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Code Issues 11 Packages Projects Releases 20 Wiki Activity

Use new PartitionKeys class

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This commit is contained in:
Matt Nadareski
2024-10-13 11:48:30 -04:00
parent 6c575d0157
commit c73e971704
2 changed files with 28 additions and 86 deletions
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10
NDecrypt.N3DS/PartitionKeys.cs
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@@ -12,15 +12,15 @@ namespace NDecrypt.N3DS
/// </summary>
public class PartitionKeys
{
public BigInteger KeyX { get; }
public BigInteger KeyX { get; set; }
public BigInteger KeyX2C { get; }
public BigInteger KeyX2C { get; set; }
public BigInteger KeyY { get; }
public BigInteger KeyY { get; set; }
public BigInteger NormalKey { get; }
public BigInteger NormalKey { get; set; }
public BigInteger NormalKey2C { get; }
public BigInteger NormalKey2C { get; set; }
/// <summary>
/// Create a new set of keys for a given partition

104
NDecrypt.N3DS/ThreeDSTool.cs
View File

@@ -1,7 +1,5 @@
using System;
using System.IO;
using System.Linq;
using System.Numerics;
using NDecrypt.Core;
using SabreTools.IO.Extensions;
using SabreTools.Models.N3DS;
@@ -23,29 +21,9 @@ namespace NDecrypt.N3DS
private readonly bool _development;
/// <summary>
/// Set of all KeyX values
/// Set of all partition keys
/// </summary>
private readonly BigInteger[] KeyXMap = new BigInteger[8];
/// <summary>
/// Set of all KeyX2C values
/// </summary>
private readonly BigInteger[] KeyX2CMap = new BigInteger[8];
/// <summary>
/// Set of all KeyY values
/// </summary>
private readonly BigInteger[] KeyYMap = new BigInteger[8];
/// <summary>
/// Set of all KeyY values
/// </summary>
private readonly BigInteger[] NormalKeyMap = new BigInteger[8];
/// <summary>
/// Set of all KeyY values
/// </summary>
private readonly BigInteger[] NormalKey2CMap = new BigInteger[8];
private readonly PartitionKeys[] KeysMap = new PartitionKeys[8];
public ThreeDSTool(bool development, DecryptArgs decryptArgs)
{
@@ -198,67 +176,31 @@ namespace NDecrypt.N3DS
/// <param name="encrypt">Indicates if the file should be encrypted or decrypted</param>
private void SetEncryptionKeys(Cart cart, int partitionIndex, bool encrypt)
{
// Get the backup header
var backupHeader = cart.CardInfoHeader!.InitialData!.BackupHeader;
// Get the partition
var partition = cart.Partitions?[partitionIndex];
if (partition == null)
return;
KeyXMap[partitionIndex] = 0;
KeyX2CMap[partitionIndex] = _development ? _decryptArgs.DevKeyX0x2C : _decryptArgs.KeyX0x2C;
// Backup headers can't have a KeyY value set
byte[]? rsaSignature = cart.Partitions![partitionIndex]!.RSA2048Signature;
if (rsaSignature != null)
KeyYMap[partitionIndex] = new BigInteger(rsaSignature.Take(16).Reverse().ToArray());
else
KeyYMap[partitionIndex] = new BigInteger(0);
NormalKeyMap[partitionIndex] = 0x00;
NormalKey2CMap[partitionIndex] = RotateLeft((RotateLeft(KeyX2CMap[partitionIndex], 2, 128) ^ KeyYMap[partitionIndex]) + _decryptArgs.AESHardwareConstant, 87, 128);
// Get partition-specific values
byte[]? rsaSignature = partition.RSA2048Signature;
// Set the header to use based on mode
BitMasks masks;
CryptoMethod method;
if (encrypt)
{
var backupHeader = cart.CardInfoHeader!.InitialData!.BackupHeader;
masks = backupHeader!.Flags!.BitMasks;
method = backupHeader.Flags.CryptoMethod;
}
else
{
masks = cart.Partitions![partitionIndex]!.Flags!.BitMasks;
method = cart.Partitions![partitionIndex]!.Flags!.CryptoMethod;
masks = partition.Flags!.BitMasks;
method = partition.Flags!.CryptoMethod;
}
if (masks.HasFlag(BitMasks.FixedCryptoKey))
{
NormalKeyMap[partitionIndex] = 0x00;
NormalKey2CMap[partitionIndex] = 0x00;
Console.WriteLine("Encryption Method: Zero Key");
}
else
{
if (method == CryptoMethod.Original)
{
KeyXMap[partitionIndex] = _development ? _decryptArgs.DevKeyX0x2C : _decryptArgs.KeyX0x2C;
Console.WriteLine("Encryption Method: Key 0x2C");
}
else if (method == CryptoMethod.Seven)
{
KeyXMap[partitionIndex] = _development ? _decryptArgs.DevKeyX0x25 : _decryptArgs.KeyX0x25;
Console.WriteLine("Encryption Method: Key 0x25");
}
else if (method == CryptoMethod.NineThree)
{
KeyXMap[partitionIndex] = _development ? _decryptArgs.DevKeyX0x18 : _decryptArgs.KeyX0x18;
