RSA 加解密

        #region RSA

        public static byte[] GetBytes(String num)

        {

            BigInteger n = new BigInteger(num, 10);

            String s = n.ToString(2);

            if (s.Length % 8 > 0)

            {

                s = new String('0', 8 - s.Length % 8) + s;

            }

            byte[] data = new byte[s.Length / 8];

            String ocetstr;

            for (int i = 0; i < data.Length; i++)

            {

                ocetstr = s.Substring(8 * i, 8);

                data[i] = Convert.ToByte(ocetstr, 2);

            }

            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 = 0; i < data.Length; i++)

            {

                s += Convert.ToString(data[i], 16);

            }

            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() / 8;



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





            int MaxLength = CellLength - 11;

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



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

            for (int i = 0; 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, 0, len);



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

                Buffer.BlockCopy(temp, 0, cipherText, i * CellLength, CellLength);

            }

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

            //return Convert.ToBase64String(cipherText);

            //return toHex(cipherText);

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



        }





        #endregion