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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /third_party/rust/rand/src/rngs/std.rs | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/rand/src/rngs/std.rs')
-rw-r--r-- | third_party/rust/rand/src/rngs/std.rs | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/third_party/rust/rand/src/rngs/std.rs b/third_party/rust/rand/src/rngs/std.rs new file mode 100644 index 0000000000..cdae8fab01 --- /dev/null +++ b/third_party/rust/rand/src/rngs/std.rs @@ -0,0 +1,98 @@ +// Copyright 2018 Developers of the Rand project. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +//! The standard RNG + +use crate::{CryptoRng, Error, RngCore, SeedableRng}; + +pub(crate) use rand_chacha::ChaCha12Core as Core; + +use rand_chacha::ChaCha12Rng as Rng; + +/// The standard RNG. The PRNG algorithm in `StdRng` is chosen to be efficient +/// on the current platform, to be statistically strong and unpredictable +/// (meaning a cryptographically secure PRNG). +/// +/// The current algorithm used is the ChaCha block cipher with 12 rounds. Please +/// see this relevant [rand issue] for the discussion. This may change as new +/// evidence of cipher security and performance becomes available. +/// +/// The algorithm is deterministic but should not be considered reproducible +/// due to dependence on configuration and possible replacement in future +/// library versions. For a secure reproducible generator, we recommend use of +/// the [rand_chacha] crate directly. +/// +/// [rand_chacha]: https://crates.io/crates/rand_chacha +/// [rand issue]: https://github.com/rust-random/rand/issues/932 +#[cfg_attr(doc_cfg, doc(cfg(feature = "std_rng")))] +#[derive(Clone, Debug, PartialEq, Eq)] +pub struct StdRng(Rng); + +impl RngCore for StdRng { + #[inline(always)] + fn next_u32(&mut self) -> u32 { + self.0.next_u32() + } + + #[inline(always)] + fn next_u64(&mut self) -> u64 { + self.0.next_u64() + } + + #[inline(always)] + fn fill_bytes(&mut self, dest: &mut [u8]) { + self.0.fill_bytes(dest); + } + + #[inline(always)] + fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> { + self.0.try_fill_bytes(dest) + } +} + +impl SeedableRng for StdRng { + type Seed = <Rng as SeedableRng>::Seed; + + #[inline(always)] + fn from_seed(seed: Self::Seed) -> Self { + StdRng(Rng::from_seed(seed)) + } + + #[inline(always)] + fn from_rng<R: RngCore>(rng: R) -> Result<Self, Error> { + Rng::from_rng(rng).map(StdRng) + } +} + +impl CryptoRng for StdRng {} + + +#[cfg(test)] +mod test { + use crate::rngs::StdRng; + use crate::{RngCore, SeedableRng}; + + #[test] + fn test_stdrng_construction() { + // Test value-stability of StdRng. This is expected to break any time + // the algorithm is changed. + #[rustfmt::skip] + let seed = [1,0,0,0, 23,0,0,0, 200,1,0,0, 210,30,0,0, + 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; + + let target = [10719222850664546238, 14064965282130556830]; + + let mut rng0 = StdRng::from_seed(seed); + let x0 = rng0.next_u64(); + + let mut rng1 = StdRng::from_rng(rng0).unwrap(); + let x1 = rng1.next_u64(); + + assert_eq!([x0, x1], target); + } +} |