Change return types of getCrypt and validateKey

`Magento\Framework\Encryption\Encryptor::validateKey` - Now returns `void`
instead of an instance of `\Magento\Framework\Encryption\Crypt`.

`Magento\Framework\Encryption\Encryptor::getCrypt` - Scope was changed from
`protected` to `private` and return value is now an instance of
`Magento\Framework\Encryption\Adapter\EncryptionAdapterInterface`

Author: pmclain

dev/tests/integration/testsuite/Magento/Framework/Encryption/ModelTest.php

@@ -42,10 +42,16 @@ public function testEncryptDecrypt2()
     public function testValidateKey()
     {
         $validKey = md5(uniqid());
-        $this->assertInstanceOf(
-            \Magento\Framework\Encryption\Adapter\EncryptionAdapterInterface::class,
-            $this->_model->validateKey($validKey)
-        );
+        $this->_model->validateKey($validKey);
+    }
+
+    /**
+     * @expectedException \Exception
+     */
+    public function testValidateKeyInvalid()
+    {
+        $invalidKey = '----    ';
+        $this->_model->validateKey($invalidKey);
     }
 
     public function testGetValidateHash()

lib/internal/Magento/Framework/Encryption/Adapter/Mcrypt.php

@@ -114,7 +114,7 @@ public function getMode(): string
      *
      * @return string
      */
-    public function getInitVector(): string
+    public function getInitVector(): ?string
     {
         return $this->initVector;
     }

lib/internal/Magento/Framework/Encryption/Encryptor.php

@@ -298,11 +298,11 @@ public function decrypt($data)
             $parts = explode(':', $data, 4);
             $partsCount = count($parts);
 
-            $initVector = false;
+            $initVector = null;
             // specified key, specified crypt, specified iv
             if (4 === $partsCount) {
                 list($keyVersion, $cryptVersion, $iv, $data) = $parts;
-                $initVector = $iv ? $iv : false;
+                $initVector = $iv ? $iv : null;
                 $keyVersion = (int)$keyVersion;
                 $cryptVersion = self::CIPHER_RIJNDAEL_256;
                 // specified key, specified crypt
@@ -337,18 +337,16 @@ public function decrypt($data)
     }
 
     /**
-     * Return crypt model, instantiate if it is empty
+     * Validate key contains only allowed characters
      *
      * @param string|null $key NULL value means usage of the default key specified on constructor
-     * @return EncryptionAdapterInterface
      * @throws \Exception
      */
     public function validateKey($key)
     {
         if (preg_match('/\s/s', $key)) {
             throw new \Exception((string)new \Magento\Framework\Phrase('The encryption key format is invalid.'));
         }
-        return $this->getCrypt($key);
     }
 
     /**
@@ -383,12 +381,15 @@ public function exportKeys()
      *
      * @param string $key
      * @param int $cipherVersion
-     * @param bool $initVector
+     * @param string $initVector
      * @return EncryptionAdapterInterface|null
      * @throws \Exception
      */
-    protected function getCrypt($key = null, $cipherVersion = null, $initVector = true)
-    {
+    private function getCrypt(
+        string $key = null,
+        int $cipherVersion = null,
+        string $initVector = null
+    ): ?EncryptionAdapterInterface {
         if (null === $key && null === $cipherVersion) {
             $cipherVersion = self::CIPHER_RIJNDAEL_256;
         }

lib/internal/Magento/Framework/Encryption/Test/Unit/EncryptorTest.php

@@ -216,12 +216,15 @@ public function testEncryptDecryptNewKeyAdded()
 
     public function testValidateKey()
     {
-        $actual = $this->_model->validateKey(self::CRYPT_KEY_1);
-        $crypt = new Sodium(self::CRYPT_KEY_1);
-        $expectedEncryptedData = base64_encode($crypt->encrypt('data'));
-        $actualEncryptedData = base64_encode($actual->encrypt('data'));
-        $this->assertNotEquals($expectedEncryptedData, $actualEncryptedData);
-        $this->assertEquals($crypt->decrypt($expectedEncryptedData), $actual->decrypt($actualEncryptedData));
+        $this->_model->validateKey(self::CRYPT_KEY_1);
+    }
+
+    /**
+     * @expectedException \Exception
+     */
+    public function testValidateKeyInvalid()
+    {
+        $this->_model->validateKey('-----    ');
     }
 
     public function testUseSpecifiedHashingAlgoDataProvider()