test: fix flaky test-webcrypto-encrypt-decrypt-aes

* Use a copy of plaintext to prevent tampering of the original * Since subtle.decrypt returns a Promise containing an ArrayBuffer and ArrayBuffers cannot be modified directly, create a Buffer from it right away so that the modification in the next line works as intended Fixes: #35586 PR-URL: #37380 Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Myles Borins <[email protected]>
nodejs · Feb 28, 2021 · df538eb · df538eb
1 parent 429dffd
commit df538eb
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Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/test/parallel/parallel.status b/test/parallel/parallel.status
@@ -25,8 +25,6 @@ test-worker-memory: PASS,FLAKY
 test-worker-message-port-transfer-terminate: PASS,FLAKY
 
 [$system==linux]
-# https://github.com/nodejs/node/issues/35586
-test-webcrypto-encrypt-decrypt-aes: PASS,FLAKY
 
 [$system==macos]
 

diff --git a/test/parallel/test-webcrypto-encrypt-decrypt-aes.js b/test/parallel/test-webcrypto-encrypt-decrypt-aes.js
@@ -9,6 +9,9 @@ const assert = require('assert');
 const { getRandomValues, subtle } = require('crypto').webcrypto;
 
 async function testEncrypt({ keyBuffer, algorithm, plaintext, result }) {
+  // Using a copy of plaintext to prevent tampering of the original
+  plaintext = Buffer.from(plaintext);
+
   const key = await subtle.importKey(
     'raw',
     keyBuffer,
@@ -23,8 +26,10 @@ async function testEncrypt({ keyBuffer, algorithm, plaintext, result }) {
     Buffer.from(output).toString('hex'),
     Buffer.from(result).toString('hex'));
 
-  const check = await subtle.decrypt(algorithm, key, output);
-  output[0] = 255 - output[0];
+  // Converting the returned ArrayBuffer into a Buffer right away,
+  // so that the next line works
+  const check = Buffer.from(await subtle.decrypt(algorithm, key, output));
+  check[0] = 255 - check[0];
 
   assert.strictEqual(
     Buffer.from(check).toString('hex'),