-- RESTful API
--
-- Copyright (c) 2019-2022 Kim Alvefur
--
-- This file is MIT/X11 licensed.
local encodings = require "util.encodings";
local base64 = encodings.base64;
local errors = require "util.error";
local http = require "net.http";
local id = require "util.id";
local jid = require "util.jid";
local json = require "util.json";
local st = require "util.stanza";
local um = require "core.usermanager";
local xml = require "util.xml";
local have_cbor, cbor = pcall(require, "cbor");
local jsonmap = module:require"jsonmap";
local tokens = module:depends("tokenauth");
local auth_mechanisms = module:get_option_set("rest_auth_mechanisms", { "Basic", "Bearer" });
local www_authenticate_header;
do
local header, realm = {}, module.host.."/"..module.name;
for mech in auth_mechanisms do
header[#header+1] = ("%s realm=%q"):format(mech, realm);
end
www_authenticate_header = table.concat(header, ", ");
end
local function check_credentials(request)
local auth_type, auth_data = string.match(request.headers.authorization, "^(%S+)%s(.+)$");
if not (auth_type and auth_data) or not auth_mechanisms:contains(auth_type) then
return false;
end
if auth_type == "Basic" then
local creds = base64.decode(auth_data);
if not creds then return false; end
local username, password = string.match(creds, "^([^:]+):(.*)$");
if not username then return false; end
username, password = encodings.stringprep.nodeprep(username), encodings.stringprep.saslprep(password);
if not username then return false; end
if not um.test_password(username, module.host, password) then
return false;
end
return { username = username, host = module.host };
elseif auth_type == "Bearer" then
if tokens.get_token_session then
return tokens.get_token_session(auth_data);
else -- COMPAT w/0.12
local token_info = tokens.get_token_info(auth_data);
if not token_info or not token_info.session then
return false;
end
return token_info.session;
end
end
return nil;
end
if module:get_option_string("authentication") == "anonymous" and module:get_option_boolean("anonymous_rest") then
www_authenticate_header = nil;
function check_credentials(request) -- luacheck: ignore 212/request
return {
username = id.medium():lower();
host = module.host;
}
end
end
local function event_suffix(jid_to)
local node, _, resource = jid.split(jid_to);
if node then
if resource then
return '/full';
else
return '/bare';
end
else
return '/host';
end
end
-- TODO This ought to be handled some way other than duplicating this
-- core.stanza_router code here.
local function compat_preevents(origin, stanza) --> boolean : handled
local to = stanza.attr.to;
local node, host, resource = jid.split(to);
local to_type, to_self;
if node then
if resource then
to_type = '/full';
else
to_type = '/bare';
if node == origin.username and host == origin.host then
stanza.attr.to = nil;
to_self = true;
end
end
else
if host then
to_type = '/host';
else
to_type = '/bare';
to_self = true;
end
end
local event_data = { origin = origin; stanza = stanza; to_self = to_self };
local result = module:fire_event("pre-stanza", event_data);
if result ~= nil then return true end
if module:fire_event('pre-' .. stanza.name .. to_type, event_data) then return true; end -- do preprocessing
return false
end
-- (table, string) -> table
local function amend_from_path(data, path)
local st_kind, st_type, st_to = path:match("^([mpi]%w+)/(%w+)/(.*)$");
if not st_kind then return; end
if st_kind == "iq" and st_type ~= "get" and st_type ~= "set" then
-- GET /iq/disco/jid
data = {
kind = "iq";
[st_type] = st_type == "ping" or data or {};
};
else
data.kind = st_kind;
data.type = st_type;
end
if st_to and st_to ~= "" then
data.to = st_to;
end
return data;
end
local function parse(mimetype, data, path) --> Stanza, error enum
mimetype = mimetype and mimetype:match("^[^; ]*");
if mimetype == "application/xmpp+xml" then
return xml.parse(data);
