LibObjectFile

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

NOTE: Currently LibObjectFile supports the following file format:

PE image file format (Portable Executable / DLL)

ELF object-file format

DWARF debugging format (version 4)

Archive ar file format (Common, GNU and BSD variants)

There is a longer term plan to support other file formats (e.g COFF, MACH-O, .lib) 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 = ElfFile.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 ElfFile to another file on the disk
using var outStream = File.OpenWrite("helloworld2");
elf.Write(outStream);

Features

Full support of Archive ar file format including Common, GNU and BSD variants.
Full support for the PE file format
- Support byte-to-byte roundtrip
- Read and write from/to a System.IO.Stream
- All PE Directories are supported
- PEFile.Relocate to relocate the image base of a PE file
- PEFile.Print to print the content of a PE file to a textual representation
- Support for calculating the checksum of a PE file
Good support for the ELF file format:
- Support byte-to-byte roundtrip
- Read and write from/to a System.IO.Stream
- Handling of LSB/MSB
- 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
Support for DWARF debugging format:
- Partial support of Version 4 (currently still the default for GCC)
- Support for the sections: .debug_info, .debug_line, .debug_aranges, .debug_abbrev and .debug_str
- Support for Dwarf expressions
- High level interface, automatic layout/offsets between sections.
- Integration with ELF to support easy reading/writing back
- Support for relocatable sections
Use of a Diagnostics API to validate file format (on read/before write)
Library requiring net8.0
- If you are looking for netstandard2.1 support you will need to use 0.4.0 version

Documentation

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

Download

LibObjectFile is available as a NuGet package:

Build

In order to build LibObjectFile, you need to have installed the .NET 8 SDK.

Running the tests require Ubuntu 22.04. dotnet test will work on Windows (via WSL) and on that version of Ubuntu. If you're using macOS or another Linux, there's a Dockerfile and a helper script under src to run tests in the right OS version.

License

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

Author

Alexandre MUTEL aka xoofx

Supporters

Supports this project with a monthly donation and help me continue improving it. [Become a supporter]

xoofx / LibObjectFile

readme