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authorDaniel Mueller <deso@posteo.net>2019-01-16 17:26:30 -0800
committerDaniel Mueller <deso@posteo.net>2019-01-16 17:26:30 -0800
commit8350ac6afb2d678b74581000a6aafe1994b72231 (patch)
tree2330da01a806921b3849c9e64d2b9f506495e2c0 /rand/rand_os/src/lib.rs
parentd6652b913b33e432a748187f9f5623cec1e9926e (diff)
downloadnitrocli-8350ac6afb2d678b74581000a6aafe1994b72231.tar.gz
nitrocli-8350ac6afb2d678b74581000a6aafe1994b72231.tar.bz2
Update nitrokey crate to 0.3.3
This change updates the nitrokey crate to version 0.3.3. Along with that change we update rand to 0.6.4 because rand 0.6.1 does not yet contain a publicly accessible rand_os. Note that we no longer require all crates in rand's workspace, but only rand_os and rand_core, which is a significant reduction in the number of lines of code compiled. Import subrepo nitrokey/:nitrokey at 7cf747d56ddc0b7eeedc3caf36dcc909907a171c Import subrepo rand/:rand at 4336232dda03323634b10ec72ddf27914aebc3a2
Diffstat (limited to 'rand/rand_os/src/lib.rs')
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+// Copyright 2018 Developers of the Rand project.
+// Copyright 2013-2015 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.
+
+//! Interface to the random number generator of the operating system.
+//!
+//! `OsRng` is the preferred external source of entropy for most applications.
+//! Commonly it is used to initialize a user-space RNG, which can then be used
+//! to generate random values with much less overhead than `OsRng`.
+//!
+//! You may prefer to use [`EntropyRng`] instead of `OsRng`. It is unlikely, but
+//! not entirely theoretical, for `OsRng` to fail. In such cases [`EntropyRng`]
+//! falls back on a good alternative entropy source.
+//!
+//! `OsRng::new()` is guaranteed to be very cheap (after the first successful
+//! call), and will never consume more than one file handle per process.
+//!
+//! # Usage example
+//! ```
+//! use rand_os::OsRng;
+//! use rand_os::rand_core::RngCore;
+//!
+//! let mut os_rng = OsRng::new().unwrap();
+//! let mut key = [0u8; 16];
+//! os_rng.fill_bytes(&mut key);
+//! let random_u64 = os_rng.next_u64();
+//! ```
+//!
+//! # Platform sources
+//!
+//! | OS | interface
+//! |------------------|---------------------------------------------------------
+//! | Linux, Android | [`getrandom`][1] system call if available, otherwise [`/dev/urandom`][2] after reading from `/dev/random` once
+//! | Windows | [`RtlGenRandom`][3]
+//! | macOS, iOS | [`SecRandomCopyBytes`][4]
+//! | FreeBSD | [`kern.arandom`][5]
+//! | OpenBSD, Bitrig | [`getentropy`][6]
+//! | NetBSD | [`/dev/urandom`][7] after reading from `/dev/random` once
+//! | Dragonfly BSD | [`/dev/random`][8]
+//! | Solaris, illumos | [`getrandom`][9] system call if available, otherwise [`/dev/random`][10]
+//! | Fuchsia OS | [`cprng_draw`][11]
+//! | Redox | [`rand:`][12]
+//! | CloudABI | [`random_get`][13]
+//! | Haiku | `/dev/random` (identical to `/dev/urandom`)
+//! | Web browsers | [`Crypto.getRandomValues`][14] (see [Support for WebAssembly and ams.js][14])
+//! | Node.js | [`crypto.randomBytes`][15] (see [Support for WebAssembly and ams.js][16])
+//!
+//! Rand doesn't have a blanket implementation for all Unix-like operating
+//! systems that reads from `/dev/urandom`. This ensures all supported operating
+//! systems are using the recommended interface and respect maximum buffer
+//! sizes.
+//!
+//! ## Support for WebAssembly and ams.js
+//!
+//! The three Emscripten targets `asmjs-unknown-emscripten`,
+//! `wasm32-unknown-emscripten` and `wasm32-experimental-emscripten` use
+//! Emscripten's emulation of `/dev/random` on web browsers and Node.js.
+//!
+//! The bare WASM target `wasm32-unknown-unknown` tries to call the javascript
+//! methods directly, using either `stdweb` or `wasm-bindgen` depending on what
+//! features are activated for this crate. Note that if both features are
+//! enabled `wasm-bindgen` will be used.
+//!
+//! ## Early boot
+//!
+//! It is possible that early in the boot process the OS hasn't had enough time
+//! yet to collect entropy to securely seed its RNG, especially on virtual
+//! machines.
+//!
+//! Some operating systems always block the thread until the RNG is securely
+//! seeded. This can take anywhere from a few seconds to more than a minute.
