如何创建使用2DES（doubleDES）加密文件的程序？

Question

我知道doubleDES没有使用中间相遇攻击的正弦但我需要创建一个执行这种加密的程序。我尝试了这个，但我认为我卡住了，只是无法弄清楚我错过了什么..

DESCryptoServiceProvider DES = new DESCryptoServiceProvider();

DES.Mode = CipherMode.ECB;
DES.Padding = PaddingMode.Zeros;
// *****ENKRIPTIMI*****
DES.Key = utf8.GetBytes(textBox1.Text.Substring(0, 8));
StreamReader sr = new StreamReader(textBox2.Text);
string permbajtja = sr.ReadToEnd();
sr.Close();
FileStream fs1 = new FileStream(textBox2.Text, FileMode.Create, FileAccess.Write);
CryptoStream cs = new CryptoStream(fs1, DES.CreateEncryptor(), CryptoStreamMode.Write);
StreamWriter sw = new StreamWriter(cs);
sw.Write(permbajtja); sw.Flush();
sw.Close();
StreamReader stream = new StreamReader(textBox2.Text);
string msg = stream.ReadToEnd();
stream.Close();
MessageBox.Show(msg);



//*****DEKRIPTIMI*****

DES.Key = utf8.GetBytes(textBox1.Text.Substring(8, 8));
FileStream fs2 = new FileStream(textBox2.Text, FileMode.Open, FileAccess.Read);
CryptoStream cs1 = new CryptoStream(fs2, DES.CreateDecryptor(), CryptoStreamMode.Read);
StreamReader sr1 = new StreamReader(cs1);
string permbajtja1 = sr1.ReadToEnd();
//    MessageBox.Show(permbajtja1);
sr1.Close();
fs2.Dispose();
fs2.Close();


StreamWriter sw1 = new StreamWriter(textBox2.Text);
sw1.Write(permbajtja1);
sw1.Flush();
sw1.Close();

****上面的部分只是为了加密*****

解密部分

DESCryptoServiceProvider DES = new DESCryptoServiceProvider();

DES.Mode = CipherMode.ECB;
DES.Padding = PaddingMode.Zeros;
// *****ENKRIPTIMI*****
DES.Key = utf8.GetBytes(textBox1.Text.Substring(8,8));
StreamReader sr = new StreamReader(textBox2.Text);
string permbajtja = sr.ReadToEnd();
sr.Close();
FileStream fs1 = new FileStream(textBox2.Text, FileMode.Create, FileAccess.Write);
CryptoStream cs = new CryptoStream(fs1, DES.CreateEncryptor(), CryptoStreamMode.Write);
StreamWriter sw = new StreamWriter(cs);
sw.Write(permbajtja); sw.Flush();
sw.Close();
StreamReader lexo = new StreamReader(textBox2.Text);
MessageBox.Show(lexo.ReadToEnd());
lexo.Close();

////*****DEKRIPTIMI*****

DES.Key = utf8.GetBytes(textBox1.Text.Substring(0, 8));
FileStream fs2 = new FileStream(textBox2.Text, FileMode.Open, FileAccess.Read);
CryptoStream cs1 = new CryptoStream(fs2, DES.CreateDecryptor(), CryptoStreamMode.Read);
StreamReader sr1 = new StreamReader(cs1);
string permbajtja1 = sr1.ReadToEnd();
MessageBox.Show(permbajtja1);
sr1.Close();
fs2.Dispose();
fs2.Close();


StreamWriter sw1 = new StreamWriter(textBox2.Text);
sw1.Write(permbajtja1);
sw1.Flush();
sw1.Close();

Answer 1

首先，您应该编写加密和解密方法：

public static string Encrypt(string originalString, byte[] key)
{
    DESCryptoServiceProvider cryptoServiceProvider = new DESCryptoServiceProvider();
    MemoryStream memoryStream = new MemoryStream();
    CryptoStream cryptoStream = new CryptoStream(memoryStream,
        cryptoServiceProvider.CreateEncryptor(key, key),
        CryptoStreamMode.Write);

    using (StreamWriter streamWriter = new StreamWriter(cryptoStream))
    {
        streamWriter.Write(originalString);
        streamWriter.Flush();
        cryptoStream.FlushFinalBlock();
        streamWriter.Flush();

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

public static string Decrypt(string cryptedString, byte[] key)
{
    DESCryptoServiceProvider cryptoServiceProvider = new DESCryptoServiceProvider();
    MemoryStream memoryStream = new MemoryStream(Convert.FromBase64String(cryptedString));
    CryptoStream cryptoStream = new CryptoStream(memoryStream,
        cryptoServiceProvider.CreateDecryptor(key, key),
        CryptoStreamMode.Read);

    using (StreamReader streamReader = new StreamReader(cryptoStream))
    {
        return streamReader.ReadToEnd();
    }
}

现在，您可以将两倍的加密方法（当然还有解密的两倍）应用于您的字符串：

byte[] key1 = ASCIIEncoding.ASCII.GetBytes("12345678");
byte[] key2 = ASCIIEncoding.ASCII.GetBytes("abcdefgh");

string originalString = "A secret string";
string cryptedString = Encrypt(Encrypt(originalString, key1), key2);
Console.WriteLine("Encrypt message: {0}", cryptedString);
Console.WriteLine("Decrypt message: {0}", Decrypt(Decrypt(cryptedString, key2), key1));

查看我的代码，它可能对您有帮助。