Add cookie parsing and building code

1 files changed, 259 insertions, 0 deletions

diff --git a/src/cow_cookie.erl b/src/cow_cookie.erl
new file mode 100644
index 0000000..4b1dbd3
--- /dev/null
+++ b/src/cow_cookie.erl
@@ -0,0 +1,259 @@
+%% Copyright (c) 2013, Loïc Hoguin <[email protected]>
+%%
+%% Permission to use, copy, modify, and/or distribute this software for any
+%% purpose with or without fee is hereby granted, provided that the above
+%% copyright notice and this permission notice appear in all copies.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+-module(cow_cookie).
+
+%% Parse.
+-export([parse_cookie/1]).
+
+%% Build.
+-export([setcookie/3]).
+
+-type cookie_option() :: {max_age, non_neg_integer()}
+	| {domain, binary()} | {path, binary()}
+	| {secure, boolean()} | {http_only, boolean()}.
+-type cookie_opts() :: [cookie_option()].
+-export_type([cookie_opts/0]).
+
+%% Parse.
+
+%% @doc Parse a cookie header string and return a list of key/values.
+
+-spec parse_cookie(binary()) -> [{binary(), binary()}] | {error, badarg}.
+parse_cookie(Cookie) ->
+	parse_cookie(Cookie, []).
+
+parse_cookie(<<>>, Acc) ->
+	lists:reverse(Acc);
+parse_cookie(<< $\s, Rest/binary >>, Acc) ->
+	parse_cookie(Rest, Acc);
+parse_cookie(<< $\t, Rest/binary >>, Acc) ->
+	parse_cookie(Rest, Acc);
+parse_cookie(<< $,, Rest/binary >>, Acc) ->
+	parse_cookie(Rest, Acc);
+parse_cookie(<< $;, Rest/binary >>, Acc) ->
+	parse_cookie(Rest, Acc);
+parse_cookie(<< $$, Rest/binary >>, Acc) ->
+	skip_cookie(Rest, Acc);
+parse_cookie(Cookie, Acc) ->
+	parse_cookie_name(Cookie, Acc, <<>>).
+
+skip_cookie(<<>>, Acc) ->
+	lists:reverse(Acc);
+skip_cookie(<< $,, Rest/binary >>, Acc) ->
+	parse_cookie(Rest, Acc);
+skip_cookie(<< $;, Rest/binary >>, Acc) ->
+	parse_cookie(Rest, Acc);
+skip_cookie(<< _, Rest/binary >>, Acc) ->
+	skip_cookie(Rest, Acc).
+
+parse_cookie_name(<<>>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $=, _/binary >>, _, <<>>) ->
+	{error, badarg};
+parse_cookie_name(<< $=, Rest/binary >>, Acc, Name) ->
+	parse_cookie_value(Rest, Acc, Name, <<>>);
+parse_cookie_name(<< $,, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $;, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $\s, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $\t, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $\r, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $\n, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $\013, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< $\014, _/binary >>, _, _) ->
+	{error, badarg};
+parse_cookie_name(<< C, Rest/binary >>, Acc, Name) ->
+	parse_cookie_name(Rest, Acc, << Name/binary, C >>).
+
+parse_cookie_value(<<>>, Acc, Name, Value) ->
+	lists:reverse([{Name, parse_cookie_trim(Value)}|Acc]);
+parse_cookie_value(<< $,, Rest/binary >>, Acc, Name, Value) ->
+	parse_cookie(Rest, [{Name, parse_cookie_trim(Value)}|Acc]);
+parse_cookie_value(<< $;, Rest/binary >>, Acc, Name, Value) ->
+	parse_cookie(Rest, [{Name, parse_cookie_trim(Value)}|Acc]);
+parse_cookie_value(<< $\t, _/binary >>, _, _, _) ->
+	{error, badarg};
+parse_cookie_value(<< $\r, _/binary >>, _, _, _) ->
+	{error, badarg};
+parse_cookie_value(<< $\n, _/binary >>, _, _, _) ->
+	{error, badarg};
+parse_cookie_value(<< $\013, _/binary >>, _, _, _) ->
+	{error, badarg};
+parse_cookie_value(<< $\014, _/binary >>, _, _, _) ->
+	{error, badarg};
+parse_cookie_value(<< C, Rest/binary >>, Acc, Name, Value) ->
+	parse_cookie_value(Rest, Acc, Name, << Value/binary, C >>).
