-module(ejabberd_acme_comm).
-export([%% Directory
directory/1,
%% Account
new_account/4,
update_account/4,
get_account/3,
delete_account/3,
%% Authorization
new_authz/4,
get_authz/1,
complete_challenge/4,
%% Authorization polling
get_authz_until_valid/1,
%% Certificate
new_cert/4,
get_cert/1,
revoke_cert/4,
get_issuer_cert/1
%% Not yet implemented
%% key_roll_over/5
%% delete_authz/3
]).
-include("ejabberd.hrl").
-include("logger.hrl").
-include("xmpp.hrl").
-include("ejabberd_acme.hrl").
-include_lib("public_key/include/public_key.hrl").
-define(REQUEST_TIMEOUT, 5000). % 5 seconds.
-define(MAX_POLL_REQUESTS, 20).
-define(POLL_WAIT_TIME, 500). % 500 ms.
%%%
%%% This module contains functions that implement all necessary http
%%% requests to the ACME Certificate Authority. Its purpose is to
%%% facilitate the acme client implementation by separating the
%%% handling/validating/parsing of all the needed http requests.
%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Directory
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec directory(url()) -> {ok, dirs(), nonce()} | {error, _}.
directory(CAUrl) ->
Url = CAUrl ++ "/directory",
prepare_get_request(Url, fun get_dirs/1).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Account Handling
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec new_account(dirs(), jose_jwk:key(), proplist(), nonce()) ->
{ok, {url(), proplist()}, nonce()} | {error, _}.
new_account(Dirs, PrivateKey, Req, Nonce) ->
#{"new-reg" := Url} = Dirs,
EJson = {[{ <<"resource">>, <<"new-reg">>}] ++ Req},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response_tos/1).
-spec update_account({url(), string()}, jose_jwk:key(), proplist(), nonce()) ->
{ok, proplist(), nonce()} | {error, _}.
update_account({CAUrl, AccId}, PrivateKey, Req, Nonce) ->
Url = CAUrl ++ "/acme/reg/" ++ AccId,
EJson = {[{ <<"resource">>, <<"reg">>}] ++ Req},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response/1).
-spec get_account({url(), string()}, jose_jwk:key(), nonce()) ->
{ok, {url(), proplist()}, nonce()} | {error, _}.
get_account({CAUrl, AccId}, PrivateKey, Nonce) ->
Url = CAUrl ++ "/acme/reg/" ++ AccId,
EJson = {[{<<"resource">>, <<"reg">>}]},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response_tos/1).
-spec delete_account({url(), string()}, jose_jwk:key(), nonce()) ->
{ok, proplist(), nonce()} | {error, _}.
delete_account({CAUrl, AccId}, PrivateKey, Nonce) ->
Url = CAUrl ++ "/acme/reg/" ++ AccId,
EJson =
{[{<<"resource">>, <<"reg">>},
{<<"status">>, <<"deactivated">>}]},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response/1).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Authorization Handling
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec new_authz(dirs(), jose_jwk:key(), proplist(), nonce()) ->
{ok, {url(), proplist()}, nonce()} | {error, _}.
new_authz(Dirs, PrivateKey, Req, Nonce) ->
#{"new-authz" := Url} = Dirs,
EJson = {[{<<"resource">>, <<"new-authz">>}] ++ Req},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response_location/1).
-spec get_authz({url(), string()}) -> {ok, proplist(), nonce()} | {error, _}.
get_authz({CAUrl, AuthzId}) ->
Url = CAUrl ++ "/acme/authz/" ++ AuthzId,
prepare_get_request(Url, fun get_response/1).
-spec complete_challenge({url(), string(), string()}, jose_jwk:key(), proplist(), nonce()) ->
{ok, proplist(), nonce()} | {error, _}.
complete_challenge({CAUrl, AuthzId, ChallId}, PrivateKey, Req, Nonce) ->
Url = CAUrl ++ "/acme/challenge/" ++ AuthzId ++ "/" ++ ChallId,
EJson = {[{<<"resource">>, <<"challenge">>}] ++ Req},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response/1).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Certificate Handling
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec new_cert(dirs(), jose_jwk:key(), proplist(), nonce()) ->
{ok, {url(), list()}, nonce()} | {error, _}.
new_cert(Dirs, PrivateKey, Req, Nonce) ->
#{"new-cert" := Url} = Dirs,
EJson = {[{<<"resource">>, <<"new-cert">>}] ++ Req},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response_link_up/1,
"application/pkix-cert").
-spec get_cert({url(), string()}) -> {ok, list(), nonce()} | {error, _}.
get_cert({CAUrl, CertId}) ->
Url = CAUrl ++ "/acme/cert/" ++ CertId,
prepare_get_request(Url, fun get_response/1, "application/pkix-cert").
