Created
September 24, 2023 22:36
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ClearR2RForAPIScan
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<Project Sdk="Microsoft.NET.Sdk"> | |
<PropertyGroup> | |
<OutputType>Exe</OutputType> | |
<TargetFramework>net8.0</TargetFramework> | |
<ImplicitUsings>enable</ImplicitUsings> | |
<Nullable>enable</Nullable> | |
</PropertyGroup> | |
</Project> |
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using System.IO.MemoryMappedFiles; | |
class Program | |
{ | |
static void Main(string[] args) | |
{ | |
ClearR2R(args[0]); | |
} | |
static void ClearR2R(string filename) | |
{ | |
using (var mappedFile = MemoryMappedFile.CreateFromFile(filename)) | |
{ | |
using (var accessor = mappedFile.CreateViewAccessor()) | |
{ | |
ClearR2R(accessor); | |
} | |
} | |
} | |
static void ClearR2R(MemoryMappedViewAccessor accessor) | |
{ | |
if (accessor.ReadUInt16(0) != 0x5A4D /* IMAGE_DOS_SIGNATURE */) | |
{ | |
Console.WriteLine("Not a PE file."); | |
return; | |
} | |
uint ntHeaderOffset = accessor.ReadUInt32(0x3c /* offsetof(IMAGE_DOS_HEADER, e_lfanew) */); | |
int corHeaderDirectoryOffset = accessor.ReadUInt16(ntHeaderOffset + 0x18 /* offsetof(IMAGE_NT_HEADERS, OptionalHeader) */) == 0x020B /* IMAGE_NT_OPTIONAL_HDR64_MAGIC */ | |
? 0xf8 : 0xe8 /* offsetof(IMAGE_NT_HEADERS, OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_COMHEADER]) */; | |
uint corHeaderRVA = accessor.ReadUInt32(ntHeaderOffset + corHeaderDirectoryOffset); | |
if (corHeaderRVA == 0) | |
{ | |
Console.WriteLine("Not a COR file."); | |
return; | |
} | |
uint corHeaderOffset = 0; | |
uint firstSectionOffset = ntHeaderOffset + 0x18 /* offsetof(IMAGE_NT_HEADERS, OptionalHeader) */ | |
+accessor.ReadUInt16(ntHeaderOffset + 0x14 /* offsetof(IMAGE_NT_HEADERS, FileHeader.SizeOfOptionalHeader) */); | |
uint numberOfSections = accessor.ReadUInt16(ntHeaderOffset + 0x6 /* offsetof(IMAGE_NT_HEADERS, FileHeader.NumberOfSections) */); | |
for (uint i = 0; i < numberOfSections; i++) | |
{ | |
uint sectionOffset = firstSectionOffset + i * 0x28 /* sizeof(IMAGE_SECTION_HEADER) */; | |
uint virtualAddress = accessor.ReadUInt32(sectionOffset + 0xc /* offsetof(IMAGE_SECTION_HEADER, VirtualAddress) */); | |
uint sizeOfRawData = accessor.ReadUInt32(sectionOffset + 0x10 /* offsetof(IMAGE_SECTION_HEADER, SizeOfRawData) */); | |
uint pointerToRawData = accessor.ReadUInt32(sectionOffset + 0x14 /* offsetof(IMAGE_SECTION_HEADER, PointerToRawData) */); | |
if (corHeaderRVA >= virtualAddress && corHeaderRVA < virtualAddress + sizeOfRawData) | |
{ | |
corHeaderOffset = corHeaderRVA - virtualAddress + pointerToRawData; | |
break; | |
} | |
} | |
if (corHeaderOffset == 0) | |
{ | |
Console.WriteLine("Invalid file."); | |
return; | |
} | |
uint nativeHeaderOffset = accessor.ReadUInt32(corHeaderOffset + 0x40 /* offsetof(IMAGE_COR20_HEADER, ManagedNativeHeader) */); | |
if (nativeHeaderOffset == 0) | |
{ | |
Console.WriteLine("Not a R2R file."); | |
return; | |
} | |
accessor.Write(corHeaderOffset + 0x40, (ulong)0); | |
} | |
} |
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