ejabberd-contrib/ejabberd_auth_http/deps/fusco/src/fusco_lib.erl

499 lines
18 KiB
Erlang

%%%-----------------------------------------------------------------------------
%%% @copyright (C) 1999-2013, Erlang Solutions Ltd
%%% @author Oscar Hellström <oscar@hellstrom.st>
%%% @author Diana Parra Corbacho <diana.corbacho@erlang-solutions.com>
%%% @author Ramon Lastres Guerrero <ramon.lastres@erlang-solutions.com>
%%% @doc This module implements various library functions used in fusco
%%%
%%% @end
%%%-----------------------------------------------------------------------------
-module(fusco_lib).
-copyright("2013, Erlang Solutions Ltd.").
-export([parse_url/1,
format_request/6,
header_value/2,
update_cookies/2,
delete_expired_cookies/2,
to_lower/1,
get_value/2,
get_value/3,
host_header/2,
is_close/1,
maybe_ipv6_enclose/1]).
-include("fusco_types.hrl").
-include("fusco.hrl").
-define(HTTP_LINE_END, <<"\r\n">>).
%%==============================================================================
%% Exported functions
%%==============================================================================
%%------------------------------------------------------------------------------
%% @spec header_value(Header, Headers) -> undefined | term()
%% Header = string()
%% Headers = [{header(), term()}]
%% Value = term()
%% @doc
%% Returns the value associated with the `Header' in `Headers'.
%% `Header' must be a lowercase string, since every header is mangled to
%% check the match.
%% @end
%%------------------------------------------------------------------------------
-spec header_value(string(), headers()) -> undefined | term().
header_value(Hdr, Hdrs) ->
%% TODO ensure headers and values are stripped
case lists:keyfind(Hdr, 1, Hdrs) of
false ->
undefined;
{Hdr, Value} ->
Value
end.
%%------------------------------------------------------------------------------
%% @spec (URL) -> #fusco_url{}
%% URL = string()
%% @doc
%% @end
%%------------------------------------------------------------------------------
-spec parse_url(string()) -> #fusco_url{}.
parse_url(URL) ->
% XXX This should be possible to do with the re module?
{Scheme, CredsHostPortPath} = split_scheme(URL),
{User, Passwd, HostPortPath} = split_credentials(CredsHostPortPath),
{Host, PortPath} = split_host(HostPortPath, []),
{Port, Path} = split_port(Scheme, PortPath, []),
#fusco_url{host = fusco_lib:to_lower(Host), port = Port, path = Path,
user = User, password = Passwd, is_ssl = (Scheme =:= https)}.
%%------------------------------------------------------------------------------
%% @spec (Path, Method, Headers, Host, Body, Cookies) ->
%% Request
%% Path = iolist()
%% Method = atom() | string()
%% Headers = [{atom() | string(), string()}]
%% Host = string()
%% Body = iolist()
%% Cookies = [#fusco_cookie{}]
%% @doc
%% @end
%%------------------------------------------------------------------------------
-spec format_request(iolist(), method(), headers(), string(), iolist(),
{boolean(), [#fusco_cookie{}]}) -> {iodata(), iodata()}.
format_request(Path, Method, Hdrs, Host, Body, Cookies) ->
{AllHdrs, ConHdr} =
add_mandatory_hdrs(Path, Hdrs, Host, Body, Cookies),
{[Method, <<" ">>, Path, <<" HTTP/1.1">>, ?HTTP_LINE_END, AllHdrs,
?HTTP_LINE_END, Body], ConHdr}.
%%------------------------------------------------------------------------------
%% @private
%% @doc Updated the state of the cookies. after we receive a response.
%% @end
%%------------------------------------------------------------------------------
-spec update_cookies(headers(), [#fusco_cookie{}]) -> [#fusco_cookie{}].
update_cookies([], []) ->
[];
update_cookies([], StateCookies) ->
StateCookies;
update_cookies(ReceivedCookies, []) ->
ReceivedCookies;
update_cookies(ReceivedCookies, StateCookies) ->
%% substitute the cookies with the same name, add the others, delete.
%% http://tools.ietf.org/search/rfc6265#section-4.1.2
%% If a user agent receives a Set-Cookie response header whose NAME is
%% the same as a pre-existing cookie, and whose Domain and Path
%% attribute values exactly (string) match those of a pre-existing
%% cookie, the new cookie supersedes the old.
lists:foldl(fun(NewCookie, Acc) ->
OldCookie =
lists:keyfind(NewCookie#fusco_cookie.name,
#fusco_cookie.name, Acc),
replace_or_add_cookie(OldCookie, NewCookie, Acc)
end, StateCookies, ReceivedCookies).