+//! Others make a best effort to use a seed from before the shutdown and don't
+//! document much.
+//!
+//! A few, Linux, NetBSD and Solaris, offer a choice between blocking, and
+//! getting an error. With `try_fill_bytes` we choose to get the error
+//! ([`ErrorKind::NotReady`]), while the other methods use a blocking interface.
+//!
+//! On Linux (when the `genrandom` system call is not available) and on NetBSD
+//! reading from `/dev/urandom` never blocks, even when the OS hasn't collected
+//! enough entropy yet. As a countermeasure we try to do a single read from
+//! `/dev/random` until we know the OS RNG is initialized (and store this in a
+//! global static).
+//!
+//! # Panics and error handling
+//!
+//! We cannot guarantee that `OsRng` will fail, but if it does, it will likely
+//! be either when `OsRng::new()` is first called or when data is first read.
+//! If you wish to catch errors early, then test reading of at least one byte
+//! from `OsRng` via [`try_fill_bytes`]. If this succeeds, it is extremely
+//! unlikely that any further errors will occur.
+//!
+//! Only [`try_fill_bytes`] is able to report the cause of an error; the other
+//! [`RngCore`] methods may (depending on the error kind) retry several times,
+//! but must eventually panic if the error persists.
+//!
+//! [`EntropyRng`]: ../rand/rngs/struct.EntropyRng.html
+//! [`RngCore`]: ../rand_core/trait.RngCore.html
+//! [`try_fill_bytes`]: ../rand_core/trait.RngCore.html#method.tymethod.try_fill_bytes
+//! [`ErrorKind::NotReady`]: ../rand_core/enum.ErrorKind.html#variant.NotReady
+//!
+//! [1]: http://man7.org/linux/man-pages/man2/getrandom.2.html
+//! [2]: http://man7.org/linux/man-pages/man4/urandom.4.html
+//! [3]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx
+//! [4]: https://developer.apple.com/documentation/security/1399291-secrandomcopybytes?language=objc
+//! [5]: https://www.freebsd.org/cgi/man.cgi?query=random&sektion=4
+//! [6]: https://man.openbsd.org/getentropy.2
+//! [7]: http://netbsd.gw.com/cgi-bin/man-cgi?random+4+NetBSD-current
+//! [8]: https://leaf.dragonflybsd.org/cgi/web-man?command=random&section=4
+//! [9]: https://docs.oracle.com/cd/E88353_01/html/E37841/getrandom-2.html
+//! [10]: https://docs.oracle.com/cd/E86824_01/html/E54777/random-7d.html
+//! [11]: https://fuchsia.googlesource.com/zircon/+/HEAD/docs/syscalls/cprng_draw.md
+//! [12]: https://github.com/redox-os/randd/blob/master/src/main.rs
+//! [13]: https://github.com/NuxiNL/cloudabi/blob/v0.20/cloudabi.txt#L1826
+//! [14]: https://www.w3.org/TR/WebCryptoAPI/#Crypto-method-getRandomValues
+//! [15]: https://nodejs.org/api/crypto.html#crypto_crypto_randombytes_size_callback
+//! [16]: #support-for-webassembly-and-amsjs
+#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk.png",
+ html_favicon_url = "https://www.rust-lang.org/favicon.ico",
+ html_root_url = "https://rust-random.github.io/rand/")]
+#![deny(missing_docs)]
+#![deny(missing_debug_implementations)]
+#![doc(test(attr(allow(unused_variables), deny(warnings))))]
+
+#![cfg_attr(feature = "stdweb", recursion_limit="128")]
+
+pub extern crate rand_core;
+#[cfg(feature = "log")]
+#[macro_use] extern crate log;
+
+// We have to do it here because we load macros
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten"),
+ feature = "wasm-bindgen"))]
+extern crate wasm_bindgen;
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten"),
+ not(feature = "wasm-bindgen"),
+ feature = "stdweb"))]
+#[macro_use] extern crate stdweb;
+
+#[cfg(target_env = "sgx")]
+extern crate rdrand;
+
+#[cfg(not(feature = "log"))]
+#[macro_use]
+mod dummy_log;
+
+use std::fmt;
+use rand_core::{CryptoRng, RngCore, Error, impls};
+
+/// A random number generator that retrieves randomness straight from the
+/// operating system.
+#[derive(Clone)]
+pub struct OsRng(imp::OsRng);
+
+impl fmt::Debug for OsRng {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ self.0.fmt(f)
+ }
+}
+
+impl OsRng {
+ /// Create a new `OsRng`.
+ pub fn new() -> Result<OsRng, Error> {
+ imp::OsRng::new().map(OsRng)
+ }
+}
+
+impl CryptoRng for OsRng {}
+
+impl RngCore for OsRng {
+ 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]) {
+ use std::{time, thread};
+
+ // We cannot return Err(..), so we try to handle before panicking.
