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author | Daniel Mueller <deso@posteo.net> | 2019-01-02 21:14:10 -0800 |
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committer | Daniel Mueller <deso@posteo.net> | 2019-01-02 21:14:10 -0800 |
commit | ecf3474223ca3d16a10f12dc2272e3b0ed72c1bb (patch) | |
tree | 03134a683791176b49ef5c92e8d6acd24c3b5a9b /rand/src/rngs/adapter/read.rs | |
parent | 686f61b75055ecb02baf9d9449525ae447a3bed1 (diff) | |
download | nitrocli-ecf3474223ca3d16a10f12dc2272e3b0ed72c1bb.tar.gz nitrocli-ecf3474223ca3d16a10f12dc2272e3b0ed72c1bb.tar.bz2 |
Update nitrokey crate to 0.2.3
This change updates the nitrokey crate to version 0.2.3. This version
bumps the rand crate used to 0.6.1, which in turn requires an additional
set of dependencies.
Import subrepo nitrokey/:nitrokey at b3e2adc5bb1300441ca74cc7672617c042f3ea31
Import subrepo rand/:rand at 73613ff903512e9503e41cc8ba9eae76269dc598
Import subrepo rustc_version/:rustc_version at 0294f2ba2018bf7be672abd53db351ce5055fa02
Import subrepo semver-parser/:semver-parser at 750da9b11a04125231b1fb293866ca036845acee
Import subrepo semver/:semver at 5eb6db94fa03f4d5c64a625a56188f496be47598
Diffstat (limited to 'rand/src/rngs/adapter/read.rs')
-rw-r--r-- | rand/src/rngs/adapter/read.rs | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/rand/src/rngs/adapter/read.rs b/rand/src/rngs/adapter/read.rs new file mode 100644 index 0000000..30b6de6 --- /dev/null +++ b/rand/src/rngs/adapter/read.rs @@ -0,0 +1,137 @@ +// Copyright 2018 Developers of the Rand project. +// Copyright 2013 The Rust Project Developers. +// +// 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. + +//! A wrapper around any Read to treat it as an RNG. + +use std::io::Read; + +use rand_core::{RngCore, Error, ErrorKind, impls}; + + +/// An RNG that reads random bytes straight from any type supporting +/// `std::io::Read`, for example files. +/// +/// This will work best with an infinite reader, but that is not required. +/// +/// This can be used with `/dev/urandom` on Unix but it is recommended to use +/// [`OsRng`] instead. +/// +/// # Panics +/// +/// `ReadRng` uses `std::io::read_exact`, which retries on interrupts. All other +/// errors from the underlying reader, including when it does not have enough +/// data, will only be reported through [`try_fill_bytes`]. The other +/// [`RngCore`] methods will panic in case of an error. +/// +/// # Example +/// +/// ``` +/// use rand::Rng; +/// use rand::rngs::adapter::ReadRng; +/// +/// let data = vec![1, 2, 3, 4, 5, 6, 7, 8]; +/// let mut rng = ReadRng::new(&data[..]); +/// println!("{:x}", rng.gen::<u32>()); +/// ``` +/// +/// [`OsRng`]: ../struct.OsRng.html +/// [`RngCore`]: ../../trait.RngCore.html +/// [`try_fill_bytes`]: ../../trait.RngCore.html#method.tymethod.try_fill_bytes +#[derive(Debug)] +pub struct ReadRng<R> { + reader: R +} + +impl<R: Read> ReadRng<R> { + /// Create a new `ReadRng` from a `Read`. + pub fn new(r: R) -> ReadRng<R> { + ReadRng { + reader: r + } + } +} + +impl<R: Read> RngCore for ReadRng<R> { + fn next_u32(&mut self) -> u32 { + impls::next_u32_via_fill(self) + } + + fn next_u64(&mut self) -> u64 { + impls::next_u64_via_fill(self) + } + + fn fill_bytes(&mut self, dest: &mut [u8]) { + self.try_fill_bytes(dest).unwrap_or_else(|err| + panic!("reading random bytes from Read implementation failed; error: {}", err)); + } + + fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> { + if dest.len() == 0 { return Ok(()); } + // Use `std::io::read_exact`, which retries on `ErrorKind::Interrupted`. + self.reader.read_exact(dest).map_err(|err| { + match err.kind() { + ::std::io::ErrorKind::UnexpectedEof => Error::with_cause( + ErrorKind::Unavailable, + "not enough bytes available, reached end of source", err), + _ => Error::with_cause(ErrorKind::Unavailable, + "error reading from Read source", err) + } + }) + } +} + +#[cfg(test)] +mod test { + use super::ReadRng; + use {RngCore, ErrorKind}; + + #[test] + fn test_reader_rng_u64() { + // transmute from the target to avoid endianness concerns. + let v = vec![0u8, 0, 0, 0, 0, 0, 0, 1, + 0 , 0, 0, 0, 0, 0, 0, 2, + 0, 0, 0, 0, 0, 0, 0, 3]; + let mut rng = ReadRng::new(&v[..]); + + assert_eq!(rng.next_u64(), 1_u64.to_be()); + assert_eq!(rng.next_u64(), 2_u64.to_be()); + assert_eq!(rng.next_u64(), 3_u64.to_be()); + } + + #[test] + fn test_reader_rng_u32() { + let v = vec![0u8, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3]; + let mut rng = ReadRng::new(&v[..]); + + assert_eq!(rng.next_u32(), 1_u32.to_be()); + assert_eq!(rng.next_u32(), 2_u32.to_be()); + assert_eq!(rng.next_u32(), 3_u32.to_be()); + } + + #[test] + fn test_reader_rng_fill_bytes() { + let v = [1u8, 2, 3, 4, 5, 6, 7, 8]; + let mut w = [0u8; 8]; + + let mut rng = ReadRng::new(&v[..]); + rng.fill_bytes(&mut w); + + assert!(v == w); + } + + #[test] + fn test_reader_rng_insufficient_bytes() { + let v = [1u8, 2, 3, 4, 5, 6, 7, 8]; + let mut w = [0u8; 9]; + + let mut rng = ReadRng::new(&v[..]); + + assert!(rng.try_fill_bytes(&mut w).err().unwrap().kind == ErrorKind::Unavailable); + } +} |