%% http://tools.ietf.org/search/rfc6265#section-4.1.2
replace_or_add_cookie(false, NewCookie, List) ->
%% Add new cookie
[NewCookie | List];
replace_or_add_cookie(#fusco_cookie{domain = Domain, path = Path},
#fusco_cookie{domain = Domain,
path = Path} = NewCookie, List) ->
%% Replace previous cookie
lists:keystore(NewCookie#fusco_cookie.name, #fusco_cookie.name, List,
NewCookie);
replace_or_add_cookie(_, NewCookie, List) ->
%% Add new cookie, path and/or domain are different
[NewCookie | List].
%%------------------------------------------------------------------------------
%% @doc Converts characters in a string ro lower case.
%% @end
%%------------------------------------------------------------------------------
-spec to_lower(string()) -> string().
to_lower(String) when is_list(String) ->
[char_to_lower(X) || X <- String].
bin_to_lower(Bin) ->
<< <<(char_to_lower(B))>> || <<B>> <= Bin >>.
%%------------------------------------------------------------------------------
%% @doc Compares header values to pre-defined values
%% Faster than string:to_lower and then compare
%% @end
%%------------------------------------------------------------------------------
is_close(<<"close">>) ->
true;
is_close(<<"Close">>) ->
true;
is_close(<<"keep-alive">>) ->
false;
is_close(<<"Keep-Alive">>) ->
false;
is_close(C) ->
is_close(C, "close").
is_close(<<C, Rest1/bits>>, [C | Rest2]) ->
is_close(Rest1, Rest2);
is_close(<<C1, Rest1/bits>>, [C2 | Rest2]) ->
case close_to_lower(C1) == C2 of
true ->
is_close(Rest1, Rest2);
false ->
false
end;
is_close(<<>>, _) ->
false;
is_close(_, []) ->
false.
close_to_lower($C) ->
$c;
close_to_lower($L) ->
$l;
close_to_lower($O) ->
$o;
close_to_lower($S) ->
$s;
close_to_lower($E) ->
$e;
close_to_lower(C) ->
C.
%%------------------------------------------------------------------------------
%% @doc Gets value from tuple list
%% @end
%%------------------------------------------------------------------------------
-spec get_value(Key, List) -> term() when
Key :: term(),
List :: [term()].
get_value(Key, List) ->
case lists:keyfind(Key, 1, List) of
{Key, Value} ->
Value;
false ->
undefined
end.
%%------------------------------------------------------------------------------
%% @doc Gets value from tuple list. If it is not present, returns default value.
%% @end
%%------------------------------------------------------------------------------
-spec get_value(Key, List, Default) -> term() when
Key :: term(),
List :: [term()],
Default :: term().
get_value(Key, List, Default) ->
case lists:keyfind(Key, 1, List) of
{Key, Value} ->
Value;
false ->
Default
end.
%%------------------------------------------------------------------------------
%% @private
%% @doc Delete the cookies that are expired (check max-age and expire fields).
%% @end
%%------------------------------------------------------------------------------
-spec delete_expired_cookies([#fusco_cookie{}], erlang:timestamp()) -> [#fusco_cookie{}].
delete_expired_cookies([], _InTimestamp) ->
[];
delete_expired_cookies(Cookies, InTimestamp) ->
[ X || X <- Cookies, not expires(X, InTimestamp)].
%%==============================================================================
%% Internal functions
%%==============================================================================
%% http://tools.ietf.org/search/rfc6265#section-4.1.2.2
%% The Max-Age attribute indicates the maximum lifetime of the cookie,
%% represented as the number of seconds until the cookie expires.
%%
%% If a cookie has both the Max-Age and the Expires attribute,
%% the Max-Age attribute has precedence and controls the expiration date of the
%% cookie. If a cookie has neither the Max-Age nor the Expires attribute,
%% the user agent will retain the cookie until "the current session is over"
expires(#fusco_cookie{max_age = 0}, _) ->
true;
expires(#fusco_cookie{max_age = Max}, InTimestamp) when Max =/= undefined ->
timer:now_diff(os:timestamp(), InTimestamp) > Max;
expires(#fusco_cookie{expires = Exp}, _) when Exp =/= undefined ->
calendar:universal_time() > Exp;
expires(_, _) ->
false.
