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, 6 insertions, 20 deletions

diff --git a/rand/rand_pcg/src/pcg64.rs b/rand/rand_pcg/src/pcg64.rs
index 9177ec2..fadc6dc 100644
--- a/rand/rand_pcg/src/pcg64.rs
+++ b/rand/rand_pcg/src/pcg64.rs
@@ -11,8 +11,8 @@
 //! PCG random number generators
 
 use core::fmt;
-use core::mem::transmute;
 use rand_core::{RngCore, SeedableRng, Error, le, impls};
+#[cfg(feature="serde1")] use serde::{Serialize, Deserialize};
 
 // This is the default multiplier used by PCG for 64-bit state.
 const MULTIPLIER: u64 = 6364136223846793005;
@@ -45,7 +45,8 @@ impl Lcg64Xsh32 {
     /// Note that PCG specifies default values for both parameters:
     ///
     /// - `state = 0xcafef00dd15ea5e5`
-    /// - `stream = 721347520444481703`
+    /// - `stream = 0xa02bdbf7bb3c0a7`
+    // Note: stream is 1442695040888963407u64 >> 1
     pub fn new(state: u64, stream: u64) -> Self {
         // The increment must be odd, hence we discard one bit:
         let increment = (stream << 1) | 1;
@@ -115,27 +116,12 @@ impl RngCore for Lcg64Xsh32 {
 
     #[inline]
     fn fill_bytes(&mut self, dest: &mut [u8]) {
-        // specialisation of impls::fill_bytes_via_next; approx 40% faster
-        let mut left = dest;
-        while left.len() >= 4 {
-            let (l, r) = {left}.split_at_mut(4);
-            left = r;
-            let chunk: [u8; 4] = unsafe {
-                transmute(self.next_u32().to_le())
-            };
-            l.copy_from_slice(&chunk);
-        }
-        let n = left.len();
-        if n > 0 {
-            let chunk: [u8; 4] = unsafe {
-                transmute(self.next_u32().to_le())
-            };
-            left.copy_from_slice(&chunk[..n]);
-        }
+        impls::fill_bytes_via_next(self, dest)
     }
 
     #[inline]
     fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        Ok(self.fill_bytes(dest))
+        self.fill_bytes(dest);
+        Ok(())
     }
 }