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, 122 insertions, 0 deletions

diff --git a/rand/rand_pcg/src/pcg128.rs b/rand/rand_pcg/src/pcg128.rs
new file mode 100644
index 0000000..9aff506
--- /dev/null
+++ b/rand/rand_pcg/src/pcg128.rs
@@ -0,0 +1,122 @@
+// 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
+
+// This is the default multiplier used by PCG for 64-bit state.
+const MULTIPLIER: u128 = 0x2360_ED05_1FC6_5DA4_4385_DF64_9FCC_F645;
+
+use core::fmt;
+use core::mem::transmute;
+use rand_core::{RngCore, SeedableRng, Error, le};
+
+/// A PCG random number generator (XSL 128/64 (MCG) variant).
+///
+/// Permuted Congruential Generator with 128-bit state, internal Multiplicative
+/// Congruential Generator, and 64-bit output via "xorshift low (bits),
+/// random rotation" output function.
+///
+/// This is a 128-bit MCG with the PCG-XSL-RR output function.
+/// Note that compared to the standard `pcg64` (128-bit LCG with PCG-XSL-RR
+/// output function), this RNG is faster, also has a long cycle, and still has
+/// good performance on statistical tests.
+///
+/// Note: this RNG is only available using Rust 1.26 or later.
+#[derive(Clone)]
+#[cfg_attr(feature="serde1", derive(Serialize,Deserialize))]
+pub struct Mcg128Xsl64 {
+    state: u128,
+}
+
+/// A friendly name for `Mcg128Xsl64`.
+pub type Pcg64Mcg = Mcg128Xsl64;
+
+impl Mcg128Xsl64 {
+    /// Construct an instance compatible with PCG seed.
+    ///
+    /// Note that PCG specifies a default value for the parameter:
+    ///
+    /// - `state = 0xcafef00dd15ea5e5`
+    pub fn new(state: u128) -> Self {
+        // Force low bit to 1, as in C version (C++ uses `state | 3` instead).
+        Mcg128Xsl64 { state: state | 1 }
+    }
+}
+
+// Custom Debug implementation that does not expose the internal state
+impl fmt::Debug for Mcg128Xsl64 {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Mcg128Xsl64 {{}}")
+    }
+}
+
+/// We use a single 126-bit seed to initialise the state and select a stream.
+/// Two `seed` bits (lowest order of last byte) are ignored.
+impl SeedableRng for Mcg128Xsl64 {
+    type Seed = [u8; 16];
+
+    fn from_seed(seed: Self::Seed) -> Self {
+        // Read as if a little-endian u128 value:
+        let mut seed_u64 = [0u64; 2];
+        le::read_u64_into(&seed, &mut seed_u64);
+        let state = (seed_u64[0] as u128) |
+                    (seed_u64[1] as u128) << 64;
+        Mcg128Xsl64::new(state)
+    }
+}
+
+impl RngCore for Mcg128Xsl64 {
+    #[inline]
+    fn next_u32(&mut self) -> u32 {
+        self.next_u64() as u32
+    }
+
+    #[inline]
+    fn next_u64(&mut self) -> u64 {
+        // prepare the LCG for the next round
+        let state = self.state.wrapping_mul(MULTIPLIER);
+        self.state = state;
+
+        // Output function XSL RR ("xorshift low (bits), random rotation")
+        // Constants are for 128-bit state, 64-bit output
+        const XSHIFT: u32 = 64;     // (128 - 64 + 64) / 2
+        const ROTATE: u32 = 122;    // 128 - 6
+
+        let rot = (state >> ROTATE) as u32;
+        let xsl = ((state >> XSHIFT) as u64) ^ (state as u64);
+        xsl.rotate_right(rot)
+    }
+
+    #[inline]
+    fn fill_bytes(&mut self, dest: &mut [u8]) {
+        // specialisation of impls::fill_bytes_via_next; approx 3x faster
+        let mut left = dest;
+        while left.len() >= 8 {
+            let (l, r) = {left}.split_at_mut(8);
+            left = r;
+            let chunk: [u8; 8] = unsafe {
+                transmute(self.next_u64().to_le())
+            };
+            l.copy_from_slice(&chunk);
+        }
+        let n = left.len();
+        if n > 0 {
+            let chunk: [u8; 8] = unsafe {
+                transmute(self.next_u64().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))
+    }
+}