PKHeX/PKHeX.Core/Saves/SAV4BR.cs
Kurt 7b6abc0520 Reduce alloc for ot/nick by raw trash reads
Legality check now catches buffer overflow mons.
Now that I have each type exposing a trash length & charcount, should be easy to have some reusable trash byte measuring methods (see the old branch)
2024-05-12 14:46:58 -05:00

376 lines
12 KiB
C#

using System;
using System.Collections.Generic;
using static System.Buffers.Binary.BinaryPrimitives;
namespace PKHeX.Core;
/// <summary>
/// Generation 4 <see cref="SaveFile"/> object for Pokémon Battle Revolution saves.
/// </summary>
public sealed class SAV4BR : SaveFile, IBoxDetailName
{
protected internal override string ShortSummary => $"{Version} #{SaveCount:0000}";
public override string Extension => string.Empty;
public override PersonalTable4 Personal => PersonalTable.DP;
public override ReadOnlySpan<ushort> HeldItems => Legal.HeldItems_DP;
private const int SAVE_COUNT = 4;
public const int SIZE_HALF = 0x1C0000;
public SAV4BR() : base(SaveUtil.SIZE_G4BR)
{
ClearBoxes();
}
public SAV4BR(byte[] data) : base(data)
{
InitializeData(data);
}
private void InitializeData(ReadOnlySpan<byte> data)
{
Data = DecryptPBRSaveData(data);
// Detect active save
var first = ReadUInt32BigEndian(Data.AsSpan(0x00004C));
var second = ReadUInt32BigEndian(Data.AsSpan(0x1C004C));
SaveCount = Math.Max(second, first);
if (second > first)
{
// swap halves
byte[] tempData = new byte[SIZE_HALF];
Array.Copy(Data, 0, tempData, 0, SIZE_HALF);
Array.Copy(Data, SIZE_HALF, Data, 0, SIZE_HALF);
tempData.CopyTo(Data, SIZE_HALF);
}
var names = (string[]) SaveNames;
for (int i = 0; i < SAVE_COUNT; i++)
{
var name = GetOTName(i);
if (string.IsNullOrWhiteSpace(name))
name = $"Empty {i + 1}";
else if (_currentSlot == -1)
_currentSlot = i;
names[i] = name;
}
if (_currentSlot == -1)
_currentSlot = 0;
CurrentSlot = _currentSlot;
}
/// <summary> Amount of times the primary save has been saved </summary>
private uint SaveCount;
protected override byte[] GetFinalData()
{
SetChecksums();
return EncryptPBRSaveData(Data);
}
// Configuration
protected override SAV4BR CloneInternal() => new(Write());
public readonly IReadOnlyList<string> SaveNames = new string[SAVE_COUNT];
private int _currentSlot = -1;
private const int SIZE_SLOT = 0x6FF00;
public int CurrentSlot
{
get => _currentSlot;
// 4 save slots, data reading depends on current slot
set
{
_currentSlot = value;
var ofs = SIZE_SLOT * _currentSlot;
Box = ofs + 0x978;
Party = ofs + 0x13A54; // first team slot after boxes
BoxName = ofs + 0x58674;
}
}
protected override int SIZE_STORED => PokeCrypto.SIZE_4STORED;
protected override int SIZE_PARTY => PokeCrypto.SIZE_4STORED + 4;
public override BK4 BlankPKM => new();
public override Type PKMType => typeof(BK4);
public override ushort MaxMoveID => 467;
public override ushort MaxSpeciesID => Legal.MaxSpeciesID_4;
public override int MaxAbilityID => Legal.MaxAbilityID_4;
public override int MaxItemID => Legal.MaxItemID_4_HGSS;
public override int MaxBallID => Legal.MaxBallID_4;
public override GameVersion MaxGameID => Legal.MaxGameID_4;
public override int MaxEV => EffortValues.Max255;
public override byte Generation => 4;
public override EntityContext Context => EntityContext.Gen4;
public override int MaxStringLengthTrainer => 7;
public override int MaxStringLengthNickname => 10;
public override int MaxMoney => 999999;
public override int Language => (int)LanguageID.English; // prevent KOR from inhabiting
public override int BoxCount => 18;
public override int PartyCount
{
get
{
int ctr = 0;
for (int i = 0; i < 6; i++)
{
if (Data[GetPartyOffset(i) + 4] != 0) // sanity
ctr++;
}
return ctr;
}
protected set
{
// Ignore, value is calculated
}
}
// Checksums
protected override void SetChecksums()
{
SetChecksum(Data, 0x0000000, 0x0000100, 0x000008);
SetChecksum(Data, 0x0000000, SIZE_HALF, SIZE_HALF - 0x80);
SetChecksum(Data, SIZE_HALF, 0x0000100, SIZE_HALF + 0x000008);