elseif mimetype == "application/json" then
local parsed, err = json.decode(data);
if not parsed then
return parsed, err;
end
if path then
parsed = amend_from_path(parsed, path);
if not parsed then return nil, "invalid-path"; end
end
return jsonmap.json2st(parsed);
elseif mimetype == "application/cbor" and have_cbor then
local parsed, err = cbor.decode(data);
if not parsed then
return parsed, err;
end
return jsonmap.json2st(parsed);
elseif mimetype == "application/x-www-form-urlencoded"then
local parsed = http.formdecode(data);
if type(parsed) == "string" then
-- This should reject GET /iq/query/to?messagebody
if path then
return nil, "invalid-query";
end
return parse("text/plain", parsed);
end
for i = #parsed, 1, -1 do
parsed[i] = nil;
end
if path then
parsed = amend_from_path(parsed, path);
if not parsed then return nil, "invalid-path"; end
end
return jsonmap.json2st(parsed);
elseif mimetype == "text/plain" then
if not path then
return st.message({ type = "chat" }, data);
end
local parsed = {};
if path then
parsed = amend_from_path(parsed, path);
if not parsed then return nil, "invalid-path"; end
end
if parsed.kind == "message" then
parsed.body = data;
elseif parsed.kind == "presence" then
parsed.show = data;
else
return nil, "invalid-path";
end
return jsonmap.json2st(parsed);
elseif not mimetype and path then
local parsed = amend_from_path({}, path);
if not parsed then return nil, "invalid-path"; end
return jsonmap.json2st(parsed);
end
return nil, "unknown-payload-type";
end
local function decide_type(accept, supported_types)
-- assumes the accept header is sorted
local ret = supported_types[1];
for i = 2, #supported_types do
if (accept:find(supported_types[i], 1, true) or 1000) < (accept:find(ret, 1, true) or 1000) then
ret = supported_types[i];
end
end
return ret;
end
local supported_inputs = {
"application/xmpp+xml",
"application/json",
"application/x-www-form-urlencoded",
"text/plain",
};
local supported_outputs = {
"application/xmpp+xml",
"application/json",
"application/x-www-form-urlencoded",
};
if have_cbor then
table.insert(supported_inputs, "application/cbor");
table.insert(supported_outputs, "application/cbor");
end
-- Only { string : string } can be form-encoded, discard the rest
-- (jsonmap also discards anything unknown or unsupported)
local function flatten(t)
local form = {};
for k, v in pairs(t) do
if type(v) == "string" then
form[k] = v;
elseif type(v) == "number" then
form[k] = tostring(v);
elseif v == true then
form[k] = "";
end
end
return form;
end
local function encode(type, s)
if type == "text/plain" then
return s:get_child_text("body") or "";
elseif type == "application/xmpp+xml" then
return tostring(s);
end
local mapped, err = jsonmap.st2json(s);
if not mapped then return mapped, err; end
if type == "application/json" then
return json.encode(mapped);
elseif type == "application/x-www-form-urlencoded" then
return http.formencode(flatten(mapped));
elseif type == "application/cbor" then
return cbor.encode(mapped);
end
error "unsupported encoding";
end
local post_errors = errors.init("mod_rest", {
noauthz = { code = 401; type = "auth"; condition = "not-authorized"; text = "No credentials provided" };
unauthz = { code = 403; type = "auth"; condition = "not-authorized"; text = "Credentials not accepted" };
parse = { code = 400; type = "modify"; condition = "not-well-formed"; text = "Failed to parse payload" };
xmlns = { code = 422; type = "modify"; condition = "invalid-namespace"; text = "'xmlns' attribute must be empty" };
name = { code = 422; type = "modify"; condition = "unsupported-stanza-type"; text = "Invalid stanza, must be 'message', 'presence' or 'iq'." };
to = { code = 422; type = "modify"; condition = "improper-addressing"; text = "Invalid destination JID" };
from = { code = 422; type = "modify"; condition = "invalid-from"; text = "Invalid source JID" };
