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
}

}