shellcoder's Introduction

Shellcoder: Write shellcode payloads in a flash!

minimum supported Rust version: 1.61.0

Feature flags

shellcoder comes with the following feature flags:

name	description	enabled by default
`std`	Use the standard library. Gives access to I/O backed and `Vec` backed implementations.	`no`

Add `shellcoder` to your library

To add shellcoder to your Rust library, you can use Cargo:

$ cargo add shellcoder

Or alternatively, edit your Cargo.toml and add the following line under the dependencies section:

shellcoder = "0.1.0"

Examples

The following code writes a simple shellcode that comprises two addresses separated by a 8-byte gap. It uses the static implementation, i.e. no dynamic memory allocation is performed.

use shellcoder::{
    Op as _,
    Shellcoder as _,
};
use shellcoder::r#static::Shellcoder;
use shellcoder::Result;

pub fn main() -> Result<()> {
  // We define a scratch buffer to be used by [`Shellcoder`].
  let mut scratch_buffer = [0u8; 0x18];

  // We instantiate a _shellcoder_, the _static_ one.
  let mut shellcoder = Shellcoder::new(&mut scratch_buffer);

  // We build the shellcode.
  let shellcode = shellcoder
    .write_le(0x10000abccu64)? // writes little-endian encoded 0x10000abcc.
    .fill(8, b'A')?            // moves the cursor 8 bytes ahead,
                               // filling the gap with 'A'
    .write_le(0x10000fffc)?    // writes little-endian encoded 0x10000fffc.
    .get();

  assert_eq!(shellcode, &[
    0xcc, 0xab, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
    0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41,
    0xfc, 0xff, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
  ]);
  Ok(())
}