From 28a7c40e29fe782ca5ea2ec7bb5591e814205355 Mon Sep 17 00:00:00 2001
From: Meghan Denny <meghan@bun.sh>
Date: Wed, 11 Dec 2024 01:07:41 -0800
Subject: [PATCH] fix test-buffer-write.js

---
 .../node/test/parallel/test-buffer-write.js   | 108 ++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 test/js/node/test/parallel/test-buffer-write.js

diff --git a/test/js/node/test/parallel/test-buffer-write.js b/test/js/node/test/parallel/test-buffer-write.js
new file mode 100644
index 0000000000..c834b6ee8f
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-write.js
@@ -0,0 +1,108 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+[-1, 10].forEach((offset) => {
+  assert.throws(
+    () => Buffer.alloc(9).write('foo', offset),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      name: 'RangeError',
+      message: 'The value of "offset" is out of range. ' +
+               `It must be >= 0 and <= 9. Received ${offset}`
+    }
+  );
+});
+
+const resultMap = new Map([
+  ['utf8', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['ucs2', Buffer.from([102, 0, 111, 0, 111, 0, 0, 0, 0])],
+  ['ascii', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['latin1', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['binary', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['utf16le', Buffer.from([102, 0, 111, 0, 111, 0, 0, 0, 0])],
+  ['base64', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['base64url', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['hex', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+]);
+
+// utf8, ucs2, ascii, latin1, utf16le
+const encodings = ['utf8', 'utf-8', 'ucs2', 'ucs-2', 'ascii', 'latin1',
+                   'binary', 'utf16le', 'utf-16le'];
+
+encodings
+  .reduce((es, e) => es.concat(e, e.toUpperCase()), [])
+  .forEach((encoding) => {
+    const buf = Buffer.alloc(9);
+    const len = Buffer.byteLength('foo', encoding);
+    assert.strictEqual(buf.write('foo', 0, len, encoding), len);
+
+    if (encoding.includes('-'))
+      encoding = encoding.replace('-', '');
+
+    assert.deepStrictEqual(buf, resultMap.get(encoding.toLowerCase()));
+  });
+
+// base64
+['base64', 'BASE64', 'base64url', 'BASE64URL'].forEach((encoding) => {
+  const buf = Buffer.alloc(9);
+  const len = Buffer.byteLength('Zm9v', encoding);
+
+  assert.strictEqual(buf.write('Zm9v', 0, len, encoding), len);
+  assert.deepStrictEqual(buf, resultMap.get(encoding.toLowerCase()));
+});
+
+// hex
+['hex', 'HEX'].forEach((encoding) => {
+  const buf = Buffer.alloc(9);
+  const len = Buffer.byteLength('666f6f', encoding);
+
+  assert.strictEqual(buf.write('666f6f', 0, len, encoding), len);
+  assert.deepStrictEqual(buf, resultMap.get(encoding.toLowerCase()));
+});
+
+// Invalid encodings
+for (let i = 1; i < 10; i++) {
+  const encoding = String(i).repeat(i);
+  const error = common.expectsError({
+    code: 'ERR_UNKNOWN_ENCODING',
+    name: 'TypeError',
+    message: `Unknown encoding: ${encoding}`
+  });
+
+  assert.ok(!Buffer.isEncoding(encoding));
+  assert.throws(() => Buffer.alloc(9).write('foo', encoding), error);
+}
+
+// UCS-2 overflow CVE-2018-12115
+for (let i = 1; i < 4; i++) {
+  // Allocate two Buffers sequentially off the pool. Run more than once in case
+  // we hit the end of the pool and don't get sequential allocations
+  const x = Buffer.allocUnsafe(4).fill(0);
+  const y = Buffer.allocUnsafe(4).fill(1);
+  // Should not write anything, pos 3 doesn't have enough room for a 16-bit char
+  assert.strictEqual(x.write('ыыыыыы', 3, 'ucs2'), 0);
+  // CVE-2018-12115 experienced via buffer overrun to next block in the pool
+  assert.strictEqual(Buffer.compare(y, Buffer.alloc(4, 1)), 0);
+}
+
+// Should not write any data when there is no space for 16-bit chars
+const z = Buffer.alloc(4, 0);
+assert.strictEqual(z.write('\u0001', 3, 'ucs2'), 0);
+assert.strictEqual(Buffer.compare(z, Buffer.alloc(4, 0)), 0);
+// Make sure longer strings are written up to the buffer end.
+assert.strictEqual(z.write('abcd', 2), 2);
+assert.deepStrictEqual([...z], [0, 0, 0x61, 0x62]);
+
+// Large overrun could corrupt the process
+assert.strictEqual(Buffer.alloc(4)
+  .write('ыыыыыы'.repeat(100), 3, 'utf16le'), 0);
+
+{
+  // .write() does not affect the byte after the written-to slice of the Buffer.
+  // Refs: https://github.com/nodejs/node/issues/26422
+  const buf = Buffer.alloc(8);
+  assert.strictEqual(buf.write('ыы', 1, 'utf16le'), 4);
+  assert.deepStrictEqual([...buf], [0, 0x4b, 0x04, 0x4b, 0x04, 0, 0, 0]);
+}