xorfiles

A command-line utility to XOR two files. Useful for certain types of CTF challenge.

Usage

./xorfiles FILE1 FILE2

Features

• XOR two files: xorfiles FILE1 FILE2
• XOR one file with stdin: xorfiles FILE1 < FILE2
• High throughput compared to Python and Ruby implementations

Installation

git clone https://github.com/sciguy16/xorfiles cargo build --release cargo run --release -- -h

Roadmap/Todo

• XOR file with stdin
• Optionally loop the shorter file (like a multi-byte XOR)
• Limit the number of bytes read/written
• Output to file
• Hexdump on the input and output stages
• Benchmark against C implementations
• Optimise the Ruby and Python benchmarks further for better competition

Benchmarks

Benchmarks run with a 1 GB file XORed with itself, generated with dd if=/dev/zero of=big_file bs=1M count=1000. The Rust version was tested in two operating modes: XOR two files together and one file with stdin.

The following command was used to measure the throughput: <implementation> big_file big_file | pv > /dev/null

| Implementation | Approx. throughput | |:--------------:|:------------------:| | Rust (files) | 6.5 MiB/s | | Rust (stdin) | 6.4 MiB/s | | Ruby | 2.45 MiB/s | | Python | 4.7 MiB/s |