mirror of
https://github.com/ferrous-systems/embedded-trainings-2020.git
synced 2024-10-31 22:28:49 +00:00
9f7bfe3384
these are for the case where USB functionality fails and compromises the radio functionality
78 lines
2 KiB
Rust
78 lines
2 KiB
Rust
#![deny(unused_must_use)]
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#![no_main]
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#![no_std]
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use hal::{
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led,
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radio::{self, Channel, Packet},
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};
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use heapless::{consts, LinearMap};
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use panic_abort as _;
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static FROM: &[u8] = &[
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// <redacted>
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];
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static TO: &[u8] = &[
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// <redacted>
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];
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// store the secret rather than the plaintext -- otherwise `strings $elf` will reveal the answer
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static SECRET: &[u8] = b"<redacted>";
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#[no_mangle]
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fn main() -> ! {
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let (mut rtx, mut rrx) = radio::claim(Channel::_26);
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let led = led::Green;
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let mut dict = LinearMap::<_, _, consts::U128>::new();
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for (&from, &to) in FROM.iter().zip(TO.iter()) {
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dict.insert(from, to).ok();
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}
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let task = async {
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let mut packet = Packet::new().await;
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let mut on = true;
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loop {
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let crcres = rrx.read(&mut packet).await;
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// toggle LED on each new packet
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if on {
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led.on();
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} else {
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led.off();
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}
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on = !on;
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if crcres.is_ok() {
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if packet.is_empty() {
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packet.copy_from_slice(SECRET);
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} else if packet.len() == 1 {
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let p = packet[0];
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let c = dict.get(&p).unwrap_or(&p);
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packet.copy_from_slice(&[*c]);
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} else {
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// encrypt
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for slot in packet.iter_mut() {
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if let Some(c) = dict.get(slot) {
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*slot = *c;
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}
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}
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let matches = &packet[..] == SECRET;
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packet.copy_from_slice(if matches {
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led::Blue.on();
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b"correct"
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} else {
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led::Blue.off();
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b"incorrect"
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});
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}
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rtx.write(&packet).await.ok();
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}
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}
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};
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executor::run!(task)
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}
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