using System.IO;
using System;
using System.Security.Cryptography;
using System.Text;
class Program
{
static void Main()
{
PasswordDeriveBytes pdb = new PasswordDeriveBytes("Kanxue2019", null);
Byte[] Key = pdb.GetBytes(0x20);
Encoding unicode = Encoding.UTF8;
Byte[] IV = unicode.GetBytes("Kanxue2019CTF-Q1");
string plaintext = null;
byte[] cipherText = Convert.FromBase64String("4RTlF9Ca2+oqExJwx68FiA==");
using (RijndaelManaged rijAlg = new RijndaelManaged())
{
rijAlg.Key = Key;
rijAlg.IV = IV;
ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
Console.WriteLine(plaintext);
}
}
结果为：Kanxue2019Q1CTF
