code: public function decrypt($data, $key)
      {
          if ($data === null || $data === '') {
              return $data;
          }
  
          $encryptPieCollector = @json_decode(base64_decode($data), true);
          if (!is_array($encryptPieCollector)) {
              return null;
          }
  
          $decryptPieCollector = [];
          foreach ($encryptPieCollector as $encryptPie) {
              $base64DecryptPie = @base64_decode($encryptPie);
              if ($base64DecryptPie === false) {
                  return null;
              }
              $decryptPie = $this->doDecrypt($base64DecryptPie, $key);
              if ($decryptPie === null) {
                  return null;
              }
              $decryptPieCollector[] = $decryptPie;
          }
  
          $decryptData = implode('', $decryptPieCollector);
  
          $rs = @base64_decode($decryptData);
  
          return $rs !== false ? $rs : null;
      }
docs: 解密
  
  @param string $data 待解密的字符串
  @param string $key 公钥/私钥
  @return string|null 失败时返回null