%% Copyright 2007 Mochi Media, Inc.
%% Copyright 2011 Thomas Burdick <[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.
%% @doc HTTP Cookie parsing and generating (RFC 2965).
-module(cowboy_cookies).
-export([parse_cookie/1, cookie/3, cookie/2]). %% API.
%% Types.
-type kv() :: {Name::binary(), Value::binary()}.
-type kvlist() :: [kv()].
-type cookie_option() :: {max_age, integer()}
| {local_time, {cowboy_clock:date(), cowboy_clock:time()}}
| {domain, binary()} | {path, binary()}
| {secure, true | false} | {http_only, true | false}.
-export_type([kv/0, kvlist/0, cookie_option/0]).
-define(QUOTE, $\").
-include_lib("eunit/include/eunit.hrl").
%% API.
%% @doc Parse the contents of a Cookie header field, ignoring cookie
%% attributes, and return a simple property list.
-spec parse_cookie(binary()) -> kvlist().
parse_cookie(<<>>) ->
[];
parse_cookie(Cookie) when is_binary(Cookie) ->
parse_cookie(Cookie, []).
%% @equiv cookie(Key, Value, [])
-spec cookie(binary(), binary()) -> kv().
cookie(Key, Value) when is_binary(Key) andalso is_binary(Value) ->
cookie(Key, Value, []).
%% @doc Generate a Set-Cookie header field tuple.
-spec cookie(binary(), binary(), [cookie_option()]) -> kv().
cookie(Key, Value, Options) when is_binary(Key)
andalso is_binary(Value) andalso is_list(Options) ->
Cookie = <<(any_to_binary(Key))/binary, "=",
(quote(Value))/binary, "; Version=1">>,
%% Set-Cookie:
%% Comment, Domain, Max-Age, Path, Secure, Version
ExpiresPart =
case proplists:get_value(max_age, Options) of
undefined ->
<<"">>;
RawAge ->
When = case proplists:get_value(local_time, Options) of
undefined ->
calendar:local_time();
LocalTime ->
LocalTime
end,
Age = case RawAge < 0 of
true ->
0;
false ->
RawAge
end,
AgeBinary = quote(Age),
CookieDate = age_to_cookie_date(Age, When),
<<"; Expires=", CookieDate/binary,
"; Max-Age=", AgeBinary/binary>>
end,
SecurePart =
case proplists:get_value(secure, Options) of
true ->
<<"; Secure">>;
_ ->
<<"">>
end,
DomainPart =
case proplists:get_value(domain, Options) of
undefined ->
<<"">>;
Domain ->
<<"; Domain=", (quote(Domain))/binary>>
end,
PathPart =
case proplists:get_value(path, Options) of
undefined ->
<<"">>;
Path ->
<<"; Path=", (quote(Path))/binary>>
end,
HttpOnlyPart =
case proplists:get_value(http_only, Options) of
true ->
<<"; HttpOnly">>;
_ ->
<<"">>
end,
CookieParts = <<Cookie/binary, ExpiresPart/binary, SecurePart/binary,
DomainPart/binary, PathPart/binary, HttpOnlyPart/binary>>,
{<<"Set-Cookie">>, CookieParts}.
%% Internal.
%% @doc Check if a character is a white space character.
-spec is_whitespace(char()) -> boolean().
is_whitespace($\s) -> true;
is_whitespace($\t) -> true;
is_whitespace($\r) -> true;
is_whitespace($\n) -> true;
is_whitespace(_) -> false.
%% @doc Check if a character is a seperator.
-spec is_separator(char()) -> boolean().
is_separator(C) when C < 32 -> true;
is_separator($\s) -> true;
is_separator($\t) -> true;
is_separator($() -> true;
is_separator($)) -> true;
is_separator($<) -> true;
is_separator($>) -> true;
is_separator($@) -> true;
is_separator($,) -> true;
is_separator($;) -> true;
is_separator($:) -> true;
is_separator($\\) -> true;
is_separator(?QUOTE) -> true;
is_separator($/) -> true;
is_separator($[) -> true;
is_separator($]) -> true;
is_separator($?) -> true;
is_separator($=) -> true;
is_separator(${) -> true;
is_separator($}) -> true;
is_separator(_) -> false.
%% @doc Check if a binary has an ASCII seperator character.
-spec has_seperator(binary()) -> boolean().
has_seperator(<<>>) ->
false;
has_seperator(<<$/, Rest/binary>>) ->
has_seperator(Rest);
has_seperator(<<C, Rest/binary>>) ->
case is_separator(C) of
true ->
true;
false ->
has_seperator(Rest)
end.
%% @doc Convert to a binary and raise an error if quoting is required. Quoting
%% is broken in different ways for different browsers. Its better to simply
%% avoiding doing it at all.
