1.dnspy反编译
AES算法
internal class a
{
// Token: 0x06000004 RID: 4 RVA: 0x0000209B File Offset: 0x0000029B
private static void a(string[] A_0)
{
Console.WriteLine("Please Input Serial:");
if (global::a.a(Console.ReadLine(), "Kanxue2019") == "4RTlF9Ca2+oqExJwx68FiA==")
{
Console.WriteLine("Congratulations! : )");
Console.ReadLine();
}
}
// Token: 0x06000005 RID: 5 RVA: 0x000020D4 File Offset: 0x000002D4
public static string a(string A_0, string A_1)
{
byte[] bytes = Encoding.UTF8.GetBytes("Kanxue2019CTF-Q1");
byte[] bytes2 = Encoding.UTF8.GetBytes(A_0);
byte[] bytes3 = new PasswordDeriveBytes(A_1, null).GetBytes(32);
ICryptoTransform transform = new RijndaelManaged
{
Mode = CipherMode.CBC
}.CreateEncryptor(bytes3, bytes);
MemoryStream memoryStream = new MemoryStream();
CryptoStream expr_4F = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write);
expr_4F.Write(bytes2, 0, bytes2.Length);
expr_4F.FlushFinalBlock();
byte[] inArray = memoryStream.ToArray();
memoryStream.Close();
expr_4F.Close();
return Convert.ToBase64String(inArray);
}
// Token: 0x04000003 RID: 3
private const string a = "Kanxue2019CTF-Q1";
// Token: 0x04000004 RID: 4
private const int b = 256;
}
2.导出工程
3.修改工程写算法
internal class a
{
// Token: 0x06000004 RID: 4 RVA: 0x0000209B File Offset: 0x0000029B
private static void Main(string[] A_0)
{
global::a.test("4RTlF9Ca2+oqExJwx68FiA==", "Kanxue2019");
}
// Token: 0x06000005 RID: 5 RVA: 0x000020D4 File Offset: 0x000002D4
public static string test(string A_0, string A_1)
{
byte[] base64 = Convert.FromBase64CharArray(A_0.ToCharArray(0,A_0.Length), 0, A_0.Length);
byte[] bytes = Encoding.UTF8.GetBytes("Kanxue2019CTF-Q1");
byte[] bytes2 = Encoding.UTF8.GetBytes(A_0);
byte[] bytes3 = new PasswordDeriveBytes(A_1, null).GetBytes(32);
ICryptoTransform transform = new RijndaelManaged
{
Mode = CipherMode.CBC
}.CreateDecryptor(bytes3, bytes);
MemoryStream memoryStream = new MemoryStream();
CryptoStream expr_4F = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write);
expr_4F.Write(base64, 0, base64.Length);
expr_4F.FlushFinalBlock();
byte[] inArray = memoryStream.ToArray();
memoryStream.Close();
expr_4F.Close();
string result = System.Text.Encoding.UTF8.GetString(inArray);
return result;
}
// Token: 0x04000003 RID: 3
private const string keyiv = "Kanxue2019CTF-Q1";
// Token: 0x04000004 RID: 4
private const int b = 256;
}
internal class a
{
// Token: 0x06000004 RID: 4 RVA: 0x0000209B File Offset: 0x0000029B
private static void Main(string[] A_0)
{
global::a.test("4RTlF9Ca2+oqExJwx68FiA==", "Kanxue2019");
}
// Token: 0x06000005 RID: 5 RVA: 0x000020D4 File Offset: 0x000002D4
public static string test(string A_0, string A_1)
{
byte[] base64 = Convert.FromBase64CharArray(A_0.ToCharArray(0,A_0.Length), 0, A_0.Length);
byte[] bytes = Encoding.UTF8.GetBytes("Kanxue2019CTF-Q1");
byte[] bytes2 = Encoding.UTF8.GetBytes(A_0);
byte[] bytes3 = new PasswordDeriveBytes(A_1, null).GetBytes(32);
ICryptoTransform transform = new RijndaelManaged
[招生]科锐逆向工程师培训(2024年11月15日实地，远程教学同时开班, 第51期)
