Add user data decryption.

src/Encryption/Encryptor.php

@@ -59,6 +59,13 @@ class Encryptor
      */
     protected $blockSize;
 
+    /**
+     * Aes key length.
+     *
+     * @var int
+     */
+    protected $aesKeyLength = 43;
+
     /**
      * Constructor.
      *
@@ -215,8 +222,8 @@ protected function getAESKey()
             throw new InvalidConfigException("Configuration mission, 'aes_key' is required.");
         }
 
-        if (strlen($this->AESKey) !== 43) {
-            throw new InvalidConfigException("The length of 'aes_key' must be 43.");
+        if (strlen($this->AESKey) !== $this->aesKeyLength) {
+            throw new InvalidConfigException("The length of 'aes_key' must be {$this->aesKeyLength}.");
         }
 
         return base64_decode($this->AESKey.'=', true);

src/MiniProgram/Encryption/Encryptor.php

@@ -0,0 +1,99 @@
+<?php
+
+/*
+ * This file is part of the overtrue/wechat.
+ *
+ * (c) overtrue <[email protected]>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+/**
+ * Encryptor.php.
+ *
+ * Part of Overtrue\WeChat.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @author    mingyoung <[email protected]>
+ * @copyright 2016
+ *
+ * @see      https://github.com/overtrue
+ * @see      http://overtrue.me
+ */
+
+namespace EasyWeChat\MiniProgram\Encryption;
+
+use EasyWeChat\Encryption\EncryptionException;
+use EasyWeChat\Encryption\Encryptor as BaseEncryptor;
+use EasyWeChat\Support\Collection;
+use Exception as BaseException;
+
+class Encryptor extends BaseEncryptor
+{
+    /**
+     * {@inheritdoc}.
+     */
+    protected $aesKeyLength = 24;
+
+    /**
+     * A non-NULL Initialization Vector.
+     *
+     * @var string
+     */
+    protected $iv;
+
+    /**
+     * Encryptor constructor.
+     *
+     * @param string $sessionKey
+     * @param string $iv
+     */
+    public function __construct($sessionKey, $iv)
+    {
+        $this->iv = base64_decode($iv, true);
+
+        parent::__construct(null, null, $sessionKey);
+    }
+
+    /**
+     * Decrypt data.
+     *
+     * @param $encrypted
+     *
+     * @return string
+     */
+    public function decryptData($encrypted)
+    {
+        return $this->decrypt($encrypted);
+    }
+
+    /**
+     * Decrypt data.
+     *
+     * @param string $encrypted
+     *
+     * @return Collection
+     *
+     * @throws EncryptionException
+     */
+    private function decrypt($encrypted)
+    {
+        try {
+            $key = $this->getAESKey();
+            $ciphertext = base64_decode($encrypted, true);
+
+            $decrypted = openssl_decrypt($ciphertext, 'aes-128-cbc', $key, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $this->iv);
+
+            $result = $this->decode($decrypted);
+        } catch (BaseException $e) {
+            throw new EncryptionException($e->getMessage(), EncryptionException::ERROR_DECRYPT_AES);
+        }
+
+        $result = json_decode($result, true);
+
+        return new Collection($result);
+    }
+}