%% @end
-spec quote(term()) -> binary().
quote(V0) ->
V = any_to_binary(V0),
case has_seperator(V) of
true ->
erlang:error({cookie_quoting_required, V});
false ->
V
end.
-spec add_seconds(integer(), cowboy_clock:datetime())
-> cowboy_clock:datetime().
add_seconds(Secs, LocalTime) ->
Greg = calendar:datetime_to_gregorian_seconds(LocalTime),
calendar:gregorian_seconds_to_datetime(Greg + Secs).
-spec age_to_cookie_date(integer(), cowboy_clock:datetime()) -> binary().
age_to_cookie_date(Age, LocalTime) ->
cowboy_clock:rfc2109(add_seconds(Age, LocalTime)).
-spec parse_cookie(binary(), kvlist()) -> kvlist().
parse_cookie(<<>>, Acc) ->
lists:reverse(Acc);
parse_cookie(String, Acc) ->
{{Token, Value}, Rest} = read_pair(String),
Acc1 = case Token of
<<"">> ->
Acc;
<<"$", _R/binary>> ->
Acc;
_ ->
[{Token, Value} | Acc]
end,
parse_cookie(Rest, Acc1).
-spec read_pair(binary()) -> {{binary(), binary()}, binary()}.
read_pair(String) ->
{Token, Rest} = read_token(skip_whitespace(String)),
{Value, Rest1} = read_value(skip_whitespace(Rest)),
{{Token, Value}, skip_past_separator(Rest1)}.
-spec read_value(binary()) -> {binary(), binary()}.
read_value(<<"=", Value/binary>>) ->
Value1 = skip_whitespace(Value),
case Value1 of
<<?QUOTE, _R/binary>> ->
read_quoted(Value1);
_ ->
read_token(Value1)
end;
read_value(String) ->
{<<"">>, String}.
-spec read_quoted(binary()) -> {binary(), binary()}.
read_quoted(<<?QUOTE, String/binary>>) ->
read_quoted(String, <<"">>).
-spec read_quoted(binary(), binary()) -> {binary(), binary()}.
read_quoted(<<"">>, Acc) ->
{Acc, <<"">>};
read_quoted(<<?QUOTE, Rest/binary>>, Acc) ->
{Acc, Rest};
read_quoted(<<$\\, Any, Rest/binary>>, Acc) ->
read_quoted(Rest, <<Acc/binary, Any>>);
read_quoted(<<C, Rest/binary>>, Acc) ->
read_quoted(Rest, <<Acc/binary, C>>).
%% @doc Drop characters while a function returns true.
-spec binary_dropwhile(fun((char()) -> boolean()), binary()) -> binary().
binary_dropwhile(_F, <<"">>) ->
<<"">>;
binary_dropwhile(F, String) ->
<<C, Rest/binary>> = String,
case F(C) of
true ->
binary_dropwhile(F, Rest);
false ->
String
end.
%% @doc Remove leading whitespace.
-spec skip_whitespace(binary()) -> binary().
skip_whitespace(String) ->
binary_dropwhile(fun is_whitespace/1, String).
%% @doc Split a binary when the current character causes F to return true.
-spec binary_splitwith(fun((char()) -> boolean()), binary(), binary())
-> {binary(), binary()}.
binary_splitwith(_F, Head, <<>>) ->
{Head, <<>>};
binary_splitwith(F, Head, Tail) ->
<<C, NTail/binary>> = Tail,
case F(C) of
true ->
{Head, Tail};
false ->
binary_splitwith(F, <<Head/binary, C>>, NTail)
end.
%% @doc Split a binary with a function returning true or false on each char.
-spec binary_splitwith(fun((char()) -> boolean()), binary())
-> {binary(), binary()}.
binary_splitwith(F, String) ->
binary_splitwith(F, <<>>, String).
%% @doc Split the binary when the next seperator is found.
-spec read_token(binary()) -> {binary(), binary()}.
read_token(String) ->
binary_splitwith(fun is_separator/1, String).
%% @doc Return string after ; or , characters.
-spec skip_past_separator(binary()) -> binary().
skip_past_separator(<<"">>) ->
<<"">>;
skip_past_separator(<<";", Rest/binary>>) ->
Rest;
skip_past_separator(<<",", Rest/binary>>) ->
Rest;
skip_past_separator(<<_C, Rest/binary>>) ->
skip_past_separator(Rest).
-spec any_to_binary(binary() | string() | atom() | integer()) -> binary().
any_to_binary(V) when is_binary(V) ->
V;
any_to_binary(V) when is_list(V) ->
erlang:list_to_binary(V);
any_to_binary(V) when is_atom(V) ->
erlang:atom_to_binary(V, latin1);
any_to_binary(V) when is_integer(V) ->
list_to_binary(integer_to_list(V)).
