%% ImgEl = xmlelement()
%% TextEl = xmlelement()
%% IdEl = xmlelement()
%% KeyEl = xmlelement()
build_captcha_html(Id, Lang) ->
case lookup_captcha(Id) of
{ok, _} ->
%ImgEl = {xmlelement, "img", [{"src", get_url(Id ++ "/image")}], []},
ImgEl =
#xmlel{name = 'img',
attrs = [
#xmlattr{name = 'src',
value = list_to_binary(get_url(Id ++ "/image"))
}
]
},
%TextEl = {xmlcdata, ?CAPTCHA_TEXT(Lang)},
TextEl = #xmlcdata{cdata = ?CAPTCHA_TEXT(Lang)},
%IdEl = {xmlelement, "input", [{"type", "hidden"},
% {"name", "id"},
% {"value", Id}], []},
IdEl =
#xmlel{name = 'input',
attrs = [
#xmlattr{name = 'type',
value = <<"hidden">>
},
#xmlattr{name = 'name',
value = <<"id">>
},
#xmlattr{name = 'value',
value = list_to_binary(Id)
}
]
},
%KeyEl = {xmlelement, "input", [{"type", "text"},
% {"name", "key"},
% {"size", "10"}], []},
KeyEl =
#xmlel{name = 'input',
attrs = [
#xmlattr{name = 'type',
value = <<"text">>
},
#xmlattr{name = 'name',
value = <<"key">>
},
#xmlattr{name = 'size',
value = <<"10">>
}
]
},
%FormEl = {xmlelement, "form", [{"action", get_url(Id)},
% {"name", "captcha"},
% {"method", "POST"}],
% [ImgEl,
% {xmlelement, "br", [], []},
% TextEl,
% {xmlelement, "br", [], []},
% IdEl,
% KeyEl,
% {xmlelement, "br", [], []},
% {xmlelement, "input", [{"type", "submit"},
% {"name", "enter"},
% {"value", "OK"}], []}
% ]},
FormEl =
#xmlel{name = 'form',
attrs = [
#xmlattr{name = 'action',
value = list_to_binary(get_url(Id))
},
#xmlattr{name = 'name',
value = <<"captcha">>
},
#xmlattr{name = 'method',
value = <<"POST">>
}
],
children = [
ImgEl,
#xmlel{name = 'br'
},
TextEl,
#xmlel{name = 'br'
},
IdEl,
KeyEl,
#xmlel{name = 'br'
},
#xmlel{name = 'input',
attrs = [
#xmlattr{name = 'type',
value = <<"submit">>
},
#xmlattr{name = 'name',
value = <<"enter">>
},
#xmlattr{name = 'value',
value = <<"OK">>
}
]
}
]
},
{FormEl, {ImgEl, TextEl, IdEl, KeyEl}};
_ ->
captcha_not_found
end.
%% @spec (Id::string(), ProvidedKey::string()) -> captcha_valid | captcha_non_valid | captcha_not_found
check_captcha(Id, ProvidedKey) ->
case string:tokens(Id, "-") of
[_, NodeID] ->
case ejabberd_cluster:get_node_by_id(NodeID) of
Node when Node == node() ->
do_check_captcha(Id, ProvidedKey);
Node ->
case catch rpc:call(Node, ?MODULE, check_captcha,
[Id, ProvidedKey], ?RPC_TIMEOUT) of
{'EXIT', _} ->
captcha_not_found;
{badrpc, _} ->
captcha_not_found;
Res ->
Res
end
end;
_ ->
captcha_not_found
end.
process_reply(El) ->
case exmpp_xml:get_element(El, x) of
undefined ->
{error, malformed};
Xdata ->
Fields = jlib:parse_xdata_submit(Xdata),
case catch {proplists:get_value("challenge", Fields),
proplists:get_value("ocr", Fields)} of
{[Id|_], [OCR|_]} ->
case check_captcha(Id, OCR) of
captcha_valid ->
ok;
captcha_non_valid ->
{error, bad_match};
captcha_not_found ->
{error, not_found}
end;
_ ->
{error, malformed}
end
end.
