crypto: read algorithm name property only once in normalizeAlgorithm

Author: panva

lib/internal/crypto/util.js

@@ -565,10 +565,13 @@ function normalizeAlgorithm(algorithm, op) {
     return { name: algName };
 
   // 6.
-  const normalizedAlgorithm = webidl.converters[desiredType](algorithm, {
-    prefix: 'Failed to normalize algorithm',
-    context: 'passed algorithm',
-  });
+  const normalizedAlgorithm = webidl.converters[desiredType](
+    { __proto__: algorithm, name: algName },
+    {
+      prefix: 'Failed to normalize algorithm',
+      context: 'passed algorithm',
+    },
+  );
   // 7.
   normalizedAlgorithm.name = algName;
 

test/parallel/test-webcrypto-util.js

@@ -17,3 +17,35 @@ const {
   assert.strictEqual(normalizeAlgorithm(algorithm, 'sign') !== algorithm, true);
   assert.deepStrictEqual(algorithm, { name: 'ECDSA', hash: 'SHA-256' });
 }
+
+// The algorithm name getter should only be invoked once during
+// normalizeAlgorithm, including for algorithms with a non-null desiredType
+// where step 6 runs the specialized dictionary converter.
+// Refs: https://github.com/web-platform-tests/wpt/pull/57614#pullrequestreview-3808145365
+{
+  let nameReadCount = 0;
+  const algorithm = {
+    get name() {
+      nameReadCount++;
+      return 'AES-GCM';
+    },
+    iv: new Uint8Array(12),
+  };
+  const normalized = normalizeAlgorithm(algorithm, 'encrypt');
+  assert.strictEqual(normalized.name, 'AES-GCM');
+  assert.strictEqual(nameReadCount, 1);
+}
+
+{
+  let nameReadCount = 0;
+  const algorithm = {
+    get name() {
+      nameReadCount++;
+      return 'ECDSA';
+    },
+    hash: 'SHA-256',
+  };
+  const normalized = normalizeAlgorithm(algorithm, 'sign');
+  assert.strictEqual(normalized.name, 'ECDSA');
+  assert.strictEqual(nameReadCount, 1);
+}