crypto: expose KeyObject.isKeyObject(obj) and CryptoKey.isCryptoKey(obj)

closes #38611

Author: panva

doc/api/crypto.md

@@ -1852,6 +1852,16 @@ passing keys as strings or `Buffer`s due to improved security features.
 The receiver obtains a cloned `KeyObject`, and the `KeyObject` does not need to
 be listed in the `transferList` argument.
 
+### Static method: `KeyObject.isKeyObject(obj)`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `obj` {Object}
+* Returns: {boolean}
+
+Returns `true` if `obj` is a `KeyObject`, `false` otherwise.
+
 ### Static method: `KeyObject.from(key)`
 <!-- YAML
 added: v15.0.0

doc/api/webcrypto.md

@@ -366,6 +366,18 @@ An error will be thrown if the given `typedArray` is larger than 65,536 bytes.
 added: v15.0.0
 -->
 
+### Static method: `CryptoKey.isCryptoKey(obj)`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `obj` {Object}
+* Returns: {boolean}
+
+Returns `true` if `obj` is a `CryptoKey`, `false` otherwise. This method
+is specific to Node.js, it is not portable to other implementations of
+[Web Crypto API][].
+
 ### `cryptoKey.algorithm`
 <!-- YAML
 added: v15.0.0

lib/internal/crypto/keys.js

@@ -116,6 +116,10 @@ const {
       });
     }
 
+    static isKeyObject(obj) {
+      return isKeyObject(obj);
+    }
+
     get type() {
       return this[kKeyType];
     }
@@ -639,8 +643,8 @@ function createPrivateKey(key) {
   return new PrivateKeyObject(handle);
 }
 
-function isKeyObject(key) {
-  return key instanceof KeyObject;
+function isKeyObject(obj) {
+  return obj != null && obj[kHandle] !== undefined;
 }
 
 // Our implementation of CryptoKey is a simple wrapper around a KeyObject
@@ -656,6 +660,10 @@ class CryptoKey extends JSTransferable {
     throw new ERR_OPERATION_FAILED('Illegal constructor');
   }
 
+  static isCryptoKey(obj) {
+    return isCryptoKey(obj);
+  }
+
   [kInspect](depth, options) {
     if (depth < 0)
       return this;

test/parallel/test-crypto-key-objects.js

@@ -757,3 +757,14 @@ const privateDsa = fixtures.readKey('dsa_private_encrypted_1025.pem',
       message: `Unsupported JWK EC curve: ${namedCurve}.`
     });
 }
+
+{
+  const buffer = Buffer.from('Hello World');
+  const keyObject = createSecretKey(buffer);
+  const keyPair = generateKeyPairSync('ed25519');
+  assert(KeyObject.isKeyObject(keyPair.publicKey));
+  assert(KeyObject.isKeyObject(keyPair.privateKey));
+  assert(KeyObject.isKeyObject(keyObject));
+
+  assert(!KeyObject.isKeyObject(buffer));
+}

test/parallel/test-webcrypto-keygen.js

@@ -220,6 +220,8 @@ const vectors = {
 
     assert(publicKey);
     assert(privateKey);
+    assert(CryptoKey.isCryptoKey(publicKey));
+    assert(CryptoKey.isCryptoKey(privateKey));
 
     assert(publicKey instanceof CryptoKey);
     assert(privateKey instanceof CryptoKey);
@@ -366,6 +368,8 @@ const vectors = {
 
     assert(publicKey);
     assert(privateKey);
+    assert(CryptoKey.isCryptoKey(publicKey));
+    assert(CryptoKey.isCryptoKey(privateKey));
 
     assert.strictEqual(publicKey.type, 'public');
     assert.strictEqual(privateKey.type, 'private');
@@ -430,6 +434,7 @@ const vectors = {
     }, true, usages);
 
     assert(key);
+    assert(CryptoKey.isCryptoKey(key));
 
     assert.strictEqual(key.type, 'secret');
     assert.strictEqual(key.extractable, true);
@@ -488,6 +493,7 @@ const vectors = {
     }
 
     assert(key);
+    assert(CryptoKey.isCryptoKey(key));
 
     assert.strictEqual(key.type, 'secret');
     assert.strictEqual(key.extractable, true);
@@ -544,6 +550,8 @@ const vectors = {
 
     assert(publicKey);
     assert(privateKey);
+    assert(CryptoKey.isCryptoKey(publicKey));
+    assert(CryptoKey.isCryptoKey(privateKey));
 
     assert.strictEqual(publicKey.type, 'public');
     assert.strictEqual(privateKey.type, 'private');
@@ -634,6 +642,8 @@ const vectors = {
     }, true, ['deriveKey']);
   assert(publicKey);
   assert(privateKey);
+  assert(CryptoKey.isCryptoKey(publicKey));
+  assert(CryptoKey.isCryptoKey(privateKey));
   assert.strictEqual(publicKey.type, 'public');
   assert.strictEqual(privateKey.type, 'private');
   assert.strictEqual(publicKey.algorithm.name, 'NODE-DH');
@@ -646,3 +656,8 @@ const vectors = {
 assert.throws(() => new CryptoKey(), {
   code: 'ERR_OPERATION_FAILED'
 });
+
+{
+  const buffer = Buffer.from('Hello World');
+  assert(!CryptoKey.isCryptoKey(buffer));
+}