process(_Handlers, #request{method='GET', lang=Lang, path=[_, Id]}) ->
case build_captcha_html(Id, Lang) of
{FormEl, CaptchaTuple} when is_tuple(CaptchaTuple) ->
Form =
%{xmlelement, "div", [{"align", "center"}],
%[FormEl]},
#xmlel{name = 'div',
attrs = [
#xmlattr{name = 'align',
value = <<"center">>
}
],
children = [FormEl]
},
ejabberd_web:make_xhtml([Form]);
captcha_not_found ->
ejabberd_web:error(not_found)
end;
process(_Handlers, #request{method='GET', path=[_, Id, "image"]}) ->
case lookup_captcha(Id) of
{ok, #captcha{key=Key}} ->
case create_image(Key) of
{ok, Type, _, Img} ->
{200,
[{"Content-Type", Type},
{"Cache-Control", "no-cache"},
{"Last-Modified", httpd_util:rfc1123_date()}],
Img};
_ ->
ejabberd_web:error(not_found)
end;
_ ->
ejabberd_web:error(not_found)
end;
process(_Handlers, #request{method='POST', q=Q, lang=Lang, path=[_, Id]}) ->
ProvidedKey = proplists:get_value("key", Q, none),
case check_captcha(Id, ProvidedKey) of
captcha_valid ->
Form =
%{xmlelement, "p", [],
% [{xmlcdata,
% translate:translate(Lang, "The captcha is valid.")
% }]},
#xmlel{name = 'p',
children = [
#xmlcdata{cdata = list_to_binary(translate:translate(Lang, "The captcha is valid."))}
]
},
ejabberd_web:make_xhtml([Form]);
captcha_non_valid ->
ejabberd_web:error(not_allowed);
captcha_not_found ->
ejabberd_web:error(not_found)
end;
process(_Handlers, _Request) ->
ejabberd_web:error(not_found).
%%====================================================================
%% gen_server callbacks
%%====================================================================
init([]) ->
mnesia:delete_table(captcha),
ets:new(captcha, [named_table, public, {keypos, #captcha.id}]),
check_captcha_setup(),
{ok, #state{}}.
handle_call(_Request, _From, State) ->
{reply, bad_request, State}.
handle_cast(_Msg, State) ->
{noreply, State}.
handle_info({remove_id, Id}, State) ->
?DEBUG("captcha ~p timed out", [Id]),
case ets:lookup(captcha, Id) of
[#captcha{args=Args, pid=Pid}] ->
if is_pid(Pid) ->
Pid ! {captcha_failed, Args};
true ->
ok
end,
ets:delete(captcha, Id);
_ ->
ok
end,
{noreply, State};
handle_info(_Info, State) ->
{noreply, State}.
terminate(_Reason, _State) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
%%--------------------------------------------------------------------
%% Function: create_image() -> {ok, Type, Key, Image} | {error, Reason}
%% Type = "image/png" | "image/jpeg" | "image/gif"
%% Key = binary()
%% Image = binary()
%% Reason = atom()
%%--------------------------------------------------------------------
create_image() ->
%% Six numbers from 1 to 9.
Key = string:substr(randoms:get_string(), 1, 6),
create_image(Key).
create_image(Key) ->
FileName = get_prog_name(),
Cmd = lists:flatten(io_lib:format("~s ~s", [FileName, Key])),
case cmd(Cmd) of
{ok, <<16#89, $P, $N, $G, $\r, $\n, 16#1a, $\n, _/binary>> = Img} ->
{ok, <<"image/png">>, Key, Img};
{ok, <<16#ff, 16#d8, _/binary>> = Img} ->
{ok, <<"image/jpeg">>, Key, Img};
{ok, <<$G, $I, $F, $8, X, $a, _/binary>> = Img} when X==$7; X==$9 ->
{ok, <<"image/gif">>, Key, Img};
{error, enodata = Reason} ->
?ERROR_MSG("Failed to process output from \"~s\". "
"Maybe ImageMagick's Convert program is not installed.",
[Cmd]),
{error, Reason};
{error, Reason} ->
?ERROR_MSG("Failed to process an output from \"~s\": ~p",
[Cmd, Reason]),
{error, Reason};
_ ->
Reason = malformed_image,
?ERROR_MSG("Failed to process an output from \"~s\": ~p",
[Cmd, Reason]),
{error, Reason}
end.
get_prog_name() ->
case ejabberd_config:get_local_option(captcha_cmd) of
FileName when is_list(FileName) ->
FileName;
_ ->
?DEBUG("The option captcha_cmd is not configured, but some "
"module wants to use the CAPTCHA feature.", []),
throw({error, option_not_configured_captcha_cmd})
end.
