From 631e433cf5f7707612f7f5de4352bd697af47ac1 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Fri, 24 Apr 2020 21:12:32 +0200
Subject: [PATCH] zlib: reject windowBits=8 when mode=GZIP
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It's also handled in C++ land now, per the previous commit, but
intercepting it in JS land makes for prettier error messages.

PR-URL: https://github.com/nodejs/node/pull/33045
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: David Carlier <devnexen@gmail.com>
---
 lib/zlib.js                                | 4 +++-
 test/parallel/test-zlib-failed-init.js     | 2 +-
 test/parallel/test-zlib-zero-windowBits.js | 2 +-
 test/parallel/test-zlib.js                 | 7 ++++---
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lib/zlib.js b/lib/zlib.js
index 19405263c92896..4bb6af0322033f 100644
--- a/lib/zlib.js
+++ b/lib/zlib.js
@@ -614,9 +614,11 @@ function Zlib(opts, mode) {
          mode === UNZIP)) {
       windowBits = 0;
     } else {
+      // `{ windowBits: 8 }` is valid for deflate but not gzip.
+      const min = Z_MIN_WINDOWBITS + (mode === GZIP ? 1 : 0);
       windowBits = checkRangesOrGetDefault(
         opts.windowBits, 'options.windowBits',
-        Z_MIN_WINDOWBITS, Z_MAX_WINDOWBITS, Z_DEFAULT_WINDOWBITS);
+        min, Z_MAX_WINDOWBITS, Z_DEFAULT_WINDOWBITS);
     }
 
     level = checkRangesOrGetDefault(
diff --git a/test/parallel/test-zlib-failed-init.js b/test/parallel/test-zlib-failed-init.js
index 1f99a378fc6eda..95f401a3718f30 100644
--- a/test/parallel/test-zlib-failed-init.js
+++ b/test/parallel/test-zlib-failed-init.js
@@ -21,7 +21,7 @@ assert.throws(
     code: 'ERR_OUT_OF_RANGE',
     name: 'RangeError',
     message: 'The value of "options.windowBits" is out of range. It must ' +
-             'be >= 8 and <= 15. Received 0'
+             'be >= 9 and <= 15. Received 0'
   }
 );
 
diff --git a/test/parallel/test-zlib-zero-windowBits.js b/test/parallel/test-zlib-zero-windowBits.js
index 730690a07c423f..a27fd6734a5425 100644
--- a/test/parallel/test-zlib-zero-windowBits.js
+++ b/test/parallel/test-zlib-zero-windowBits.js
@@ -28,6 +28,6 @@ const zlib = require('zlib');
     code: 'ERR_OUT_OF_RANGE',
     name: 'RangeError',
     message: 'The value of "options.windowBits" is out of range. ' +
-             'It must be >= 8 and <= 15. Received 0'
+             'It must be >= 9 and <= 15. Received 0'
   });
 }
diff --git a/test/parallel/test-zlib.js b/test/parallel/test-zlib.js
index 662bf1abe0ba33..02e66167d11b4f 100644
--- a/test/parallel/test-zlib.js
+++ b/test/parallel/test-zlib.js
@@ -29,9 +29,10 @@ const fixtures = require('../common/fixtures');
 
 // Should not segfault.
 assert.throws(() => zlib.gzipSync(Buffer.alloc(0), { windowBits: 8 }), {
-  code: 'ERR_ZLIB_INITIALIZATION_FAILED',
-  name: 'Error',
-  message: 'Initialization failed',
+  code: 'ERR_OUT_OF_RANGE',
+  name: 'RangeError',
+  message: 'The value of "options.windowBits" is out of range. ' +
+           'It must be >= 9 and <= 15. Received 8',
 });
 
 let zlibPairs = [