blob: 3e16f2a86415d9b8da4b8a461f4ba908561addb1 (
plain)
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
|
//! CSPRNG
const std = @import("std");
const Random = std.rand.Random;
const min = std.math.min;
const mem = std.mem;
const Xoodoo = @This();
const State = std.crypto.core.Xoodoo;
state: State,
const rate = 16;
pub const secret_seed_length = 32;
/// The seed must be uniform, secret and `secret_seed_length` bytes long.
pub fn init(secret_seed: [secret_seed_length]u8) Xoodoo {
var initial_state: [State.block_bytes]u8 = undefined;
mem.copy(u8, initial_state[0..secret_seed_length], &secret_seed);
mem.set(u8, initial_state[secret_seed_length..], 0);
var state = State.init(initial_state);
state.permute();
return Xoodoo{ .state = state };
}
pub fn random(self: *Xoodoo) Random {
return Random.init(self, fill);
}
pub fn fill(self: *Xoodoo, buf: []u8) void {
var i: usize = 0;
while (true) {
const left = buf.len - i;
const n = min(left, rate);
self.state.extract(buf[i..][0..n]);
if (left == 0) break;
self.state.permute();
i += n;
}
self.state.clear(0, rate);
self.state.permute();
}
|
