C#加密类

             var es= EncryptSugar.GetInstance();             string Word = "abc";             var wordEncrypt = es.Encrypto(word);//加密             var wordDecrypt = es.Decrypto(wordEncrypt);//解密             var wordmd5 = es.MD5(word);//md5加密

using System;using System.Collections.Generic;using System.Text;using System.Security.Cryptography;using System.xml;using System.IO;using System.Linq;namespace SyntacticSugar{    /// <summary>    /// ** 描述：加密类    /// ** 创始时间：2015-6-30    /// ** 修改时间：-    /// ** 作者：sunkaixuan    /// ** 使用说明：http://www.cnblogs.com/sunkaixuan/p/4610729.html    /// </summary>    public class EncryptSugar    {        PRivate static readonly object _instanceLock = new object();        private static EncryptSugar _instance = null;        private static SymmetricAlgorithm mobjCryptoService;        private static string _key;        private static readonly object _cacheLock = new object();        private static Dictionary<string, string> _cache = new Dictionary<string, string>();        /// <summary>        /// 最大缓存条数        /// </summary>        private static int _maxCacheNum = 10000;        /// <summary>        /// 对称加密类的构造函数        /// </summary>        public static EncryptSugar GetInstance()        {            if (_instance == null)            {                lock (_instanceLock)                {                    if (_instance == null)                    {                        mobjCryptoService = new RijndaelManaged();                        _key = "Guz(%&as1213^^d(fa%(HilJ$lhj!y6&(*jkP87jH7";                        _instance = new EncryptSugar();                    }                }            }            return _instance;        }        /// <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)        {            if (_cache.ContainsKey(source))            {                return _cache[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();            string reval = Convert.ToBase64String(bytOut);            lock (_cacheLock)            {                if (_cache.Count > _maxCacheNum)                {                    foreach (var it in _cache.Take(_maxCacheNum/5))                    {                        _cache.Remove(it.Key);                    }                }                _cache.Add(source, reval);            }            return reval; ;        }        /// <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)        {            lock (_cacheLock)            {                if (_cache.Any(it => it.Value == source))                {                    return _cache.Single(it => it.Value == source).Key;                }            }            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();        }        /// <summary>        /// MD5加密,不可逆        /// </summary>        /// <param name="source"></param>        /// <returns></returns>        public string MD5(string source)        {            return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(source, "MD5");        }        #region 私有函数        /// <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 = "asdfas&&dfg*$#+)*Y41sdgsdgs&*%$$$^&&GGslsadKdfK1";            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);        }        #endregion    }}