+ const MAX_RETRY_PERIOD: u32 = 10; // max 10s
+ const WAIT_DUR_MS: u32 = 100; // retry every 100ms
+ let wait_dur = time::Duration::from_millis(WAIT_DUR_MS as u64);
+ const RETRY_LIMIT: u32 = (MAX_RETRY_PERIOD * 1000) / WAIT_DUR_MS;
+ const TRANSIENT_RETRIES: u32 = 8;
+ let mut err_count = 0;
+ let mut error_logged = false;
+
+ // Maybe block until the OS RNG is initialized
+ let mut read = 0;
+ if let Ok(n) = self.0.test_initialized(dest, true) { read = n };
+ let dest = &mut dest[read..];
+
+ loop {
+ if let Err(e) = self.try_fill_bytes(dest) {
+ if err_count >= RETRY_LIMIT {
+ error!("OsRng failed too many times; last error: {}", e);
+ panic!("OsRng failed too many times; last error: {}", e);
+ }
+
+ if e.kind.should_wait() {
+ if !error_logged {
+ warn!("OsRng failed; waiting up to {}s and retrying. Error: {}",
+ MAX_RETRY_PERIOD, e);
+ error_logged = true;
+ }
+ err_count += 1;
+ thread::sleep(wait_dur);
+ continue;
+ } else if e.kind.should_retry() {
+ if !error_logged {
+ warn!("OsRng failed; retrying up to {} times. Error: {}",
+ TRANSIENT_RETRIES, e);
+ error_logged = true;
+ }
+ err_count += (RETRY_LIMIT + TRANSIENT_RETRIES - 1)
+ / TRANSIENT_RETRIES; // round up
+ continue;
+ } else {
+ error!("OsRng failed: {}", e);
+ panic!("OsRng fatal error: {}", e);
+ }
+ }
+
+ break;
+ }
+ }
+
+ fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+ // Some systems do not support reading 0 random bytes.
+ // (And why waste a system call?)
+ if dest.len() == 0 { return Ok(()); }
+
+ let read = self.0.test_initialized(dest, false)?;
+ let dest = &mut dest[read..];
+
+ let max = self.0.max_chunk_size();
+ if dest.len() <= max {
+ trace!("OsRng: reading {} bytes via {}",
+ dest.len(), self.0.method_str());
+ } else {
+ trace!("OsRng: reading {} bytes via {} in {} chunks of {} bytes",
+ dest.len(), self.0.method_str(), (dest.len() + max) / max, max);
+ }
+ for slice in dest.chunks_mut(max) {
+ self.0.fill_chunk(slice)?;
+ }
+ Ok(())
+ }
+}
+
+trait OsRngImpl where Self: Sized {
+ // Create a new `OsRng` platform interface.
+ fn new() -> Result<Self, Error>;
+
+ // Fill a chunk with random bytes.
+ fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error>;
+
+ // Test whether the OS RNG is initialized. This method may not be possible
+ // to support cheaply (or at all) on all operating systems.
+ //
+ // If `blocking` is set, this will cause the OS the block execution until
+ // its RNG is initialized.
+ //
+ // Random values that are read while this are stored in `dest`, the amount
+ // of read bytes is returned.
+ fn test_initialized(&mut self, _dest: &mut [u8], _blocking: bool)
+ -> Result<usize, Error> { Ok(0) }
+
+ // Maximum chunk size supported.
+ fn max_chunk_size(&self) -> usize { ::std::usize::MAX }
+
+ // Name of the OS interface (used for logging).
