cpupes2-decrypt/CpUpES2-Decrypt/Program.cs

126 lines
5.6 KiB
C#

using Org.BouncyCastle.Crypto.Encodings;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace CpUpES2_Decrypt
{
class Program
{
public static byte[] Aes_128_Decrypt(byte[] message, byte[] Key, byte[] Iv)
{
Aes aes = new AesManaged();
aes.Key = Key;
aes.IV = Iv;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
ICryptoTransform cipher;
cipher = aes.CreateDecryptor();
return cipher.TransformFinalBlock(message, 0, message.Length);
}
static int Main(string[] args)
{
RsaKeyParameters Rsa_Public_Key = new RsaKeyParameters(false, new BigInteger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new BigInteger("10001", 16));
if(args.Length < 1)
{
Console.WriteLine("Usage: CpUpES2Decrypt.exe <UpdaterES2.CpUp File>");
return 2;
}
else if(File.Exists(args[0]))
{
// Parse Header
FileStream fs = File.OpenRead(args[0]);
BinaryReader bfs = new BinaryReader(fs);
UInt32 Magic = bfs.ReadUInt32();
UInt32 Version = bfs.ReadUInt32();
UInt64 Reserved = bfs.ReadUInt64();
UInt32 Type = bfs.ReadUInt32();
UInt32 FullSize = bfs.ReadUInt32();
UInt32 StartAddress = bfs.ReadUInt32();
UInt32 ExtractedSize = bfs.ReadUInt32();
if (Magic == 0x43705570) //CpUp
{
Console.WriteLine("CpUp Magic: 0x" + Magic.ToString("X"));
Console.WriteLine("CpUp Version: 0x" + Version.ToString("X"));
Console.WriteLine("CpUp Reserved Space: 0x" + Reserved.ToString("X"));
Console.WriteLine("CpUp Type: 0x" + Type.ToString("X"));
Console.WriteLine("CpUp Size: 0x" + FullSize.ToString("X"));
Console.WriteLine("CpUp Start Address: 0x" + StartAddress.ToString("X"));
Console.WriteLine("CpUp Extracted Size: 0x" + ExtractedSize.ToString("X"));
Console.WriteLine("\n\nRSA Decrypting Key Information...");
// Dervie AES Key
Pkcs1Encoding pkcs1Encoding = new Pkcs1Encoding(new RsaEngine());
pkcs1Encoding.Init(false, Rsa_Public_Key);
pkcs1Encoding.GetInputBlockSize();
fs.Seek(-0x100, SeekOrigin.End);
Byte[] HeaderData = new Byte[0x100];
fs.Read(HeaderData, 0x00, 0x100);
Byte[] HeaderDecrypted = pkcs1Encoding.ProcessBlock(HeaderData, 0, 0x100);
Byte[] Iv = new Byte[0x10];
Byte[] Key = new Byte[0x10];
Byte[] Sha1Hash = new Byte[0x14];
Array.ConstrainedCopy(HeaderDecrypted, 0x0, Iv, 0x0, 0x10);
Array.ConstrainedCopy(HeaderDecrypted, 0x10, Key, 0x0, 0x10);
Array.ConstrainedCopy(HeaderDecrypted, 0x20, Sha1Hash, 0x0, 0x14);
Console.WriteLine("CpUp Key: " + BitConverter.ToString(Key));
Console.WriteLine("CpUp Iv: " + BitConverter.ToString(Iv));
Console.WriteLine("CpUp Sha1: " + BitConverter.ToString(Sha1Hash));
Console.WriteLine("\n\nAES Decrytping CpUp File...");
// Decrypt Update
fs.Seek(StartAddress, SeekOrigin.Begin);
Byte[] UpdateData = new Byte[(FullSize - StartAddress) - 0x100];
fs.Read(UpdateData, 0x00, UpdateData.Length);
Byte[] UpdateDecrypted = Aes_128_Decrypt(UpdateData, Key, Iv);
fs.Close();
String FileName = Path.ChangeExtension(args[0], "tar.gz");
fs = File.OpenWrite(FileName);
fs.Write(UpdateDecrypted, 0x00, (Int32)ExtractedSize);
fs.Close();
Console.WriteLine("Decrypted file saved to: " + FileName);
ConsoleColor PrevColor = Console.ForegroundColor;
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("\n\nBlessed Be!");
Console.ForegroundColor = PrevColor;
return 0;
}
else
{
Console.WriteLine("Invalid CPUP! (Magic = 0x" + Magic.ToString("X")+")");
return 1;
}
}
else
{
Console.WriteLine("File not Found: " + args[0]);
return 4;
}
}
}
}