from_auth = { code = 403; type = "auth"; condition = "not-authorized"; text = "Not authorized to send stanza with requested 'from'" };
iq_type = { code = 422; type = "modify"; condition = "invalid-xml"; text = "'iq' stanza must be of type 'get' or 'set'" };
iq_tags = { code = 422; type = "modify"; condition = "bad-format"; text = "'iq' stanza must have exactly one child tag" };
mediatype = { code = 415; type = "cancel"; condition = "bad-format"; text = "Unsupported media type" };
});
-- GET → iq-get
local function parse_request(request, path)
if path and request.method == "GET" then
-- e.g. /version/{to}
if request.url.query then
return parse("application/x-www-form-urlencoded", request.url.query, "iq/"..path);
end
return parse(nil, nil, "iq/"..path);
else
return parse(request.headers.content_type, request.body, path);
end
end
local function handle_request(event, path)
local request, response = event.request, event.response;
local from;
local origin;
local echo = path == "echo";
if echo then path = nil; end
if not request.headers.authorization and www_authenticate_header then
response.headers.www_authenticate = www_authenticate_header;
return post_errors.new("noauthz");
else
origin = check_credentials(request);
if not origin then
return post_errors.new("unauthz");
end
from = jid.join(origin.username, origin.host, origin.resource);
origin.type = "c2s";
origin.log = module._log;
end
local payload, err = parse_request(request, path);
if not payload then
-- parse fail
local ctx = { error = err, type = request.headers.content_type, data = request.body, };
if err == "unknown-payload-type" then
return post_errors.new("mediatype", ctx);
end
return post_errors.new("parse", ctx);
end
if (payload.attr.xmlns or "jabber:client") ~= "jabber:client" then
return post_errors.new("xmlns");
elseif payload.name ~= "message" and payload.name ~= "presence" and payload.name ~= "iq" then
return post_errors.new("name");
end
local to = jid.prep(payload.attr.to);
if payload.attr.to and not to then
return post_errors.new("to");
end
if payload.attr.from then
local requested_from = jid.prep(payload.attr.from);
if not requested_from then
return post_errors.new("from");
end
if jid.compare(requested_from, from) then
from = requested_from;
else
return post_errors.new("from_auth");
end
end
payload.attr = {
from = from,
to = to,
id = payload.attr.id or id.medium(),
type = payload.attr.type,
["xml:lang"] = payload.attr["xml:lang"],
};
module:log("debug", "Received[rest]: %s", payload:top_tag());
local send_type = decide_type((request.headers.accept or "") ..",".. (request.headers.content_type or ""), supported_outputs)
if echo then
local ret, err = errors.coerce(encode(send_type, payload));
if not ret then return err; end
response.headers.content_type = send_type;
return ret;
end
if payload.name == "iq" then
local responses = st.stanza("xmpp");
function origin.send(stanza)
responses:add_direct_child(stanza);
end
if compat_preevents(origin, payload) then return 202; end
if payload.attr.type ~= "get" and payload.attr.type ~= "set" then
return post_errors.new("iq_type");
elseif #payload.tags ~= 1 then
return post_errors.new("iq_tags");
end
-- special handling of multiple responses to MAM queries primarily from
-- remote hosts, local go directly to origin.send()
local archive_event_name = "message"..event_suffix(from);
local archive_handler;
local archive_query = payload:get_child("query", "urn:xmpp:mam:2");
if archive_query then
archive_handler = function(result_event)
if result_event.stanza:find("{urn:xmpp:mam:2}result/@queryid") == archive_query.attr.queryid then
origin.send(result_event.stanza);
return true;
end
end
module:hook(archive_event_name, archive_handler, 1);
end
local p = module:send_iq(payload, origin):next(
function (result)
module:log("debug", "Sending[rest]: %s", result.stanza:top_tag());
