fix: improve getRawBody parsing & handle error(s)

.changeset/odd-ligers-swim.md

@@ -0,0 +1,7 @@
+---
+'@sveltejs/adapter-node': patch
+'@sveltejs/adapter-vercel': patch
+'@sveltejs/kit': patch
+---
+
+ensure `content-length` limit respected; handle `getRawBody` error(s)

packages/adapter-node/src/server.js

@@ -40,12 +40,22 @@ export function createServer({ render }) {
 		prerendered_handler,
 		async (req, res) => {
 			const parsed = new URL(req.url || '', 'http://localhost');
+
+			let body;
+
+			try {
+				body = await getRawBody(req);
+			} catch (err) {
+				res.statusCode = err.status || 400;
+				return res.end(err.reason || 'Invalid request body');
+			}
+
 			const rendered = await render({
 				method: req.method,
 				headers: req.headers, // TODO: what about repeated headers, i.e. string[]
 				path: parsed.pathname,
-				rawBody: await getRawBody(req),
-				query: parsed.searchParams
+				query: parsed.searchParams,
+				rawBody: body
 			});
 
 			if (rendered) {

packages/adapter-vercel/files/entry.js

@@ -7,12 +7,21 @@ import { render } from '../output/server/app.js'; // eslint-disable-line import/
 export default async (req, res) => {
 	const { pathname, searchParams } = new URL(req.url || '', 'http://localhost');
 
+	let body;
+
+	try {
+		body = await getRawBody(req);
+	} catch (err) {
+		res.statusCode = err.status || 400;
+		return res.end(err.reason || 'Invalid request body');
+	}
+
 	const rendered = await render({
 		method: req.method,
 		headers: req.headers,
 		path: pathname,
 		query: searchParams,
-		rawBody: await getRawBody(req)
+		rawBody: body
 	});
 
 	if (rendered) {

packages/kit/src/core/dev/index.js

@@ -153,7 +153,14 @@ class Watcher extends EventEmitter {
 					const root = (await this.vite.ssrLoadModule(`/${this.dir}/generated/root.svelte`))
 						.default;
 
-					const rawBody = await getRawBody(req);
+					let body;
+
+					try {
+						body = await getRawBody(req);
+					} catch (err) {
+						res.statusCode = err.status || 400;
+						return res.end(err.reason || 'Invalid request body');
+					}
 
 					const host = /** @type {string} */ (this.config.kit.host ||
 						req.headers[this.config.kit.hostHeader || 'host']);
@@ -165,7 +172,7 @@ class Watcher extends EventEmitter {
 							host,
 							path: parsed.pathname,
 							query: new URLSearchParams(parsed.query),
-							rawBody
+							rawBody: body
 						},
 						{
 							amp: this.config.kit.amp,

packages/kit/src/core/node/index.js

@@ -1,44 +1,45 @@
 /**
  * @param {import('http').IncomingMessage} req
- * @returns {Promise<import('types/hooks').StrictBody>}
+ * @returns {Promise<import('types/hooks').StrictBody | null>}
  */
 export function getRawBody(req) {
 	return new Promise((fulfil, reject) => {
 		const h = req.headers;
 
 		if (!h['content-type']) {
-			fulfil(null);
-			return;
+			return fulfil(null);
 		}
 
 		req.on('error', reject);
 
 		const length = Number(h['content-length']);
 
-		/** @type {Uint8Array} */
-		let data;
-
-		if (!isNaN(length)) {
-			data = new Uint8Array(length);
+		// https://github.com/jshttp/type-is/blob/c1f4388c71c8a01f79934e68f630ca4a15fffcd6/index.js#L81-L95
+		if (isNaN(length) && h['transfer-encoding'] == null) {
+			return fulfil(null);
+		}
 
-			let i = 0;
+		let data = new Uint8Array(length || 0);
 
+		if (length > 0) {
+			let offset = 0;
 			req.on('data', (chunk) => {
-				data.set(chunk, i);
-				i += chunk.length;
-			});
-		} else {
-			// https://github.com/jshttp/type-is/blob/c1f4388c71c8a01f79934e68f630ca4a15fffcd6/index.js#L81-L95
-			if (h['transfer-encoding'] === undefined) {
-				fulfil(null);
-				return;
-			}
+				const new_len = offset + Buffer.byteLength(chunk);
 
-			data = new Uint8Array(0);
+				if (new_len > length) {
+					return reject({
+						status: 413,
+						reason: 'Exceeded "Content-Length" limit'
+					});
+				}
 
+				data.set(chunk, offset);
+				offset = new_len;
+			});
+		} else {
 			req.on('data', (chunk) => {
 				const new_data = new Uint8Array(data.length + chunk.length);
-				new_data.set(data);
+				new_data.set(data, 0);
 				new_data.set(chunk, data.length);
 				data = new_data;
 			});
@@ -48,11 +49,11 @@ export function getRawBody(req) {
 			const [type] = h['content-type'].split(/;\s*/);
 
 			if (type === 'application/octet-stream') {
-				fulfil(data);
+				return fulfil(data);
 			}
 
-			const decoder = new TextDecoder(h['content-encoding'] || 'utf-8');
-			fulfil(decoder.decode(data));
+			const encoding = h['content-encoding'] || 'utf-8';
+			fulfil(new TextDecoder(encoding).decode(data));
 		});
 	});
 }

packages/kit/src/core/start/index.js

@@ -53,14 +53,23 @@ export async function start({ port, host, config, https: use_https = false, cwd
 
 		assets_handler(req, res, () => {
 			static_handler(req, res, async () => {
+				let body;
+
+				try {
+					body = await getRawBody(req);
+				} catch (err) {
+					res.statusCode = err.status || 400;
+					return res.end(err.reason || 'Invalid request body');
+				}
+
 				const rendered = await app.render({
 					host: /** @type {string} */ (config.kit.host ||
 						req.headers[config.kit.hostHeader || 'host']),
 					method: req.method,
 					headers: /** @type {import('types/helper').Headers} */ (req.headers),
 					path: decodeURIComponent(parsed.pathname),
-					rawBody: await getRawBody(req),
-					query: new URLSearchParams(parsed.query || '')
+					query: new URLSearchParams(parsed.query || ''),
+					rawBody: body
 				});
 
 				if (rendered) {

packages/kit/types/hooks.d.ts

@@ -5,14 +5,14 @@ export type StrictBody = string | Uint8Array;
 export type Incoming = Omit<Location, 'params'> & {
 	method: string;
 	headers: Headers;
-	rawBody: StrictBody;
+	rawBody: StrictBody | null;
 	body?: ParameterizedBody;
 };
 
 export type ServerRequest<Locals = Record<string, any>, Body = unknown> = Location & {
 	method: string;
 	headers: Headers;
-	rawBody: StrictBody;
+	rawBody: StrictBody | null;
 	body: ParameterizedBody<Body>;
 	locals: Locals;
 };