%% Copyright (c) 2013-2020, 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).
-export([parse_cookie/1]).
-export([parse_set_cookie/1]).
-export([cookie/1]).
-export([setcookie/3]).
-type cookie_attrs() :: #{
expires => calendar:datetime(),
max_age => calendar:datetime(),
domain => binary(),
path => binary(),
secure => true,
http_only => true,
same_site => strict | lax | none
}.
-export_type([cookie_attrs/0]).
-type cookie_opts() :: #{
domain => binary(),
http_only => boolean(),
max_age => non_neg_integer(),
path => binary(),
same_site => strict | lax | none,
secure => boolean()
}.
-export_type([cookie_opts/0]).
-include("cow_inline.hrl").
%% Cookie header.
-spec parse_cookie(binary()) -> [{binary(), binary()}].
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(Cookie, Acc) ->
parse_cookie_name(Cookie, Acc, <<>>).
parse_cookie_name(<<>>, Acc, Name) ->
lists:reverse([{<<>>, parse_cookie_trim(Name)}|Acc]);
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(<< $;, Rest/binary >>, Acc, Name) ->
parse_cookie(Rest, [{<<>>, parse_cookie_trim(Name)}|Acc]);
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(<< $\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">>}
]},
%% 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)">>}]},
%% Comma in value. Google Analytics sets that kind of cookies.
{<<"refk=sOUZDzq2w2; sk=B602064E0139D842D620C7569640DBB4C81C45080651"
"9CC124EF794863E10E80; __utma=64249653.825741573.1380181332.1400"
"015657.1400019557.703; __utmb=64249653.1.10.1400019557; __utmc="
"64249653; __utmz=64249653.1400019557.703.13.utmcsr=bluesky.chic"
"agotribune.com|utmccn=(referral)|utmcmd=referral|utmcct=/origin"
"als/chi-12-indispensable-digital-tools-bsi,0,0.storygallery">>, [
{<<"refk">>, <<"sOUZDzq2w2">>},
{<<"sk">>, <<"B602064E0139D842D620C7569640DBB4C81C45080651"
"9CC124EF794863E10E80">>},
{<<"__utma">>, <<"64249653.825741573.1380181332.1400"
"015657.1400019557.703">>},
{<<"__utmb">>, <<"64249653.1.10.1400019557">>},
{<<"__utmc">>, <<"64249653">>},
{<<"__utmz">>, <<"64249653.1400019557.703.13.utmcsr=bluesky.chic"
"agotribune.com|utmccn=(referral)|utmcmd=referral|utmcct=/origin"
"als/chi-12-indispensable-digital-tools-bsi,0,0.storygallery">>}
]},
%% Potential edge cases (initially from Mochiweb).
{<<"foo=\\x">>, [{<<"foo">>, <<"\\x">>}]},
{<<"foo=;bar=">>, [{<<"foo">>, <<>>}, {<<"bar">>, <<>>}]},
{<<"foo=\\\";;bar=good ">>,
[{<<"foo">>, <<"\\\"">>}, {<<"bar">>, <<"good">>}]},
{<<"foo=\"\\\";bar=good">>,
[{<<"foo">>, <<"\"\\\"">>}, {<<"bar">>, <<"good">>}]},
{<<>>, []}, %% Flash player.
{<<"foo=bar , baz=wibble ">>, [{<<"foo">>, <<"bar , baz=wibble">>}]},
%% Technically invalid, but seen in the wild
{<<"foo">>, [{<<>>, <<"foo">>}]},
{<<"foo ">>, [{<<>>, <<"foo">>}]},
{<<"foo;">>, [{<<>>, <<"foo">>}]},
{<<"bar;foo=1">>, [{<<>>, <<"bar">>}, {<<"foo">>, <<"1">>}]}
],
[{V, fun() -> R = parse_cookie(V) end} || {V, R} <- Tests].
parse_cookie_error_test_() ->
%% Value.
Tests = [
<<"=">>
],
[{V, fun() -> {'EXIT', {badarg, _}} = (catch parse_cookie(V)) end} || V <- Tests].
-endif.
%% Set-Cookie header.
