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Diffstat (limited to 'rand/src/rngs/mod.rs')
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diff --git a/rand/src/rngs/mod.rs b/rand/src/rngs/mod.rs deleted file mode 100644 index abf3243..0000000 --- a/rand/src/rngs/mod.rs +++ /dev/null @@ -1,119 +0,0 @@ -// 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. - -//! Random number generators and adapters -//! -//! ## Background: Random number generators (RNGs) -//! -//! Computers cannot produce random numbers from nowhere. We classify -//! random number generators as follows: -//! -//! - "True" random number generators (TRNGs) use hard-to-predict data sources -//! (e.g. the high-resolution parts of event timings and sensor jitter) to -//! harvest random bit-sequences, apply algorithms to remove bias and -//! estimate available entropy, then combine these bits into a byte-sequence -//! or an entropy pool. This job is usually done by the operating system or -//! a hardware generator (HRNG). -//! - "Pseudo"-random number generators (PRNGs) use algorithms to transform a -//! seed into a sequence of pseudo-random numbers. These generators can be -//! fast and produce well-distributed unpredictable random numbers (or not). -//! They are usually deterministic: given algorithm and seed, the output -//! sequence can be reproduced. They have finite period and eventually loop; -//! with many algorithms this period is fixed and can be proven sufficiently -//! long, while others are chaotic and the period depends on the seed. -//! - "Cryptographically secure" pseudo-random number generators (CSPRNGs) -//! are the sub-set of PRNGs which are secure. Security of the generator -//! relies both on hiding the internal state and using a strong algorithm. -//! -//! ## Traits and functionality -//! -//! All RNGs implement the [`RngCore`] trait, as a consequence of which the -//! [`Rng`] extension trait is automatically implemented. Secure RNGs may -//! additionally implement the [`CryptoRng`] trait. -//! -//! All PRNGs require a seed to produce their random number sequence. The -//! [`SeedableRng`] trait provides three ways of constructing PRNGs: -//! -//! - `from_seed` accepts a type specific to the PRNG -//! - `from_rng` allows a PRNG to be seeded from any other RNG -//! - `seed_from_u64` allows any PRNG to be seeded from a `u64` insecurely -//! - `from_entropy` securely seeds a PRNG from fresh entropy -//! -//! Use the [`rand_core`] crate when implementing your own RNGs. -//! -//! ## Our generators -//! -//! This crate provides several random number generators: -//! -//! - [`OsRng`] is an interface to the operating system's random number -//! source. Typically the operating system uses a CSPRNG with entropy -//! provided by a TRNG and some type of on-going re-seeding. -//! - [`ThreadRng`], provided by the [`thread_rng`] function, is a handle to a -//! thread-local CSPRNG with periodic seeding from [`OsRng`]. Because this -//! is local, it is typically much faster than [`OsRng`]. It should be -//! secure, though the paranoid may prefer [`OsRng`]. -//! - [`StdRng`] is a CSPRNG chosen for good performance and trust of security -//! (based on reviews, maturity and usage). The current algorithm is ChaCha20, -//! which is well established and rigorously analysed. -//! [`StdRng`] provides the algorithm used by [`ThreadRng`] but without -//! periodic reseeding. -//! - [`SmallRng`] is an **insecure** PRNG designed to be fast, simple, require -//! little memory, and have good output quality. -//! -//! The algorithms selected for [`StdRng`] and [`SmallRng`] may change in any -//! release and may be platform-dependent, therefore they should be considered -//! **not reproducible**. -//! -//! ## Additional generators -//! -//! **TRNGs**: The [`rdrand`] crate provides an interface to the RDRAND and -//! RDSEED instructions available in modern Intel and AMD CPUs. -//! The [`rand_jitter`] crate provides a user-space implementation of -//! entropy harvesting from CPU timer jitter, but is very slow and has -//! [security issues](https://github.com/rust-random/rand/issues/699). -//! -//! **PRNGs**: Several companion crates are available, providing individual or -//! families of PRNG algorithms. These provide the implementations behind -//! [`StdRng`] and [`SmallRng`] but can also be used directly, indeed *should* -//! be used directly when **reproducibility** matters. -//! Some suggestions are: [`rand_chacha`], [`rand_pcg`], [`rand_xoshiro`]. -//! A full list can be found by searching for crates with the [`rng` tag]. -//! -//! [`SmallRng`]: rngs::SmallRng -//! [`StdRng`]: rngs::StdRng -//! [`OsRng`]: rngs::OsRng -//! [`ThreadRng`]: rngs::ThreadRng -//! [`mock::StepRng`]: rngs::mock::StepRng -//! [`adapter::ReadRng`]: rngs::adapter::ReadRng -//! [`adapter::ReseedingRng`]: rngs::adapter::ReseedingRng -//! [`rdrand`]: https://crates.io/crates/rdrand -//! [`rand_jitter`]: https://crates.io/crates/rand_jitter -//! [`rand_chacha`]: https://crates.io/crates/rand_chacha -//! [`rand_pcg`]: https://crates.io/crates/rand_pcg -//! [`rand_xoshiro`]: https://crates.io/crates/rand_xoshiro -//! [`rng` tag]: https://crates.io/keywords/rng - -pub mod adapter; - -#[cfg(feature="std")] mod entropy; -pub mod mock; // Public so we don't export `StepRng` directly, making it a bit - // more clear it is intended for testing. -#[cfg(feature="small_rng")] -mod small; -mod std; -#[cfg(feature="std")] pub(crate) mod thread; - -#[allow(deprecated)] -#[cfg(feature="std")] pub use self::entropy::EntropyRng; - -#[cfg(feature="small_rng")] -pub use self::small::SmallRng; -pub use self::std::StdRng; -#[cfg(feature="std")] pub use self::thread::ThreadRng; - -#[cfg(feature="getrandom")] pub use rand_core::OsRng; |