.net 加密

// 对称加密帮助类
public class CryptoHelper {

    // 对称加密算法提供器
    private ICryptoTransform encryptor;     // 加密器对象
    private ICryptoTransform decryptor;     // 解密器对象
    private const int BufferSize = 1024;

    public CryptoHelper(string algorithmName, string key) {
        SymmetricAlgorithm provider = SymmetricAlgorithm.Create(algorithmName);
        provider.Key = Encoding.UTF8.GetBytes(key);
        provider.IV = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

        encryptor = provider.CreateEncryptor();
        decryptor = provider.CreateDecryptor();
    }

    public CryptoHelper(string key) : this("TripleDES", key) { }

    // 加密算法
    public string Encrypt(string clearText) {
        // 创建明文流
        byte[] clearBuffer = Encoding.UTF8.GetBytes(clearText);
        MemoryStream clearStream = new MemoryStream(clearBuffer);

        // 创建空的密文流
        MemoryStream encryptedStream = new MemoryStream();

        CryptoStream cryptoStream =
            new CryptoStream(encryptedStream, encryptor, CryptoStreamMode.Write);

        // 将明文流写入到buffer中
        // 将buffer中的数据写入到cryptoStream中
        int bytesRead = 0;
        byte[] buffer = new byte[BufferSize];
        do {
            bytesRead = clearStream.Read(buffer, 0, BufferSize);
            cryptoStream.Write(buffer, 0, bytesRead);
        } while (bytesRead > 0);

        cryptoStream.FlushFinalBlock();

        // 获取加密后的文本
        buffer = encryptedStream.ToArray();
        string encryptedText = Convert.ToBase64String(buffer);
        return encryptedText;
    }

    // 解密算法
    public string Decrypt(string encryptedText) {
        byte[] encryptedBuffer = Convert.FromBase64String(encryptedText);
        Stream encryptedStream = new MemoryStream(encryptedBuffer);

        MemoryStream clearStream = new MemoryStream();
        CryptoStream cryptoStream =
            new CryptoStream(encryptedStream, decryptor, CryptoStreamMode.Read);

        int bytesRead = 0;
        byte[] buffer = new byte[BufferSize];

        do {
            bytesRead = cryptoStream.Read(buffer, 0, BufferSize);
            clearStream.Write(buffer, 0, bytesRead);
        } while (bytesRead > 0);

        buffer = clearStream.GetBuffer();
        string clearText =
            Encoding.UTF8.GetString(buffer, 0, (int)clearStream.Length);

        return clearText;
    }

    public static string Encrypt(string clearText, string key) {
        CryptoHelper helper = new CryptoHelper(key);
        return helper.Encrypt(clearText);
    }

    public static string Decrypt(string encryptedText, string key) {
        CryptoHelper helper = new CryptoHelper(key);
        return helper.Decrypt(encryptedText);
    }
}

测试

static void Main(string[] args) {
    string key = "ABCDEFGHIJKLMNOP";
    string clearText = "欢迎访问www.tracefact.net";

    CryptoHelper helper = new CryptoHelper(key);
    
    string encryptedText = helper.Encrypt(clearText);
    Console.WriteLine(encryptedText);

    clearText = CryptoHelper.Decrypt(encryptedText, key);
    Console.WriteLine(clearText);
}