response.headers.content_type = send_type;
if responses[1] then
local tail = responses[#responses];
if tail.name ~= "iq" or tail.attr.from ~= result.stanza.attr.from or tail.attr.id ~= result.stanza.attr.id then
origin.send(result.stanza);
end
end
if responses[2] then
return encode(send_type, responses);
end
return encode(send_type, result.stanza);
end,
function (error)
if not errors.is_err(error) then
module:log("error", "Uncaught native error: %s", error);
return select(2, errors.coerce(nil, error));
elseif error.context and error.context.stanza then
response.headers.content_type = send_type;
module:log("debug", "Sending[rest]: %s", error.context.stanza:top_tag());
return encode(send_type, error.context.stanza);
else
return error;
end
end);
if archive_handler then
p:finally(function ()
module:unhook(archive_event_name, archive_handler);
end)
end
return p;
else
function origin.send(stanza)
module:log("debug", "Sending[rest]: %s", stanza:top_tag());
response.headers.content_type = send_type;
response:send(encode(send_type, stanza));
return true;
end
if compat_preevents(origin, payload) then return 202; end
module:send(payload, origin);
return 202;
end
end
module:depends("http");
local demo_handlers = {};
if module:get_option_path("rest_demo_resources", nil) then
demo_handlers = module:require"apidemo";
end
-- Handle stanzas submitted via HTTP
module:provides("http", {
route = {
POST = handle_request;
["POST /*"] = handle_request;
["GET /*"] = handle_request;
-- Only if api_demo_resources are set
["GET /"] = demo_handlers.redirect;
["GET /demo/"] = demo_handlers.main_page;
["GET /demo/openapi.yaml"] = demo_handlers.schema;
["GET /demo/*"] = demo_handlers.resources;
};
});
-- Forward stanzas from XMPP to HTTP and return any reply
local rest_url = module:get_option_string("rest_callback_url", nil);
if rest_url then
local function get_url() return rest_url; end
if rest_url:find("%b{}") then
local httputil = require "util.http";
local render_url = require"util.interpolation".new("%b{}", httputil.urlencode);
function get_url(stanza)
local at = stanza.attr;
return render_url(rest_url, { kind = stanza.name, type = at.type, to = at.to, from = at.from });
end
end
local send_type = module:get_option_string("rest_callback_content_type", "application/xmpp+xml");
if send_type == "json" then
send_type = "application/json";
end
module:set_status("info", "Not yet connected");
http.request(get_url(st.stanza("meta", { type = "info", to = module.host, from = module.host })), {
method = "OPTIONS",
}, function (body, code, response)
if code == 0 then
module:log_status("error", "Could not connect to callback URL %q: %s", rest_url, body);
elseif code == 200 then
module:set_status("info", "Connected");
if response.headers.accept then
send_type = decide_type(response.headers.accept, supported_outputs);
module:log("debug", "Set 'rest_callback_content_type' = %q based on Accept header", send_type);
end
else
module:log_status("warn", "Unexpected response code %d from OPTIONS probe", code);
module:log("warn", "Endpoint said: %s", body);
end
end);
local code2err = require "net.http.errors".registry;
local function handle_stanza(event)
local stanza, origin = event.stanza, event.origin;
local reply_allowed = stanza.attr.type ~= "error";
local reply_needed = reply_allowed and stanza.name == "iq";
local receipt;
if reply_allowed and stanza.name == "message" and stanza.attr.id and stanza:get_child("urn:xmpp:receipts", "request") then
reply_needed = true;
receipt = st.stanza("received", { xmlns = "urn:xmpp:receipts", id = stanza.id });
end
local request_body = encode(send_type, stanza);
-- Keep only the top level element and let the rest be GC'd
stanza = st.clone(stanza, true);
module:log("debug", "Sending[rest]: %s", stanza:top_tag());
http.request(get_url(stanza), {
body = request_body,
headers = {
["Content-Type"] = send_type,