%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
split_scheme("http://" ++ HostPortPath) ->
{http, HostPortPath};
split_scheme("https://" ++ HostPortPath) ->
{https, HostPortPath}.
%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
split_credentials(CredsHostPortPath) ->
case string:tokens(CredsHostPortPath, "@") of
[HostPortPath] ->
{"", "", HostPortPath};
[Creds, HostPortPath] ->
% RFC1738 (section 3.1) says:
% "The user name (and password), if present, are followed by a
% commercial at-sign "@". Within the user and password field, any ":",
% "@", or "/" must be encoded."
% The mentioned encoding is the "percent" encoding.
case string:tokens(Creds, ":") of
[User] ->
% RFC1738 says ":password" is optional
{http_uri:decode(User), "", HostPortPath};
[User, Passwd] ->
{http_uri:decode(User), http_uri:decode(Passwd), HostPortPath}
end
end.
%%------------------------------------------------------------------------------
%% @private
%% @doc
%% @end
%%------------------------------------------------------------------------------
-spec split_host(string(), string()) -> {string(), string()}.
split_host("[" ++ Rest, []) ->
% IPv6 address literals are enclosed by square brackets (RFC2732)
case string:str(Rest, "]") of
0 ->
split_host(Rest, "[");
N ->
{IPv6Address, "]" ++ PortPath0} = lists:split(N - 1, Rest),
case PortPath0 of
":" ++ PortPath ->
{IPv6Address, PortPath};
_ ->
{IPv6Address, PortPath0}
end
end;
split_host([$: | PortPath], Host) ->
{lists:reverse(Host), PortPath};
split_host([$/ | _] = PortPath, Host) ->
{lists:reverse(Host), PortPath};
split_host([$? | _] = Query, Host) ->
%% The query string follows the hostname, without a slash. The
%% path is empty, but for HTTP an empty path is equivalent to "/"
%% (RFC 3986, section 6.2.3), so let's add the slash ourselves.
{lists:reverse(Host), "/" ++ Query};
split_host([H | T], Host) ->
split_host(T, [H | Host]);
split_host([], Host) ->
{lists:reverse(Host), []}.
%%------------------------------------------------------------------------------
%% @private
%% @doc
%% @end
%%------------------------------------------------------------------------------
split_port(http, [$/ | _] = Path, []) ->
{80, Path};
split_port(https, [$/ | _] = Path, []) ->
{443, Path};
split_port(http, [], []) ->
{80, "/"};
split_port(https, [], []) ->
{443, "/"};
split_port(_, [], Port) ->
{list_to_integer(lists:reverse(Port)), "/"};
split_port(_,[$/ | _] = Path, Port) ->
{list_to_integer(lists:reverse(Port)), Path};
split_port(Scheme, [P | T], Port) ->
split_port(Scheme, T, [P | Port]).
%%------------------------------------------------------------------------------
%% @private
%% @doc
%% @end
%%------------------------------------------------------------------------------
-spec add_mandatory_hdrs(string(), headers(), host(),
iolist(), {boolean(), [#fusco_cookie{}]}) -> {iodata(), iodata()}.
add_mandatory_hdrs(_Path, Hdrs, Host, Body, {_, []}) ->
add_headers(Hdrs, Body, Host, undefined, []);
add_mandatory_hdrs(_Path, Hdrs, Host, Body, {false, _}) ->
add_headers(Hdrs, Body, Host, undefined, []);
add_mandatory_hdrs(Path, Hdrs, Host, Body, {true, Cookies}) ->
Result = {ContentHdrs, ConHdr} =
add_headers(Hdrs, Body, Host, undefined, []),
%% http://tools.ietf.org/search/rfc6265#section-4.1.2.4
%% only include cookies if the cookie path is a prefix of the request path
%% TODO optimize cookie handling
case lists:filter(
fun(#fusco_cookie{path_tokens = undefined}) ->
true;
(#fusco_cookie{path_tokens = CookiePath}) ->
SubPath = binary:split(Path, <<"/">>, [global]),
is_prefix(CookiePath, SubPath)
end, Cookies)
of
[] ->
Result;
IncludeCookies ->
{add_cookie_headers(ContentHdrs, IncludeCookies), ConHdr}
end.
%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
%% http://tools.ietf.org/search/rfc6265#section-4.2.1
add_cookie_headers(Hdrs, Cookies) ->
[[<<"Cookie: ">>, make_cookie_string(Cookies, []), ?HTTP_LINE_END]
| Hdrs].
