util.xmppstream: Add tests for various XML features forbidden by the RFC

spec/util_xmppstream_spec.lua

@@ -2,59 +2,62 @@
 local xmppstream = require "util.xmppstream";
 
 describe("util.xmppstream", function()
+	local function test(xml, expect_success, ex)
+		local stanzas = {};
+		local session = { notopen = true };
+		local callbacks = {
+			stream_ns = "streamns";
+			stream_tag = "stream";
+			default_ns = "stanzans";
+			streamopened = function (_session)
+				assert.are.equal(session, _session);
+				assert.are.equal(session.notopen, true);
+				_session.notopen = nil;
+				return true;
+			end;
+			handlestanza = function (_session, stanza)
+				assert.are.equal(session, _session);
+				assert.are.equal(_session.notopen, nil);
+				table.insert(stanzas, stanza);
+			end;
+			streamclosed = function (_session)
+				assert.are.equal(session, _session);
+				assert.are.equal(_session.notopen, nil);
+				_session.notopen = nil;
+			end;
+		}
+		if type(ex) == "table" then
+			for k, v in pairs(ex) do
+				if k ~= "_size_limit" then
+					callbacks[k] = v;
+				end
+			end
+		end
+		local stream = xmppstream.new(session, callbacks, ex and ex._size_limit or nil);
+		local ok, err = pcall(function ()
+			assert(stream:feed(xml));
+		end);
+
+		if ok and type(expect_success) == "function" then
+			expect_success(stanzas);
+		end
+		assert.are.equal(not not ok, not not expect_success, "Expected "..(expect_success and ("success ("..tostring(err)..")") or "failure"));
+	end
+
+	local function test_stanza(stanza, expect_success, ex)
+		return test([[<stream:stream xmlns:stream="streamns" xmlns="stanzans">]]..stanza, expect_success, ex);
+	end
+
 	describe("#new()", function()
 		it("should work", function()
-			local function test(xml, expect_success, ex)
-				local stanzas = {};
-				local session = { notopen = true };
-				local callbacks = {
-					stream_ns = "streamns";
-					stream_tag = "stream";
-					default_ns = "stanzans";
-					streamopened = function (_session)
-						assert.are.equal(session, _session);
-						assert.are.equal(session.notopen, true);
-						_session.notopen = nil;
-						return true;
-					end;
-					handlestanza = function (_session, stanza)
-						assert.are.equal(session, _session);
-						assert.are.equal(_session.notopen, nil);
-						table.insert(stanzas, stanza);
-					end;
-					streamclosed = function (_session)
-						assert.are.equal(session, _session);
-						assert.are.equal(_session.notopen, nil);
-						_session.notopen = nil;
-					end;
-				}
-				if type(ex) == "table" then
-					for k, v in pairs(ex) do
-						if k ~= "_size_limit" then
-							callbacks[k] = v;
-						end
-					end
-				end
-				local stream = xmppstream.new(session, callbacks, size_limit);
-				local ok, err = pcall(function ()
-					assert(stream:feed(xml));
-				end);
-
-				if ok and type(expect_success) == "function" then
-					expect_success(stanzas);
-				end
-				assert.are.equal(not not ok, not not expect_success, "Expected "..(expect_success and ("success ("..tostring(err)..")") or "failure"));
-			end
-
-			local function test_stanza(stanza, expect_success, ex)
-				return test([[<stream:stream xmlns:stream="streamns" xmlns="stanzans">]]..stanza, expect_success, ex);
-			end
-
 			test([[<stream:stream xmlns:stream="streamns"/>]], true);
 			test([[<stream xmlns="streamns"/>]], true);
 
+			-- Incorrect stream tag name should be rejected
 			test([[<stream1 xmlns="streamns"/>]], false);
+			-- Incorrect stream namespace should be rejected
 			test([[<stream xmlns="streamns1"/>]], false);
+			-- Invalid XML should be rejected
 			test("<>", false);
 
 			test_stanza("<message/>", function (stanzas)
@@ -87,4 +90,47 @@ describe("util.xmppstream", function()
 			end);
 		end);
 	end);
+
+	it("should allow an XML declaration", function ()
+		test([[<?xml version="1.0" encoding="UTF-8"?><stream xmlns="streamns"/>]], true);
+		test([[<?xml version="1.0" encoding="UTF-8" standalone="yes" ?><stream xmlns="streamns"/>]], true);
+		test([[<?xml version="1.0" encoding="utf-8" ?><stream xmlns="streamns"/>]], true);
+	end);
+
+	it("should not accept XML versions other than 1.0", function ()
+		test([[<?xml version="1.1" encoding="utf-8" ?><stream xmlns="streamns"/>]], false);
+	end);
+
+	it("should not allow a misplaced XML declaration", function ()
+		test([[<stream xmlns="streamns"><?xml version="1.0" encoding="UTF-8"?></stream>]], false);
+	end);
+
+	describe("should forbid restricted XML:", function ()
+		it("comments", function ()
+			test_stanza("<!-- hello world -->", false);
+		end);
+		it("DOCTYPE", function ()
+			test([[<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE stream SYSTEM "mydtd.dtd">]], false);
+		end);
+		it("incorrect encoding specification", function ()
+			-- This is actually caught by the underlying XML parser
+			test([[<?xml version="1.0" encoding="UTF-16"?><stream xmlns="streamns"/>]], false);
+		end);
+		it("non-UTF8 encodings: ISO-8859-1", function ()
+			test([[<?xml version="1.0" encoding="ISO-8859-1"?><stream xmlns="streamns"/>]], false);
+		end);
+		it("non-UTF8 encodings: UTF-16", function ()
+			-- <?xml version="1.0" encoding="UTF-16"?><stream xmlns="streamns"/>
+			-- encoded into UTF-16
+			local hx = ([[fffe3c003f0078006d006c002000760065007200730069006f006e003d00
+			220031002e0030002200200065006e0063006f00640069006e0067003d00
+			22005500540046002d003100360022003f003e003c007300740072006500
+			61006d00200078006d006c006e0073003d00220073007400720065006100
+			6d006e00730022002f003e00]]):gsub("%x%x", function (c) return string.char(tonumber(c, 16)); end);
+			test(hx, false);
+		end);
+		it("processing instructions", function ()
+			test([[<stream xmlns="streamns"><?xml-stylesheet type="text/xsl" href="style.xsl"?></stream>]], false);
+		end);
+	end);
 end);