Update nitrokey crate to 0.4.0

This change finally updates the version of the nitrokey crate that we
consume to 0.4.0. Along with that we update rand_core, one of its
dependencies, to 0.5.1. Further more we add cfg-if in version 0.1.10 and
getrandom in version 0.1.13, both of which are now new (non-development)
dependencies.

Import subrepo nitrokey/:nitrokey at e81057037e9b4f370b64c0a030a725bc6bdfb870
Import subrepo cfg-if/:cfg-if at 4484a6faf816ff8058088ad857b0c6bb2f4b02b2
Import subrepo getrandom/:getrandom at d661aa7e1b8cc80b47dabe3d2135b3b47d2858af
Import subrepo rand/:rand at d877ed528248b52d947e0484364a4e1ae59ca502

21 files changed, 96 insertions, 1591 deletions

diff --git a/rand/rand_os/CHANGELOG.md b/rand/rand_os/CHANGELOG.md
index 459f7bd..b0c6549 100644
--- a/rand/rand_os/CHANGELOG.md
+++ b/rand/rand_os/CHANGELOG.md
@@ -4,9 +4,31 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.2.2] - 2019-09-02
+### Changed
+- `OsRng` added to `rand_core`, rendering this crate deprecated (#863)
+
+## [0.2.1] - 2019-08-08
+### Fixed
+- Fix `no_std` support.
+
+## [0.2.0] - 2019-06-06
+### Changed
+- Minimum Supported Rust Version has changed to 1.32.
+- Replaced implementation with a backwards-compatible shim around
+[getrandom](https://crates.io/crates/getrandom).
+
+## [0.1.3] - 2019-03-05
+### Fixed
+- Fix support for Illumos (#730)
+- Fix deprecation warnings from atomic init (#739)
+
+## [0.1.2] - 2019-01-28
+### Changed
+- Fuchsia: Replaced fuchsia-zircon with fuchsia-cprng
 
 ## [0.1.1] - 2019-01-08
-### Additions
+### Added
 - Add support for x86_64-fortanix-unknown-sgx target (#670)
 
 ## [0.1.0] - 2019-01-04
diff --git a/rand/rand_os/Cargo.toml b/rand/rand_os/Cargo.toml
index 2f9224a..c8010e2 100644
--- a/rand/rand_os/Cargo.toml
+++ b/rand/rand_os/Cargo.toml
@@ -1,38 +1,26 @@
 [package]
 name = "rand_os"
-version = "0.1.1"
+version = "0.2.2"
 authors = ["The Rand Project Developers"]
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 readme = "README.md"
 repository = "https://github.com/rust-random/rand"
 documentation = "https://docs.rs/rand_os"
 homepage = "https://crates.io/crates/rand_os"
 description = "OS backed Random Number Generator"
 keywords = ["random", "rng", "os"]
+edition = "2018"
 
 [badges]
 travis-ci = { repository = "rust-random/rand" }
 appveyor = { repository = "rust-random/rand" }
 
-[dependencies]
-rand_core = { path = "../rand_core", version = "0.3", default-features = false }
-log = { version = "0.4", optional = true }
-
-[target.'cfg(unix)'.dependencies]
-libc = "0.2"
-
-[target.'cfg(windows)'.dependencies]
-winapi = { version = "0.3", features = ["minwindef", "ntsecapi", "winnt"] }
-
-[target.'cfg(target_os = "cloudabi")'.dependencies]
-cloudabi = "0.0.3"
+[features]
+log = ["getrandom/log"]
+# re-export optional WASM dependencies to avoid breakage:
+wasm-bindgen = ["getrandom/wasm-bindgen"]
+stdweb = ["getrandom/stdweb"]
 
-[target.'cfg(target_os = "fuchsia")'.dependencies]
-fuchsia-zircon = "0.3.2"
-
-[target.wasm32-unknown-unknown.dependencies]
-wasm-bindgen = { version = "0.2.12", optional = true }
-stdweb = { version = "0.4", optional = true }
-
-[target.'cfg(target_env = "sgx")'.dependencies]
-rdrand = "0.4.0"
+[dependencies]
+rand_core = { path = "../rand_core", version = "0.5", features = ["getrandom"] }
+getrandom = "0.1.1"
diff --git a/rand/rand_os/README.md b/rand/rand_os/README.md
index 4f48b63..7b68b35 100644
--- a/rand/rand_os/README.md
+++ b/rand/rand_os/README.md
@@ -6,23 +6,25 @@
 [![Book](https://img.shields.io/badge/book-master-yellow.svg)](https://rust-random.github.io/book/)
 [![API](https://img.shields.io/badge/api-master-yellow.svg)](https://rust-random.github.io/rand/rand_os)
 [![API](https://docs.rs/rand_os/badge.svg)](https://docs.rs/rand_os)
-[![Minimum rustc version](https://img.shields.io/badge/rustc-1.22+-lightgray.svg)](https://github.com/rust-random/rand#rust-version-requirements)
+[![Minimum rustc version](https://img.shields.io/badge/rustc-1.32+-lightgray.svg)](https://github.com/rust-random/rand#rust-version-requirements)
 
 A random number generator that retrieves randomness straight from the
 operating system.
 
-This crate depends on [rand_core](https://crates.io/crates/rand_core) and is
-part of the [Rand project](https://github.com/rust-random/rand).
+**This crate is deprecated:** `OsRng` is available in `rand_core` since version 0.5.1.
 
