1 // Copyright 2022 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 //! Helper functions around `rand`'s offerings for convenient test usage.
16 #![no_std]
17
18 extern crate alloc;
19
20 use alloc::vec::Vec;
21 use crypto_provider::{CryptoProvider, CryptoRng};
22 use log::info;
23 use rand::{Rng as _, SeedableRng};
24 pub use {rand, rand_pcg};
25
26 /// Returns a random Vec with the provided length.
random_vec<C: CryptoProvider>(rng: &mut C::CryptoRng, len: usize) -> Vec<u8>27 pub fn random_vec<C: CryptoProvider>(rng: &mut C::CryptoRng, len: usize) -> Vec<u8> {
28 let mut bytes = Vec::<u8>::new();
29 bytes.extend((0..len).map(|_| rng.gen::<u8>()));
30 bytes
31 }
32
33 /// Returns a random array with the provided length.
random_bytes<const B: usize, C: CryptoProvider>(rng: &mut C::CryptoRng) -> [u8; B]34 pub fn random_bytes<const B: usize, C: CryptoProvider>(rng: &mut C::CryptoRng) -> [u8; B] {
35 let mut bytes = [0; B];
36 rng.fill(bytes.as_mut_slice());
37 bytes
38 }
39
40 /// Uses a RustCrypto Rng to return a random Vec with the provided length
random_vec_rc<R: rand::Rng>(rng: &mut R, len: usize) -> Vec<u8>41 pub fn random_vec_rc<R: rand::Rng>(rng: &mut R, len: usize) -> Vec<u8> {
42 let mut bytes = Vec::<u8>::new();
43 bytes.extend((0..len).map(|_| rng.gen::<u8>()));
44 bytes
45 }
46
47 /// Uses a RustCrypto Rng to return random bytes with the provided length
random_bytes_rc<const B: usize, R: rand::Rng>(rng: &mut R) -> [u8; B]48 pub fn random_bytes_rc<const B: usize, R: rand::Rng>(rng: &mut R) -> [u8; B] {
49 let mut bytes = [0; B];
50 rng.fill(bytes.as_mut_slice());
51 bytes
52 }
53
54 /// Returns a fast rng seeded with the thread rng (which is itself seeded from the OS).
seeded_rng() -> rand_pcg::Pcg6455 pub fn seeded_rng() -> rand_pcg::Pcg64 {
56 let mut seed: <rand_pcg::Pcg64 as rand::SeedableRng>::Seed = Default::default();
57 rand::thread_rng().fill(&mut seed);
58 // print it out so if a test fails, the seed will be visible for further investigation
59 info!("seed: {:?}", seed);
60 rand_pcg::Pcg64::from_seed(seed)
61 }
62