%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
make_cookie_string([], Acc) ->
Acc;
make_cookie_string([Cookie | Rest], []) ->
make_cookie_string(Rest, cookie_string(Cookie));
make_cookie_string([Cookie | Rest], Acc) ->
make_cookie_string(Rest, [cookie_string(Cookie), "; " | Acc]).
%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
cookie_string(#fusco_cookie{name = Name, value = Value}) ->
[Name, <<"=">>, Value].
%%------------------------------------------------------------------------------
%% @private
%% Host header: http://tools.ietf.org/html/rfc2616#section-14.23
%%------------------------------------------------------------------------------
add_headers([{H, V} | T], undefined, undefined, Connection, Acc)
when Connection =/= undefined ->
add_headers(T, undefined, undefined, Connection,
[[H, <<": ">>, V, ?HTTP_LINE_END] | Acc]);
add_headers([{H, V} | T], Body, Host, Connection, Acc) ->
case bin_to_lower(H) of
<<"connection">> ->
add_headers(T, Body, Host, V,
[[H, <<": ">>, V, ?HTTP_LINE_END] | Acc]);
<<"host">> ->
add_headers(T, Body, undefined, Connection,
[[H, <<": ">>, V, ?HTTP_LINE_END] | Acc]);
<<"content-length">> ->
add_headers(T, undefined, Host, Connection,
[[H, <<": ">>, V, ?HTTP_LINE_END] | Acc]);
_ ->
add_headers(T, Body, Host, Connection,
[[H, <<": ">>, V, ?HTTP_LINE_END] | Acc])
end;
add_headers([], undefined, Host, Connection, Headers) ->
case Host of
undefined ->
{Headers, Connection};
_ ->
{[[<<"Host: ">>, Host, ?HTTP_LINE_END] | Headers], Connection}
end;
add_headers([], Body, Host, Connection, Headers) ->
ContentLength = integer_to_list(iolist_size(Body)),
case ContentLength > 0 of
true ->
add_headers([], undefined, Host, Connection,
[[<<"Content-Length: ">>, ContentLength, ?HTTP_LINE_END]
| Headers]);
_ ->
add_headers([], undefined, Host, Connection, Headers)
end.
%%------------------------------------------------------------------------------
%% @doc
%% @end
%%------------------------------------------------------------------------------
-spec host_header(host(), port_num()) -> any().
host_header(Host, 80) -> maybe_ipv6_enclose(Host);
% When proxying after an HTTP CONNECT session is established, squid doesn't
% like the :443 suffix in the Host header.
host_header(Host, 443) -> maybe_ipv6_enclose(Host);
host_header(Host, Port) -> [maybe_ipv6_enclose(Host), $:, integer_to_list(Port)].
%%------------------------------------------------------------------------------
%% @private
%% @doc
%% @end
%%------------------------------------------------------------------------------
-spec maybe_ipv6_enclose(host()) -> host().
maybe_ipv6_enclose(Host) ->
case inet_parse:address(Host) of
{ok, {_, _, _, _, _, _, _, _}} ->
% IPv6 address literals are enclosed by square brackets (RFC2732)
[$[, Host, $]];
_ ->
Host
end.
%%------------------------------------------------------------------------------
%% @private
%% @doc
%% @end
%%------------------------------------------------------------------------------
char_to_lower($A) -> $a;
char_to_lower($B) -> $b;
char_to_lower($C) -> $c;
char_to_lower($D) -> $d;
char_to_lower($E) -> $e;
char_to_lower($F) -> $f;
char_to_lower($G) -> $g;
char_to_lower($H) -> $h;
char_to_lower($I) -> $i;
char_to_lower($J) -> $j;
char_to_lower($K) -> $k;
char_to_lower($L) -> $l;
char_to_lower($M) -> $m;
char_to_lower($N) -> $n;
char_to_lower($O) -> $o;
char_to_lower($P) -> $p;
char_to_lower($Q) -> $q;
char_to_lower($R) -> $r;
char_to_lower($S) -> $s;
char_to_lower($T) -> $t;
char_to_lower($U) -> $u;
char_to_lower($V) -> $v;
char_to_lower($W) -> $w;
char_to_lower($X) -> $x;
char_to_lower($Y) -> $y;
char_to_lower($Z) -> $z;
char_to_lower(Ch) -> Ch.
is_prefix([<<>>], _) ->
true;
is_prefix([H | T1], [H | T2]) ->
is_prefix(T1, T2);
is_prefix([], _) ->
true;
is_prefix(_, []) ->
false;
is_prefix(_, _) ->
false.