SetChecksum(Data, SIZE_HALF, SIZE_HALF, SIZE_HALF + SIZE_HALF - 0x80);
}
public override bool ChecksumsValid => IsChecksumsValid(Data);
public override string ChecksumInfo => $"Checksums valid: {ChecksumsValid}.";
public static bool IsChecksumsValid(Span<byte> sav)
{
return VerifyChecksum(sav, 0x0000000, 0x0000100, 0x000008)
&& VerifyChecksum(sav, 0x0000000, SIZE_HALF, SIZE_HALF - 0x80)
&& VerifyChecksum(sav, SIZE_HALF, 0x0000100, SIZE_HALF + 0x000008)
&& VerifyChecksum(sav, SIZE_HALF, SIZE_HALF, SIZE_HALF + SIZE_HALF - 0x80);
}
// Trainer Info
public override GameVersion Version { get => GameVersion.BATREV; set { } }
private string GetOTName(int slot)
{
var ofs = 0x390 + (SIZE_SLOT * slot);
var span = Data.AsSpan(ofs, 16);
return GetString(span);
}
private void SetOTName(int slot, ReadOnlySpan<char> name)
{
var ofs = 0x390 + (SIZE_SLOT * slot);
var span = Data.AsSpan(ofs, 16);
SetString(span, name, 7, StringConverterOption.ClearZero);
}
public string CurrentOT { get => GetOTName(_currentSlot); set => SetOTName(_currentSlot, value); }
// Storage
public override int GetPartyOffset(int slot) => Party + (SIZE_PARTY * slot);
public override int GetBoxOffset(int box) => Box + (SIZE_STORED * box * 30);
public override uint Money
{
get => (uint)((Data[(_currentSlot * SIZE_SLOT) + 0x12861] << 16) | (Data[(_currentSlot * SIZE_SLOT) + 0x12862] << 8) | Data[(_currentSlot * SIZE_SLOT) + 0x12863]);
set
{
Data[(_currentSlot * SIZE_SLOT) + 0x12861] = (byte)((value >> 16) & 0xFF);
Data[(_currentSlot * SIZE_SLOT) + 0x12862] = (byte)((value >> 8) & 0xFF);
Data[(_currentSlot * SIZE_SLOT) + 0x12863] = (byte)(value & 0xFF);
}
}
public override ushort TID16
{
get => (ushort)((Data[(_currentSlot * SIZE_SLOT) + 0x12867] << 8) | Data[(_currentSlot * SIZE_SLOT) + 0x12860]);
set
{
Data[(_currentSlot * SIZE_SLOT) + 0x12867] = (byte)(value >> 8);
Data[(_currentSlot * SIZE_SLOT) + 0x12860] = (byte)(value & 0xFF);
}
}
public override ushort SID16
{
get => (ushort)((Data[(_currentSlot * SIZE_SLOT) + 0x12865] << 8) | Data[(_currentSlot * SIZE_SLOT) + 0x12866]);
set
{
Data[(_currentSlot * SIZE_SLOT) + 0x12865] = (byte)(value >> 8);
Data[(_currentSlot * SIZE_SLOT) + 0x12866] = (byte)(value & 0xFF);
}
}
// Save file does not have Box Name / Wallpaper info
private int BoxName = -1;
private const int BoxNameLength = 0x28;
private Span<byte> GetBoxNameSpan(int box)
{
int ofs = BoxName + (box * BoxNameLength);
return Data.AsSpan(ofs, BoxNameLength);
}
public string GetBoxName(int box)
{
if (BoxName < 0)
return BoxDetailNameExtensions.GetDefaultBoxNameCaps(box);
var span = GetBoxNameSpan(box);
if (ReadUInt16BigEndian(span) == 0)
return BoxDetailNameExtensions.GetDefaultBoxNameCaps(box);
return GetString(span);
}
public void SetBoxName(int box, ReadOnlySpan<char> value)
{
if (BoxName < 0)
return;
var span = GetBoxNameSpan(box);
if (ReadUInt16BigEndian(span) == 0)
return;
SetString(span, value, BoxNameLength / 2, StringConverterOption.ClearZero);
}
protected override BK4 GetPKM(byte[] data)
{
if (data.Length != SIZE_STORED)
Array.Resize(ref data, SIZE_STORED);
return BK4.ReadUnshuffle(data);
}
protected override byte[] DecryptPKM(byte[] data) => data;
protected override void SetDex(PKM pk) { /* There's no PokéDex */ }
protected override void SetPKM(PKM pk, bool isParty = false)
{
var pk4 = (BK4)pk;
// Apply to this Save File
pk4.UpdateHandler(this);
pk.RefreshChecksum();
}
protected override void SetPartyValues(PKM pk, bool isParty)
{
if (pk is G4PKM g4)
g4.Sanity = isParty ? (ushort)0xC000 : (ushort)0x4000;
}
public static byte[] DecryptPBRSaveData(ReadOnlySpan<byte> input)
{
byte[] output = new byte[input.Length];
Span<ushort> keys = stackalloc ushort[4];
for (int offset = 0; offset < SaveUtil.SIZE_G4BR; offset += SIZE_HALF)
{
var inSlice = input.Slice(offset, SIZE_HALF);
var outSlice = output.AsSpan(offset, SIZE_HALF);
// First 8 bytes are the encryption keys for this chunk.
