drillhash 0.1.0

Drillhash is an asic-resistant hashing algorithm for Ore.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45

use crate::{exit, read_noise};

use super::Op;

#[derive(Debug)]
pub struct Div {
    mask: u64,
    b: u64,
    r: u8,
}

impl Default for Div {
    fn default() -> Div {
        Div {
            mask: 0b_10101010_10101010_10101010_10101010_10101010_10101010_10101010_10101010,
            b: u64::from_le_bytes(core::array::from_fn(|i| b"ore"[i % 3])),
            r: 0b_01010101,
        }
    }
}

impl Op for Div {
    fn op(&mut self, addr: &mut u64, challenge: [u8; 32], nonce: [u8; 8], noise: &[u8]) -> bool {
        // Pre-arithmetic
        self.update_state(addr, challenge, nonce, noise);

        // Divide
        *addr =
            (addr.rotate_right(self.r.into()) ^ self.mask).wrapping_div(self.b.saturating_add(1));

        // Post-arithmetic
        self.update_state(addr, challenge, nonce, noise);

        // Exit code
        exit(addr)
    }

    fn update_state(&mut self, addr: &mut u64, challenge: [u8; 32], nonce: [u8; 8], noise: &[u8]) {
        self.mask ^= self.mask.rotate_right(1)
            ^ u64::from_le_bytes(read_noise(addr, challenge, nonce, noise));
        self.b ^=
            self.b.rotate_right(1) ^ u64::from_le_bytes(read_noise(addr, challenge, nonce, noise));
        self.r ^= self.mask.to_le_bytes()[7] ^ self.b.to_le_bytes()[7];
    }
}