-module(acme_challenge).
-export ([key_authorization/2,
solve_challenge/3,
process/2,
register_hooks/1,
unregister_hooks/1,
acme_handler/3
]).
%% Challenge Types
%% ================
%% 1. http-01: https://tools.ietf.org/html/draft-ietf-acme-acme-05#section-7.2
%% 2. dns-01: https://tools.ietf.org/html/draft-ietf-acme-acme-05#section-7.3
%% 3. tls-sni-01: https://tools.ietf.org/html/draft-ietf-acme-acme-05#section-7.4
%% 4. (?) oob-01: https://tools.ietf.org/html/draft-ietf-acme-acme-05#section-7.5
-include("logger.hrl").
-include("xmpp.hrl").
-include("ejabberd_http.hrl").
-include("ejabberd_acme.hrl").
%% This is the default endpoint for the http challenge
%% This hooks is called from ejabberd_http
acme_handler(Handlers, _Host, Request) ->
case Request#request.path of
[<<".well-known">>|_] ->
[{[<<".well-known">>],acme_challenge}|Handlers];
_ ->
Handlers
end.
%% TODO: Maybe validate request here??
process(LocalPath, _Request) ->
Result = ets_get_key_authorization(LocalPath),
{200,
[{<<"Content-Type">>, <<"text/plain">>}],
Result}.
register_hooks(_Domain) ->
?INFO_MSG("Registering hook for ACME HTTP headers", []),
ejabberd_hooks:add(http_request_handlers, ?MODULE, acme_handler, 50).
unregister_hooks(_Domain) ->
?INFO_MSG("Unregistering hook for ACME HTTP headers", []),
ejabberd_hooks:delete(http_request_handlers, ?MODULE, acme_handler, 50).
-spec key_authorization(bitstring(), jose_jwk:key()) -> bitstring().
key_authorization(Token, Key) ->
Thumbprint = jose_jwk:thumbprint(Key),
KeyAuthorization = erlang:iolist_to_binary([Token, <<".">>, Thumbprint]),
KeyAuthorization.
-spec parse_challenge({proplist()}) -> {ok, acme_challenge()} | {error, _}.
parse_challenge(Challenge0) ->
try
{Challenge} = Challenge0,
{<<"type">>,Type} = proplists:lookup(<<"type">>, Challenge),
{<<"status">>,Status} = proplists:lookup(<<"status">>, Challenge),
{<<"uri">>,Uri} = proplists:lookup(<<"uri">>, Challenge),
{<<"token">>,Token} = proplists:lookup(<<"token">>, Challenge),
Res =
#challenge{
type = Type,
status = list_to_atom(bitstring_to_list(Status)),
uri = bitstring_to_list(Uri),
token = Token
},
{ok, Res}
catch
_:Error ->
{error, Error}
end.
-spec solve_challenge(bitstring(), [{proplist()}], _) ->
{ok, url(), bitstring()} | {error, _}.
solve_challenge(ChallengeType, Challenges, Options) ->
ParsedChallenges = [parse_challenge(Chall) || Chall <- Challenges],
case lists:any(fun is_error/1, ParsedChallenges) of
true ->
?ERROR_MSG("Error parsing challenges: ~p~n", [Challenges]),
{error, parse_challenge};
false ->
case [C || {ok, C} <- ParsedChallenges, is_challenge_type(ChallengeType, C)] of
[Challenge] ->
solve_challenge1(Challenge, Options);
_ ->
?ERROR_MSG("Challenge ~p not found in challenges: ~p~n", [ChallengeType, Challenges]),
{error, not_found}
end
end.
-spec solve_challenge1(acme_challenge(), {jose_jwk:key(), string()}) ->
{ok, url(), bitstring()} | {error, _}.
solve_challenge1(Chal = #challenge{type = <<"http-01">>, token=Tkn}, Key) ->
KeyAuthz = key_authorization(Tkn, Key),
%% save_key_authorization(Chal, Tkn, KeyAuthz, HttpDir);
ets_put_key_authorization(Tkn, KeyAuthz),
{ok, Chal#challenge.uri, KeyAuthz};
solve_challenge1(Challenge, _Key) ->
?ERROR_MSG("Unknown Challenge Type: ~p", [Challenge]),
{error, unknown_challenge}.
-spec ets_put_key_authorization(bitstring(), bitstring()) -> ok.
ets_put_key_authorization(Tkn, KeyAuthz) ->
Tab = ets_get_acme_table(),
Key = [<<"acme-challenge">>, Tkn],
ets:insert(Tab, {Key, KeyAuthz}),
ok.
-spec ets_get_key_authorization([bitstring()]) -> bitstring().
ets_get_key_authorization(Key) ->
Tab = ets_get_acme_table(),
case ets:lookup(Tab, Key) of
[{Key, KeyAuthz}] ->
ets:delete(Tab, Key),
KeyAuthz;
_ ->
?ERROR_MSG("Unable to serve key authorization in: ~p", [Key]),
<<"">>
end.
-spec ets_get_acme_table() -> atom().
ets_get_acme_table() ->
case ets:info(acme) of
undefined ->
ets:new(acme, [named_table, public]);
_ ->
acme
end.
%% Useful functions
is_challenge_type(DesiredType, #challenge{type = Type}) when DesiredType =:= Type ->
true;
is_challenge_type(_DesiredType, #challenge{type = _Type}) ->
false.
-spec is_error({'error', _}) -> 'true';
({'ok', _}) -> 'false'.
is_error({error, _}) -> true;
is_error(_) -> false.
