crypto: add KeyObject.prototype.equals method

PR-URL: #42093 Reviewed-By: Ben Noordhuis <[email protected]> Reviewed-By: Tobias Nießen <[email protected]>
nodejs · Feb 26, 2022 · aa97c9d · aa97c9d · Astrabacus · Dec 23, 2023
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diff --git a/doc/api/crypto.md b/doc/api/crypto.md
@@ -2082,6 +2082,20 @@ encryption mechanism, PEM-level encryption is not supported when encrypting
 a PKCS#8 key. See [RFC 5208][] for PKCS#8 encryption and [RFC 1421][] for
 PKCS#1 and SEC1 encryption.
 
+### `keyObject.equals(otherKeyObject)`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* `otherKeyObject`: {KeyObject} A `KeyObject` with which to
+  compare `keyObject`.
+* Returns: {boolean}
+
+Returns `true` or `false` depending on whether the keys have exactly the same
+type, value, and parameters. This method is not
+[constant time](https://en.wikipedia.org/wiki/Timing_attack).
+
 ### `keyObject.symmetricKeySize`
 
 <!-- YAML

diff --git a/lib/internal/crypto/keys.js b/lib/internal/crypto/keys.js
@@ -124,6 +124,16 @@ const {
         throw new ERR_INVALID_ARG_TYPE('key', 'CryptoKey', key);
       return key[kKeyObject];
     }
+
+    equals(otherKeyObject) {
+      if (!isKeyObject(otherKeyObject)) {
+        throw new ERR_INVALID_ARG_TYPE(
+          'otherKeyObject', 'KeyObject', otherKeyObject);
+      }
+
+      return otherKeyObject.type === this.type &&
+        this[kHandle].equals(otherKeyObject[kHandle]);
+    }
   }
 
   class SecretKeyObject extends KeyObject {

diff --git a/src/crypto/crypto_keys.cc b/src/crypto/crypto_keys.cc
@@ -921,6 +921,7 @@ v8::Local<v8::Function> KeyObjectHandle::Initialize(Environment* env) {
   env->SetProtoMethod(t, "initEDRaw", InitEDRaw);
   env->SetProtoMethod(t, "initJwk", InitJWK);
   env->SetProtoMethod(t, "keyDetail", GetKeyDetail);
+  env->SetProtoMethod(t, "equals", Equals);
 
   auto function = t->GetFunction(env->context()).ToLocalChecked();
   env->set_crypto_key_object_handle_constructor(function);
@@ -939,6 +940,7 @@ void KeyObjectHandle::RegisterExternalReferences(
   registry->Register(InitEDRaw);
   registry->Register(InitJWK);
   registry->Register(GetKeyDetail);
+  registry->Register(Equals);
 }
 
 MaybeLocal<Object> KeyObjectHandle::Create(
@@ -1134,6 +1136,54 @@ void KeyObjectHandle::InitEDRaw(const FunctionCallbackInfo<Value>& args) {
   args.GetReturnValue().Set(true);
 }
 
+void KeyObjectHandle::Equals(const FunctionCallbackInfo<Value>& args) {
+  KeyObjectHandle* self_handle;
+  KeyObjectHandle* arg_handle;
+  ASSIGN_OR_RETURN_UNWRAP(&self_handle, args.Holder());
+  ASSIGN_OR_RETURN_UNWRAP(&arg_handle, args[0].As<Object>());
+  std::shared_ptr<KeyObjectData> key = self_handle->Data();
+  std::shared_ptr<KeyObjectData> key2 = arg_handle->Data();
+
+  KeyType key_type = key->GetKeyType();
+  CHECK_EQ(key_type, key2->GetKeyType());
+
+  bool ret;
+  switch (key_type) {
+    case kKeyTypeSecret: {
+      size_t size = key->GetSymmetricKeySize();
+      if (size == key2->GetSymmetricKeySize()) {
+        ret = CRYPTO_memcmp(
+          key->GetSymmetricKey(),
+          key2->GetSymmetricKey(),
+          size) == 0;
+      } else {
+        ret = false;
+      }
+      break;
+    }
+    case kKeyTypePublic:
+    case kKeyTypePrivate: {
+      EVP_PKEY* pkey = key->GetAsymmetricKey().get();
+      EVP_PKEY* pkey2 = key2->GetAsymmetricKey().get();
+#if OPENSSL_VERSION_MAJOR >= 3
+      int ok = EVP_PKEY_eq(pkey, pkey2);
+#else
+      int ok = EVP_PKEY_cmp(pkey, pkey2);
+#endif
+      if (ok == -2) {
+        Environment* env = Environment::GetCurrent(args);
+        return THROW_ERR_CRYPTO_UNSUPPORTED_OPERATION(env);
+      }
+      ret = ok == 1;
+      break;
+    }
+    default:
+      UNREACHABLE("unsupported key type");
+  }
+
+  args.GetReturnValue().Set(ret);
+}
+
 void KeyObjectHandle::GetKeyDetail(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   KeyObjectHandle* key;

