--- Revision None
+++ Revision 323731663237
@@ -0,0 +1,56 @@
+-module(mycaptcha).
+-compile(export_all).
+
+-record(captcha, 	{key, value}).
+
+new() ->
+	CryptKey = crypto:rand_bytes(16),
+
+	ok = try mnesia:dirty_write({captcha, 0, CryptKey})
+	catch
+		_:_ ->
+			{atomic, ok} = mnesia:create_table(captcha, [{ram_copies, [node()]}, {attributes, record_info(fields, captcha)}]),
+			mnesia:dirty_write({captcha, 0, CryptKey})
+	end,
+
+	FileName = lists:flatmap(fun(Item) -> integer_to_list(Item) end, tuple_to_list(now())),
+
+	Code = generate_rand(5),
+
+	File = io_lib:format("/tmp/~s.png",[FileName]),
+
+	Cmd = io_lib:format("convert -background 'none' -fill '#222222' -size 175 -gravity Center -wave 5x100 -swirl 50 -font DejaVu-Serif-Book -pointsize 28 label:~s -draw 'Bezier 10,40 50,35 100,35 150,35 200,50 250,35 300,35' ~s", [Code, File]),
+	os:cmd(Cmd),
+
+	{ok, BinPng} = file:read_file(File),
+	file:delete(File),
+
+	Sha = crypto:sha_mac(CryptKey, integer_to_list(lists:sum(Code)) ++ Code),
+	CodeHex = mochihex:to_hex(Sha),
+
+	{CodeHex, BinPng}.
+
+check(CodeHex, Code) ->
+	Sha = mochihex:to_bin(CodeHex),
+	[Rec] = mnesia:dirty_read({captcha, 0}),
+	CryptKey = Rec#captcha.value,
+
+	case crypto:sha_mac(CryptKey, integer_to_list(lists:sum(Code)) ++ Code) of
+		Sha ->
+			true;
+
+		_ ->
+			false
+	end.
+
+generate_rand(Length) ->
+	Now = now(),
+	random:seed(element(1, Now), element(2, Now), element(3, Now)),
+	lists:foldl(fun(_I, Acc) -> [do_rand(0) | Acc] end, [], lists:seq(1, Length)).
+
+do_rand(R) when R > 46, R < 58; R > 64, R < 91; R > 96 ->  
+R;
+
+do_rand(_R) ->
+	%do_rand(48 + random:uniform(74)). %% exluding zero
+	do_rand(47 + random:uniform(75)).