["Content-Language"] = stanza.attr["xml:lang"],
Accept = table.concat(supported_inputs, ", ");
},
}):next(function (response)
module:set_status("info", "Connected");
local reply;
local code, body = response.code, response.body;
if not reply_allowed then
return;
elseif code == 202 or code == 204 then
if not reply_needed then
-- Delivered, no reply
return;
end
else
local parsed, err = parse(response.headers["content-type"], body);
if not parsed then
module:log("warn", "Failed parsing data from REST callback: %s, %q", err, body);
elseif parsed.name ~= stanza.name then
module:log("warn", "REST callback responded with the wrong stanza type, got %s but expected %s", parsed.name, stanza.name);
else
parsed.attr = {
from = stanza.attr.to,
to = stanza.attr.from,
id = parsed.attr.id or id.medium();
type = parsed.attr.type,
["xml:lang"] = parsed.attr["xml:lang"],
};
if parsed.name == "message" and parsed.attr.type == "groupchat" then
parsed.attr.to = jid.bare(stanza.attr.from);
end
if not stanza.attr.type and parsed:get_child("error") then
parsed.attr.type = "error";
end
if parsed.attr.type == "error" then
parsed.attr.id = stanza.attr.id;
elseif parsed.name == "iq" then
parsed.attr.id = stanza.attr.id;
parsed.attr.type = "result";
end
reply = parsed;
end
end
if not reply then
local code_hundreds = code - (code % 100);
if code_hundreds == 200 then
reply = st.reply(stanza);
if stanza.name ~= "iq" then
reply.attr.id = id.medium();
end
-- TODO presence/status=body ?
elseif code2err[code] then
reply = st.error_reply(stanza, errors.new(code, nil, code2err));
elseif code_hundreds == 400 then
reply = st.error_reply(stanza, "modify", "bad-request", body);
elseif code_hundreds == 500 then
reply = st.error_reply(stanza, "cancel", "internal-server-error", body);
else
reply = st.error_reply(stanza, "cancel", "undefined-condition", body);
end
end
if receipt then
reply:add_direct_child(receipt);
end
module:log("debug", "Received[rest]: %s", reply:top_tag());
origin.send(reply);
end,
function (err)
module:log_status("error", "Could not connect to callback URL %q: %s", rest_url, err);
origin.send(st.error_reply(stanza, "wait", "recipient-unavailable", err.text));
end):catch(function (err)
module:log("error", "Error[rest]: %s", err);
end);
return true;
end
local send_kinds = module:get_option_set("rest_callback_stanzas", { "message", "presence", "iq" });
local event_presets = {
-- Don't override everything on normal VirtualHosts by default
["local"] = { "host" },
-- Comonents get to handle all kinds of stanzas
["component"] = { "bare", "full", "host" },
};
local hook_events = module:get_option_set("rest_callback_events", event_presets[module:get_host_type()]);
for kind in send_kinds do
for event in hook_events do
module:hook(kind.."/"..event, handle_stanza, -1);
end
end
end
local supported_errors = {
"text/html",
"application/xmpp+xml",
"application/json",
};
local http_server = require "net.http.server";
module:hook_object_event(http_server, "http-error", function (event)
local request, response = event.request, event.response;
local response_as = decide_type(request and request.headers.accept or "", supported_errors);
if response_as == "application/xmpp+xml" then
if response then
response.headers.content_type = "application/xmpp+xml";
end
local stream_error = st.stanza("error", { xmlns = "http://etherx.jabber.org/streams" });
if event.error then
stream_error:tag(event.error.condition, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }):up();
if event.error.text then
stream_error:text_tag("text", event.error.text, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' });
end
end
return tostring(stream_error);
elseif response_as == "application/json" then
if response then
response.headers.content_type = "application/json";
end
return json.encode({
type = "error",
error = event.error,
code = event.code,
});
end
end, 1);