+ fn method_str(&self) -> &'static str;
+}
+
+#[cfg(any(target_os = "linux", target_os = "android",
+ target_os = "netbsd", target_os = "dragonfly",
+ target_os = "solaris", target_os = "redox",
+ target_os = "haiku", target_os = "emscripten"))]
+mod random_device;
+
+macro_rules! mod_use {
+ ($cond:meta, $module:ident) => {
+ #[$cond]
+ mod $module;
+ #[$cond]
+ use $module as imp;
+ }
+}
+
+mod_use!(cfg(target_os = "android"), linux_android);
+mod_use!(cfg(target_os = "bitrig"), openbsd_bitrig);
+mod_use!(cfg(target_os = "cloudabi"), cloudabi);
+mod_use!(cfg(target_os = "dragonfly"), dragonfly_haiku_emscripten);
+mod_use!(cfg(target_os = "emscripten"), dragonfly_haiku_emscripten);
+mod_use!(cfg(target_os = "freebsd"), freebsd);
+mod_use!(cfg(target_os = "fuchsia"), fuchsia);
+mod_use!(cfg(target_os = "haiku"), dragonfly_haiku_emscripten);
+mod_use!(cfg(target_os = "ios"), macos);
+mod_use!(cfg(target_os = "linux"), linux_android);
+mod_use!(cfg(target_os = "macos"), macos);
+mod_use!(cfg(target_os = "netbsd"), netbsd);
+mod_use!(cfg(target_os = "openbsd"), openbsd_bitrig);
+mod_use!(cfg(target_os = "redox"), redox);
+mod_use!(cfg(target_os = "solaris"), solaris);
+mod_use!(cfg(windows), windows);
+mod_use!(cfg(target_env = "sgx"), sgx);
+
+mod_use!(
+ cfg(all(
+ target_arch = "wasm32",
+ not(target_os = "emscripten"),
+ feature = "wasm-bindgen"
+ )),
+ wasm32_bindgen
+);
+
+mod_use!(
+ cfg(all(
+ target_arch = "wasm32",
+ not(target_os = "emscripten"),
+ not(feature = "wasm-bindgen"),
+ feature = "stdweb",
+ )),
+ wasm32_stdweb
+);
+
+/// Per #678 we use run-time failure where WASM bindings are missing
+#[cfg(all(
+ target_arch = "wasm32",
+ not(target_os = "emscripten"),
+ not(feature = "wasm-bindgen"),
+ not(feature = "stdweb"),
+))]
+mod imp {
+ use rand_core::{Error, ErrorKind};
+ use super::OsRngImpl;
+
+ #[derive(Clone, Debug)]
+ pub struct OsRng;
+
+ impl OsRngImpl for OsRng {
+ fn new() -> Result<OsRng, Error> {
+ Err(Error::new(ErrorKind::Unavailable,
+ "OsRng: support for wasm32 requires emscripten, stdweb or wasm-bindgen"))
+ }
+
+ fn fill_chunk(&mut self, _dest: &mut [u8]) -> Result<(), Error> {
+ unimplemented!()
+ }
+
+ fn method_str(&self) -> &'static str { unimplemented!() }
+ }
+}
+
+#[cfg(not(any(
+ target_os = "android",
+ target_os = "bitrig",
+ target_os = "cloudabi",
+ target_os = "dragonfly",
+ target_os = "emscripten",
+ target_os = "freebsd",
+ target_os = "fuchsia",
+ target_os = "haiku",
+ target_os = "ios",
+ target_os = "linux",
+ target_os = "macos",
+ target_os = "netbsd",
+ target_os = "openbsd",
+ target_os = "redox",
+ target_os = "solaris",
+ windows,
+ target_arch = "wasm32",
+ target_env = "sgx"
+)))]
+compile_error!("OS RNG support is not available for this platform");
+
+// Due to rustwasm/wasm-bindgen#201 this can't be defined in the inner os
+// modules, so hack around it for now and place it at the root.
+#[cfg(all(feature = "wasm-bindgen", target_arch = "wasm32"))]
+#[doc(hidden)]
+#[allow(missing_debug_implementations)]
+pub mod __wbg_shims {
+
+ // `extern { type Foo; }` isn't supported on 1.22 syntactically, so use a
+ // macro to work around that.
+ macro_rules! rust_122_compat {
+ ($($t:tt)*) => ($($t)*)
+ }
+
+ rust_122_compat! {
+ extern crate wasm_bindgen;
+
+ pub use wasm_bindgen::prelude::*;
+
+ #[wasm_bindgen]
+ extern "C" {
+ pub type Function;
+ #[wasm_bindgen(constructor)]
+ pub fn new(s: &str) -> Function;
+ #[wasm_bindgen(method)]
+ pub fn call(this: &Function, self_: &JsValue) -> JsValue;
+
+ pub type This;
+ #[wasm_bindgen(method, getter, structural, js_name = self)]
+ pub fn self_(me: &This) -> JsValue;
+ #[wasm_bindgen(method, getter, structural)]
+ pub fn crypto(me: &This) -> JsValue;
+
+ #[derive(Clone, Debug)]
+ pub type BrowserCrypto;
+
+ // TODO: these `structural` annotations here ideally wouldn't be here to
+ // avoid a JS shim, but for now with feature detection they're
+ // unavoidable.
+ #[wasm_bindgen(method, js_name = getRandomValues, structural, getter)]
+ pub fn get_random_values_fn(me: &BrowserCrypto) -> JsValue;
+ #[wasm_bindgen(method, js_name = getRandomValues, structural)]
+ pub fn get_random_values(me: &BrowserCrypto, buf: &mut [u8]);
+
+ #[wasm_bindgen(js_name = require)]
+ pub fn node_require(s: &str) -> NodeCrypto;
+
+ #[derive(Clone, Debug)]
+ pub type NodeCrypto;
+
+ #[wasm_bindgen(method, js_name = randomFillSync, structural)]
+ pub fn random_fill_sync(me: &NodeCrypto, buf: &mut [u8]);
+ }
+ }
+}