c#实现加密与解密的实例代码

class DESKey
{
public const string DesKeyStr = "BLUE2013";

#region DES加密
/// <summary>
/// DES加密
/// </summary>
/// <param name="pToEncrypt">需要加密的字符串</param>
/// <returns>加密后的字符串</returns>
public static string DESEncrypt(string pToEncrypt, string DesKeyStr)
{
try
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);
des.Key = ASCIIEncoding.ASCII.GetBytes(DesKeyStr);
des.IV = ASCIIEncoding.ASCII.GetBytes(DesKeyStr);
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();
}
catch
{
return "";
}
}
#endregion

#region DES解密
/// <summary>
/// DES解密
/// </summary>
/// <param name="pToDecrypt">加密后的字符串</param>
/// <returns>解密后的字符串</returns>
public static string DESDecrypt(string pToDecrypt, string DesKeyStr)
{
try
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();

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;
}

des.Key = ASCIIEncoding.ASCII.GetBytes(DesKeyStr);
des.IV = ASCIIEncoding.ASCII.GetBytes(DesKeyStr);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();

StringBuilder ret = new StringBuilder();

return System.Text.Encoding.Default.GetString(ms.ToArray());
}
catch
{
return "";
}
}
#endregion
}