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[MapleLib] Support new WZ files (GMS v230)
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@genment
genment committed Feb 12, 2022
1 parent 9f12be3 commit f6fb7b8
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Showing 2 changed files with 73 additions and 35 deletions.
15 changes: 2 additions & 13 deletions MapleLib/WzLib/WzDirectory.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -263,17 +263,6 @@ internal void ParseDirectory(bool lazyParse = false)
}
}

// Offsets are calculated manually
if (this.wzFile != null && this.wzFile.b64BitClient) // This only applies for 64-bit client based WZ files.
{
long startOffset = reader.BaseStream.Position;
foreach (WzImage image in WzImages)
{
image.Offset = (uint)startOffset;
startOffset += image.BlockSize; // TODO: Test saving the wz after it is changed. This may break
}
}

foreach (WzDirectory subdir in subDirs)
{
if (subdir.Checksum != 0)
Expand All @@ -289,7 +278,7 @@ internal void ParseDirectory(bool lazyParse = false)
/// </summary>
/// <param name="wzWriter"></param>
/// <param name="fs"></param>
internal void SaveImages(BinaryWriter wzWriter, FileStream fs)
internal void SaveImages(BinaryWriter wzWriter, FileStream fs)
{
// List<string> wzImageNameTracking = new List<string>(); // Check for duplicate WZ image name that could cause errors later on.

Expand Down Expand Up @@ -335,7 +324,7 @@ internal void SaveImages(BinaryWriter wzWriter, FileStream fs)
/// <param name="bIsWzUserKeyDefault">Uses the default MapleStory UserKey or a custom key.</param>
/// <param name="prevOpenedStream">The previously opened file stream</param>
/// <returns></returns>
internal int GenerateDataFile(byte[] useIv, bool bIsWzUserKeyDefault, FileStream prevOpenedStream)
internal int GenerateDataFile(byte[] useIv, bool bIsWzUserKeyDefault, FileStream prevOpenedStream)
{
bool useCustomIv = useIv != null; // whole shit gonna be re-written if its a custom IV specified

Expand Down
93 changes: 71 additions & 22 deletions MapleLib/WzLib/WzFile.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,8 @@ public class WzFile : WzObject
internal WzDirectory wzDir;
internal WzHeader header;
internal string name = "";
internal short wzVersionHeader = 0;
internal ushort wzVersionHeader = 0;
internal const ushort wzVersionHeader64bit = 777;
internal uint versionHash = 0;
internal short mapleStoryPatchVersion = 0;
internal WzMapleVersion maplepLocalVersion;
Expand Down Expand Up @@ -119,7 +120,7 @@ public override void Dispose()
/// </summary>
/// <param name="gameVersion"></param>
/// <param name="version"></param>
public WzFile(short gameVersion, WzMapleVersion version)
public WzFile(short gameVersion, WzMapleVersion version)
{
wzDir = new WzDirectory();
this.Header = WzHeader.GetDefault();
Expand Down Expand Up @@ -222,12 +223,20 @@ internal WzFileParseStatus ParseMainWzDirectory(bool lazyParse = false)
byte[] unk2 = reader.ReadBytes((int)(Header.FStart - (ulong)reader.BaseStream.Position));
reader.Header = this.Header;

this.wzVersionHeader = 0;
if (!this.b64BitClient)
this.wzVersionHeader = reader.ReadInt16();
Check64BitClient(reader); // update b64BitClient flag

// the value of wzVersionHeader is less important. It is used for reading/writing from/to WzFile Header, and calculating the versionHash.
// it can be any number if the client is 64-bit. Assigning 777 is just for convenience when calculating the versionHash.
this.wzVersionHeader = b64BitClient ? wzVersionHeader64bit : reader.ReadUInt16();

if (mapleStoryPatchVersion == -1)
{
// for 64-bit client, return immediately if version 777 works correctly.
if (b64BitClient && TryDecodeWithWZVersionNumber(reader, wzVersionHeader, wzVersionHeader64bit, lazyParse))
{
return WzFileParseStatus.Success;
}

// Attempt to get version from MapleStory.exe first
short maplestoryVerDetectedFromClient = GetMapleStoryVerFromExe(this.path, out this.mapleLocaleVersion);

