用c#语言，调用程序库中的des算法，实现DES加密和解密

在C#中，你可以使用System.Security.Cryptography命名空间下的`DESCryptoServiceProvider`类来进行DES（Data Encryption Standard）加密和解密操作。这里是一个简单的示例： ```csharp using System; using System.IO; using System.Security.Cryptography; public class DESExample { public static void Encrypt(string plainText, string key) { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); byte[] salt = new byte[8]; using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider()) { rng.GetBytes(salt); } ICryptoTransform encryptor = des.CreateEncryptor(key, salt); using (MemoryStream ms = new MemoryStream()) { using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write)) { using (StreamWriter sw = new StreamWriter(cs)) { sw.Write(plainText); } byte[] encryptedBytes = ms.ToArray(); // 将盐和加密后的数据组合在一起 byte[] combined = Combine(salt, encryptedBytes); Console.WriteLine("Encrypted data: " + Convert.ToBase64String(combined)); } } des.Clear(); // 清理资源 } public static void Decrypt(byte[] combinedData, string key) { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); byte[] salt = ExtractSalt(combinedData); // 提取盐值 ICryptoTransform decryptor = des.CreateDecryptor(key, salt); using (MemoryStream ms = new MemoryStream(combinedData)) { using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read)) { using (StreamReader sr = new StreamReader(cs)) { string decryptedText = sr.ReadToEnd(); Console.WriteLine("Decrypted text: " + decryptedText); } } des.Clear(); } } private static byte[] Combine(byte[] salt, byte[] encryptedBytes) { return salt.Concat(encryptedBytes).ToArray(); } private static byte[] ExtractSalt(byte[] combinedData) { int saltLength = salt.Length; return combinedData.Skip(combinedData.Length - saltLength).Take(saltLength).ToArray(); } } // 调用示例 string plainText = "Hello, DES!"; string key = "YourKey123"; // 16字节的密钥 DESExample.Encrypt(plainText, key); ``` 在这个例子中，我们首先创建了一个`DESCryptoServiceProvider`实例，并生成一个随机的盐值。然后分别用于加密和解密过程。请注意，在实际应用中你需要妥善保管密钥，因为它是加密过程的关键。