-This crate aims to support all of Rust's `std` platforms with a system-provided
-entropy source. Unlike other Rand crates, this crate does not support `no_std`
-(handling this gracefully is a current discussion topic).
+This crate provides `OsRng` as a shim around
+[getrandom](https://crates.io/crates/getrandom)
+implementing `RngCore` from [rand_core](https://crates.io/crates/rand_core).
+
+Note: the `rand` crate provides an equivalent `OsRng`; the two implementations
+are equivalent, though distinct types.
 
 Links:
 
 -   [API documentation (master)](https://rust-random.github.io/rand/rand_os)
 -   [API documentation (docs.rs)](https://docs.rs/rand_os)
--   [Changelog](CHANGELOG.md)
+-   [Changelog](https://github.com/rust-random/rand/blob/master/rand_os/CHANGELOG.md)
 
 ## License
 
diff --git a/rand/rand_os/src/cloudabi.rs b/rand/rand_os/src/cloudabi.rs
deleted file mode 100644
index 8b96a2b..0000000
--- a/rand/rand_os/src/cloudabi.rs
+++ /dev/null
@@ -1,39 +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.
-
-//! Implementation for CloudABI
-
-extern crate cloudabi;
-
-use std::io;
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-#[derive(Clone, Debug)]
-pub struct OsRng;
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> { Ok(OsRng) }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let errno = unsafe { cloudabi::random_get(dest) };
-        if errno == cloudabi::errno::SUCCESS {
-            Ok(())
-        } else {
-            // Cloudlibc provides its own `strerror` implementation so we
-            // can use `from_raw_os_error` here.
-            Err(Error::with_cause(
-                ErrorKind::Unavailable,
-                "random_get() system call failed",
-                io::Error::from_raw_os_error(errno as i32),
-            ))
-        }
-    }
-
-    fn method_str(&self) -> &'static str { "cloudabi::random_get" }
-}
diff --git a/rand/rand_os/src/dragonfly_haiku_emscripten.rs b/rand/rand_os/src/dragonfly_haiku_emscripten.rs
deleted file mode 100644
index 6132d7a..0000000
--- a/rand/rand_os/src/dragonfly_haiku_emscripten.rs
+++ /dev/null
@@ -1,39 +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.
-
-//! Implementation for DragonFly / Haiku / Emscripten
-
-use rand_core::Error;
-use super::random_device;
-use super::OsRngImpl;
-use std::fs::File;
-
-#[derive(Clone, Debug)]
-pub struct OsRng();
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        random_device::open("/dev/random", &|p| File::open(p))?;
-        Ok(OsRng())
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        random_device::read(dest)
-    }
-
-    #[cfg(target_os = "emscripten")]
-    fn max_chunk_size(&self) -> usize {
-        // `Crypto.getRandomValues` documents `dest` should be at most 65536
-        // bytes. `crypto.randomBytes` documents: "To minimize threadpool
-        // task length variation, partition large randomBytes requests when
-        // doing so as part of fulfilling a client request.
-        65536
-    }
-
-    fn method_str(&self) -> &'static str { "/dev/random" }
-}
diff --git a/rand/rand_os/src/dummy_log.rs b/rand/rand_os/src/dummy_log.rs
deleted file mode 100644
index ccfe4ba..0000000
--- a/rand/rand_os/src/dummy_log.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-#[allow(unused)]
-macro_rules! trace { ($($x:tt)*) => () }
-#[allow(unused)]
-macro_rules! debug { ($($x:tt)*) => () }
-#[allow(unused)]
-macro_rules! info { ($($x:tt)*) => () }
-#[allow(unused)]
-macro_rules! warn { ($($x:tt)*) => () }
-#[allow(unused)]
-macro_rules! error { ($($x:tt)*) => () }
diff --git a/rand/rand_os/src/freebsd.rs b/rand/rand_os/src/freebsd.rs
deleted file mode 100644
index 6b8e672..0000000
--- a/rand/rand_os/src/freebsd.rs
+++ /dev/null
@@ -1,45 +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.
-
-//! Implementation for FreeBSD
-
-extern crate libc;
-
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-use std::ptr;
-use std::io;
-
-#[derive(Clone, Debug)]
-pub struct OsRng;
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> { Ok(OsRng) }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let mib = [libc::CTL_KERN, libc::KERN_ARND];
-        let mut len = dest.len();
-        let ret = unsafe {
-            libc::sysctl(mib.as_ptr(), mib.len() as libc::c_uint,
-                         dest.as_mut_ptr() as *mut _, &mut len,
-                         ptr::null(), 0)
-        };
-        if ret == -1 || len != dest.len() {
-            return Err(Error::with_cause(
-                ErrorKind::Unavailable,
-                "kern.arandom sysctl failed",
-                io::Error::last_os_error()));
-        }
-        Ok(())
-    }
-
-    fn max_chunk_size(&self) -> usize { 256 }
-
-    fn method_str(&self) -> &'static str { "kern.arandom" }
-}
diff --git a/rand/rand_os/src/fuchsia.rs b/rand/rand_os/src/fuchsia.rs
deleted file mode 100644
index 7063ff6..0000000
--- a/rand/rand_os/src/fuchsia.rs
+++ /dev/null
@@ -1,43 +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.
-
-//! Implementation for Fuchsia Zircon
-
-extern crate fuchsia_zircon;
-
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-#[derive(Clone, Debug)]
-pub struct OsRng;
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> { Ok(OsRng) }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let mut read = 0;
-        while read < dest.len() {
-            match fuchsia_zircon::cprng_draw(&mut dest[read..]) {
-                Ok(actual) => read += actual,
-                Err(e) => {
-                    return Err(Error::with_cause(
-                        ErrorKind::Unavailable,
-                        "cprng_draw failed",
-                        e.into_io_error()));
-                }
-            };
-        }
-        Ok(())
-    }
-
-    fn max_chunk_size(&self) -> usize {
-        fuchsia_zircon::sys::ZX_CPRNG_DRAW_MAX_LEN
-    }
-
-    fn method_str(&self) -> &'static str { "cprng_draw" }
-}
diff --git a/rand/rand_os/src/lib.rs b/rand/rand_os/src/lib.rs
index 67b0dfe..abfdf79 100644
--- a/rand/rand_os/src/lib.rs
+++ b/rand/rand_os/src/lib.rs
@@ -8,118 +8,8 @@
 // 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
+// Note: keep this code in sync with the rand::rngs::os module!
+
 #![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/")]
@@ -127,46 +17,54 @@
 #![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;
+#![no_std]  // but see getrandom crate
 
