DES加密解密

/// <summary>
/// des加密
/// </summary>
/// <param name="text">加密内容</param>
/// <param name="key">密码(可自己设置8位数密码)</param>
/// <returns></returns>
public static string Encrypt(string text, string key)
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
byte[] inputByteArray = Encoding.GetEncoding("UTF-8").GetBytes(text);

byte[] a = ASCIIEncoding.ASCII.GetBytes(key);
des.Key = ASCIIEncoding.ASCII.GetBytes(key);
des.IV = ASCIIEncoding.ASCII.GetBytes(key);
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);//将第一个参数转换为十六进制数,长度为2,不足前面补0
}
return ret.ToString();
}

/// <summary>
/// des解密
/// </summary>
/// <param name="cyphertext">解密内容</param>
/// <param name="key">密码(可自己设置8位数密码)</param>
/// <returns></returns>
public static string Decrypt(string cyphertext, string key)
{
if (string.IsNullOrEmpty(cyphertext))
return string.Empty;
DESCryptoServiceProvider des = new DESCryptoServiceProvider();

byte[] inputByteArray = new byte[cyphertext.Length / 2];
for (int x = 0; x < cyphertext.Length / 2; x++)
{
int i = (Convert.ToInt32(cyphertext.Substring(x * 2, 2), 16));
inputByteArray[x] = (byte)i;
}

des.Key = ASCIIEncoding.ASCII.GetBytes(key);
des.IV = ASCIIEncoding.ASCII.GetBytes(key);
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.GetEncoding("UTF-8").GetString(ms.ToArray());
}