-spec revoke_cert(dirs(), jose_jwk:key(), proplist(), nonce()) ->
{ok, _, nonce()} | {error, _}.
revoke_cert(Dirs, PrivateKey, Req, Nonce) ->
#{"revoke-cert" := Url} = Dirs,
EJson = {[{<<"resource">>, <<"revoke-cert">>}] ++ Req},
prepare_post_request(Url, PrivateKey, EJson, Nonce, fun get_response/1,
"application/pkix-cert").
-spec get_issuer_cert(url()) -> {ok, list(), nonce()} | {error, _}.
get_issuer_cert(IssuerCertUrl) ->
prepare_get_request(IssuerCertUrl, fun get_response/1, "application/pkix-cert").
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Handle Response Functions
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec get_dirs({ok, proplist(), proplist()}) -> {ok, map(), nonce()}.
get_dirs({ok, Head, Return}) ->
NewNonce = get_nonce(Head),
StrDirectories = [{bitstring_to_list(X), bitstring_to_list(Y)} ||
{X, Y} <- Return, is_bitstring(X) andalso is_bitstring(Y)],
NewDirs = maps:from_list(StrDirectories),
{ok, NewDirs, NewNonce}.
-spec get_response({ok, proplist(), proplist()}) -> {ok, proplist(), nonce()}.
get_response({ok, Head, Return}) ->
NewNonce = get_nonce(Head),
{ok, Return, NewNonce}.
-spec get_response_tos({ok, proplist(), proplist()}) -> {ok, {url(), proplist()}, nonce()}.
get_response_tos({ok, Head, Return}) ->
TOSUrl = get_tos(Head),
NewNonce = get_nonce(Head),
{ok, {TOSUrl, Return}, NewNonce}.
-spec get_response_location({ok, proplist(), proplist()}) -> {ok, {url(), proplist()}, nonce()}.
get_response_location({ok, Head, Return}) ->
Location = get_location(Head),
NewNonce = get_nonce(Head),
{ok, {Location, Return}, NewNonce}.
-spec get_response_link_up({ok, proplist(), proplist()}) -> {ok, {url(), proplist()}, nonce()}.
get_response_link_up({ok, Head, Return}) ->
LinkUp = get_link_up(Head),
NewNonce = get_nonce(Head),
{ok, {LinkUp, Return}, NewNonce}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Authorization Polling
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec get_authz_until_valid({url(), string()}) -> {ok, proplist(), nonce()} | {error, _}.
get_authz_until_valid({CAUrl, AuthzId}) ->
get_authz_until_valid({CAUrl, AuthzId}, ?MAX_POLL_REQUESTS).
-spec get_authz_until_valid({url(), string()}, non_neg_integer()) ->
{ok, proplist(), nonce()} | {error, _}.
get_authz_until_valid({_CAUrl, _AuthzId}, 0) ->
?ERROR_MSG("Maximum request limit waiting for validation reached", []),
{error, max_request_limit};
get_authz_until_valid({CAUrl, AuthzId}, N) ->
case get_authz({CAUrl, AuthzId}) of
{ok, Resp, Nonce} ->
case is_authz_valid(Resp) of
true ->
{ok, Resp, Nonce};
false ->
timer:sleep(?POLL_WAIT_TIME),
get_authz_until_valid({CAUrl, AuthzId}, N-1)
end;
{error, _} = Err ->
Err
end.
-spec is_authz_valid(proplist()) -> boolean().
is_authz_valid(Authz) ->
case proplists:lookup(<<"status">>, Authz) of
{<<"status">>, <<"valid">>} ->
true;
_ ->
false
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Request Functions
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% TODO: Fix the duplicated code at the below 4 functions
-spec make_post_request(url(), bitstring(), string()) ->
{ok, proplist(), proplist()} | {error, _}.
make_post_request(Url, ReqBody, ResponseType) ->
Options = [],
HttpOptions = [{timeout, ?REQUEST_TIMEOUT}],
case httpc:request(post,
{Url, [], "application/jose+json", ReqBody}, HttpOptions, Options) of
{ok, {{_, Code, _}, Head, Body}} when Code >= 200, Code =< 299 ->
decode_response(Head, Body, ResponseType);
Error ->
failed_http_request(Error, Url)
end.
-spec make_get_request(url(), string()) ->
{ok, proplist(), proplist()} | {error, _}.
make_get_request(Url, ResponseType) ->
Options = [],
HttpOptions = [{timeout, ?REQUEST_TIMEOUT}],
case httpc:request(get, {Url, []}, HttpOptions, Options) of
{ok, {{_, Code, _}, Head, Body}} when Code >= 200, Code =< 299 ->
decode_response(Head, Body, ResponseType);
Error ->
failed_http_request(Error, Url)
end.
-spec prepare_post_request(url(), jose_jwk:key(), jiffy:json_value(),
nonce(), handle_resp_fun()) -> {ok, _, nonce()} | {error, _}.
prepare_post_request(Url, PrivateKey, EJson, Nonce, HandleRespFun) ->
prepare_post_request(Url, PrivateKey, EJson, Nonce, HandleRespFun, "application/jose+json").
