view mod_pubsub_post/mod_pubsub_post.lua @ 3866:c0df50ce96f0

mod_rest: Handle internal http request errors early and then return Skips over attempted parsing of the payload which usually failed since the body is an error string like "connection refused", so this produced useless errors.
author Kim Alvefur <zash@zash.se>
date Sat, 25 Jan 2020 20:22:12 +0100
parents 0d3926e49b55
children f7381268a597
line wrap: on
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module:depends("http");

local st = require "util.stanza";
local json = require "util.json";
local xml = require "util.xml";
local uuid_generate = require "util.uuid".generate;
local timestamp_generate = require "util.datetime".datetime;
local hashes = require "util.hashes";
local from_hex = require "util.hex".from;
local hmacs = {
	sha1 = hashes.hmac_sha1;
	sha256 = hashes.hmac_sha256;
	sha384 = hashes.hmac_sha384;
	sha512 = hashes.hmac_sha512;
};

local pubsub_service = module:depends("pubsub").service;

local error_mapping = {
	["forbidden"] = 403;
	["item-not-found"] = 404;
	["internal-server-error"] = 500;
	["conflict"] = 409;
};

local function publish_payload(node, actor, item_id, payload)
	local post_item = st.stanza("item", { xmlns = "http://jabber.org/protocol/pubsub", id = item_id, })
		:add_child(payload);
	local ok, err = pubsub_service:publish(node, actor, item_id, post_item);
	module:log("debug", ":publish(%q, true, %q, %s) -> %q", node, item_id, payload:top_tag(), err or "");
	if not ok then
		return error_mapping[err] or 500;
	end
	return 202;
end

local function handle_json(node, actor, data)
	local parsed, err = json.decode(data);
	if not parsed then
		return { status_code = 400; body = tostring(err); }
	end
	if type(parsed) ~= "table" then
		return { status_code = 400; body = "object or array expected"; };
	end
	local wrapper = st.stanza("json", { xmlns="urn:xmpp:json:0" }):text(data);
	return publish_payload(node, actor, type(parsed.id) == "string" and parsed.id or "current", wrapper);
end

local function publish_atom(node, actor, feed)
	for entry in feed:childtags("entry") do
		local item_id = entry:get_child_text("id");
		if not item_id then
			item_id = uuid_generate();
			entry:tag("id"):text(item_id):up();
		end
		if not entry:get_child_text("published") then
			entry:tag("published"):text(timestamp_generate()):up();
		end
		local resp = publish_payload(node, actor, item_id, entry);
		if resp ~= 202 then return resp; end
	end
	return 202;
end

local function handle_xml(node, actor, payload)
	local xmlpayload, err = xml.parse(payload);
	if not xmlpayload then
		module:log("debug", "XML parse error: %s\n%q", err, payload);
		return { status_code = 400, body = tostring(err) };
	end
	if xmlpayload.attr.xmlns == "http://www.w3.org/2005/Atom" and xmlpayload.name == "feed" then
		return publish_atom(node, actor, xmlpayload);
	else
		return publish_payload(node, actor, "current", xmlpayload);
	end
end

local actor_source = module:get_option_string("pubsub_post_actor"); -- COMPAT
local default_secret = module:get_option_string("pubsub_post_default_secret");
local actor_secrets = module:get_option("pubsub_post_secrets");
local actors = module:get_option("pubsub_post_actors");
local default_actor = module:get_option_string("pubsub_post_default_actor");
if not default_actor and actor_source == "superuser" then
	default_actor = true;
end

local function verify_signature(secret, body, signature)
	if not signature then return false; end
	local algo, digest = signature:match("^([^=]+)=(%x+)");
	if not algo then return false; end
	local hmac = hmacs[algo];
	if not algo then return false; end
	return hmac(secret, body) == from_hex(digest);
end

function handle_POST(event, path)
	local request = event.request;

	local content_type = request.headers.content_type or "application/octet-stream";
	local actor = actors and actors[path] or default_actor or request.ip;
	local secret = actor_secrets and actor_secrets[path] or default_secret;

	module:log("debug", "Handling POST to node %q by %q with %q: \n%s\n", path, actor, content_type, request.body);

	if secret and not verify_signature(secret, request.body, request.headers.x_hub_signature) then
		module:log("debug", "Signature validation failed");
		return 401;
	end

	if not actor then
		return 401;
	end

	if content_type == "application/xml" or content_type:sub(-4) == "+xml" then
		return handle_xml(path, actor, request.body);
	elseif content_type == "application/json" or content_type:sub(-5) == "+json" then
		return handle_json(path, actor, request.body);
	end

	module:log("debug", "Unsupported content-type: %q", content_type);
	return 415;
end

module:provides("http", {
	route = {
		["POST /*"] = handle_POST;
	};
});

function module.load()
	module:log("debug", "Loaded at %s", module:http_url());
end