LibObjectFile

LibObjectFile is a .NET library to read, manipulate and write linker and executable object files (e.g ELF, COFF...)

NOTE: Currently LibObjectFile supports only the ELF object-file format

There is a longer term plan to support other file formats (e.g COFF, MACH-O) but as I don't have a need for them right now, it is left as an exercise for PR contributors! ;)

Usage

// Reads an ELF file
using var inStream = File.OpenRead("helloworld");
var elf = ElfObjectFile.Read(inStream);
foreach(var section in elf.Sections)
{
    Console.WriteLine(section.Name);
}
// Print the content of the ELF as readelf output
elf.Print(Console.Out);
// Write the ElfObjectFile to another file on the disk
using var outStream = File.OpenWrite("helloworld2");
elf.Write(outStream);

Features

• Good support for the ELF file format:
  • Correct handling of LSB/MSB
  • Read and write from/to a System.IO.Stream
  • Support the following sections:
    • String Table
    • Symbol Table
    • Relocation Table: supported I386, X86_64, ARM and AARCH64 relocations (others can be exposed by adding some mappings)
    • Note Table
    • Other sections fallback to ElfCustomSection
  • Program headers with or without sections
  • Print with readelf similar output
• Library requiring .NET netstandard2.1+ and compatible with netcoreapp3.0+

Documentation

The doc/readme.md explains how the library is designed and can be used.

Known Issues

PR Welcome if you are willing to contribute to one of these issues:

ELF

There are still a few missing implementation of ElfSection for completeness:

• Dynamic Linking Table (SHT_DYNAMIC)
• Version Symbol Table (SHT_VERSYM)
• Version Needs Table (SHT_VERNEED)

These sections are currently loaded as ElfCustomSection but should have their own ElfXXXTable (e.g ElfDynamicLinkingTable, ElfVersionSymbolTable...)

Other file formats

In a future version I would like to implement the following file format:

• COFF
• Mach-O
• Portable in Memory file format to easily convert between ELF/COFF/Mach-O file formats.

Download

LibObjectFile is available as a NuGet package:

Build

In order to build LibObjectFile, you need to have installed the .NET Core 3.0 SDK

License

This software is released under the BSD-Clause 2 license.

Author

Alexandre MUTEL aka xoofx