%% Tests.
-ifdef(TEST).
quote_test() ->
%% ?assertError eunit macro is not compatible with coverage module
_ = try quote(<<":wq">>)
catch error:{cookie_quoting_required, <<":wq">>} -> ok
end,
?assertEqual(<<"foo">>,quote(foo)),
ok.
parse_cookie_test() ->
%% RFC example
C1 = <<"$Version=\"1\"; Customer=\"WILE_E_COYOTE\"; $Path=\"/acme\";
Part_Number=\"Rocket_Launcher_0001\"; $Path=\"/acme\";
Shipping=\"FedEx\"; $Path=\"/acme\"">>,
?assertEqual(
[{<<"Customer">>,<<"WILE_E_COYOTE">>},
{<<"Part_Number">>,<<"Rocket_Launcher_0001">>},
{<<"Shipping">>,<<"FedEx">>}],
parse_cookie(C1)),
%% Potential edge cases
?assertEqual(
[{<<"foo">>, <<"x">>}],
parse_cookie(<<"foo=\"\\x\"">>)),
?assertEqual(
[],
parse_cookie(<<"=">>)),
?assertEqual(
[{<<"foo">>, <<"">>}, {<<"bar">>, <<"">>}],
parse_cookie(<<" foo ; bar ">>)),
?assertEqual(
[{<<"foo">>, <<"">>}, {<<"bar">>, <<"">>}],
parse_cookie(<<"foo=;bar=">>)),
?assertEqual(
[{<<"foo">>, <<"\";">>}, {<<"bar">>, <<"">>}],
parse_cookie(<<"foo = \"\\\";\";bar ">>)),
?assertEqual(
[{<<"foo">>, <<"\";bar">>}],
parse_cookie(<<"foo=\"\\\";bar">>)),
?assertEqual(
[],
parse_cookie(<<"">>)),
?assertEqual(
[{<<"foo">>, <<"bar">>}, {<<"baz">>, <<"wibble">>}],
parse_cookie(<<"foo=bar , baz=wibble ">>)),
ok.
domain_test() ->
?assertEqual(
{<<"Set-Cookie">>,
<<"Customer=WILE_E_COYOTE; "
"Version=1; "
"Domain=acme.com; "
"HttpOnly">>},
cookie(<<"Customer">>, <<"WILE_E_COYOTE">>,
[{http_only, true}, {domain, <<"acme.com">>}])),
ok.
local_time_test() ->
{<<"Set-Cookie">>, B} = cookie(<<"Customer">>, <<"WILE_E_COYOTE">>,
[{max_age, 111}, {secure, true}]),
?assertMatch(
[<<"Customer=WILE_E_COYOTE">>,
<<" Version=1">>,
<<" Expires=", _R/binary>>,
<<" Max-Age=111">>,
<<" Secure">>],
binary:split(B, <<";">>, [global])),
ok.
-spec cookie_test() -> no_return(). %% Not actually true, just a bad option.
cookie_test() ->
C1 = {<<"Set-Cookie">>,
<<"Customer=WILE_E_COYOTE; "
"Version=1; "
"Path=/acme">>},
C1 = cookie(<<"Customer">>, <<"WILE_E_COYOTE">>, [{path, <<"/acme">>}]),
C1 = cookie(<<"Customer">>, <<"WILE_E_COYOTE">>,
[{path, <<"/acme">>}, {badoption, <<"negatory">>}]),
{<<"Set-Cookie">>,<<"=NoKey; Version=1">>}
= cookie(<<"">>, <<"NoKey">>, []),
{<<"Set-Cookie">>,<<"=NoKey; Version=1">>}
= cookie(<<"">>, <<"NoKey">>),
LocalTime = calendar:universal_time_to_local_time(
{{2007, 5, 15}, {13, 45, 33}}),
C2 = {<<"Set-Cookie">>,
<<"Customer=WILE_E_COYOTE; "
"Version=1; "
"Expires=Tue, 15 May 2007 13:45:33 GMT; "
"Max-Age=0">>},
C2 = cookie(<<"Customer">>, <<"WILE_E_COYOTE">>,
[{max_age, -111}, {local_time, LocalTime}]),
C3 = {<<"Set-Cookie">>,
<<"Customer=WILE_E_COYOTE; "
"Version=1; "
"Expires=Wed, 16 May 2007 13:45:50 GMT; "
"Max-Age=86417">>},
C3 = cookie(<<"Customer">>, <<"WILE_E_COYOTE">>,
[{max_age, 86417}, {local_time, LocalTime}]),
ok.
-endif.
