//获得16位随机字符串，填充到明文之前

$random = $this->getRandomStr();

$text = $random . pack("N", strlen($text)) . $text . $appid;

$iv = substr($this->key, 0, 16);

$size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

//使用自定义的填充方式对明文进行补位填充

$pkc_encoder = new PKCS7Encoder;

$text = $pkc_encoder->encode($text);

mcrypt_generic_init($module, $this->key, $iv);

//加密

$encrypted = mcrypt_generic($module, $text);

mcrypt_generic_deinit($module);

mcrypt_module_close($module);

//获得16位随机字符串，填充到明文之前

$random = $this->getRandomStr();

$text = $random . pack("N", strlen($text)) . $text . $appid;

$iv = substr($this->key, 0, 16);

$encrypted = openssl_encrypt($text, 'AES-256-CBC', $this->key, OPENSSL_RAW_DATA|OPENSSL_ZERO_PADDING, $iv); 

$ciphertext_dec = base64_decode($encrypted);

$iv = substr($this->key, 0, 16);

$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

mcrypt_generic_init($module, $this->key, $iv);

//解密

$decrypted = mdecrypt_generic($module, $ciphertext_dec);

mcrypt_generic_deinit($module);

mcrypt_module_close($module);

$ciphertext_dec = base64_decode($encrypted);

$iv = substr($this->key, 0, 16);

$decrypted = openssl_decrypt($ciphertext_dec, 'AES-256-CBC', $this->key, OPENSSL_RAW_DATA|OPENSSL_ZERO_PADDING, $iv);