C#加密与解密函数

 

asp.net中简单方法

1.public static string MD5(string toCryString)
        {
            return FormsAuthentication.HashPasswordForStoringInConfigFile(toCryString, "MD5");
        }
2.public static string MD5(string str)
  {
   MD5 md5 = new MD5CryptoServiceProvider();
   byte[] result = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(str));
   string str2 = "";
   for(int i=0;i<result.Length;i++)
   {
    str2 += string.Format("{0:x}",result[i]);
   }
   return str2;
  }

带有偏移量的方法

//加密函数 
        public string Encrypt(string SToEncrypt, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.Default.GetBytes(SToEncrypt);
           // byte[]  inputByteArray=Encoding.UTF8.GetBytes(SToEncrypt); 

            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, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            ret.ToString();
            return ret.ToString();
        } 
        //解密方法 
        public string Decrypt(string SToDecrypt, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

              byte[] inputByteArray = new byte[SToDecrypt.Length / 2];
            for (int x = 0; x < SToDecrypt.Length / 2; x++)
            {
                int i = (Convert.ToInt32(SToDecrypt.Substring(x * 2, 2), 16));
                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, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return System.Text.Encoding.UTF8.GetString(ms.ToArray());
        }

 对称加密算法

       private SymmetricAlgorithm mobjCryptoService;
        private string Key;
        string origi;

        public Form1()
        {
            InitializeComponent();
            mobjCryptoService = new RijndaelManaged();
            Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";

        }
        /// <summary>
        /// 获得密钥
        /// </summary>
        /// <returns>密钥</returns>
        private byte[] GetLegalKey()
        {
            string sTemp = Key;
            mobjCryptoService.GenerateKey();
            byte[] bytTemp = mobjCryptoService.Key;
            int KeyLength = bytTemp.Length;
            if (sTemp.Length > KeyLength)
                sTemp = sTemp.Substring(0, KeyLength);
            else if (sTemp.Length < KeyLength)
                sTemp = sTemp.PadRight(KeyLength, ' ');
            return ASCIIEncoding.ASCII.GetBytes(sTemp);
        }
        /// <summary>
        /// 获得初始向量IV
        /// </summary>
        /// <returns>初试向量IV</returns>
        private byte[] GetLegalIV()
        {
            string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk";
            mobjCryptoService.GenerateIV();
            byte[] bytTemp = mobjCryptoService.IV;
            int IVLength = bytTemp.Length;
            if (sTemp.Length > IVLength)
                sTemp = sTemp.Substring(0, IVLength);
            else if (sTemp.Length < IVLength)
                sTemp = sTemp.PadRight(IVLength, ' ');
            return ASCIIEncoding.ASCII.GetBytes(sTemp);
        }
        /// <summary>
        /// 加密方法
        /// </summary>
        /// <param name="Source">待加密的串</param>
        /// <returns>经过加密的串</returns>
        public string Encrypto(string Source)
        {
            byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);
            MemoryStream ms = new MemoryStream();
            mobjCryptoService.Key = GetLegalKey();
            mobjCryptoService.IV = GetLegalIV();
            ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
            cs.Write(bytIn, 0, bytIn.Length);
            cs.FlushFinalBlock();
            ms.Close();
            byte[] bytOut = ms.ToArray();
            return Convert.ToBase64String(bytOut);
        }
        /// <summary>
        /// 解密方法
        /// </summary>
        /// <param name="Source">待解密的串</param>
        /// <returns>经过解密的串</returns>
        public string Decrypto(string Source)
        {
            byte[] bytIn = Convert.FromBase64String(Source);
            MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);
            mobjCryptoService.Key = GetLegalKey();
            mobjCryptoService.IV = GetLegalIV();
            ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cs);
            return sr.ReadToEnd();
        }