From 63a138e02f3581b457c483e4f2f0651065f3037c Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Wed, 11 Nov 2020 18:55:03 +0100
Subject: [PATCH] crypto: fix passing TypedArray to webcrypto AES methods
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Refs: https://www.w3.org/TR/WebCryptoAPI/#subtlecrypto-interface
Fixes: https://github.com/nodejs/node/issues/36083

PR-URL: https://github.com/nodejs/node/pull/36087
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
---
 lib/internal/crypto/aes.js                    |  8 +++-
 .../test-webcrypto-encrypt-decrypt-aes.js     | 40 ++++++++++++++++++-
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/lib/internal/crypto/aes.js b/lib/internal/crypto/aes.js
index f0814c725469e6..ab3ee099cd0d69 100644
--- a/lib/internal/crypto/aes.js
+++ b/lib/internal/crypto/aes.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const {
+  ArrayBufferIsView,
   ArrayBufferPrototypeSlice,
   ArrayFrom,
   ArrayPrototypeIncludes,
@@ -8,6 +9,7 @@ const {
   MathFloor,
   Promise,
   SafeSet,
+  TypedArrayPrototypeSlice,
 } = primordials;
 
 const {
@@ -183,8 +185,10 @@ function asyncAesGcmCipher(
   let tag;
   switch (mode) {
     case kWebCryptoCipherDecrypt:
-      tag = ArrayBufferPrototypeSlice(data, -tagByteLength);
-      data = ArrayBufferPrototypeSlice(data, 0, -tagByteLength);
+      const slice = ArrayBufferIsView(data) ?
+        TypedArrayPrototypeSlice : ArrayBufferPrototypeSlice;
+      tag = slice(data, -tagByteLength);
+      data = slice(data, 0, -tagByteLength);
       break;
     case kWebCryptoCipherEncrypt:
       tag = tagByteLength;
diff --git a/test/parallel/test-webcrypto-encrypt-decrypt-aes.js b/test/parallel/test-webcrypto-encrypt-decrypt-aes.js
index ec1635c991ce13..38d2b70bcb0567 100644
--- a/test/parallel/test-webcrypto-encrypt-decrypt-aes.js
+++ b/test/parallel/test-webcrypto-encrypt-decrypt-aes.js
@@ -6,7 +6,7 @@ if (!common.hasCrypto)
   common.skip('missing crypto');
 
 const assert = require('assert');
-const { subtle } = require('crypto').webcrypto;
+const { getRandomValues, subtle } = require('crypto').webcrypto;
 
 async function testEncrypt({ keyBuffer, algorithm, plaintext, result }) {
   const key = await subtle.importKey(
@@ -196,3 +196,41 @@ async function testDecrypt({ keyBuffer, algorithm, result }) {
     await Promise.all(variations);
   })().then(common.mustCall());
 }
+
+{
+  (async function() {
+    const secretKey = await subtle.generateKey(
+      {
+        name: 'AES-GCM',
+        length: 256,
+      },
+      false,
+      ['encrypt', 'decrypt'],
+    );
+
+    const iv = getRandomValues(new Uint8Array(12));
+    const aad = getRandomValues(new Uint8Array(32));
+
+    const encrypted = await subtle.encrypt(
+      {
+        name: 'AES-GCM',
+        iv,
+        additionalData: aad,
+        tagLength: 128
+      },
+      secretKey,
+      getRandomValues(new Uint8Array(32))
+    );
+
+    await subtle.decrypt(
+      {
+        name: 'AES-GCM',
+        iv,
+        additionalData: aad,
+        tagLength: 128,
+      },
+      secretKey,
+      new Uint8Array(encrypted),
+    );
+  })().then(common.mustCall());
+}