-spec parse_set_cookie(binary())
-> {ok, binary(), binary(), cookie_attrs()}
| ignore.
parse_set_cookie(SetCookie) ->
{NameValuePair, UnparsedAttrs} = take_until_semicolon(SetCookie, <<>>),
{Name, Value} = case binary:split(NameValuePair, <<$=>>) of
[Value0] -> {<<>>, trim(Value0)};
[Name0, Value0] -> {trim(Name0), trim(Value0)}
end,
case {Name, Value} of
{<<>>, <<>>} ->
ignore;
_ ->
Attrs = parse_set_cookie_attrs(UnparsedAttrs, #{}),
{ok, Name, Value, Attrs}
end.
parse_set_cookie_attrs(<<>>, Attrs) ->
Attrs;
parse_set_cookie_attrs(<<$;,Rest0/bits>>, Attrs) ->
{Av, Rest} = take_until_semicolon(Rest0, <<>>),
{Name, Value} = case binary:split(Av, <<$=>>) of
[Name0] -> {trim(Name0), <<>>};
[Name0, Value0] -> {trim(Name0), trim(Value0)}
end,
case parse_set_cookie_attr(?LOWER(Name), Value) of
{ok, AttrName, AttrValue} ->
parse_set_cookie_attrs(Rest, Attrs#{AttrName => AttrValue});
{ignore, AttrName} ->
parse_set_cookie_attrs(Rest, maps:remove(AttrName, Attrs));
ignore ->
parse_set_cookie_attrs(Rest, Attrs)
end.
take_until_semicolon(Rest = <<$;,_/bits>>, Acc) -> {Acc, Rest};
take_until_semicolon(<<C,R/bits>>, Acc) -> take_until_semicolon(R, <<Acc/binary,C>>);
take_until_semicolon(<<>>, Acc) -> {Acc, <<>>}.
trim(String) ->
string:trim(String, both, [$\s, $\t]).
parse_set_cookie_attr(<<"expires">>, Value) ->
try cow_date:parse_date(Value) of
DateTime ->
{ok, expires, DateTime}
catch _:_ ->
ignore
end;
parse_set_cookie_attr(<<"max-age">>, Value) ->
try binary_to_integer(Value) of
MaxAge when MaxAge =< 0 ->
%% Year 0 corresponds to 1 BC.
{ok, max_age, {{0, 1, 1}, {0, 0, 0}}};
MaxAge ->
CurrentTime = erlang:universaltime(),
{ok, max_age, calendar:gregorian_seconds_to_datetime(
calendar:datetime_to_gregorian_seconds(CurrentTime) + MaxAge)}
catch _:_ ->
ignore
end;
parse_set_cookie_attr(<<"domain">>, Value) ->
case Value of
<<>> ->
ignore;
<<".",Rest/bits>> ->
{ok, domain, ?LOWER(Rest)};
_ ->
{ok, domain, ?LOWER(Value)}
end;
parse_set_cookie_attr(<<"path">>, Value) ->
case Value of
<<"/",_/bits>> ->
{ok, path, Value};
%% When the path is not absolute, or the path is empty, the default-path will be used.
%% Note that the default-path is also used when there are no path attributes,
%% so we are simply ignoring the attribute here.
_ ->
{ignore, path}
end;
parse_set_cookie_attr(<<"secure">>, _) ->
{ok, secure, true};
parse_set_cookie_attr(<<"httponly">>, _) ->
{ok, http_only, true};
parse_set_cookie_attr(<<"samesite">>, Value) ->
case ?LOWER(Value) of
<<"strict">> ->
{ok, same_site, strict};
<<"lax">> ->
{ok, same_site, lax};
%% Clients may have different defaults than "None".
<<"none">> ->
{ok, same_site, none};
%% Unknown values and lack of value are equivalent.
_ ->
ignore
end;
parse_set_cookie_attr(_, _) ->
ignore.
-ifdef(TEST).
parse_set_cookie_test_() ->
Tests = [
{<<"a=b">>, {ok, <<"a">>, <<"b">>, #{}}},
{<<"a=b; Secure">>, {ok, <<"a">>, <<"b">>, #{secure => true}}},
{<<"a=b; HttpOnly">>, {ok, <<"a">>, <<"b">>, #{http_only => true}}},
{<<"a=b; Expires=Wed, 21 Oct 2015 07:28:00 GMT; Expires=Wed, 21 Oct 2015 07:29:00 GMT">>,
{ok, <<"a">>, <<"b">>, #{expires => {{2015,10,21},{7,29,0}}}}},
{<<"a=b; Max-Age=999; Max-Age=0">>,
{ok, <<"a">>, <<"b">>, #{max_age => {{0,1,1},{0,0,0}}}}},
{<<"a=b; Domain=example.org; Domain=foo.example.org">>,
{ok, <<"a">>, <<"b">>, #{domain => <<"foo.example.org">>}}},
{<<"a=b; Path=/path/to/resource; Path=/">>,
{ok, <<"a">>, <<"b">>, #{path => <<"/">>}}},
{<<"a=b; SameSite=Lax; SameSite=Strict">>,
{ok, <<"a">>, <<"b">>, #{same_site => strict}}}
],
[{SetCookie, fun() -> Res = parse_set_cookie(SetCookie) end}
|| {SetCookie, Res} <- Tests].
