gistfile1.hrl

%%         if not value: return None
%%         parts = value.split("|")
%%         if len(parts) != 3: return None
%%         if include_name:
%%             signature = self._cookie_signature(name, parts[0], parts[1])
%%         else:
%%             signature = self._cookie_signature(parts[0], parts[1])
%%         if not _time_independent_equals(parts[2], signature):
%%             logging.warning("Invalid cookie signature %r", value)
%%             return None
%%         timestamp = int(parts[1])
%%         if timestamp < time.time() - 31 * 86400:
%%             logging.warning("Expired cookie %r", value)
%%             return None
%%         try:
%%             return base64.b64decode(parts[0])
%%         except:
%%             return None

	case [Cookie || " session_key=" ++ Cookie <- string:tokens(Req:get_header_value("Cookie"), ";")] of
		[Cookie] ->
			case string:tokens(Cookie, "|") of
				[P0, P1, P2] ->
					Msg = string:concat("session_key", string:concat(P0, P1)),
					Signature = hmac_sha1_hex("11oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=", Msg),

					case time_independent_equals(P2, Signature) of
						false ->
							undefined;
						true ->
							{Mega, Secs, _} = erlang:now(),
							{Timestamp, _} = string:to_integer(P1),
					
							case Timestamp < Mega * 1000000 + Secs - (31 * 86400) of
								false ->
									try base64:decode(P0) of
										Value -> Value
									catch
										_ -> undefined
									end;
								true ->
									undefined
							end
					end;
				_ ->
					undefined
			end;
		[] ->
			undefined
	end.