amacocian/Daybreak
1
0
Fork 0
mirror of https://github.com/gwdevhub/Daybreak.git synced 2026-07-15 15:19:57 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix executable update (Closes #1526) (#1529)

Browse Source
This commit is contained in:
Alexandru Victor Macocian
2026-04-29 14:34:51 +02:00
parent b7d58f5e4c
commit 09aed18d9d
1 changed files with 33 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Daybreak.Core/Services/Guildwars/Utils/GuildWarsExecutableParser.cs
+33 -7
View File
@@ -2,16 +2,16 @@
using PeNet.Header.Pe;
namespace Daybreak.Services.Guildwars.Utils;
/// <summary>
/// https://github.com/gwdevhub/gwlauncher/blob/master/GW%20Launcher/Guildwars/FileIdFinder.cs
/// </summary>
internal sealed class GuildWarsExecutableParser
{
// Used by older Guild Wars versions
private readonly static byte[] VersionPattern = [0x8B, 0xC8, 0x33, 0xDB, 0x39, 0x8D, 0xC0, 0xFD, 0xFF, 0xFF, 0x0F, 0x95, 0xC3];
// Used by newer Guild Wars versions
private readonly static byte?[] FileIdFunctionPattern = [0x55, 0x8B, 0xEC, 0x83, 0xEC, 0x08, 0xE8, null, null, null, null, 0x83, 0x3D, null, null, null, null, 0x00];
// Used by newer Guild Wars versions. Matches ProcessVersionUpdate prologue:
// push ebp; mov ebp,esp; sub esp,N; call <addr>; cmp dword ptr [global], 0
// Byte 5 (stack size) is wildcarded since it changes across builds.
private readonly static byte?[] FileIdFunctionPattern = [0x55, 0x8B, 0xEC, 0x83, 0xEC, null, 0xE8, null, null, null, null, 0x83, 0x3D, null, null, null, null, 0x00];
private readonly PeFile peFile;
private readonly ImageSectionHeader textSection;
@@ -38,13 +38,39 @@ internal sealed class GuildWarsExecutableParser
return Task.Run(() =>
{
var patternRva = this.FindWithWildcards(FileIdFunctionPattern);
var callRva = patternRva + 0x32;
var fileIdFunctionRva = this.FollowCall(callRva);
var fileIdFunctionRva = this.FindGetFileIdCall(patternRva);
var fileId = (int)this.Read(fileIdFunctionRva + 1);
return fileId;
}, cancellationToken);
}
// GetFileId is a tiny function: mov eax, <imm32>; ret (bytes: B8 xx xx xx xx C3).
// Scan E8 (call) instructions within the matched function and follow each one
// to find the call whose target matches that shape.
private uint FindGetFileIdCall(uint functionRva, int scanLength = 0x80)
{
for (int offset = 0; offset < scanLength; offset++)
{
var rva = functionRva + (uint)offset;
var posInFile = this.RvaToOffset(rva);
if (this.peFile.RawFile.ReadByte(posInFile) != 0xE8)
{
continue;
}
var targetRva = rva + (uint)BitConverter.ToInt32(this.peFile.RawFile.ToArray(), posInFile + 1) + 5;
var targetOffset = this.RvaToOffset(targetRva);
// Check for: B8 xx xx xx xx C3 (mov eax, imm32; ret)
if (this.peFile.RawFile.ReadByte(targetOffset) == 0xB8 &&
this.peFile.RawFile.ReadByte(targetOffset + 5) == 0xC3)
{
return targetRva;
}
}
throw new Exception("Couldn't find GetFileId call within the function");
}
private uint FindWithWildcards(byte?[] pattern, int offset = 0)
{
var buffer = this.peFile.RawFile.AsSpan((int)this.textSection.PointerToRawData, (int)this.textSection.SizeOfRawData);