-endif.
%% Build a cookie header.
-spec cookie([{iodata(), iodata()}]) -> iolist().
cookie([]) ->
[];
cookie([{<<>>, Value}]) ->
[Value];
cookie([{Name, Value}]) ->
[Name, $=, Value];
cookie([{<<>>, Value}|Tail]) ->
[Value, $;, $\s|cookie(Tail)];
cookie([{Name, Value}|Tail]) ->
[Name, $=, Value, $;, $\s|cookie(Tail)].
-ifdef(TEST).
cookie_test_() ->
Tests = [
{[], <<>>},
{[{<<"a">>, <<"b">>}], <<"a=b">>},
{[{<<"a">>, <<"b">>}, {<<"c">>, <<"d">>}], <<"a=b; c=d">>},
{[{<<>>, <<"b">>}, {<<"c">>, <<"d">>}], <<"b; c=d">>},
{[{<<"a">>, <<"b">>}, {<<>>, <<"d">>}], <<"a=b; d">>}
],
[{Res, fun() -> Res = iolist_to_binary(cookie(Cookies)) end}
|| {Cookies, Res} <- Tests].
-endif.
%% Convert a cookie name, value and options to its iodata form.
%%
%% Initially from Mochiweb:
%% * Copyright 2007 Mochi Media, Inc.
%% Initial binary implementation:
%% * Copyright 2011 Thomas Burdick <[email protected]>
%%
%% @todo Rename the function to set_cookie eventually.
-spec setcookie(iodata(), iodata(), cookie_opts()) -> iolist().
setcookie(Name, Value, Opts) ->
nomatch = binary:match(iolist_to_binary(Name), [<<$=>>, <<$,>>, <<$;>>,
<<$\s>>, <<$\t>>, <<$\r>>, <<$\n>>, <<$\013>>, <<$\014>>]),
nomatch = binary:match(iolist_to_binary(Value), [<<$,>>, <<$;>>,
<<$\s>>, <<$\t>>, <<$\r>>, <<$\n>>, <<$\013>>, <<$\014>>]),
[Name, <<"=">>, Value, <<"; Version=1">>, attributes(maps:to_list(Opts))].
attributes([]) -> [];
attributes([{domain, Domain}|Tail]) -> [<<"; Domain=">>, Domain|attributes(Tail)];
attributes([{http_only, false}|Tail]) -> attributes(Tail);
attributes([{http_only, true}|Tail]) -> [<<"; HttpOnly">>|attributes(Tail)];
%% MSIE requires an Expires date in the past to delete a cookie.
attributes([{max_age, 0}|Tail]) ->
[<<"; Expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0">>|attributes(Tail)];
attributes([{max_age, MaxAge}|Tail]) when is_integer(MaxAge), MaxAge > 0 ->
Secs = calendar:datetime_to_gregorian_seconds(calendar:universal_time()),
Expires = cow_date:rfc2109(calendar:gregorian_seconds_to_datetime(Secs + MaxAge)),
[<<"; Expires=">>, Expires, <<"; Max-Age=">>, integer_to_list(MaxAge)|attributes(Tail)];
attributes([Opt={max_age, _}|_]) ->
error({badarg, Opt});
attributes([{path, Path}|Tail]) -> [<<"; Path=">>, Path|attributes(Tail)];
attributes([{secure, false}|Tail]) -> attributes(Tail);
attributes([{secure, true}|Tail]) -> [<<"; Secure">>|attributes(Tail)];
attributes([{same_site, lax}|Tail]) -> [<<"; SameSite=Lax">>|attributes(Tail)];
attributes([{same_site, strict}|Tail]) -> [<<"; SameSite=Strict">>|attributes(Tail)];
attributes([{same_site, none}|Tail]) -> [<<"; SameSite=None">>|attributes(Tail)];
%% Skip unknown options.
attributes([_|Tail]) -> attributes(Tail).
-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">>,
#{secure => true},
<<"Customer=WILE_E_COYOTE; Version=1; Secure">>},
{<<"Customer">>, <<"WILE_E_COYOTE">>,
#{secure => false, http_only => false},
<<"Customer=WILE_E_COYOTE; Version=1">>},
{<<"Customer">>, <<"WILE_E_COYOTE">>,
#{same_site => lax},
<<"Customer=WILE_E_COYOTE; Version=1; SameSite=Lax">>},
{<<"Customer">>, <<"WILE_E_COYOTE">>,
#{same_site => strict},
<<"Customer=WILE_E_COYOTE; Version=1; SameSite=Strict">>},
{<<"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', {{badarg, {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.