-#[cfg(target_env = "sgx")]
-extern crate rdrand;
+#![deprecated(since="0.2.2", note="OsRng is now provided by rand_core and rand")]
 
-#[cfg(not(feature = "log"))]
-#[macro_use]
-mod dummy_log;
+pub use rand_core;  // re-export
 
-use std::fmt;
+use getrandom::getrandom;
 use rand_core::{CryptoRng, RngCore, Error, impls};
 
-/// A random number generator that retrieves randomness straight from the
+/// A random number generator that retrieves randomness from 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)
-    }
-}
+///
+/// This is a zero-sized struct. It can be freely constructed with `OsRng`.
+///
+/// The implementation is provided by the [getrandom] crate. Refer to
+/// [getrandom] documentation for details.
+///
+/// # Blocking and error handling
+///
+/// It is possible that when used during early boot the first call to `OsRng`
+/// will block until the system's RNG is initialised. It is also possible
+/// (though highly unlikely) for `OsRng` to fail on some platforms, most
+/// likely due to system mis-configuration.
+///
+/// After the first successful call, it is highly unlikely that failures or
+/// significant delays will occur (although performance should be expected to
+/// be much slower than a user-space PRNG).
+///
+/// # Usage example
+/// ```
+/// #![allow(deprecated)]
+/// use rand_os::rand_core::RngCore;
+/// use rand_os::OsRng;
+///
+/// let mut key = [0u8; 16];
+/// OsRng.fill_bytes(&mut key);
+/// let random_u64 = OsRng.next_u64();
+/// ```
+///
+/// [getrandom]: https://crates.io/crates/getrandom
+#[derive(Clone, Copy, Debug, Default)]
+pub struct OsRng;
 
 impl OsRng {
     /// Create a new `OsRng`.
+    #[deprecated(since="0.2.0", note="replace OsRng::new().unwrap() with just OsRng")]
     pub fn new() -> Result<OsRng, Error> {
-        imp::OsRng::new().map(OsRng)
+        Ok(OsRng)
     }
 }
 
@@ -182,258 +80,27 @@ impl RngCore for OsRng {
     }
 
     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;
+        if let Err(e) = self.try_fill_bytes(dest) {
+            panic!("Error: {}", e);
         }
     }
 
     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)?;
-        }
+        getrandom(dest)?;
         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!() }
-    }
+#[test]
+fn test_os_rng() {
+    let x = OsRng.next_u64();
+    let y = OsRng.next_u64();
+    assert!(x != 0);
+    assert!(x != y);
 }
 
