#region RSA

        public static byte[] GetBytes(String num)

        {

            BigInteger n = new BigInteger(num, );

            String s = n.ToString();

            if (s.Length %  > )

            {

                s = new String('',  - s.Length % ) + s;

            }

            byte[] data = new byte[s.Length / ];

            String ocetstr;

            for (int i = ; i < data.Length; i++)

            {

                ocetstr = s.Substring( * i, );

                data[i] = Convert.ToByte(ocetstr, );

            }

            return data;

        }

        /// <summary>

        /// 字节数组转16进制字符串

        /// </summary>

        /// <param name="bytes"></param>

        /// <returns></returns>

        public static String ConvByteArrayToHex(byte[] data)

        {

            String s = "";

            for (int i = ; i < data.Length; i++)

            {

                s += Convert.ToString(data[i], );

            }

            return s.ToUpper();

        }

        public static string RSAEncrypt(string Modulus, string Exponent, string content)

        {

            var param = new RSAParameters();

            param.Exponent = GetBytes(Exponent);

            param.Modulus = GetBytes(Modulus);

            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();

            rsa.ImportParameters(param);

            int CellLength = new BigInteger(param.Modulus).bitCount() / ;

            byte[] bInput = Encoding.UTF8.GetBytes(content);

            int MaxLength = CellLength - ;

            int GroupLength = (int)Math.Ceiling(bInput.Length * 1.00 / MaxLength);

            byte[] cipherText = new byte[GroupLength * CellLength];

            for (int i = ; i < GroupLength; i++)

            {

                int len = MaxLength < bInput.Length - MaxLength * i ? MaxLength

                        : bInput.Length - MaxLength * i;

                byte[] inByte = new byte[len];

                Buffer.BlockCopy(bInput, MaxLength * i, inByte, , len);

                byte[] temp = rsa.Encrypt(inByte, false);

                Buffer.BlockCopy(temp, , cipherText, i * CellLength, CellLength);

            }

            //cipherText = rsa.Encrypt(bInput, false);

            //return Convert.ToBase64String(cipherText);

            //return toHex(cipherText);

            return BitConverter.ToString(cipherText).Replace("-", "");

        }

        #endregion