%% @doc (Str::string()) -> string()
get_url(Str) ->
case ejabberd_config:get_local_option(captcha_host) of
Host when is_list(Host) ->
"http://" ++ Host ++ "/captcha/" ++ Str;
_ ->
"http://" ++ ?MYNAME ++ "/captcha/" ++ Str
end.
%%--------------------------------------------------------------------
%% Function: cmd(Cmd) -> Data | {error, Reason}
%% Cmd = string()
%% Data = binary()
%% Description: os:cmd/1 replacement
%%--------------------------------------------------------------------
-define(CMD_TIMEOUT, 5000).
-define(MAX_FILE_SIZE, 64*1024).
cmd(Cmd) ->
Port = open_port({spawn, Cmd}, [stream, eof, binary]),
TRef = erlang:start_timer(?CMD_TIMEOUT, self(), timeout),
recv_data(Port, TRef, <<>>).
recv_data(Port, TRef, Buf) ->
receive
{Port, {data, Bytes}} ->
NewBuf = <<Buf/binary, Bytes/binary>>,
if size(NewBuf) > ?MAX_FILE_SIZE ->
return(Port, TRef, {error, efbig});
true ->
recv_data(Port, TRef, NewBuf)
end;
{Port, {data, _}} ->
return(Port, TRef, {error, efbig});
{Port, eof} when Buf /= <<>> ->
return(Port, TRef, {ok, Buf});
{Port, eof} ->
return(Port, TRef, {error, enodata});
{timeout, TRef, _} ->
return(Port, TRef, {error, timeout})
end.
return(Port, TRef, Result) ->
case erlang:cancel_timer(TRef) of
false ->
receive
{timeout, TRef, _} ->
ok
after 0 ->
ok
end;
_ ->
ok
end,
catch port_close(Port),
Result.
is_feature_enabled() ->
try get_prog_name() of
Prog when is_list(Prog) -> true
catch
_:_ -> false
end.
is_feature_available() ->
case is_feature_enabled() of
false -> false;
true ->
case create_image() of
{ok, _, _, _} -> true;
_Error -> false
end
end.
check_captcha_setup() ->
case is_feature_enabled() andalso not is_feature_available() of
true ->
?CRITICAL_MSG("Captcha is enabled in the option captcha_cmd, "
"but it can't generate images.", []);
false ->
ok
end.
lookup_captcha(Id) ->
case string:tokens(Id, "-") of
[_, NodeID] ->
case ejabberd_cluster:get_node_by_id(NodeID) of
Node when Node == node() ->
case ets:lookup(captcha, Id) of
[C] ->
{ok, C};
_ ->
{error, enoent}
end;
Node ->
case catch rpc:call(Node, ets, lookup,
[captcha, Id], ?RPC_TIMEOUT) of
[C] ->
{ok, C};
_ ->
{error, enoent}
end
end;
_ ->
{error, enoent}
end.
do_check_captcha(Id, ProvidedKey) ->
case ets:lookup(captcha, Id) of
[#captcha{pid = Pid, args = Args, key = ValidKey, tref = Tref}] ->
ets:delete(captcha, Id),
erlang:cancel_timer(Tref),
if ValidKey == ProvidedKey ->
if is_pid(Pid) ->
Pid ! {captcha_succeed, Args};
true ->
ok
end,
captcha_valid;
true ->
if is_pid(Pid) ->
Pid ! {captcha_failed, Args};
true ->
ok
end,
captcha_non_valid
end;
_ ->
captcha_not_found
end.
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