-#[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]);
-        }
-    }
+#[test]
+fn test_construction() {
+    let mut rng = OsRng::default();
+    assert!(rng.next_u64() != 0);
 }
diff --git a/rand/rand_os/src/linux_android.rs b/rand/rand_os/src/linux_android.rs
deleted file mode 100644
index 9622f93..0000000
--- a/rand/rand_os/src/linux_android.rs
+++ /dev/null
@@ -1,182 +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.
-
-//! Implementation for Linux / Android
-
-extern crate libc;
-
-use rand_core::{Error, ErrorKind};
-use super::random_device;
-use super::OsRngImpl;
-
-use std::io;
-use std::io::Read;
-use std::fs::{File, OpenOptions};
-use std::os::unix::fs::OpenOptionsExt;
-use std::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
-use std::sync::{Once, ONCE_INIT};
-
-#[derive(Clone, Debug)]
-pub struct OsRng {
-    method: OsRngMethod,
-    initialized: bool,
-}
-
-#[derive(Clone, Debug)]
-enum OsRngMethod {
-    GetRandom,
-    RandomDevice,
-}
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        if is_getrandom_available() {
-            return Ok(OsRng { method: OsRngMethod::GetRandom,
-                              initialized: false });
-        }
-        random_device::open("/dev/urandom", &|p| File::open(p))?;
-        Ok(OsRng { method: OsRngMethod::RandomDevice, initialized: false })
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        match self.method {
-            OsRngMethod::GetRandom => getrandom_try_fill(dest, false),
-            OsRngMethod::RandomDevice => random_device::read(dest),
-        }
-    }
-
-    fn test_initialized(&mut self, dest: &mut [u8], blocking: bool)
-        -> Result<usize, Error>
-    {
-        static OS_RNG_INITIALIZED: AtomicBool = ATOMIC_BOOL_INIT;
-        if !self.initialized {
-            self.initialized = OS_RNG_INITIALIZED.load(Ordering::Relaxed);
-        }
-        if self.initialized { return Ok(0); }
-
-        let result = match self.method {
-            OsRngMethod::GetRandom => {
-                getrandom_try_fill(dest, blocking)?;
-                Ok(dest.len())
-            }
-            OsRngMethod::RandomDevice => {
-                info!("OsRng: testing random device /dev/random");
-                let mut file = OpenOptions::new()
-                    .read(true)
-                    .custom_flags(if blocking { 0 } else { libc::O_NONBLOCK })
-                    .open("/dev/random")
-                    .map_err(random_device::map_err)?;
-                file.read(&mut dest[..1]).map_err(random_device::map_err)?;
-                Ok(1)
-            }
-        };
-        OS_RNG_INITIALIZED.store(true, Ordering::Relaxed);
-        self.initialized = true;
-        result
-    }
-
-    fn method_str(&self) -> &'static str {
-        match self.method {
-            OsRngMethod::GetRandom => "getrandom",
-            OsRngMethod::RandomDevice => "/dev/urandom",
-        }
-    }
-}
-
-#[cfg(target_arch = "x86_64")]
-const NR_GETRANDOM: libc::c_long = 318;
-#[cfg(target_arch = "x86")]
-const NR_GETRANDOM: libc::c_long = 355;
-#[cfg(target_arch = "arm")]
-const NR_GETRANDOM: libc::c_long = 384;
-#[cfg(target_arch = "aarch64")]
-const NR_GETRANDOM: libc::c_long = 278;
- #[cfg(target_arch = "s390x")]
-const NR_GETRANDOM: libc::c_long = 349;
-#[cfg(target_arch = "powerpc")]
-const NR_GETRANDOM: libc::c_long = 359;
-#[cfg(target_arch = "powerpc64")]
-const NR_GETRANDOM: libc::c_long = 359;
-#[cfg(target_arch = "mips")] // old ABI
-const NR_GETRANDOM: libc::c_long = 4353;
-#[cfg(target_arch = "mips64")]
-const NR_GETRANDOM: libc::c_long = 5313;
-#[cfg(target_arch = "sparc")]
-const NR_GETRANDOM: libc::c_long = 347;
-#[cfg(target_arch = "sparc64")]
-const NR_GETRANDOM: libc::c_long = 347;
-#[cfg(not(any(target_arch = "x86_64", target_arch = "x86",
-              target_arch = "arm", target_arch = "aarch64",
-              target_arch = "s390x", target_arch = "powerpc",
-              target_arch = "powerpc64", target_arch = "mips",
-              target_arch = "mips64", target_arch = "sparc",
-              target_arch = "sparc64")))]
-const NR_GETRANDOM: libc::c_long = 0;
-
-fn getrandom(buf: &mut [u8], blocking: bool) -> libc::c_long {
-    const GRND_NONBLOCK: libc::c_uint = 0x0001;
-
-    if NR_GETRANDOM == 0 { return -1 };
-
-    unsafe {
-        libc::syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(),
-                      if blocking { 0 } else { GRND_NONBLOCK })
-    }
-}
-
-fn getrandom_try_fill(dest: &mut [u8], blocking: bool) -> Result<(), Error> {
-    let mut read = 0;
-    while read < dest.len() {
-        let result = getrandom(&mut dest[read..], blocking);
-        if result == -1 {
-            let err = io::Error::last_os_error();
-            let kind = err.kind();
-            if kind == io::ErrorKind::Interrupted {
-                continue;
-            } else if kind == io::ErrorKind::WouldBlock {
-                return Err(Error::with_cause(
-                    ErrorKind::NotReady,
-                    "getrandom not ready",
-                    err,
-                ));
-            } else {
-                return Err(Error::with_cause(
-                    ErrorKind::Unavailable,
-                    "unexpected getrandom error",
-                    err,
-                ));
-            }
-        } else {
-            read += result as usize;
-        }
-    }
-    Ok(())
-}
-
-fn is_getrandom_available() -> bool {
-    static CHECKER: Once = ONCE_INIT;