Console.WriteLine("Encryption Method: Key 0x18");
}
else if (method == CryptoMethod.NineSix)
{
KeyXMap[partitionIndex] = _development ? _decryptArgs.DevKeyX0x1B : _decryptArgs.KeyX0x1B;
Console.WriteLine("Encryption Method: Key 0x1B");
}
NormalKeyMap[partitionIndex] = RotateLeft((RotateLeft(KeyXMap[partitionIndex], 2, 128) ^ KeyYMap[partitionIndex]) + _decryptArgs.AESHardwareConstant, 87, 128);
}
// Get the partition keys
KeysMap[partitionIndex] = new PartitionKeys(_decryptArgs, rsaSignature, masks, method, _development);
}
/// <summary>
@@ -288,7 +230,7 @@ namespace NDecrypt.N3DS
Console.WriteLine($"Partition {partitionIndex} ExeFS: " + (encrypt ? "Encrypting" : "Decrypting") + ": ExHeader");
// Create the Plain AES cipher for this partition
var cipher = CreateAESCipher(NormalKey2CMap[partitionIndex], cart.PlainIV(partitionIndex), encrypt);
var cipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey2C, cart.PlainIV(partitionIndex), encrypt);
// Process the extended header
byte[] readBytes = reader.ReadBytes(Constants.CXTExtendedDataHeaderLength);
@@ -352,8 +294,8 @@ namespace NDecrypt.N3DS
// Create the ExeFS AES ciphers for this partition
byte[] exefsIVWithOffsetForHeader = AddToByteArray(cart.ExeFSIV(partitionIndex), (int)ctroffset);
var firstCipher = CreateAESCipher(NormalKeyMap[partitionIndex], exefsIVWithOffsetForHeader, encrypt);
var secondCipher = CreateAESCipher(NormalKey2CMap[partitionIndex], exefsIVWithOffsetForHeader, !encrypt);
var firstCipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey, exefsIVWithOffsetForHeader, encrypt);
var secondCipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey2C, exefsIVWithOffsetForHeader, !encrypt);
// Seek to the file entry
reader.Seek(exeFsOffset + fileHeader.FileOffset, SeekOrigin.Begin);
@@ -413,7 +355,7 @@ namespace NDecrypt.N3DS
Console.WriteLine($"Partition {partitionIndex} ExeFS: " + (encrypt ? "Encrypting" : "Decrypting") + $": ExeFS Filename Table");
// Create the ExeFS AES cipher for this partition
var cipher = CreateAESCipher(NormalKey2CMap[partitionIndex], cart.ExeFSIV(partitionIndex), encrypt);
var cipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey2C, cart.ExeFSIV(partitionIndex), encrypt);
// Process the filename table
byte[] readBytes = reader.ReadBytes((int)cart.MediaUnitSize());
@@ -461,7 +403,7 @@ namespace NDecrypt.N3DS
// Create the ExeFS AES cipher for this partition
byte[] exefsIVWithOffset = AddToByteArray(cart.ExeFSIV(partitionIndex), ctroffsetE);
var cipher = CreateAESCipher(NormalKey2CMap[partitionIndex], exefsIVWithOffset, encrypt);
var cipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey2C, exefsIVWithOffset, encrypt);
// Seek to the ExeFS
reader.Seek(exeFsOffset, SeekOrigin.Begin);
@@ -558,7 +500,7 @@ namespace NDecrypt.N3DS
int romfsSizeB = (int)((long)romFsSize % (1024 * 1024));
// Create the RomFS AES cipher for this partition
var cipher = CreateAESCipher(NormalKeyMap[partitionIndex], cart.RomFSIV(partitionIndex), encrypt: false);
var cipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey, cart.RomFSIV(partitionIndex), encrypt: false);
// Seek to the RomFS
reader.Seek(romFsOffset, SeekOrigin.Begin);
@@ -696,17 +638,17 @@ namespace NDecrypt.N3DS
// Except if using zero-key
if (backupHeader!.Flags!.BitMasks.HasFlag(BitMasks.FixedCryptoKey))
{
NormalKeyMap[partitionIndex] = 0x00;
KeysMap[partitionIndex].NormalKey = 0x00;
}
else
{
KeyXMap[partitionIndex] = (_development ? _decryptArgs.DevKeyX0x2C : _decryptArgs.KeyX0x2C);
NormalKeyMap[partitionIndex] = RotateLeft((RotateLeft(KeyXMap[partitionIndex], 2, 128) ^ KeyYMap[partitionIndex]) + _decryptArgs.AESHardwareConstant, 87, 128);
KeysMap[partitionIndex].KeyX = (_development ? _decryptArgs.DevKeyX0x2C : _decryptArgs.KeyX0x2C);
KeysMap[partitionIndex].NormalKey = RotateLeft((RotateLeft(KeysMap[partitionIndex].KeyX, 2, 128) ^ KeysMap[partitionIndex].KeyY) + _decryptArgs.AESHardwareConstant, 87, 128);
}
}
// Create the RomFS AES cipher for this partition
var cipher = CreateAESCipher(NormalKeyMap[partitionIndex], cart.RomFSIV(partitionIndex), encrypt: true);
var cipher = CreateAESCipher(KeysMap[partitionIndex].NormalKey, cart.RomFSIV(partitionIndex), encrypt: true);
// Seek to the RomFS
reader.Seek(romFsOffset, SeekOrigin.Begin);