Concurrent search of MD5-hashed IP through the entire IPv4 space in Rust

main.rs

// [dependencies]
// rust-crypto = "0.2.36"

extern crate crypto;
use std::thread;
use crypto::md5::Md5;
use crypto::digest::Digest;
use std::process;

fn main() {
    let wanted = "f0fdb4c3f58e3e3f"; // <- Modify me
    let n_threads = 8; // <- Modify me
    let mut threads = Vec::new();

    for i in 0..n_threads {
        let bs = 256/n_threads;
        threads.push(thread::spawn(move || {
            let start = bs*i;
            for ii in 0..bs {
                for j in 0..256 {
                    println!("{}{}.{}.", "\t".repeat(i), ii+start, j); 
                    for k in 0..256 {
                        for l in 0..256 {
                            let ip = format!("{}.{}.{}.{}", ii+start, j, k, l); 
                            let mut md5 = Md5::new();
                            md5.input_str(&ip);
                            let result = md5.result_str();
                            if result.as_str().starts_with(wanted) {
                                println!("MATCH! Hash: {} IP: {}", result, ip);
                                process::exit(0);
                            }
                        }
                    }
                }
            }
        }));
    }   
    threads.into_iter().map(|x| x.join().expect("Join failed.")).count();
}