-spec prepare_post_request(url(), jose_jwk:key(), jiffy:json_value(),
nonce(), handle_resp_fun(), string()) -> {ok, _, nonce()} | {error, _}.
prepare_post_request(Url, PrivateKey, EJson, Nonce, HandleRespFun, ResponseType) ->
case encode(EJson) of
{ok, ReqBody} ->
FinalBody = sign_encode_json_jose(PrivateKey, ReqBody, Nonce),
case make_post_request(Url, FinalBody, ResponseType) of
{ok, Head, Return} ->
HandleRespFun({ok, Head, Return});
Error ->
Error
end;
{error, Reason} ->
?ERROR_MSG("Error: ~p when encoding: ~p", [Reason, EJson]),
{error, Reason}
end.
-spec prepare_get_request(url(), handle_resp_fun()) ->
{ok, _, nonce()} | {error, _}.
prepare_get_request(Url, HandleRespFun) ->
prepare_get_request(Url, HandleRespFun, "application/jose+json").
-spec prepare_get_request(url(), handle_resp_fun(), string()) ->
{ok, _, nonce()} | {error, _}.
prepare_get_request(Url, HandleRespFun, ResponseType) ->
case make_get_request(Url, ResponseType) of
{ok, Head, Return} ->
HandleRespFun({ok, Head, Return});
Error ->
Error
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Jose Json Functions
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec sign_json_jose(jose_jwk:key(), bitstring(), nonce()) -> {_, jws()}.
sign_json_jose(Key, Json, Nonce) ->
PubKey = ejabberd_acme:to_public(Key),
{_, BinaryPubKey} = jose_jwk:to_binary(PubKey),
PubKeyJson = jiffy:decode(BinaryPubKey),
%% TODO: Ensure this works for all cases
AlgMap = jose_jwk:signer(Key),
JwsMap =
#{ <<"jwk">> => PubKeyJson,
%% <<"b64">> => true,
<<"nonce">> => list_to_bitstring(Nonce)
},
JwsObj0 = maps:merge(JwsMap, AlgMap),
JwsObj = jose_jws:from(JwsObj0),
jose_jws:sign(Key, Json, JwsObj).
-spec sign_encode_json_jose(jose_jwk:key(), bitstring(), nonce()) -> bitstring().
sign_encode_json_jose(Key, Json, Nonce) ->
{_, Signed} = sign_json_jose(Key, Json, Nonce),
%% This depends on jose library, so we can consider it safe
jiffy:encode(Signed).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Useful funs
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec get_nonce(proplist()) -> nonce() | 'none'.
get_nonce(Head) ->
case proplists:lookup("replay-nonce", Head) of
{"replay-nonce", Nonce} -> Nonce;
none -> none
end.
-spec get_location(proplist()) -> url() | 'none'.
get_location(Head) ->
case proplists:lookup("location", Head) of
{"location", Location} -> Location;
none -> none
end.
-spec get_tos(proplist()) -> url() | 'none'.
get_tos(Head) ->
get_header_link(Head, "\"terms-of-service\"").
-spec get_link_up(proplist()) -> url() | 'none'.
get_link_up(Head) ->
get_header_link(Head, "rel=\"up\"").
%% TODO: Find a more reliable way to extract this
-spec get_header_link(proplist(), string()) -> url() | 'none'.
get_header_link(Head, Suffix) ->
try
[{_, Link}] = [{K, V} || {K, V} <- Head,
K =:= "link" andalso
lists:suffix(Suffix, V)],
[Link1, _] = string:tokens(Link, ";"),
Link2 = string:strip(Link1, left, $<),
string:strip(Link2, right, $>)
catch
_:_ ->
none
end.
decode_response(Head, Body, "application/pkix-cert") ->
{ok, Head, Body};
decode_response(Head, Body, "application/jose+json") ->
case decode(Body) of
{ok, Return} ->
{ok, Head, Return};
{error, Reason} ->
?ERROR_MSG("Problem decoding: ~s", [Body]),
{error, Reason}
end.
encode(EJson) ->
try
{ok, jiffy:encode(EJson)}
catch
_:Reason ->
{error, Reason}
end.
decode(Json) ->
try
{Result} = jiffy:decode(Json),
{ok, Result}
catch
_:Reason ->
{error, Reason}
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Handle Failed HTTP Requests
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec failed_http_request({ok, _} | {error, _}, url()) -> {error, _}.
failed_http_request({ok, {{_, Code, Reason}, _Head, Body}}, Url) ->
?ERROR_MSG("Got unexpected status code from <~s>: ~B, Body: ~s",
[Url, Code, Body]),
throw({error, {unexpected_code, Code, Reason}});
failed_http_request({error, Reason}, Url) ->
?ERROR_MSG("Error making a request to <~s>: ~p",
[Url, Reason]),
throw({error, Reason}).
