C#64位加密/解密

/// <summary>
/// 加密/解密类
/// </summary>
public class EncAndDec
{
//加密/解密钥匙
const string KEY_64 = "jzw7tz8g";//注意了，是8个字符，64位
const string IV_64 = "tvbzn9i7";//注意了，是8个字符，64位

const string ClientLocal_KEY_64 = "xinxinwb";
const string ClientLocal_IV_64 = "39389993";

/// <summary>
/// 加密的方法，通过2个密匙进行加密
/// </summary>
/// <param name="data">加密的数据</param>
/// <returns>返回加密后的字符串</returns>
public static string Encode(string data)
{
EncAndDec ed = new EncAndDec();
return ed.Encode(data, KEY_64, IV_64);
}
/// <summary>
/// 解密的方法
/// </summary>
/// <param name="data">解密的数据</param>
/// <returns>返回加密前的字符串</returns>
public static string Decode(string data)
{
EncAndDec ed = new EncAndDec();
return ed.Decode(data, KEY_64, IV_64);
}

/// <summary>
/// 客户本地加密的方法，通过2个密匙进行加密
/// </summary>
/// <param name="data">加密的数据</param>
/// <returns>返回加密后的字符串</returns>
public static string EncodeClientLocal(string data)
{
EncAndDec ed = new EncAndDec();
return ed.Encode(data, ClientLocal_KEY_64, ClientLocal_IV_64);
}
/// <summary>
/// 客户本地解密的方法
/// </summary>
/// <param name="data">解密的数据</param>
/// <returns>返回加密前的字符串</returns>
public static string DecodeClientLocal(string data)
{
EncAndDec ed = new EncAndDec();
return ed.Decode(data, ClientLocal_KEY_64, ClientLocal_IV_64);
}

#region DEC加密的方法
/// <summary>
/// 加密的方法，通过2个密匙进行加密
/// </summary>
/// <param name="data">通过Md5加密一次</param>
/// <param name="KEY_64"></param>
/// <param name="IV_64"></param>
/// <returns></returns>
private string Encode(string data, string KEY_64, string IV_64)
{

KEY_64 = ToMD5(KEY_64);
IV_64 = ToMD5(IV_64);
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
int i = cryptoProvider.KeySize;
MemoryStream ms = new MemoryStream();
CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

StreamWriter sw = new StreamWriter(cst);
sw.Write(data);
sw.Flush();
cst.FlushFinalBlock();
sw.Flush();
return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

}
/// <summary>
/// 解密的方法（）
/// </summary>
/// <param name="data"></param>
/// <param name="KEY_64"></param>
/// <param name="IV_64"></param>
/// <returns></returns>
private string Decode(string data, string KEY_64, string IV_64)
{
KEY_64 = ToMD5(KEY_64);
IV_64 = ToMD5(IV_64);
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

byte[] byEnc;
try
{
byEnc = Convert.FromBase64String(data);
}
catch
{
return null;
}

DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
MemoryStream ms = new MemoryStream(byEnc);
CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
StreamReader sr = new StreamReader(cst);
return sr.ReadToEnd();
}
#endregion

#region MD5加密
/// <summary>
/// 转换MD5密码
/// </summary>
/// <param name="pass"></param>
/// <returns></returns>
public static string ToMD5(string KEY)
{
byte[] result = Encoding.Default.GetBytes(KEY);
MD5 md5 = new MD5CryptoServiceProvider();
byte[] output = md5.ComputeHash(result);

string KEY_64 = BitConverter.ToString(output).Replace("-", "").Substring(0, 8);
return KEY_64;

}
#endregion

}