Crate goblin

libgoblin

libgoblin is a cross-platform trifecta of binary parsing and loading fun. It supports:

• An ELF32/64 parser, and raw C structs
• A 32/64-bit, zero-copy, endian aware, Mach-o parser, and raw C structs
• A PE32/PE32+ (64-bit) parser, and raw C structs
• A Unix archive parser and loader

Goblin requires at least rustc 1.36.0, uses the 2018 rust edition, and is developed on stable.

Goblin primarily supports the following important use cases:

1. Core, std-free #[repr(C)] structs, tiny compile time, 32/64 (or both) at your leisure

2. Type punning. Define a function once on a type, but have it work on 32 or 64-bit variants - without really changing anything, and no macros! See examples/automagic.rs for a basic example.

3. std mode. This throws in read and write impls via Pread and Pwrite, reading from file, convenience allocations, extra methods, etc. This is for clients who can allocate and want to read binaries off disk.

4. Endian_fd. A truly terrible name :laughing: this is for binary analysis like in panopticon which needs to read binaries of foreign endianness, or as a basis for constructing cross platform foreign architecture binutils, e.g. cargo-sym and bingrep are simple examples of this, but the sky is the limit.

Example

use goblin::{error, Object};
use std::path::Path;
use std::env;
use std::fs;

fn run () -> error::Result<()> {
    for (i, arg) in env::args().enumerate() {
        if i == 1 {
            let path = Path::new(arg.as_str());
            let buffer = fs::read(path)?;
            match Object::parse(&buffer)? {
                Object::Elf(elf) => {
                    println!("elf: {:#?}", &elf);
                },
                Object::PE(pe) => {
                    println!("pe: {:#?}", &pe);
                },
                Object::Mach(mach) => {
                    println!("mach: {:#?}", &mach);
                },
                Object::Archive(archive) => {
                    println!("archive: {:#?}", &archive);
                },
                Object::Unknown(magic) => { println!("unknown magic: {:#x}", magic) }
            }
        }
    }
    Ok(())
}

Feature Usage

libgoblin is engineered to be tailored towards very different use-case scenarios, for example:

• a no-std mode; just simply set default features to false
• a endian aware parsing and reading
• for binary loaders which don’t require this, simply use elf32 and elf64 (and std of course)

For example, if you are writing a 64-bit kernel, or just want a barebones C-like header interface which defines the structures, just select elf64, --cfg feature="elf64", which will compile without std.

Similarly, if you want to use host endianness loading via the various from_fd methods, --cfg feature="std", which will not use the byteorder extern crate, and read the bytes from disk in the endianness of the host machine.

If you want endian aware reading, and you don’t use default, then you need to opt in as normal via endian_fd

Modules

• archive
  Implements a simple parser and extractor for a Unix Archive.
• container
  Binary container size information and byte-order context
• elf
  The generic ELF module, which gives access to ELF constants and other helper functions, which are independent of ELF bithood. Also defines an Elf struct which implements a unified parser that returns a wrapped Elf64 or Elf32 binary.
• elf32
  The ELF 32-bit struct definitions and associated values, re-exported for easy “type-punning”
• elf64
  The ELF 64-bit struct definitions and associated values, re-exported for easy “type-punning”
• error
  A custom Goblin error
• mach
  The Mach-o, mostly zero-copy, binary format parser and raw struct definitions
• pe
  A PE32 and PE32+ parser
• strtab
  A byte-offset based string table. Commonly used in ELF binaries, Unix archives, and even PE binaries.

Structs

• HintData
  Information obtained from a peek Hint

Enums

• Hint
  A hint at the underlying binary format for 16 bytes of arbitrary data
• Object
  A parseable object that goblin understands

Functions

• peek
  Peeks at the underlying Read object. Requires the underlying bytes to have at least 16 byte length. Resets the seek to Start after reading.
• peek_bytes
  Peeks at bytes, and returns a Hint