+
+parse_cookie_trim(Value = <<>>) ->
+	Value;
+parse_cookie_trim(Value) ->
+	case binary:last(Value) of
+		$\s ->
+			Size = byte_size(Value) - 1,
+			<< Value2:Size/binary, _ >> = Value,
+			parse_cookie_trim(Value2);
+		_ ->
+			Value
+	end.
+
+-ifdef(TEST).
+parse_cookie_test_() ->
+	%% {Value, Result}.
+	Tests = [
+		{<<"name=value; name2=value2">>, [
+			{<<"name">>, <<"value">>},
+			{<<"name2">>, <<"value2">>}
+		]},
+		{<<"$Version=1; Customer=WILE_E_COYOTE; $Path=/acme">>, [
+			{<<"Customer">>, <<"WILE_E_COYOTE">>}
+		]},
+		{<<"$Version=1; Customer=WILE_E_COYOTE; $Path=/acme; "
+			"Part_Number=Rocket_Launcher_0001; $Path=/acme; "
+			"Shipping=FedEx; $Path=/acme">>, [
+			{<<"Customer">>, <<"WILE_E_COYOTE">>},
+			{<<"Part_Number">>, <<"Rocket_Launcher_0001">>},
+			{<<"Shipping">>, <<"FedEx">>}
+		]},
+		%% Space in value.
+		{<<"foo=Thu Jul 11 2013 15:38:43 GMT+0400 (MSK)">>,
+			[{<<"foo">>, <<"Thu Jul 11 2013 15:38:43 GMT+0400 (MSK)">>}]},
+		%% Potential edge cases (initially from Mochiweb).
+		{<<"foo=\\x">>, [{<<"foo">>, <<"\\x">>}]},
+		{<<"=">>, {error, badarg}},
+		{<<"  foo ; bar  ">>, {error, badarg}},
+		{<<"foo=;bar=">>, [{<<"foo">>, <<>>}, {<<"bar">>, <<>>}]},
+		{<<"foo=\\\";;bar ">>, {error, badarg}},
+		{<<"foo=\\\";;bar=good ">>,
+			[{<<"foo">>, <<"\\\"">>}, {<<"bar">>, <<"good">>}]},
+		{<<"foo=\"\\\";bar">>, {error, badarg}},
+		{<<>>, []},
+		{<<"foo=bar , baz=wibble ">>,
+			[{<<"foo">>, <<"bar">>}, {<<"baz">>, <<"wibble">>}]}
+	],
+	[{V, fun() -> R = parse_cookie(V) end} || {V, R} <- Tests].
+-endif.
+
+%% Build.
+
+%% @doc Convert a cookie name, value and options to its iodata form.
+%% @end
+%%
+%% Initially from Mochiweb:
+%%   * Copyright 2007 Mochi Media, Inc.
+%% Initial binary implementation:
+%%   * Copyright 2011 Thomas Burdick <[email protected]>
+
+-spec setcookie(iodata(), iodata(), cookie_opts()) -> iodata().
+setcookie(Name, Value, Opts) ->
+	nomatch = binary:match(iolist_to_binary(Name), [<<$=>>, <<$,>>, <<$;>>,
+			<<$\s>>, <<$\t>>, <<$\r>>, <<$\n>>, <<$\013>>, <<$\014>>]),
+	nomatch = binary:match(iolist_to_binary(Value), [<<$,>>, <<$;>>,
+			<<$\s>>, <<$\t>>, <<$\r>>, <<$\n>>, <<$\013>>, <<$\014>>]),
+	MaxAgeBin = case lists:keyfind(max_age, 1, Opts) of
+		false -> <<>>;
+		{_, 0} ->
+			%% MSIE requires an Expires date in the past to delete a cookie.
