求助：.NET方法转成PHP方法。

Question

   public static string Encrypt(string stringToEncrypt, string key)
        {
            var des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.Unicode.GetBytes(stringToEncrypt);
            des.Key = Encoding.UTF8.GetBytes(key);
            des.IV = Encoding.UTF8.GetBytes(key);
            var ms = new MemoryStream();
            var cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            var ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }

            ret.ToString();
            return ret.ToString();
        }