fix(retry): reject partial content length mismatch

Signed-off-by: Matteo Collina <hello@matteocollina.com>

Author: mcollina

lib/handler/retry-handler.js

@@ -15,6 +15,26 @@ function calculateRetryAfterHeader (retryAfter) {
   return isNaN(retryTime) ? 0 : retryTime - Date.now()
 }
 
+function validatePartialResponseContentLength (headers, range, statusCode, retryCount) {
+  const contentLength = headers['content-length']
+  if (contentLength == null) {
+    return
+  }
+
+  if (!Number.isFinite(range.start) || !Number.isFinite(range.end)) {
+    return
+  }
+
+  const length = Number(contentLength)
+  const expectedLength = range.end - range.start + 1
+  if (!Number.isFinite(length) || length !== expectedLength) {
+    throw new RequestRetryError('Content-Length mismatch', statusCode, {
+      headers,
+      data: { count: retryCount }
+    })
+  }
+}
+
 class RetryHandler {
   constructor (opts, { dispatch, handler }) {
     const { retryOptions, ...dispatchOpts } = opts
@@ -229,6 +249,8 @@ class RetryHandler {
         })
       }
 
+      validatePartialResponseContentLength(headers, contentRange, statusCode, this.retryCount)
+
       const { start, size, end = size ? size - 1 : null } = contentRange
 
       assert(this.start === start, 'content-range mismatch')
@@ -253,6 +275,8 @@ class RetryHandler {
           return
         }
 
+        validatePartialResponseContentLength(headers, range, statusCode, this.retryCount)
+
         const { start, size, end = size ? size - 1 : null } = range
         assert(
           start != null && Number.isFinite(start),

test/interceptors/retry.js

@@ -392,6 +392,59 @@ test('Should handle 206 partial content', async t => {
   t.strictEqual(counter, 1)
 })
 
+test('Should reject initial 206 partial content with mismatched content-length', async t => {
+  t = tspl(t, { plan: 3 })
+
+  let x = 0
+  const server = createServer({ joinDuplicateHeaders: true }, (req, res) => {
+    if (x === 0) {
+      t.strictEqual(req.headers.range, 'bytes=0-99')
+      res.statusCode = 206
+      res.setHeader('content-range', 'bytes 0-99/300')
+      res.setHeader('content-length', '300')
+      res.end('1'.repeat(99))
+      res.socket?.destroy()
+    } else if (x === 1) {
+      res.statusCode = 206
+      res.setHeader('content-range', 'bytes 99-99/300')
+      res.setHeader('content-length', '1')
+      res.end('1')
+    }
+    x++
+  })
+
+  server.listen(0)
+
+  await once(server, 'listening')
+
+  const client = new Client(
+    `http://localhost:${server.address().port}`
+  ).compose(retry())
+
+  after(async () => {
+    await client.close()
+    server.close()
+
+    await once(server, 'close')
+  })
+
+  await t.rejects(async () => {
+    const response = await client.request({
+      method: 'GET',
+      path: '/',
+      headers: {
+        range: 'bytes=0-99'
+      }
+    })
+    await response.body.text()
+  }, {
+    name: 'RequestRetryError',
+    code: 'UND_ERR_REQ_RETRY',
+    message: 'Content-Length mismatch'
+  })
+  t.strictEqual(x, 1)
+})
+
 test('Should handle 206 partial content - bad-etag', async t => {
   t = tspl(t, { plan: 5 })
 
@@ -407,7 +460,7 @@ test('Should handle 206 partial content - bad-etag', async t => {
       }, 1e2)
     } else if (x === 1) {
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'erwsd')
       res.statusCode = 206
       res.end('def')

test/retry-handler2.js

@@ -671,7 +671,7 @@ test('Should handle 206 partial content | throwOnError: false', async t => {
       }, 1e2)
     } else if (x === 1) {
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'asd')
       res.statusCode = 206
       res.end('def')
@@ -768,7 +768,7 @@ test('Should handle 206 partial content - bad-etag | throwOnError: false', async
       }, 1e2)
     } else if (x === 1) {
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'erwsd')
       res.statusCode = 206
       res.end('def')
@@ -1223,7 +1223,7 @@ test('Issue#2986 - Handle custom 206 | throwOnError: false', async t => {
       }, 1e2)
     } else if (x === 1) {
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'asd')
       res.statusCode = 206
       res.end('def')
@@ -1324,7 +1324,7 @@ test('Issue#3128 - Support if-match | throwOnError: false', async t => {
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
       t.deepStrictEqual(req.headers['if-match'], 'asd')
 
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'asd')
       res.statusCode = 206
       res.end('def')
@@ -1425,7 +1425,7 @@ test('Issue#3128 - Should ignore weak etags | throwOnError: false', async t => {
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
       t.equal(req.headers['if-match'], undefined)
 
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'W/asd')
       res.statusCode = 206
       res.end('def')
@@ -1526,7 +1526,7 @@ test('Weak etags are ignored on range-requests | throwOnError: false', async t =
       t.deepStrictEqual(req.headers.range, 'bytes=3-')
       t.equal(req.headers['if-match'], undefined)
 
-      res.setHeader('content-range', 'bytes 3-6/6')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'W/efg')
       res.statusCode = 206
       res.end('def')