random.rs

// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.

// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Parity.  If not, see <http://www.gnu.org/licenses/>.

use rand::distributions::Alphanumeric;
use rand::rngs::OsRng;
use rand::{Rng, RngCore};

pub trait Random {
    fn random() -> Self
    where
        Self: Sized;
}

impl Random for [u8; 16] {
    fn random() -> Self {
        let mut result = [0u8; 16];
        let mut rng = OsRng::new().unwrap();
        rng.fill_bytes(&mut result);
        result
    }
}

impl Random for [u8; 32] {
    fn random() -> Self {
        let mut result = [0u8; 32];
        let mut rng = OsRng::new().unwrap();
        rng.fill_bytes(&mut result);
        result
    }
}

/// Generate a random string of given length.
pub fn random_string(length: usize) -> String {
    let mut rng = OsRng::new().expect("Not able to operate without random source.");
    rng.sample_iter(&Alphanumeric).take(length).collect()
}