sha1collisiondetection 0.1.0

SHA-1 hash function with collision detection and mitigation
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
46
47

use sha1::Sha1;
use digest::Digest;
use sha1collisiondetection::Sha1CD;

fn initialize() -> digest::Output<Sha1CD> {
    let mut d = digest::Output::<Sha1CD>::default();
    getrandom::getrandom(&mut d[..]).unwrap();
    d
}

#[test]
fn short() {
    /// How often to run the test.
    const N: usize = 100_000;

    let mut d = initialize();
    for _ in 0..N {
        let a = Sha1::digest(&d);
        let b = Sha1CD::digest(&d);
        assert_eq!(a, b);
        d = a;
    }
}

#[test]
fn long() {
    /// How often to run the test.  Careful, quadratic runtime.
    const N: usize = 1_000;
    /// SHA1 divides input into blocks.
    const BS: usize = 64;

    let d = initialize();
    let mut buf = Vec::with_capacity(20 * N);
    buf.extend_from_slice(&d[..]);
    for i in 0..N {
        let input = if buf.len() > 2 * BS {
            // Exercise padding.
            &buf[..buf.len() - (i % BS)]
        } else {
            &buf[..]
        };
        let a = Sha1::digest(input);
        let b = Sha1CD::digest(input);
        assert_eq!(a, b);
        buf.extend_from_slice(&a[..]);
    }
}