+			<<"; Expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0">>;
+		{_, MaxAge} when is_integer(MaxAge), MaxAge > 0 ->
+			UTC = calendar:universal_time(),
+			Secs = calendar:datetime_to_gregorian_seconds(UTC),
+			Expires = calendar:gregorian_seconds_to_datetime(Secs + MaxAge),
+			[<<"; Expires=">>, cow_date:rfc2109(Expires),
+				<<"; Max-Age=">>, integer_to_list(MaxAge)]
+	end,
+	DomainBin = case lists:keyfind(domain, 1, Opts) of
+		false -> <<>>;
+		{_, Domain} -> [<<"; Domain=">>, Domain]
+	end,
+	PathBin = case lists:keyfind(path, 1, Opts) of
+		false -> <<>>;
+		{_, Path} -> [<<"; Path=">>, Path]
+	end,
+	SecureBin = case lists:keyfind(secure, 1, Opts) of
+		false -> <<>>;
+		{_, true} -> <<"; Secure">>
+	end,
+	HttpOnlyBin = case lists:keyfind(http_only, 1, Opts) of
+		false -> <<>>;
+		{_, true} -> <<"; HttpOnly">>
+	end,
+	[Name, <<"=">>, Value, <<"; Version=1">>,
+		MaxAgeBin, DomainBin, PathBin, SecureBin, HttpOnlyBin].
+
+-ifdef(TEST).
+setcookie_test_() ->
+	%% {Name, Value, Opts, Result}
+	Tests = [
+		{<<"Customer">>, <<"WILE_E_COYOTE">>,
+			[{http_only, true}, {domain, <<"acme.com">>}],
+			<<"Customer=WILE_E_COYOTE; Version=1; "
+				"Domain=acme.com; HttpOnly">>},
+		{<<"Customer">>, <<"WILE_E_COYOTE">>,
+			[{path, <<"/acme">>}],
+			<<"Customer=WILE_E_COYOTE; Version=1; Path=/acme">>},
+		{<<"Customer">>, <<"WILE_E_COYOTE">>,
+			[{path, <<"/acme">>}, {badoption, <<"negatory">>}],
+			<<"Customer=WILE_E_COYOTE; Version=1; Path=/acme">>}
+	],
+	[{R, fun() -> R = iolist_to_binary(setcookie(N, V, O)) end}
+		|| {N, V, O, R} <- Tests].
+
+setcookie_max_age_test() ->
+	F = fun(N, V, O) ->
+		binary:split(iolist_to_binary(
+			setcookie(N, V, O)), <<";">>, [global])
+	end,
+	[<<"Customer=WILE_E_COYOTE">>,
+		<<" Version=1">>,
+		<<" Expires=", _/binary>>,
+		<<" Max-Age=111">>,
+		<<" Secure">>] = F(<<"Customer">>, <<"WILE_E_COYOTE">>,
+			[{max_age, 111}, {secure, true}]),
+	case catch F(<<"Customer">>, <<"WILE_E_COYOTE">>, [{max_age, -111}]) of
+		{'EXIT', {{case_clause, {max_age, -111}}, _}} -> ok
+	end,
+	[<<"Customer=WILE_E_COYOTE">>,
+		<<" Version=1">>,
+		<<" Expires=", _/binary>>,
+		<<" Max-Age=86417">>] = F(<<"Customer">>, <<"WILE_E_COYOTE">>,
+			 [{max_age, 86417}]),
+	ok.
+
+setcookie_failures_test_() ->
+	F = fun(N, V) ->
+		try setcookie(N, V, []) of
+			_ ->
+				false
+		catch _:_ ->
+			true
+		end
+	end,
+	Tests = [
+		{<<"Na=me">>, <<"Value">>},
+		{<<"Name;">>, <<"Value">>},
+		{<<"\r\name">>, <<"Value">>},
+		{<<"Name">>, <<"Value;">>},
+		{<<"Name">>, <<"\value">>}
+	],
+	[{iolist_to_binary(io_lib:format("{~p, ~p} failure", [N, V])),
+		fun() -> true = F(N, V) end}
+		|| {N, V} <- Tests].
+-endif.