Expand All @@ -238,38 +247,75 @@ internal WzFileParseStatus ParseMainWzDirectory(bool lazyParse = false)
for (int j = maplestoryVerDetectedFromClient; j < MAX_PATCH_VERSION; j++)
{
if (TryDecodeWithWZVersionNumber(reader, wzVersionHeader, j, lazyParse))
{
return WzFileParseStatus.Success;
}
{
return WzFileParseStatus.Success;
}
}
//parseErrorMessage = "Error with game version hash : The specified game version is incorrect and WzLib was unable to determine the version itself";
return WzFileParseStatus.Error_Game_Ver_Hash;
}
else
{
if (!this.b64BitClient)
{
this.versionHash = CheckAndGetVersionHash(wzVersionHeader, mapleStoryPatchVersion);
}
this.versionHash = CheckAndGetVersionHash(wzVersionHeader, mapleStoryPatchVersion);
reader.Hash = this.versionHash;
WzDirectory directory = new WzDirectory(reader, this.name, this.versionHash, this.WzIv, this);
directory.ParseDirectory();
this.wzDir = directory;
}
return WzFileParseStatus.Success;
}

private bool TryDecodeWithWZVersionNumber(WzBinaryReader reader, int useWzVersionHeader, int useMapleStoryPatchVersion, bool lazyParse)
{
this.mapleStoryPatchVersion = (short)useMapleStoryPatchVersion;

if (!this.b64BitClient)
/// <summary>
/// encVer detecting:
/// Since KMST1132 (GMSv230, 2022/02/09), wz removed the 2-byte encVer at 0x3C, and use a fixed encVer 777.
/// Here we try to read the first 2 bytes from data part (0x3C) and guess if it looks like an encVer.
///
/// Credit: WzComparerR2 project
/// </summary>
private void Check64BitClient(WzBinaryReader reader)
{
if (this.Header.FSize >= 2)
{
this.wzVersionHeader = reader.ReadUInt16();
if (this.wzVersionHeader > 0xff)
{
b64BitClient = true;
}
else if (this.wzVersionHeader == 0x80)
{
// there's an exceptional case that the first field of data part is a compressed int which determines the property count,
// if the value greater than 127 and also to be a multiple of 256, the first 5 bytes will become to
// 80 00 xx xx xx
// so we additional check the int value, at most time the child node count in a WzFile won't greater than 65536 (0xFFFF).
if (this.Header.FSize >= 5)
{
reader.BaseStream.Position = this.header.FStart; // go back to 0x3C
int propCount = reader.ReadCompressedInt();
if (propCount > 0 && (propCount & 0xFF) == 0 && propCount <= 0xFFFF)
{
b64BitClient = true;
}
}
}
}
else
{
this.versionHash = CheckAndGetVersionHash(useWzVersionHeader, mapleStoryPatchVersion);
if (this.versionHash == 0) // ugly hack, but that's the only way if the version number isnt known (nexon stores this in the .exe)
return false;
// Obviously, if data part have only 1 byte, encVer must be deleted.
b64BitClient = true;
}

// reset position
reader.BaseStream.Position = this.Header.FStart;
}

private bool TryDecodeWithWZVersionNumber(WzBinaryReader reader, int useWzVersionHeader, int useMapleStoryPatchVersion, bool lazyParse)
{
this.mapleStoryPatchVersion = (short)useMapleStoryPatchVersion;

this.versionHash = CheckAndGetVersionHash(useWzVersionHeader, mapleStoryPatchVersion);
if (this.versionHash == 0) // ugly hack, but that's the only way if the version number isnt known (nexon stores this in the .exe)
return false;

reader.Hash = this.versionHash;
long fallbackOffsetPosition = reader.BaseStream.Position; // save position to rollback to, if should parsing fail from here
WzDirectory testDirectory;
Expand Down Expand Up @@ -443,12 +489,15 @@ private static uint CheckAndGetVersionHash(int wzVersionHeader, int maplestoryPa
VersionHash = (32 * VersionHash) + (int)VersionNumberStr[i] + 1;
}

if (wzVersionHeader == wzVersionHeader64bit)
return (uint)VersionHash; // always 59192

int a = (VersionHash >> 24) & 0xFF;
int b = (VersionHash >> 16) & 0xFF;
int c = (VersionHash >> 8) & 0xFF;
int d = VersionHash & 0xFF;
int DecryptedVersionNumber = (0xff ^ a ^ b ^ c ^ d);

if (wzVersionHeader == DecryptedVersionNumber)
return (uint)VersionHash;
return 0; // invalid
Expand Down Expand Up @@ -507,7 +556,7 @@ public void SaveToDisk(string path, WzMapleVersion savingToPreferredWzVer = WzMa
{
wzWriter.Hash = versionHash;

uint totalLen = wzDir.GetImgOffsets(wzDir.GetOffsets(Header.FStart + 2));
uint totalLen = wzDir.GetImgOffsets(wzDir.GetOffsets(Header.FStart + (b64BitClient ? 0 : 2u)));
Header.FSize = totalLen - Header.FStart;
for (int i = 0; i < 4; i++)
{
Expand Down

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