Update nitrokey crate to 0.2.3

This change updates the nitrokey crate to version 0.2.3. This version
bumps the rand crate used to 0.6.1, which in turn requires an additional
set of dependencies.

Import subrepo nitrokey/:nitrokey at b3e2adc5bb1300441ca74cc7672617c042f3ea31
Import subrepo rand/:rand at 73613ff903512e9503e41cc8ba9eae76269dc598
Import subrepo rustc_version/:rustc_version at 0294f2ba2018bf7be672abd53db351ce5055fa02
Import subrepo semver-parser/:semver-parser at 750da9b11a04125231b1fb293866ca036845acee
Import subrepo semver/:semver at 5eb6db94fa03f4d5c64a625a56188f496be47598

1 files changed, 141 insertions, 0 deletions

diff --git a/rand/rand_pcg/src/pcg64.rs b/rand/rand_pcg/src/pcg64.rs
new file mode 100644
index 0000000..9177ec2
--- /dev/null
+++ b/rand/rand_pcg/src/pcg64.rs
@@ -0,0 +1,141 @@
+// Copyright 2018 Developers of the Rand project.
+// Copyright 2017 Paul Dicker.
+// Copyright 2014-2017 Melissa O'Neill and PCG Project contributors
+//
+// 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.
+
+//! PCG random number generators
+
+use core::fmt;
+use core::mem::transmute;
+use rand_core::{RngCore, SeedableRng, Error, le, impls};
+
+// This is the default multiplier used by PCG for 64-bit state.
+const MULTIPLIER: u64 = 6364136223846793005;
+
+/// A PCG random number generator (XSH RR 64/32 (LCG) variant).
+///
+/// Permuted Congruential Generator with 64-bit state, internal Linear
+/// Congruential Generator, and 32-bit output via "xorshift high (bits),
+/// random rotation" output function.
+///
+/// This is a 64-bit LCG with explicitly chosen stream with the PCG-XSH-RR
+/// output function. This combination is the standard `pcg32`.
+///
+/// Despite the name, this implementation uses 16 bytes (128 bit) space
+/// comprising 64 bits of state and 64 bits stream selector. These are both set
+/// by `SeedableRng`, using a 128-bit seed.
+#[derive(Clone)]
+#[cfg_attr(feature="serde1", derive(Serialize,Deserialize))]
+pub struct Lcg64Xsh32 {
+    state: u64,
+    increment: u64,
+}
+
+/// `Lcg64Xsh32` is also officially known as `pcg32`.
+pub type Pcg32 = Lcg64Xsh32;
+
+impl Lcg64Xsh32 {
+    /// Construct an instance compatible with PCG seed and stream.
+    ///
+    /// Note that PCG specifies default values for both parameters:
+    ///
+    /// - `state = 0xcafef00dd15ea5e5`
+    /// - `stream = 721347520444481703`
+    pub fn new(state: u64, stream: u64) -> Self {
+        // The increment must be odd, hence we discard one bit:
+        let increment = (stream << 1) | 1;
+        Lcg64Xsh32::from_state_incr(state, increment)
+    }
+
+    #[inline]
+    fn from_state_incr(state: u64, increment: u64) -> Self {
+        let mut pcg = Lcg64Xsh32 { state, increment };
+        // Move away from inital value:
+        pcg.state = pcg.state.wrapping_add(pcg.increment);
+        pcg.step();
+        pcg
+    }
+
+    #[inline]
+    fn step(&mut self) {
+        // prepare the LCG for the next round
+        self.state = self.state
+            .wrapping_mul(MULTIPLIER)
+            .wrapping_add(self.increment);
+    }
+}
+
+// Custom Debug implementation that does not expose the internal state
+impl fmt::Debug for Lcg64Xsh32 {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Lcg64Xsh32 {{}}")
+    }
+}
+
+/// We use a single 127-bit seed to initialise the state and select a stream.
+/// One `seed` bit (lowest bit of `seed[8]`) is ignored.
+impl SeedableRng for Lcg64Xsh32 {
+    type Seed = [u8; 16];
+
+    fn from_seed(seed: Self::Seed) -> Self {
+        let mut seed_u64 = [0u64; 2];
+        le::read_u64_into(&seed, &mut seed_u64);
+
+        // The increment must be odd, hence we discard one bit:
+        Lcg64Xsh32::from_state_incr(seed_u64[0], seed_u64[1] | 1)
+    }
+}
+
+impl RngCore for Lcg64Xsh32 {
+    #[inline]
+    fn next_u32(&mut self) -> u32 {
+        let state = self.state;
+        self.step();
+
+        // Output function XSH RR: xorshift high (bits), followed by a random rotate
+        // Constants are for 64-bit state, 32-bit output
+        const ROTATE: u32 = 59; // 64 - 5
+        const XSHIFT: u32 = 18; // (5 + 32) / 2
+        const SPARE: u32 = 27;  // 64 - 32 - 5
+
+        let rot = (state >> ROTATE) as u32;
+        let xsh = (((state >> XSHIFT) ^ state) >> SPARE) as u32;
+        xsh.rotate_right(rot)
+    }
+
+    #[inline]
+    fn next_u64(&mut self) -> u64 {
+        impls::next_u64_via_u32(self)
+    }
+
+    #[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]);
+        }
+    }
+
+    #[inline]
+    fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+        Ok(self.fill_bytes(dest))
+    }
+}