-    static AVAILABLE: AtomicBool = ATOMIC_BOOL_INIT;
-
-    if NR_GETRANDOM == 0 { return false };
-
-    CHECKER.call_once(|| {
-        debug!("OsRng: testing getrandom");
-        let mut buf: [u8; 0] = [];
-        let result = getrandom(&mut buf, false);
-        let available = if result == -1 {
-            let err = io::Error::last_os_error().raw_os_error();
-            err != Some(libc::ENOSYS)
-        } else {
-            true
-        };
-        AVAILABLE.store(available, Ordering::Relaxed);
-        info!("OsRng: using {}", if available { "getrandom" } else { "/dev/urandom" });
-    });
-
-    AVAILABLE.load(Ordering::Relaxed)
-}
diff --git a/rand/rand_os/src/macos.rs b/rand/rand_os/src/macos.rs
deleted file mode 100644
index 6c67251..0000000
--- a/rand/rand_os/src/macos.rs
+++ /dev/null
@@ -1,53 +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.
-
-//! Implementation for MacOS / iOS
-
-extern crate libc;
-
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-use std::io;
-use self::libc::{c_int, size_t};
-
-#[derive(Clone, Debug)]
-pub struct OsRng;
-
-enum SecRandom {}
-
-#[allow(non_upper_case_globals)]
-const kSecRandomDefault: *const SecRandom = 0 as *const SecRandom;
-
-#[link(name = "Security", kind = "framework")]
-extern {
-    fn SecRandomCopyBytes(rnd: *const SecRandom,
-                          count: size_t, bytes: *mut u8) -> c_int;
-}
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> { Ok(OsRng) }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let ret = unsafe {
-            SecRandomCopyBytes(kSecRandomDefault,
-                               dest.len() as size_t,
-                               dest.as_mut_ptr())
-        };
-        if ret == -1 {
-            Err(Error::with_cause(
-                ErrorKind::Unavailable,
-                "couldn't generate random bytes",
-                io::Error::last_os_error()))
-        } else {
-            Ok(())
-        }
-    }
-
-    fn method_str(&self) -> &'static str { "SecRandomCopyBytes" }
-}
diff --git a/rand/rand_os/src/netbsd.rs b/rand/rand_os/src/netbsd.rs
deleted file mode 100644
index cf4b6c7..0000000
--- a/rand/rand_os/src/netbsd.rs
+++ /dev/null
@@ -1,54 +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.
-
-//! Implementation for NetBSD
-
-use rand_core::Error;
-use super::random_device;
-use super::OsRngImpl;
-
-use std::fs::File;
-use std::io::Read;
-use std::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
-
-#[derive(Clone, Debug)]
-pub struct OsRng { initialized: bool }
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        random_device::open("/dev/urandom", &|p| File::open(p))?;
-        Ok(OsRng { initialized: false })
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        random_device::read(dest)
-    }
-
-    // Read a single byte from `/dev/random` to determine if the OS RNG is
-    // already seeded. NetBSD always blocks if not yet ready.
-    fn test_initialized(&mut self, dest: &mut [u8], _blocking: bool)
-        -> Result<usize, Error>
-    {
-        static OS_RNG_INITIALIZED: AtomicBool = ATOMIC_BOOL_INIT;
-        if !self.initialized {
-            self.initialized = OS_RNG_INITIALIZED.load(Ordering::Relaxed);
-        }
-        if self.initialized { return Ok(0); }
-
-        info!("OsRng: testing random device /dev/random");
-        let mut file =
-            File::open("/dev/random").map_err(random_device::map_err)?;
-        file.read(&mut dest[..1]).map_err(random_device::map_err)?;
-
-        OS_RNG_INITIALIZED.store(true, Ordering::Relaxed);
-        self.initialized = true;
-        Ok(1)
-    }
-
-    fn method_str(&self) -> &'static str { "/dev/urandom" }
-}
diff --git a/rand/rand_os/src/openbsd_bitrig.rs b/rand/rand_os/src/openbsd_bitrig.rs
deleted file mode 100644
index c9b35a6..0000000
--- a/rand/rand_os/src/openbsd_bitrig.rs
+++ /dev/null
@@ -1,40 +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.
-
-//! Implementation for OpenBSD / Bitrig
-
-extern crate libc;
-
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-use std::io;
-
-#[derive(Clone, Debug)]
-pub struct OsRng;
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> { Ok(OsRng) }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let ret = unsafe {
-            libc::getentropy(dest.as_mut_ptr() as *mut libc::c_void, dest.len())
-        };
-        if ret == -1 {
-            return Err(Error::with_cause(
-                ErrorKind::Unavailable,
-                "getentropy failed",
-                io::Error::last_os_error()));
-        }
-        Ok(())
-    }
-
-    fn max_chunk_size(&self) -> usize { 256 }
-
-    fn method_str(&self) -> &'static str { "getentropy" }
-}
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)
-    }
-}
diff --git a/rand/rand_os/src/redox.rs b/rand/rand_os/src/redox.rs
deleted file mode 100644
index 36fae26..0000000
--- a/rand/rand_os/src/redox.rs
+++ /dev/null
@@ -1,30 +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.
-
-//! Implementation for Redox
-
-use rand_core::Error;
-use super::random_device;
-use super::OsRngImpl;
-use std::fs::File;
-
-#[derive(Clone, Debug)]
-pub struct OsRng();
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        random_device::open("rand:", &|p| File::open(p))?;
-        Ok(OsRng())
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        random_device::read(dest)
-    }
-
-    fn method_str(&self) -> &'static str { "'rand:'" }
-}
