local unified_push_secret = assert(module:get_option_string("unified_push_secret"), "required option: unified_push_secret");
local push_registration_ttl = module:get_option_number("unified_push_registration_ttl", 86400);
local base64 = require "util.encodings".base64;
local datetime = require "util.datetime";
local id = require "util.id";
local jwt_sign, jwt_verify = require "util.jwt".init("HS256", unified_push_secret);
local st = require "util.stanza";
local urlencode = require "util.http".urlencode;
local xmlns_up = "http://gultsch.de/xmpp/drafts/unified-push";
module:depends("http");
module:depends("disco");
module:add_feature(xmlns_up);
local function check_sha256(s)
if not s then return nil, "no value provided"; end
local d = base64.decode(s);
if not d then return nil, "invalid base64"; end
if #d ~= 32 then return nil, "incorrect decoded length, expected 32"; end
return s;
end
-- Handle incoming registration from XMPP client
function handle_register(event)
local origin, stanza = event.origin, event.stanza;
local instance, instance_err = check_sha256(stanza.tags[1].attr.instance);
if not instance then
return st.error_reply(stanza, "modify", "bad-request", "instance: "..instance_err);
end
local application, application_err = check_sha256(stanza.tags[1].attr.application);
if not application then
return st.error_reply(stanza, "modify", "bad-request", "application: "..application_err);
end
local expiry = os.time() + push_registration_ttl;
local url = module:http_url("push").."/"..urlencode(jwt_sign({
instance = instance;
application = application;
sub = stanza.attr.from;
exp = expiry;
}));
module:log("debug", "New push registration successful");
return origin.send(st.reply(stanza):tag("registered", {
expiration = datetime.datetime(expiry);
endpoint = url;
xmlns = xmlns_up;
}));
end
module:hook("iq-set/host/"..xmlns_up..":register", handle_register);
-- Handle incoming POST
function handle_push(event, subpath)
module:log("debug", "Incoming push received!");
local ok, data = jwt_verify(subpath);
if not ok then
module:log("debug", "Received push to unacceptable token (%s)", data);
return 404;
end
local payload = event.request.body;
if not payload or payload == "" then
module:log("warn", "Missing or empty push payload");
return 400;
elseif #payload > 4096 then
module:log("warn", "Push payload too large");
return 413;
end
local push_id = event.request.id or id.short();
module:log("debug", "Push notification received [%s], relaying to device...", push_id);
local push_iq = st.iq({ type = "set", to = data.sub, from = module.host, id = push_id })
:text_tag("push", base64.encode(payload), { instance = data.instance, application = data.application, xmlns = xmlns_up });
return module:send_iq(push_iq):next(function ()
module:log("debug", "Push notification delivered [%s]", push_id);
return 201;
end, function (error_event)
local e_type, e_cond, e_text = error_event.stanza:get_error();
if e_cond == "item-not-found" or e_cond == "feature-not-implemented" then
module:log("debug", "Push rejected [%s]", push_id);
return 404;
elseif e_cond == "service-unavailable" or e_cond == "recipient-unavailable" then
module:log("debug", "Recipient temporarily unavailable [%s]", push_id);
return 503;
end
module:log("warn", "Unexpected push error response: %s/%s/%s", e_type, e_cond, e_text);
return 500;
end);
end
module:provides("http", {
name = "push";
route = {
["GET /*"] = function (event)
event.response.headers.content_type = "application/json";
return [[{"unifiedpush":{"version":1}}]];
end;
["POST /*"] = handle_push;
};
});