zlib: fix brotli flush range

Fixes: #38407

PR-URL: #38408
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

lib/zlib.js

@@ -86,7 +86,7 @@ const {
   BROTLI_DECODE, BROTLI_ENCODE,
   // Brotli operations (~flush levels)
   BROTLI_OPERATION_PROCESS, BROTLI_OPERATION_FLUSH,
-  BROTLI_OPERATION_FINISH
+  BROTLI_OPERATION_FINISH, BROTLI_OPERATION_EMIT_METADATA,
 } = constants;
 
 // Translation table for return codes.
@@ -236,6 +236,13 @@ const checkRangesOrGetDefault = hideStackFrames(
   }
 );
 
+const FLUSH_BOUND = [
+  [ Z_NO_FLUSH, Z_BLOCK ],
+  [ BROTLI_OPERATION_PROCESS, BROTLI_OPERATION_EMIT_METADATA ],
+];
+const FLUSH_BOUND_IDX_NORMAL = 0;
+const FLUSH_BOUND_IDX_BROTLI = 1;
+
 // The base class for all Zlib-style streams.
 function ZlibBase(opts, mode, handle, { flush, finishFlush, fullFlush }) {
   let chunkSize = Z_DEFAULT_CHUNK;
@@ -245,6 +252,13 @@ function ZlibBase(opts, mode, handle, { flush, finishFlush, fullFlush }) {
   assert(typeof mode === 'number');
   assert(mode >= DEFLATE && mode <= BROTLI_ENCODE);
 
+  let flushBoundIdx;
+  if (mode !== BROTLI_ENCODE && mode !== BROTLI_DECODE) {
+    flushBoundIdx = FLUSH_BOUND_IDX_NORMAL;
+  } else {
+    flushBoundIdx = FLUSH_BOUND_IDX_BROTLI;
+  }
+
   if (opts) {
     chunkSize = opts.chunkSize;
     if (!checkFiniteNumber(chunkSize, 'options.chunkSize')) {
@@ -256,11 +270,12 @@ function ZlibBase(opts, mode, handle, { flush, finishFlush, fullFlush }) {
 
     flush = checkRangesOrGetDefault(
       opts.flush, 'options.flush',
-      Z_NO_FLUSH, Z_BLOCK, flush);
+      FLUSH_BOUND[flushBoundIdx][0], FLUSH_BOUND[flushBoundIdx][1], flush);
 
     finishFlush = checkRangesOrGetDefault(
       opts.finishFlush, 'options.finishFlush',
-      Z_NO_FLUSH, Z_BLOCK, finishFlush);
+      FLUSH_BOUND[flushBoundIdx][0], FLUSH_BOUND[flushBoundIdx][1],
+      finishFlush);
 
     maxOutputLength = checkRangesOrGetDefault(
       opts.maxOutputLength, 'options.maxOutputLength',

test/parallel/test-zlib-brotli.js

@@ -71,3 +71,24 @@ const sampleBuffer = fixtures.readSync('/pss-vectors.json');
     message: 'Initialization failed'
   });
 }
+
+{
+  // Test options.flush range
+  assert.throws(() => {
+    zlib.brotliCompressSync('', { flush: zlib.constants.Z_FINISH });
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "options.flush" is out of range. It must be >= 0 ' +
+      'and <= 3. Received 4',
+  });
+
+  assert.throws(() => {
+    zlib.brotliCompressSync('', { finishFlush: zlib.constants.Z_FINISH });
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "options.finishFlush" is out of range. It must be ' +
+      '>= 0 and <= 3. Received 4',
+  });
+}