DES加密/解密中的C#编码

Question

我的主要方法运行没有错误，但解密的消息不正确。我几乎可以肯定我没有正确编码，但我无法确定问题所在。任何帮助将不胜感激。

这是我的第一篇文章，所以如果我无意中违反了规则或未遵守指南，请告诉我。

static void Main(string[] args)
{
    string unencryptedString = "cat";
    string encryptedString;
    string decryptedString;

    string password = "password";

    System.Console.WriteLine("Unencrypted String: " + unencryptedString);
    System.Console.WriteLine("Password: " + password);

    encryptedString = StandardEncryptor.Encrypt(unencryptedString, password);
    System.Console.WriteLine("Encrypted String: " + encryptedString);

    decryptedString = StandardEncryptor.Decrypt(encryptedString, password);
    System.Console.WriteLine("Decrypted String: " + decryptedString);

    System.Console.ReadLine();
}

public static string Encrypt(string message, string password)
{
    // Encode message and password
    byte[] messageBytes = ASCIIEncoding.ASCII.GetBytes(message);
    byte[] passwordBytes = ASCIIEncoding.ASCII.GetBytes(password);

    // Set encryption settings -- Use password for both key and init. vector
    DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
    ICryptoTransform transform = provider.CreateEncryptor(passwordBytes, passwordBytes);
    CryptoStreamMode mode = CryptoStreamMode.Write;

    // Set up streams and encrypt
    MemoryStream memStream = new MemoryStream();
    CryptoStream cryptoStream = new CryptoStream(memStream, transform, mode);
    cryptoStream.Write(messageBytes, 0, messageBytes.Length);
    cryptoStream.FlushFinalBlock();

    // Read the encrypted message from the memory stream
    byte[] encryptedMessageBytes = new byte[memStream.Length];
    memStream.Position = 0;
    memStream.Read(encryptedMessageBytes, 0, encryptedMessageBytes.Length);

    // Encode the encrypted message as base64 string
    string encryptedMessage = Convert.ToBase64String(encryptedMessageBytes);

    return encryptedMessage; 
}

public static string Decrypt(string encryptedMessage, string password)
{
    // Convert encrypted message and password to bytes
    byte[] encryptedMessageBytes = Convert.FromBase64String(encryptedMessage);
    byte[] passwordBytes = ASCIIEncoding.ASCII.GetBytes(password);

    // Set encryption settings -- Use password for both key and init. vector
    DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
    ICryptoTransform transform = provider.CreateDecryptor(passwordBytes, passwordBytes);
    CryptoStreamMode mode = CryptoStreamMode.Write;

    // Set up streams and decrypt
    MemoryStream memStream = new MemoryStream();
    CryptoStream cryptoStream = new CryptoStream(memStream, transform, mode);
    cryptoStream.Write(encryptedMessageBytes, 0, encryptedMessageBytes.Length);
    cryptoStream.FlushFinalBlock();

    // Read decrypted message from memory stream
    byte[] decryptedMessageBytes = new byte[memStream.Length];
    memStream.Position = 0;
    memStream.Read(decryptedMessageBytes, 0, decryptedMessageBytes.Length);

    // Encode deencrypted binary data to base64 string
    string message = Convert.ToBase64String(decryptedMessageBytes);

    return message;
}

Answer 1

问题出在倒数第二行吗？

string message = Convert.ToBase64String(decryptedMessageBytes);

我可能偏离了轨道，但我不认为您打算将字符串字节转换回 base64。您只需要将字节转换回字符串吗？

string message = ASCIIEncoding.ASCII.FromBytes(decryptedMessageBytes);

Answer 2

看起来问题出在解密中：

// Encode deencrypted binary data to base64 string
string message = Convert.ToBase64String(decryptedMessageBytes);

我认为您不想对解密的数据执行此操作。解密后的字节已经是 ASCII 码了。

Answer 3

我用这个解决了这个问题

//Encode deencrypted binary data to base64 string
string message = ASCIIEncoding.ASCII.GetString(decryptedMessageBytes);