diff --git a/src/crypto/crypto_keys.h b/src/crypto/crypto_keys.h
@@ -189,6 +189,7 @@ class KeyObjectHandle : public BaseObject {
   static void InitEDRaw(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void InitJWK(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void GetKeyDetail(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void Equals(const v8::FunctionCallbackInfo<v8::Value>& args);
 
   static void ExportJWK(const v8::FunctionCallbackInfo<v8::Value>& args);
 

diff --git a/test/parallel/test-crypto-key-objects.js b/test/parallel/test-crypto-key-objects.js
@@ -21,6 +21,7 @@ const {
   privateDecrypt,
   privateEncrypt,
   getCurves,
+  generateKeySync,
   generateKeyPairSync,
   webcrypto,
 } = require('crypto');
@@ -846,3 +847,51 @@ const privateDsa = fixtures.readKey('dsa_private_encrypted_1025.pem',
     assert(!isKeyObject(cryptoKey));
   });
 }
+
+{
+  const first = Buffer.from('Hello');
+  const second = Buffer.from('World');
+  const keyObject = createSecretKey(first);
+  assert(createSecretKey(first).equals(createSecretKey(first)));
+  assert(!createSecretKey(first).equals(createSecretKey(second)));
+
+  assert.throws(() => keyObject.equals(0), {
+    name: 'TypeError',
+    code: 'ERR_INVALID_ARG_TYPE',
+    message: 'The "otherKeyObject" argument must be an instance of KeyObject. Received type number (0)'
+  });
+
+  assert(keyObject.equals(keyObject));
+  assert(!keyObject.equals(createPublicKey(publicPem)));
+  assert(!keyObject.equals(createPrivateKey(privatePem)));
+}
+
+{
+  const first = generateKeyPairSync('ed25519');
+  const second = generateKeyPairSync('ed25519');
+  const secret = generateKeySync('aes', { length: 128 });
+
+  assert(first.publicKey.equals(first.publicKey));
+  assert(first.publicKey.equals(createPublicKey(
+    first.publicKey.export({ format: 'pem', type: 'spki' }))));
+  assert(!first.publicKey.equals(second.publicKey));
+  assert(!first.publicKey.equals(second.privateKey));
+  assert(!first.publicKey.equals(secret));
+
+  assert(first.privateKey.equals(first.privateKey));
+  assert(first.privateKey.equals(createPrivateKey(
+    first.privateKey.export({ format: 'pem', type: 'pkcs8' }))));
+  assert(!first.privateKey.equals(second.privateKey));
+  assert(!first.privateKey.equals(second.publicKey));
+  assert(!first.privateKey.equals(secret));
+}
+
+{
+  const first = generateKeyPairSync('ed25519');
+  const second = generateKeyPairSync('ed448');
+
+  assert(!first.publicKey.equals(second.publicKey));
+  assert(!first.publicKey.equals(second.privateKey));
+  assert(!first.privateKey.equals(second.privateKey));
+  assert(!first.privateKey.equals(second.publicKey));
+}