MD5Helper辅助类

DES加密和解密

    public class MD5Helper

    {

        ///DES加密

        ///sKey

        public  string MD5Encrypt(string pToEncrypt, string sKey)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, , inputByteArray.Length);

            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();

            foreach (byte b in ms.ToArray())

            {

                ret.AppendFormat("{0:X2}", b);

            }

            ret.ToString();

            return ret.ToString();

        }

        ///DES解密

        public  string MD5Decrypt(string pToDecrypt, string sKey)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = new byte[pToDecrypt.Length / ];

            for (int x = ; x < pToDecrypt.Length / ; x++)

            {

                int i = (Convert.ToInt32(pToDecrypt.Substring(x * , ), ));

                inputByteArray[x] = (byte)i;

            }

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, , inputByteArray.Length);

            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();

            return System.Text.Encoding.Default.GetString(ms.ToArray());

        }

        public  string MD5Encrypt(string pToEncrypt, string sKey, out string msg)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            StringBuilder ret = new StringBuilder();

            try

            {

                byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);

                msg = "SUCC:";

                int length = sKey.Length;

                if (length < )

                { msg = "ERR:密钥长度不能小于8"; return ""; }

                int _dif = length - ;

                int _sub_Index = _dif /  + _dif % ;

                _sub_Index = _sub_Index <=  ?  : _sub_Index;

                sKey = sKey.Substring(_sub_Index, );

                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

                MemoryStream ms = new MemoryStream();

                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

                cs.Write(inputByteArray, , inputByteArray.Length);

                cs.FlushFinalBlock();

                foreach (byte b in ms.ToArray())

                {

                    ret.AppendFormat("{0:X2}", b);

                }

            }

            catch (Exception ex)

            {

                msg = "ERR:" + ex.Message;

            }

            return ret.ToString();

        }

        ///DES解密

        public  string MD5Decrypt(string pToDecrypt, string sKey, out string msg)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            string _value = "";

            try

            {

                msg = "SUCC:";

                int length = sKey.Length;

                if (length < )

                { msg = "ERR:密钥长度不能小于8"; return ""; }

                int _dif = length - ;

                int _sub_Index = _dif /  + _dif % ;

                _sub_Index = _sub_Index <=  ?  : _sub_Index;

                sKey = sKey.Substring(_sub_Index, );

                byte[] inputByteArray = new byte[pToDecrypt.Length / ];

                for (int x = ; x < pToDecrypt.Length / ; x++)

                {

                    int i = (Convert.ToInt32(pToDecrypt.Substring(x * , ), ));

                    inputByteArray[x] = (byte)i;

                }

                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

                MemoryStream ms = new MemoryStream();

                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

                cs.Write(inputByteArray, , inputByteArray.Length);

                cs.FlushFinalBlock();

                StringBuilder ret = new StringBuilder();

                _value = Encoding.Default.GetString(ms.ToArray());

            }

            catch (Exception ex)

            {

                msg = "ERR:" + ex.Message;

            }

            return _value;

        }

    }

调用方法

 MD5Helper md5 = new MD5Helper();

 string key = ConfigurationManager.AppSettings["MD5Encrypt"];

 loginPassword = md5.MD5Encrypt(loginPassword, key);