diff --git a/rand/rand_os/src/sgx.rs b/rand/rand_os/src/sgx.rs
deleted file mode 100644
index 43ae0ef..0000000
--- a/rand/rand_os/src/sgx.rs
+++ /dev/null
@@ -1,38 +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.
-
-use super::OsRngImpl;
-use Error;
-use rdrand::RdRand;
-use rand_core::RngCore;
-use std::fmt::{Debug, Formatter, Result as FmtResult};
-
-#[derive(Clone)]
-pub struct OsRng{
-    gen: RdRand
-}
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        let rng = RdRand::new()?;
-        Ok(OsRng{ gen: rng })
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        self.gen.try_fill_bytes(dest)
-    }
-
-    fn method_str(&self) -> &'static str { "RDRAND" }
-}
-
-impl Debug for OsRng {
-    fn fmt(&self, f: &mut Formatter) -> FmtResult {
-        f.debug_struct("OsRng")
-            .finish()
-    }
-}
diff --git a/rand/rand_os/src/solaris.rs b/rand/rand_os/src/solaris.rs
deleted file mode 100644
index e8965fd..0000000
--- a/rand/rand_os/src/solaris.rs
+++ /dev/null
@@ -1,175 +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.
-
-//! Implementation for the Solaris family
-//!
-//! Read from `/dev/random`, with chunks of limited size (1040 bytes).
-//! `/dev/random` uses the Hash_DRBG with SHA512 algorithm from NIST SP 800-90A.
-//! `/dev/urandom` uses the FIPS 186-2 algorithm, which is considered less
-//! secure. We choose to read from `/dev/random`.
-//!
-//! Since Solaris 11.3 the `getrandom` syscall is available. To make sure we can
-//! compile on both Solaris and on OpenSolaris derivatives, that do not have the
-//! function, we do a direct syscall instead of calling a library function.
-//!
-//! We have no way to differentiate between Solaris, illumos, SmartOS, etc.
-extern crate libc;
-
-use rand_core::{Error, ErrorKind};
-use super::random_device;
-use super::OsRngImpl;
-
-use std::io;
-use std::io::Read;
-use std::fs::{File, OpenOptions};
-use std::os::unix::fs::OpenOptionsExt;
-use std::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
-use std::cmp;
-
-#[derive(Clone, Debug)]
-pub struct OsRng {
-    method: OsRngMethod,
-    initialized: bool,
-}
-
-#[derive(Clone, Debug)]
-enum OsRngMethod {
-    GetRandom,
-    RandomDevice,
-}
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        if is_getrandom_available() {
-            return Ok(OsRng { method: OsRngMethod::GetRandom,
-                              initialized: false });
-        }
-        let open = |p| OpenOptions::new()
-            .read(true)
-            .custom_flags(libc::O_NONBLOCK)
-            .open(p);
-        random_device::open("/dev/random", &open)?;
-        Ok(OsRng { method: OsRngMethod::RandomDevice, initialized: false })
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        match self.method {
-            OsRngMethod::GetRandom => getrandom_try_fill(dest, false),
-            OsRngMethod::RandomDevice => random_device::read(dest),
-        }
-    }
-
-    fn test_initialized(&mut self, dest: &mut [u8], blocking: bool)
-        -> Result<usize, Error>
-    {
-        static OS_RNG_INITIALIZED: AtomicBool = ATOMIC_BOOL_INIT;
-        if !self.initialized {
-            self.initialized = OS_RNG_INITIALIZED.load(Ordering::Relaxed);
-        }
-        if self.initialized { return Ok(0); }
-
-        let chunk_len = cmp::min(1024, dest.len());
-        let dest = &mut dest[..chunk_len];
-
-        match self.method {
-            OsRngMethod::GetRandom => getrandom_try_fill(dest, blocking)?,
-            OsRngMethod::RandomDevice => {
-                if blocking {
-                    info!("OsRng: testing random device /dev/random");
-                    // We already have a non-blocking handle, but now need a
-                    // blocking one. Not much choice except opening it twice
-                    let mut file = File::open("/dev/random")
-                        .map_err(random_device::map_err)?;
-                    file.read(dest).map_err(random_device::map_err)?;
-                } else {
-                    self.fill_chunk(dest)?;
-                }
-            }
-        };
-        OS_RNG_INITIALIZED.store(true, Ordering::Relaxed);
-        self.initialized = true;
-        Ok(chunk_len)
-    }
-
-    fn max_chunk_size(&self) -> usize {
-        // The documentation says 1024 is the maximum for getrandom, but
-        // 1040 for /dev/random.
-        1024
-    }
-
-    fn method_str(&self) -> &'static str {
-        match self.method {
-            OsRngMethod::GetRandom => "getrandom",
-            OsRngMethod::RandomDevice => "/dev/random",
-        }
-    }
-}
-
-fn getrandom(buf: &mut [u8], blocking: bool) -> libc::c_long {
-    extern "C" {
-        fn syscall(number: libc::c_long, ...) -> libc::c_long;
-    }
-
-    const SYS_GETRANDOM: libc::c_long = 143;
-    const GRND_NONBLOCK: libc::c_uint = 0x0001;
-    const GRND_RANDOM: libc::c_uint = 0x0002;
-
-    unsafe {
-        syscall(SYS_GETRANDOM, buf.as_mut_ptr(), buf.len(),
-                if blocking { 0 } else { GRND_NONBLOCK } | GRND_RANDOM)
-    }
-}
-
-fn getrandom_try_fill(dest: &mut [u8], blocking: bool) -> Result<(), Error> {
-    let result = getrandom(dest, blocking);
-    if result == -1 || result == 0 {
-        let err = io::Error::last_os_error();
-        let kind = err.kind();
-        if kind == io::ErrorKind::WouldBlock {
-            return Err(Error::with_cause(
-                ErrorKind::NotReady,
-                "getrandom not ready",
-                err,
