DES加密

//加密方法

private string encrypt(string strToEncrypt)
{
if (strToEncrypt == null || strToEncrypt == "") return strToEncrypt;
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
//把字符串放到byte数组中，主意编码方式
byte[] inputByteArray = Encoding.Default.GetBytes(strToEncrypt);
//建立加密对象的密钥和偏移量
des.Key = new byte[] { 1, 3, 5, 7, 2, 4, 6, 8 };
des.Mode = CipherMode.ECB;
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);
}
return ret.ToString();
}

//解密方法

private string Decrypt(string pToDecrypt)
{
if (pToDecrypt == null || pToDecrypt == "") return pToDecrypt;
try
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
//Put the input string into the byte array
byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
for (int x = 0; x < pToDecrypt.Length / 2; x++)
{
int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
inputByteArray[x] = (byte)i;
}
//key

des.Key = new byte[] { 1, 3, 5, 7, 2, 4, 6, 8 }; ;
//des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
des.Mode = CipherMode.ECB;
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
//建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象
StringBuilder ret = new StringBuilder();
return System.Text.Encoding.Default.GetString(ms.ToArray());
}
catch (Exception Exp)
{
return String.Empty;
}
}