var keySlice = inSlice[..(keys.Length * 2)];
GeniusCrypto.ReadKeys(keySlice, keys);
// Copy over the keys to the result.
keySlice.CopyTo(outSlice);
// Decrypt the input, result stored in output.
Range r = new(8, SIZE_HALF);
GeniusCrypto.Decrypt(inSlice[r], outSlice[r], keys);
}
return output;
}
private static byte[] EncryptPBRSaveData(ReadOnlySpan<byte> input)
{
byte[] output = new byte[input.Length];
Span<ushort> keys = stackalloc ushort[4];
for (int offset = 0; offset < SaveUtil.SIZE_G4BR; offset += SIZE_HALF)
{
var inSlice = input.Slice(offset, SIZE_HALF);
var outSlice = output.AsSpan(offset, SIZE_HALF);
// First 8 bytes are the encryption keys for this chunk.
var keySlice = inSlice[..(keys.Length * 2)];
GeniusCrypto.ReadKeys(keySlice, keys);
// Copy over the keys to the result.
keySlice.CopyTo(outSlice);
// Decrypt the input, result stored in output.
Range r = new(8, SIZE_HALF);
GeniusCrypto.Encrypt(inSlice[r], outSlice[r], keys);
}
return output;
}
public static bool VerifyChecksum(Span<byte> input, int offset, int len, int chkOffset)
{
// Read original checksum data, and clear it for recomputing
Span<uint> originalChecksums = stackalloc uint[16];
var checkSpan = input.Slice(chkOffset, 4 * originalChecksums.Length);
for (int i = 0; i < originalChecksums.Length; i++)
{
var chk = checkSpan.Slice(i * 4, 4);
originalChecksums[i] = ReadUInt32BigEndian(chk);
}
checkSpan.Clear();
// Compute current checksum of the specified span
Span<uint> checksums = stackalloc uint[16];
var span = input.Slice(offset, len);
ComputeChecksums(span, checksums);
// Restore original checksums
WriteChecksums(checkSpan, originalChecksums);
// Check if they match
return checksums.SequenceEqual(originalChecksums);
}
private static void SetChecksum(Span<byte> input, int offset, int len, int chkOffset)
{
// Wipe Checksum region.
var checkSpan = input.Slice(chkOffset, 4 * 16);
checkSpan.Clear();
// Compute current checksum of the specified span
Span<uint> checksums = stackalloc uint[16];
var span = input.Slice(offset, len);
ComputeChecksums(span, checksums);
WriteChecksums(checkSpan, checksums);
}
private static void WriteChecksums(Span<byte> span, Span<uint> checksums)
{
for (int i = 0; i < checksums.Length; i++)
{
var dest = span[(i * 4)..];
WriteUInt32BigEndian(dest, checksums[i]);
}
}
private static void ComputeChecksums(Span<byte> span, Span<uint> checksums)
{
for (int i = 0; i < span.Length; i += 2)
{
uint value = ReadUInt16BigEndian(span[i..]);
for (int c = 0; c < checksums.Length; c++)
checksums[c] += ((value >> c) & 1);
}
}
public override string GetString(ReadOnlySpan<byte> data)
=> StringConverter4GC.GetStringUnicode(data);
public override int LoadString(ReadOnlySpan<byte> data, Span<char> destBuffer)
=> StringConverter4GC.LoadStringUnicode(data, destBuffer);
public override int SetString(Span<byte> destBuffer, ReadOnlySpan<char> value, int maxLength, StringConverterOption option)
=> StringConverter4GC.SetStringUnicode(value, destBuffer, maxLength, option);
}