c# DeS 加密解密字符串

public static class DESSecurity

{

#region DES加密字符串

/// <summary>

/// DES加密方法

/// </summary>

/// <param name="plain">明文</param>

/// <param name="key">密钥</param>

/// <param name="iv">向量</param>

/// <param name="isBase64">生成的密码是否用base64编码</param>

/// <returns>密文</returns>

public static String EncryptDES(string plain, byte[] rgbKey, byte[] rgbIV)

{

if (rgbKey.Length != 8) throw new ArgumentException("长度必须为8。", "rgbKey");

if (rgbIV.Length != 8) throw new ArgumentException("长度必须为8。", "rgbIV");

DESCryptoServiceProvider des = new DESCryptoServiceProvider();

MemoryStream ms = new MemoryStream();

CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);

using (StreamWriter sw = new StreamWriter(cs))

{

sw.Write(plain);

sw.Flush();

cs.FlushFinalBlock();

ms.Flush();

return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

}

}

#endregion

#region DES解密字符串

/// <summary>

/// DES解密方法

/// </summary>

/// <param name="cipher">密文</param>

/// <param name="key">密钥</param>

/// <param name="iv">向量</param>

/// <param name="isBase64">密文是否用base64解码</param>

/// <returns>明文</returns>

public static String DecryptDES(string cipher, byte[] key64, byte[] iv64)

{

byte[] bytesCipher;

bytesCipher = Convert.FromBase64String(cipher);

DESCryptoServiceProvider des = new DESCryptoServiceProvider();

MemoryStream ms = new MemoryStream(bytesCipher);

CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(key64, iv64), CryptoStreamMode.Read);

using (StreamReader sr = new StreamReader(cs))

{

return sr.ReadToEnd();

}

}

#endregion

}