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spec/util_stanza_spec.lua @ 12181:783056b4e448 0.11 0.11.12

util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.
author Jonas Schäfer <jonas@wielicki.name>
date Mon, 10 Jan 2022 18:23:54 +0100
parent 11205:9d1e21c23784
child 11206:f051394762ff
line wrap: on
line source


local st = require "util.stanza";

describe("util.stanza", function()
	describe("#preserialize()", function()
		it("should work", function()
			local stanza = st.stanza("message", { type = "chat" }):text_tag("body", "Hello");
			local stanza2 = st.preserialize(stanza);
			assert.is_table(stanza2, "Preserialized stanza is a table");
			assert.is_nil(getmetatable(stanza2), "Preserialized stanza has no metatable");
			assert.is_string(stanza2.name, "Preserialized stanza has a name field");
			assert.equal(stanza.name, stanza2.name, "Preserialized stanza has same name as the input stanza");
			assert.same(stanza.attr, stanza2.attr, "Preserialized stanza same attr table as input stanza");
			assert.is_nil(stanza2.tags, "Preserialized stanza has no tag list");
			assert.is_nil(stanza2.last_add, "Preserialized stanza has no last_add marker");
			assert.is_table(stanza2[1], "Preserialized child element preserved");
			assert.equal("body", stanza2[1].name, "Preserialized child element name preserved");
		end);
	end);

	describe("#deserialize()", function()
		it("should work", function()
			local stanza = { name = "message", attr = { type = "chat" }, { name = "body", attr = { }, "Hello" } };
			local stanza2 = st.deserialize(st.preserialize(stanza));

			assert.is_table(stanza2, "Deserialized stanza is a table");
			assert.equal(st.stanza_mt, getmetatable(stanza2), "Deserialized stanza has stanza metatable");
			assert.is_string(stanza2.name, "Deserialized stanza has a name field");
			assert.equal(stanza.name, stanza2.name, "Deserialized stanza has same name as the input table");
			assert.same(stanza.attr, stanza2.attr, "Deserialized stanza same attr table as input table");
			assert.is_table(stanza2.tags, "Deserialized stanza has tag list");
			assert.is_table(stanza2[1], "Deserialized child element preserved");
			assert.equal("body", stanza2[1].name, "Deserialized child element name preserved");
		end);
	end);

	describe("#stanza()", function()
		it("should work", function()
			local s = st.stanza("foo", { xmlns = "myxmlns", a = "attr-a" });
			assert.are.equal(s.name, "foo");
			assert.are.equal(s.attr.xmlns, "myxmlns");
			assert.are.equal(s.attr.a, "attr-a");

			local s1 = st.stanza("s1");
			assert.are.equal(s1.name, "s1");
			assert.are.equal(s1.attr.xmlns, nil);
			assert.are.equal(#s1, 0);
			assert.are.equal(#s1.tags, 0);

			s1:tag("child1");
			assert.are.equal(#s1.tags, 1);
			assert.are.equal(s1.tags[1].name, "child1");

			s1:tag("grandchild1"):up();
			assert.are.equal(#s1.tags, 1);
			assert.are.equal(s1.tags[1].name, "child1");
			assert.are.equal(#s1.tags[1], 1);
			assert.are.equal(s1.tags[1][1].name, "grandchild1");

			s1:up():tag("child2");
			assert.are.equal(#s1.tags, 2, tostring(s1));
			assert.are.equal(s1.tags[1].name, "child1");
			assert.are.equal(s1.tags[2].name, "child2");
			assert.are.equal(#s1.tags[1], 1);
			assert.are.equal(s1.tags[1][1].name, "grandchild1");

			s1:up():text("Hello world");
			assert.are.equal(#s1.tags, 2);
			assert.are.equal(#s1, 3);
			assert.are.equal(s1.tags[1].name, "child1");
			assert.are.equal(s1.tags[2].name, "child2");
			assert.are.equal(#s1.tags[1], 1);
			assert.are.equal(s1.tags[1][1].name, "grandchild1");
		end);
		it("should work with unicode values", function ()
			local s = st.stanza("Объект", { xmlns = "myxmlns", ["Объект"] = "&" });
			assert.are.equal(s.name, "Объект");
			assert.are.equal(s.attr.xmlns, "myxmlns");
			assert.are.equal(s.attr["Объект"], "&");
		end);
		it("should allow :text() with nil and empty strings", function ()
			local s_control = st.stanza("foo");
			assert.same(st.stanza("foo"):text(), s_control);
			assert.same(st.stanza("foo"):text(nil), s_control);
			assert.same(st.stanza("foo"):text(""), s_control);
		end);
	end);