-            ));
-        } else {
-            return Err(Error::with_cause(
-                ErrorKind::Unavailable,
-                "unexpected getrandom error",
-                err,
-            ));
-        }
-    } else if result != dest.len() as i64 {
-        return Err(Error::new(ErrorKind::Unavailable,
-                              "unexpected getrandom error"));
-    }
-    Ok(())
-}
-
-fn is_getrandom_available() -> bool {
-    use std::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
-    use std::sync::{Once, ONCE_INIT};
-
-    static CHECKER: Once = ONCE_INIT;
-    static AVAILABLE: AtomicBool = ATOMIC_BOOL_INIT;
-
-    CHECKER.call_once(|| {
-        debug!("OsRng: testing getrandom");
-        let mut buf: [u8; 0] = [];
-        let result = getrandom(&mut buf, false);
-        let available = if result == -1 {
-            let err = io::Error::last_os_error().raw_os_error();
-            err != Some(libc::ENOSYS)
-        } else {
-            true
-        };
-        AVAILABLE.store(available, Ordering::Relaxed);
-        info!("OsRng: using {}", if available { "getrandom" } else { "/dev/random" });
-    });
-
-    AVAILABLE.load(Ordering::Relaxed)
-}
diff --git a/rand/rand_os/src/wasm32_bindgen.rs b/rand/rand_os/src/wasm32_bindgen.rs
deleted file mode 100644
index 8e7c979..0000000
--- a/rand/rand_os/src/wasm32_bindgen.rs
+++ /dev/null
@@ -1,125 +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.
-
-//! Implementation for WASM via wasm-bindgen
-
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-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]);
-}
-
-#[derive(Clone, Debug)]
-pub enum OsRng {
-    Node(NodeCrypto),
-    Browser(BrowserCrypto),
-}
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        // First up we need to detect if we're running in node.js or a
-        // browser. To do this we get ahold of the `this` object (in a bit
-        // of a roundabout fashion).
-        //
-        // Once we have `this` we look at its `self` property, which is
-        // only defined on the web (either a main window or web worker).
-        let this = Function::new("return this").call(&JsValue::undefined());
-        assert!(this != JsValue::undefined());
-        let this = This::from(this);
-        let is_browser = this.self_() != JsValue::undefined();
-
-        if !is_browser {
-            return Ok(OsRng::Node(node_require("crypto")))
-        }
-
-        // If `self` is defined then we're in a browser somehow (main window
-        // or web worker). Here we want to try to use
-        // `crypto.getRandomValues`, but if `crypto` isn't defined we assume
-        // we're in an older web browser and the OS RNG isn't available.
-        let crypto = this.crypto();
-        if crypto.is_undefined() {
-            let msg = "self.crypto is undefined";
-            return Err(Error::new(ErrorKind::Unavailable, msg))
-        }
-
-        // Test if `crypto.getRandomValues` is undefined as well
-        let crypto: BrowserCrypto = crypto.into();
-        if crypto.get_random_values_fn().is_undefined() {
-            let msg = "crypto.getRandomValues is undefined";
-            return Err(Error::new(ErrorKind::Unavailable, msg))
-        }
-
-        // Ok! `self.crypto.getRandomValues` is a defined value, so let's
-        // assume we can do browser crypto.
-        Ok(OsRng::Browser(crypto))
-    }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        match *self {
-            OsRng::Node(ref n) => n.random_fill_sync(dest),
-            OsRng::Browser(ref n) => n.get_random_values(dest),
-        }
-        Ok(())
-    }
-
-    fn max_chunk_size(&self) -> usize {
-        match *self {
-            OsRng::Node(_) => usize::max_value(),
-            OsRng::Browser(_) => {
-                // see https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
-                //
-                // where it says:
-                //
-                // > A QuotaExceededError DOMException is thrown if the
-                // > requested length is greater than 65536 bytes.
-                65536
-            }
-        }
-    }
-
-    fn method_str(&self) -> &'static str {
-        match *self {
-            OsRng::Node(_) => "crypto.randomFillSync",
-            OsRng::Browser(_) => "crypto.getRandomValues",
-        }
-    }
-}
diff --git a/rand/rand_os/src/wasm32_stdweb.rs b/rand/rand_os/src/wasm32_stdweb.rs
deleted file mode 100644
index 3be0ce6..0000000
--- a/rand/rand_os/src/wasm32_stdweb.rs
+++ /dev/null
@@ -1,107 +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.
-
-//! Implementation for WASM via stdweb
-
-use std::mem;
-use stdweb::unstable::TryInto;
-use stdweb::web::error::Error as WebError;
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-#[derive(Clone, Debug)]
-enum OsRngMethod {
-    Browser,
-    Node
-}
-
-#[derive(Clone, Debug)]
-pub struct OsRng(OsRngMethod);
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> {
-        let result = js! {
-            try {
-                if (
-                    typeof self === "object" &&
-                    typeof self.crypto === "object" &&
-                    typeof self.crypto.getRandomValues === "function"
-                ) {
-                    return { success: true, ty: 1 };
-                }
-
-                if (typeof require("crypto").randomBytes === "function") {
-                    return { success: true, ty: 2 };
-                }
-
