zig/lib/std/rand/Gimli.zig
Andrew Kelley d29871977f remove redundant license headers from zig standard library
We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.

Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
2021-08-24 12:25:09 -07:00

35 lines
958 B
Zig

//! CSPRNG
const std = @import("std");
const Random = std.rand.Random;
const mem = std.mem;
const Gimli = @This();
random: Random,
state: std.crypto.core.Gimli,
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) Gimli {
var initial_state: [std.crypto.core.Gimli.BLOCKBYTES]u8 = undefined;
mem.copy(u8, initial_state[0..secret_seed_length], &secret_seed);
mem.set(u8, initial_state[secret_seed_length..], 0);
var self = Gimli{
.random = Random{ .fillFn = fill },
.state = std.crypto.core.Gimli.init(initial_state),
};
return self;
}
fn fill(r: *Random, buf: []u8) void {
const self = @fieldParentPtr(Gimli, "random", r);
if (buf.len != 0) {
self.state.squeeze(buf);
} else {
self.state.permute();
}
mem.set(u8, self.state.toSlice()[0..std.crypto.core.Gimli.RATE], 0);
}