	describe("#message()", function()
		it("should work", function()
			local m = st.message();
			assert.are.equal(m.name, "message");
		end);
	end);

	describe("#iq()", function()
		it("should create an iq stanza", function()
			local i = st.iq({ id = "foo" });
			assert.are.equal("iq", i.name);
			assert.are.equal("foo", i.attr.id);
		end);

		it("should reject stanzas with no id", function ()
			assert.has.error_match(function ()
				st.iq();
			end, "id attribute");

			assert.has.error_match(function ()
				st.iq({ foo = "bar" });
			end, "id attribute");
		end);
	end);

	describe("#presence()", function ()
		it("should work", function()
			local p = st.presence();
			assert.are.equal(p.name, "presence");
		end);
	end);

	describe("#reply()", function()
		it("should work for <s>", function()
			-- Test stanza
			local s = st.stanza("s", { to = "touser", from = "fromuser", id = "123" })
				:tag("child1");
			-- Make reply stanza
			local r = st.reply(s);
			assert.are.equal(r.name, s.name);
			assert.are.equal(r.id, s.id);
			assert.are.equal(r.attr.to, s.attr.from);
			assert.are.equal(r.attr.from, s.attr.to);
			assert.are.equal(#r.tags, 0, "A reply should not include children of the original stanza");
		end);

		it("should work for <iq get>", function()
			-- Test stanza
			local s = st.stanza("iq", { to = "touser", from = "fromuser", id = "123", type = "get" })
				:tag("child1");
			-- Make reply stanza
			local r = st.reply(s);
			assert.are.equal(r.name, s.name);
			assert.are.equal(r.id, s.id);
			assert.are.equal(r.attr.to, s.attr.from);
			assert.are.equal(r.attr.from, s.attr.to);
			assert.are.equal(r.attr.type, "result");
			assert.are.equal(#r.tags, 0, "A reply should not include children of the original stanza");
		end);

		it("should work for <iq set>", function()
			-- Test stanza
			local s = st.stanza("iq", { to = "touser", from = "fromuser", id = "123", type = "set" })
				:tag("child1");
			-- Make reply stanza
			local r = st.reply(s);
			assert.are.equal(r.name, s.name);
			assert.are.equal(r.id, s.id);
			assert.are.equal(r.attr.to, s.attr.from);
			assert.are.equal(r.attr.from, s.attr.to);
			assert.are.equal(r.attr.type, "result");
			assert.are.equal(#r.tags, 0, "A reply should not include children of the original stanza");
		end);
	end);

	describe("#error_reply()", function()
		it("should work for <s>", function()
			-- Test stanza
			local s = st.stanza("s", { to = "touser", from = "fromuser", id = "123" })
				:tag("child1");
			-- Make reply stanza
			local r = st.error_reply(s, "cancel", "service-unavailable");
			assert.are.equal(r.name, s.name);
			assert.are.equal(r.id, s.id);
			assert.are.equal(r.attr.to, s.attr.from);
			assert.are.equal(r.attr.from, s.attr.to);
			assert.are.equal(#r.tags, 1);
			assert.are.equal(r.tags[1].tags[1].name, "service-unavailable");
		end);

		it("should work for <iq get>", function()
			-- Test stanza
			local s = st.stanza("iq", { to = "touser", from = "fromuser", id = "123", type = "get" })
				:tag("child1");
			-- Make reply stanza
			local r = st.error_reply(s, "cancel", "service-unavailable");
			assert.are.equal(r.name, s.name);
			assert.are.equal(r.id, s.id);
			assert.are.equal(r.attr.to, s.attr.from);
			assert.are.equal(r.attr.from, s.attr.to);
			assert.are.equal(r.attr.type, "error");
			assert.are.equal(#r.tags, 1);
			assert.are.equal(r.tags[1].tags[1].name, "service-unavailable");
		end);
	end);

	describe("should reject #invalid", function ()
		local invalid_names = {
			["empty string"] = "", ["characters"] = "<>";
		}
		local invalid_data = {
			["number"] = 1234, ["table"] = {};
			["utf8"] = string.char(0xF4, 0x90, 0x80, 0x80);
			["nil"] = "nil"; ["boolean"] = true;
			["control characters"] = "\0\1\2\3";
		};

