chore: MESSAGE_MAX_PARSE_LENGTH environment variable

apps/meteor/app/ui-master/server/index.ts

@@ -6,6 +6,7 @@ import { Inject } from 'meteor/meteorhacks:inject-initial';
 import { Tracker } from 'meteor/tracker';
 
 import { applyHeadInjections, headInjections, injectIntoBody, injectIntoHead } from './inject';
+import { getMessageMaxParseLength } from '../../../lib/getMessageMaxParseLength';
 import { withDebouncing } from '../../../lib/utils/highOrderFunctions';
 import { settings } from '../../settings/server';
 import { getURL } from '../../utils/server/getURL';
@@ -126,6 +127,9 @@ Meteor.startup(() => {
 	})(__meteor_runtime_config__.ROOT_URL_PATH_PREFIX);
 
 	injectIntoHead('base', `<base href="${baseUrl}">`);
+
+	const escapedMessageMaxParseLength = escapeHTML(String(getMessageMaxParseLength()));
+	injectIntoHead('MESSAGE_MAX_PARSE_LENGTH', `<meta name="rc-message-parser-max-length" content="${escapedMessageMaxParseLength}" />`);
 });
 
 const renderDynamicCssList = withDebouncing({ wait: 500 })(async () => {

apps/meteor/lib/constants.ts

@@ -2,3 +2,4 @@ export const NOTIFICATION_ATTACHMENT_COLOR = '#FD745E';
 export const MAX_MULTIPLE_UPLOADED_FILES = 10;
 export const MAX_CUSTOM_SOUND_SIZE_BYTES = 5242880;
 export const CUSTOM_SOUND_ALLOWED_MIME_TYPES = ['audio/mpeg', 'audio/mp3', 'audio/wav', 'audio/x-wav'];
+export const MESSAGE_MAX_PARSE_LENGTH_DEFAULT = 0;

apps/meteor/lib/getMessageMaxParseLength.ts

@@ -0,0 +1,6 @@
+import { MESSAGE_MAX_PARSE_LENGTH_DEFAULT } from './constants';
+
+export function getMessageMaxParseLength(): number {
+	const parsed = Number.parseInt(process.env.MESSAGE_MAX_PARSE_LENGTH ?? '', 10);
+	return Number.isFinite(parsed) ? parsed : MESSAGE_MAX_PARSE_LENGTH_DEFAULT;
+}

apps/meteor/server/services/messages/hooks/BeforeSaveMarkdownParser.ts

@@ -2,6 +2,8 @@ import { isE2EEMessage } from '@rocket.chat/core-typings';
 import type { IMessage } from '@rocket.chat/core-typings';
 import { parse } from '@rocket.chat/message-parser';
 
+import { getMessageMaxParseLength } from '../../../../lib/getMessageMaxParseLength';
+
 type ParserConfig = {
 	colors?: boolean;
 	emoticons?: boolean;
@@ -26,6 +28,12 @@ export class BeforeSaveMarkdownParser {
 			return message;
 		}
 
+		const messageMaxParseLength = getMessageMaxParseLength();
+		if (messageMaxParseLength > 0 && message.msg && message.msg.length > messageMaxParseLength) {
+			delete message.md;
+			return message;
+		}
+
 		try {
 			if (message.msg) {
 				message.md = parse(message.msg, config);

apps/meteor/tests/unit/lib/getMessageMaxParseLength.spec.ts

@@ -0,0 +1,39 @@
+import { expect } from 'chai';
+
+import { getMessageMaxParseLength } from '../../../lib/getMessageMaxParseLength';
+
+describe('getMessageMaxParseLength', () => {
+	afterEach(() => {
+		delete process.env.MESSAGE_MAX_PARSE_LENGTH;
+	});
+
+	it('should return 0 (default) when env var is not set', () => {
+		delete process.env.MESSAGE_MAX_PARSE_LENGTH;
+		expect(getMessageMaxParseLength()).to.equal(0);
+	});
+
+	it('should return 0 (default) when env var is empty string', () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = '';
+		expect(getMessageMaxParseLength()).to.equal(0);
+	});
+
+	it('should return 0 (default) when env var is not a number', () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = 'abc';
+		expect(getMessageMaxParseLength()).to.equal(0);
+	});
+
+	it('should return the parsed number when env var is a valid integer', () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = '5000';
+		expect(getMessageMaxParseLength()).to.equal(5000);
+	});
+
+	it('should return 0 when env var is "0"', () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = '0';
+		expect(getMessageMaxParseLength()).to.equal(0);
+	});
+
+	it('should return 0 (default) when env var is Infinity', () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = 'Infinity';
+		expect(getMessageMaxParseLength()).to.equal(0);
+	});
+});

apps/meteor/tests/unit/server/services/messages/hooks/BeforeSaveMarkdownParser.tests.ts

@@ -1,4 +1,5 @@
 import { expect } from 'chai';
+import { beforeEach } from 'mocha';
 
 import { BeforeSaveMarkdownParser } from '../../../../../../server/services/messages/hooks/BeforeSaveMarkdownParser';
 
@@ -16,6 +17,14 @@ const createMessage = (msg?: string, extra: any = {}) => ({
 });
 
 describe('Markdown parser', () => {
+	beforeEach(() => {
+		delete process.env.MESSAGE_MAX_PARSE_LENGTH;
+	});
+
+	afterEach(() => {
+		delete process.env.MESSAGE_MAX_PARSE_LENGTH;
+	});
+
 	it('should do nothing if markdown parser is disabled', async () => {
 		const markdownParser = new BeforeSaveMarkdownParser(false);
 
@@ -38,11 +47,36 @@ describe('Markdown parser', () => {
 		expect(message).to.not.have.property('md');
 	});
 
-	it('should parse markdown', async () => {
+	it('should skip parsing when msg exceeds MESSAGE_MAX_PARSE_LENGTH', async () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = '10';
 		const markdownParser = new BeforeSaveMarkdownParser(true);
 
 		const message = await markdownParser.parseMarkdown({
-			message: createMessage('hey'),
+			message: createMessage('a'.repeat(11)),
+			config: {},
+		});
+
+		expect(message).to.not.have.property('md');
+	});
+
+	it('should parse normally when msg is within MESSAGE_MAX_PARSE_LENGTH', async () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = '100';
+		const markdownParser = new BeforeSaveMarkdownParser(true);
+
+		const message = await markdownParser.parseMarkdown({
+			message: createMessage('short msg'),
+			config: {},
+		});
+
+		expect(message).to.have.property('md');
+	});
+
+	it('should parse normally when MESSAGE_MAX_PARSE_LENGTH is 0', async () => {
+		process.env.MESSAGE_MAX_PARSE_LENGTH = '0';
+		const markdownParser = new BeforeSaveMarkdownParser(true);
+
+		const message = await markdownParser.parseMarkdown({
+			message: createMessage('short msg'),
 			config: {},
 		});