public static CompilationMode GetCompilationModeTruncatedWithExplanation(this FileInfo info)
{
if (!info.Exists)
{
throw new ArgumentException($"{info.FullName} does not exist");
}
var intPtr = IntPtr.Zero;
try
{
uint unmanagedBufferSize = 4096;
intPtr = Marshal.AllocHGlobal((int)unmanagedBufferSize);
using (var stream = new FileReaderStream(info.FullName))
{
stream.Read(intPtr, unmanagedBufferSize);
}
//Check DOS header magic number
if (Marshal.ReadInt16(intPtr) != Constants.PEMagic)
{
return(CompilationMode.Invalid);
}
// This will get the address for the WinNT header
var lfanewAddressOffset = Marshal.OffsetOf <IMAGE_DOS_HEADER>(nameof(IMAGE_DOS_HEADER.e_lfanew)).ToInt32();
var ntHeaderAddressOffset = Marshal.ReadInt32(intPtr + lfanewAddressOffset);
var ntHeaderAddress = intPtr + ntHeaderAddressOffset;
// Determine WinNT header signature number address
var signatureAddressOffset = Marshal.OffsetOf <IMAGE_NT_HEADERS32>(nameof(IMAGE_NT_HEADERS32.Signature)).ToInt32();
// Check WinNT header signature
var signature = Marshal.ReadInt32(ntHeaderAddress + signatureAddressOffset);
if (signature != Constants.NTHeaderSignature)
{
return(CompilationMode.Invalid);
}
//Determine file bitness by reading magic from IMAGE_OPTIONAL_HEADER
var optionalHeaderAddressOffset = Marshal.OffsetOf <IMAGE_NT_HEADERS32>(nameof(IMAGE_NT_HEADERS32.OptionalHeader)).ToInt32();
var magicValueAddressOffset = Marshal.OffsetOf <IMAGE_OPTIONAL_HEADER32>(nameof(IMAGE_OPTIONAL_HEADER32.Magic)).ToInt32();
var magic = (MagicType)Marshal.ReadInt16(ntHeaderAddress + optionalHeaderAddressOffset + magicValueAddressOffset);
//Check magic value is one of known MagicType values
if (Enum.GetValues(typeof(MagicType)).OfType <MagicType>().All(v => v != magic))
{
//Invalid magic
return(CompilationMode.Invalid);
}
var result = CompilationMode.Invalid;
uint clrHeaderSize = 0;
switch (magic)
{
case MagicType.IMAGE_NT_OPTIONAL_HDR32_MAGIC:
{
var optionalHeaderOffset = Marshal.OffsetOf <IMAGE_NT_HEADERS32>(nameof(IMAGE_NT_HEADERS32.OptionalHeader)).ToInt32();
var clrRuntimeHeaderOffset =
Marshal.OffsetOf <IMAGE_OPTIONAL_HEADER32>(nameof(IMAGE_OPTIONAL_HEADER32.CLRRuntimeHeader)).ToInt32();
var clrRuntimeHeaderImageDataDirectorySizeOffset =
Marshal.OffsetOf <IMAGE_DATA_DIRECTORY>(nameof(IMAGE_DATA_DIRECTORY.Size)).ToInt32();
clrHeaderSize = (uint)Marshal.ReadInt32(ntHeaderAddress +
optionalHeaderOffset +
clrRuntimeHeaderOffset +
clrRuntimeHeaderImageDataDirectorySizeOffset);
result |= CompilationMode.Bit32;
}
break;
case MagicType.IMAGE_NT_OPTIONAL_HDR64_MAGIC:
{
var optionalHeaderOffset = Marshal.OffsetOf <IMAGE_NT_HEADERS64>(nameof(IMAGE_NT_HEADERS64.OptionalHeader)).ToInt32();
var clrRuntimeHeaderOffset =
Marshal.OffsetOf <IMAGE_OPTIONAL_HEADER64>(nameof(IMAGE_OPTIONAL_HEADER64.CLRRuntimeHeader)).ToInt32();
var clrRuntimeHeaderImageDataDirectorySizeOffset =
Marshal.OffsetOf <IMAGE_DATA_DIRECTORY>(nameof(IMAGE_DATA_DIRECTORY.Size)).ToInt32();
clrHeaderSize = (uint)Marshal.ReadInt32(ntHeaderAddress +
optionalHeaderOffset +
clrRuntimeHeaderOffset +
clrRuntimeHeaderImageDataDirectorySizeOffset);
result |= CompilationMode.Bit64;
}
break;
}
result |= clrHeaderSize != 0
? CompilationMode.CLR
: CompilationMode.Native;
return(result);
}
finally
{
if (intPtr != IntPtr.Zero)
{
Marshal.FreeHGlobal(intPtr);
}
}
}
public static CompilationMode GetCompilationModeTruncated(this FileInfo info)
{
if (!info.Exists)
{
throw new ArgumentException($"{info.FullName} does not exist");
}
var intPtr = IntPtr.Zero;
try
{
uint unmanagedBufferSize = 4096;
intPtr = Marshal.AllocHGlobal((int)unmanagedBufferSize);
using (var stream = new FileReaderStream(info.FullName))
{
stream.Read(intPtr, unmanagedBufferSize);
}
//Check DOS header magic number
if (Marshal.ReadInt16(intPtr) != Constants.PEMagic)
{
return(CompilationMode.Invalid);
}
// This will get the address for the WinNT header
var ntHeaderAddressOffset = Marshal.ReadInt32(intPtr + 60);
// Check WinNT header signature
var signature = Marshal.ReadInt32(intPtr + ntHeaderAddressOffset);
if (signature != Constants.NTHeaderSignature)
{
return(CompilationMode.Invalid);
}
//Determine file bitness by reading magic from IMAGE_OPTIONAL_HEADER
var magic = (MagicType)Marshal.ReadInt16(intPtr + ntHeaderAddressOffset + 24);
//Check magic value is one of known MagicType values
if (Enum.GetValues(typeof(MagicType)).OfType <MagicType>().All(v => v != magic))
{
return(CompilationMode.Invalid);
}
var result = CompilationMode.Invalid;
uint clrHeaderSize = 0;
switch (magic)
{
case MagicType.IMAGE_NT_OPTIONAL_HDR32_MAGIC:
{
clrHeaderSize = (uint)Marshal.ReadInt32(intPtr + ntHeaderAddressOffset + 24 + 208 + 4);
result |= CompilationMode.Bit32;
}
break;
case MagicType.IMAGE_NT_OPTIONAL_HDR64_MAGIC:
{
clrHeaderSize = (uint)Marshal.ReadInt32(intPtr + ntHeaderAddressOffset + 24 + 224 + 4);
result |= CompilationMode.Bit64;
}
break;
}
result |= clrHeaderSize != 0
? CompilationMode.CLR
: CompilationMode.Native;
return(result);
}
finally
{
if (intPtr != IntPtr.Zero)
{
Marshal.FreeHGlobal(intPtr);
}
}
}