		for value_type, value in pairs(invalid_names) do
			it(value_type.." in tag names", function ()
				assert.error_matches(function ()
					st.stanza(value);
				end, value_type);
			end);
			it(value_type.." in attribute names", function ()
				assert.error_matches(function ()
					st.stanza("valid", { [value] = "valid" });
				end, value_type);
			end);
		end
		for value_type, value in pairs(invalid_data) do
			if value == "nil" then value = nil; end
			it(value_type.." in tag names", function ()
				assert.error_matches(function ()
					st.stanza(value);
				end, value_type);
			end);
			it(value_type.." in attribute names", function ()
				assert.error_matches(function ()
					st.stanza("valid", { [value] = "valid" });
				end, value_type);
			end);
			if value ~= nil then
				it(value_type.." in attribute values", function ()
					assert.error_matches(function ()
						st.stanza("valid", { valid = value });
					end, value_type);
				end);
				it(value_type.." in text node", function ()
					assert.error_matches(function ()
						st.stanza("valid"):text(value);
					end, value_type);
				end);
			end
		end
	end);

	describe("#is_stanza", function ()
		-- is_stanza(any) -> boolean
		it("identifies stanzas as stanzas", function ()
			assert.truthy(st.is_stanza(st.stanza("x")));
		end);
		it("identifies strings as not stanzas", function ()
			assert.falsy(st.is_stanza(""));
		end);
		it("identifies numbers as not stanzas", function ()
			assert.falsy(st.is_stanza(1));
		end);
		it("identifies tables as not stanzas", function ()
			assert.falsy(st.is_stanza({}));
		end);
	end);

	describe("#remove_children", function ()
		it("should work", function ()
			local s = st.stanza("x", {xmlns="test"})
				:tag("y", {xmlns="test"}):up()
				:tag("z", {xmlns="test2"}):up()
				:tag("x", {xmlns="test2"}):up()

			s:remove_children("x");
			assert.falsy(s:get_child("x"))
			assert.truthy(s:get_child("z","test2"));
			assert.truthy(s:get_child("x","test2"));

			s:remove_children(nil, "test2");
			assert.truthy(s:get_child("y"))
			assert.falsy(s:get_child(nil,"test2"));

			s:remove_children();
			assert.falsy(s.tags[1]);
		end);
	end);

	describe("#maptags", function ()
		it("should work", function ()
			local s = st.stanza("test")
				:tag("one"):up()
				:tag("two"):up()
				:tag("one"):up()
				:tag("three"):up();

			local function one_filter(tag)
				if tag.name == "one" then
					return nil;
				end
				return tag;
			end
			assert.equal(4, #s.tags);
			s:maptags(one_filter);
			assert.equal(2, #s.tags);
		end);

		it("should work with multiple consecutive text nodes", function ()
			local s = st.deserialize({
				"\n";
				{
					"away";
					name = "show";
					attr = {};
				};
				"\n";
				{
					"I am away";
					name = "status";
					attr = {};
				};
				"\n";
				{
					"0";
					name = "priority";
					attr = {};
				};
				"\n";
				{
					name = "c";
					attr = {
						xmlns = "http://jabber.org/protocol/caps";
						node = "http://psi-im.org";
						hash = "sha-1";
					};
				};
				"\n";
				"\n";
				name = "presence";
				attr = {
					to = "user@example.com/jflsjfld";
					from = "room@chat.example.org/nick";
				};
			});

			assert.equal(4, #s.tags);

			s:maptags(function (tag) return tag; end);
			assert.equal(4, #s.tags);

			s:maptags(function (tag)
				if tag.name == "c" then
					return nil;
				end
				return tag;
			end);
			assert.equal(3, #s.tags);
		end);
		it("errors on invalid data - #981", function ()
			local s = st.message({}, "Hello");
			s.tags[1] = st.clone(s.tags[1]);
			assert.has_error_match(function ()
				s:maptags(function () end);
			end, "Invalid stanza");
		end);
	end);

	describe("#clone", function ()
		it("works", function ()
			local s = st.message({type="chat"}, "Hello"):reset();
			local c = st.clone(s);
			assert.same(s, c);
		end);

		it("works", function ()
			assert.has_error(function ()
				st.clone("this is not a stanza");
			end);
		end);
	end);
end);