From fab9180ee571378cd271e971502e5e2ae7af46d5 Mon Sep 17 00:00:00 2001
From: Filip Skokan <panva.ip@gmail.com>
Date: Tue, 22 Sep 2026 22:13:37 +0200
Subject: [PATCH] crypto: isolate cipher job errors

Use only errors captured by the cipher job when converting its result.
Unrelated errors on the event loop thread must not turn a successful
operation into a failure or trigger an assertion.

Signed-off-by: Filip Skokan <panva.ip@gmail.com>
Assisted-by: Codex
PR-URL: https://github.com/nodejs/node/pull/66237
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Aviv Keller <me@aviv.sh>
---
 src/crypto/crypto_cipher.h                    |  7 +--
 .../test-webcrypto-cipher-unrelated-errors.js | 45 +++++++++++++++++++
 2 files changed, 47 insertions(+), 5 deletions(-)
 create mode 100644 test/parallel/test-webcrypto-cipher-unrelated-errors.js

diff --git a/src/crypto/crypto_cipher.h b/src/crypto/crypto_cipher.h
index f6deb774ea3..8817171a2be 100644
--- a/src/crypto/crypto_cipher.h
+++ b/src/crypto/crypto_cipher.h
@@ -219,6 +219,7 @@ class CipherJob final : public CryptoJob<CipherTraits> {
   WebCryptoCipherMode cipher_mode() const { return cipher_mode_; }
 
   void DoThreadPoolWork() override {
+    ncrypto::ClearErrorOnReturn clear_error_on_return;
     const WebCryptoCipherStatus status =
         CipherTraits::DoCipher(
             AsyncWrap::env(),
@@ -253,11 +254,7 @@ class CipherJob final : public CryptoJob<CipherTraits> {
     Environment* env = AsyncWrap::env();
     CryptoErrorStore* errors = CryptoJob<CipherTraits>::errors();
 
-    if (errors->Empty())
-      errors->Capture();
-
-    if (out_.size() > 0 || errors->Empty()) {
-      CHECK(errors->Empty());
+    if (errors->Empty()) {
       *err = v8::Undefined(env->isolate());
       *result = out_.ToArrayBuffer(env);
       if (result->IsEmpty()) {
diff --git a/test/parallel/test-webcrypto-cipher-unrelated-errors.js b/test/parallel/test-webcrypto-cipher-unrelated-errors.js
new file mode 100644
index 00000000000..258733b0440
--- /dev/null
+++ b/test/parallel/test-webcrypto-cipher-unrelated-errors.js
@@ -0,0 +1,45 @@
+'use strict';
+
+const common = require('../common');
+
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+const assert = require('assert');
+const { scrypt, scryptSync } = require('crypto');
+const { subtle } = globalThis.crypto;
+
+if (typeof scryptSync !== 'function')
+  common.skip('no scrypt support');
+
+function failScrypt(sync) {
+  // The failed parameter check leaves an error on the main thread's
+  // OpenSSL error queue. Cipher jobs must only use their own errors.
+  assert.throws(() => {
+    if (sync) {
+      scryptSync('password', 'salt', 64, { N: 2 ** 17 });
+    } else {
+      scrypt('password', 'salt', 64, { N: 2 ** 17 }, common.mustNotCall());
+    }
+  }, { code: 'ERR_CRYPTO_INVALID_SCRYPT_PARAMS' });
+}
+
+(async () => {
+  const key = await subtle.importKey(
+    'raw', new Uint8Array(16), 'AES-GCM', false, ['encrypt', 'decrypt']);
+  const algorithm = { name: 'AES-GCM', iv: new Uint8Array(12) };
+
+  for (const sync of [true, false]) {
+    for (const byteLength of [0, 16]) {
+      const plaintext = new Uint8Array(byteLength);
+      failScrypt(sync);
+      const ciphertext = await subtle.encrypt(algorithm, key, plaintext);
+      assert.strictEqual(ciphertext.byteLength, byteLength + 16);
+
+      failScrypt(sync);
+      assert.deepStrictEqual(
+        new Uint8Array(await subtle.decrypt(algorithm, key, ciphertext)),
+        plaintext);
+    }
+  }
+})().then(common.mustCall());