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

1 files changed, 44 insertions, 0 deletions

diff --git a/rand/rand_jitter/src/platform.rs b/rand/rand_jitter/src/platform.rs
new file mode 100644
index 0000000..8e3d0fb
--- /dev/null
+++ b/rand/rand_jitter/src/platform.rs
@@ -0,0 +1,44 @@
+// 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.
+
+#[cfg(not(any(target_os = "macos", target_os = "ios", target_os = "windows")))]
+pub fn get_nstime() -> u64 {
+    use std::time::{SystemTime, UNIX_EPOCH};
+
+    let dur = SystemTime::now().duration_since(UNIX_EPOCH).unwrap();
+    // The correct way to calculate the current time is
+    // `dur.as_secs() * 1_000_000_000 + dur.subsec_nanos() as u64`
+    // But this is faster, and the difference in terms of entropy is
+    // negligible (log2(10^9) == 29.9).
+    dur.as_secs() << 30 | dur.subsec_nanos() as u64
+}
+
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+pub fn get_nstime() -> u64 {
+    use libc;
+    
+    // On Mac OS and iOS std::time::SystemTime only has 1000ns resolution.
+    // We use `mach_absolute_time` instead. This provides a CPU dependent
+    // unit, to get real nanoseconds the result should by multiplied by
+    // numer/denom from `mach_timebase_info`.
+    // But we are not interested in the exact nanoseconds, just entropy. So
+    // we use the raw result.
+    unsafe { libc::mach_absolute_time() }
+}
+
+#[cfg(target_os = "windows")]
+pub fn get_nstime() -> u64 {
+    use winapi;
+
+    unsafe {
+        let mut t = super::mem::zeroed();
+        winapi::um::profileapi::QueryPerformanceCounter(&mut t);
+        *t.QuadPart() as u64
+    }
+}