codebreaker-rs

A Rust library to decrypt & encrypt any cheat code for CodeBreaker PS2.

Add the crate as a dependency to your Cargo.toml:

[dependencies]
codebreaker = "0.4"

Now you can start decrypting some codes:

use codebreaker::Codebreaker;

let input: Vec<(u32, u32)> = vec![
    (0x2043AFCC, 0x2411FFFF),
    (0x2A973DBD, 0x00000000),
    (0xB4336FA9, 0x4DFEFB79),
    (0x973E0B2A, 0xA7D4AF10),
];
let output: Vec<(u32, u32)> = vec![
    (0x2043AFCC, 0x2411FFFF),
    (0x201F6024, 0x00000000),
    (0xBEEFC0DE, 0x00000000),
    (0x2096F5B8, 0x000000BE),
];

let mut cb = Codebreaker::new();
for (i, code) in input.iter().enumerate() {
    assert_eq!(cb.auto_decrypt_code(code.0, code.1), output[i]);
}

Read the full documentation for more examples.

The codebreaker crate is no_std and currently supports little-endian targets only. The CB v7 implementation intentionally preserves byte-level behavior from the original C code.

• 2006: I cracked the CodeBreaker PS2 v7 code encryption by reverse-engineering MIPS R5900 assembly and converting it to C. I decrypted the first v7 codes on March 8 and released CB2crypt, a Windows tool built on that code, on March 23.
• 2007: Released cb2util in April, built on the same code, and extended it until 2013 to handle CodeBreaker's file formats.
• 2020: Ported the code to Rust for fun and profit and published it as this crate. I wrote about it in 7 Things I Learned From Porting a C Crypto Library to Rust.
• 2026: Checked against the CodeBreaker v9.2 firmware, mostly with Claude Code and Opus 5.5. A homegrown Ghidra script ran the firmware's own decryption code on more than 10,000 code lines and compared the results with this crate. This found two regressions in 0.4.0 and two older bugs, all fixed now, and added support for the FFFFFFFF lines that turn CB v7 off. A quirk in the firmware's RSA code and a rarely used encryption option are left out on purpose and explained in the code. Later cross-checked against CodeBreaker v10: the crypto primitives match v9.2, while beefcode rekeying and encryption-option handling differ.

Copyright (c) Mathias Lafeldt

Licensed under the Apache License, Version 2.0 or the MIT license, at your option.