-                return { success: false, error: new Error("not supported") };
-            } catch(err) {
-                return { success: false, error: err };
-            }
-        };
-
-        if js!{ return @{ result.as_ref() }.success } == true {
-            let ty = js!{ return @{ result }.ty };
-
-            if ty == 1 { Ok(OsRng(OsRngMethod::Browser)) }
-            else if ty == 2 { Ok(OsRng(OsRngMethod::Node)) }
-            else { unreachable!() }
-        } else {
-            let err: WebError = js!{ return @{ result }.error }.try_into().unwrap();
-            Err(Error::with_cause(ErrorKind::Unavailable, "WASM Error", err))
-        }
-    }
-
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        assert_eq!(mem::size_of::<usize>(), 4);
-
-        let len = dest.len() as u32;
-        let ptr = dest.as_mut_ptr() as i32;
-
-        let result = match self.0 {
-            OsRngMethod::Browser => js! {
-                try {
-                    let array = new Uint8Array(@{ len });
-                    self.crypto.getRandomValues(array);
-                    HEAPU8.set(array, @{ ptr });
-
-                    return { success: true };
-                } catch(err) {
-                    return { success: false, error: err };
-                }
-            },
-            OsRngMethod::Node => js! {
-                try {
-                    let bytes = require("crypto").randomBytes(@{ len });
-                    HEAPU8.set(new Uint8Array(bytes), @{ ptr });
-
-                    return { success: true };
-                } catch(err) {
-                    return { success: false, error: err };
-                }
-            }
-        };
-
-        if js!{ return @{ result.as_ref() }.success } == true {
-            Ok(())
-        } else {
-            let err: WebError = js!{ return @{ result }.error }.try_into().unwrap();
-            Err(Error::with_cause(ErrorKind::Unexpected, "WASM Error", err))
-        }
-    }
-
-    fn max_chunk_size(&self) -> usize { 65536 }
-
-    fn method_str(&self) -> &'static str {
-        match self.0 {
-            OsRngMethod::Browser => "Crypto.getRandomValues",
-            OsRngMethod::Node => "crypto.randomBytes",
-        }
-    }
-}
diff --git a/rand/rand_os/src/windows.rs b/rand/rand_os/src/windows.rs
deleted file mode 100644
index 6b06c7a..0000000
--- a/rand/rand_os/src/windows.rs
+++ /dev/null
@@ -1,44 +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.
-
-//! Implementation for Windows
-
-extern crate winapi;
-
-use rand_core::{Error, ErrorKind};
-use super::OsRngImpl;
-
-use std::io;
-
-use self::winapi::shared::minwindef::ULONG;
-use self::winapi::um::ntsecapi::RtlGenRandom;
-use self::winapi::um::winnt::PVOID;
-
-#[derive(Clone, Debug)]
-pub struct OsRng;
-
-impl OsRngImpl for OsRng {
-    fn new() -> Result<OsRng, Error> { Ok(OsRng) }
-
-    fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        let ret = unsafe {
-            RtlGenRandom(dest.as_mut_ptr() as PVOID, dest.len() as ULONG)
-        };
-        if ret == 0 {
-            return Err(Error::with_cause(
-                ErrorKind::Unavailable,
-                "couldn't generate random bytes",
-                io::Error::last_os_error()));
-        }
-        Ok(())
-    }
-
-    fn max_chunk_size(&self) -> usize { <ULONG>::max_value() as usize }
-
-    fn method_str(&self) -> &'static str { "RtlGenRandom" }
-}
diff --git a/rand/rand_os/tests/mod.rs b/rand/rand_os/tests/mod.rs
deleted file mode 100644
index 2130e16..0000000
--- a/rand/rand_os/tests/mod.rs
+++ /dev/null
@@ -1,80 +0,0 @@
-extern crate rand_os;
-
-use rand_os::rand_core::RngCore;
-use rand_os::OsRng;
-
-#[test]
-fn test_os_rng() {
-    let mut r = OsRng::new().unwrap();
-
-    r.next_u32();
-    r.next_u64();
-
-    let mut v1 = [0u8; 1000];
-    r.fill_bytes(&mut v1);
-
-    let mut v2 = [0u8; 1000];
-    r.fill_bytes(&mut v2);
-
-    let mut n_diff_bits = 0;
-    for i in 0..v1.len() {
-        n_diff_bits += (v1[i] ^ v2[i]).count_ones();
-    }
-
-    // Check at least 1 bit per byte differs. p(failure) < 1e-1000 with random input.
-    assert!(n_diff_bits >= v1.len() as u32);
-}
-
-#[test]
-fn test_os_rng_empty() {
-    let mut r = OsRng::new().unwrap();
-
-    let mut empty = [0u8; 0];
-    r.fill_bytes(&mut empty);
-}
-
-#[test]
-fn test_os_rng_huge() {
-    let mut r = OsRng::new().unwrap();
-
-    let mut huge = [0u8; 100_000];
-    r.fill_bytes(&mut huge);
-}
-
-#[cfg(not(any(target_arch = "wasm32", target_arch = "asmjs")))]
-#[test]
-fn test_os_rng_tasks() {
-    use std::sync::mpsc::channel;
-    use std::thread;
-
-    let mut txs = vec!();
-    for _ in 0..20 {
-        let (tx, rx) = channel();
-        txs.push(tx);
-
-        thread::spawn(move|| {
-            // wait until all the tasks are ready to go.
-            rx.recv().unwrap();
-
-            // deschedule to attempt to interleave things as much
-            // as possible (XXX: is this a good test?)
-            let mut r = OsRng::new().unwrap();
-            thread::yield_now();
-            let mut v = [0u8; 1000];
-
-            for _ in 0..100 {
-                r.next_u32();
-                thread::yield_now();
-                r.next_u64();
-                thread::yield_now();
-                r.fill_bytes(&mut v);
-                thread::yield_now();
-            }
-        });
-    }
-
-    // start all the tasks
-    for tx in txs.iter() {
-        tx.send(()).unwrap();
-    }
-}