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Diffstat (limited to 'rand/rand_os/src/random_device.rs')
-rw-r--r-- | rand/rand_os/src/random_device.rs | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/rand/rand_os/src/random_device.rs b/rand/rand_os/src/random_device.rs deleted file mode 100644 index 5da9194..0000000 --- a/rand/rand_os/src/random_device.rs +++ /dev/null @@ -1,70 +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. - -//! Helper functions to read from a random device such as `/dev/urandom`. -//! -//! All instances use a single internal file handle, to prevent possible -//! exhaustion of file descriptors. -use rand_core::{Error, ErrorKind}; -use std::fs::File; -use std::io; -use std::io::Read; -use std::sync::{Once, Mutex, ONCE_INIT}; - -// TODO: remove outer Option when `Mutex::new(None)` is a constant expression -static mut READ_RNG_FILE: Option<Mutex<Option<File>>> = None; -static READ_RNG_ONCE: Once = ONCE_INIT; - -#[allow(unused)] -pub fn open<F>(path: &'static str, open_fn: F) -> Result<(), Error> - where F: Fn(&'static str) -> Result<File, io::Error> -{ - READ_RNG_ONCE.call_once(|| { - unsafe { READ_RNG_FILE = Some(Mutex::new(None)) } - }); - - // We try opening the file outside the `call_once` fn because we cannot - // clone the error, thus we must retry on failure. - - let mutex = unsafe { READ_RNG_FILE.as_ref().unwrap() }; - let mut guard = mutex.lock().unwrap(); - if (*guard).is_none() { - info!("OsRng: opening random device {}", path); - let file = open_fn(path).map_err(map_err)?; - *guard = Some(file); - }; - Ok(()) -} - -pub fn read(dest: &mut [u8]) -> Result<(), Error> { - // We expect this function only to be used after `random_device::open` - // was succesful. Therefore we can assume that our memory was set with a - // valid object. - let mutex = unsafe { READ_RNG_FILE.as_ref().unwrap() }; - let mut guard = mutex.lock().unwrap(); - let file = (*guard).as_mut().unwrap(); - - // Use `std::io::read_exact`, which retries on `ErrorKind::Interrupted`. - file.read_exact(dest).map_err(|err| { - Error::with_cause(ErrorKind::Unavailable, - "error reading random device", err) - }) - -} - -pub fn map_err(err: io::Error) -> Error { - match err.kind() { - io::ErrorKind::Interrupted => - Error::new(ErrorKind::Transient, "interrupted"), - io::ErrorKind::WouldBlock => - Error::with_cause(ErrorKind::NotReady, - "OS RNG not yet seeded", err), - _ => Error::with_cause(ErrorKind::Unavailable, - "error while opening random device", err) - } -} |