Update nitrokey crate to 0.3.3

This change updates the nitrokey crate to version 0.3.3. Along with that
change we update rand to 0.6.4 because rand 0.6.1 does not yet contain a
publicly accessible rand_os. Note that we no longer require all
crates in rand's workspace, but only rand_os and rand_core, which is a
significant reduction in the number of lines of code compiled.

Import subrepo nitrokey/:nitrokey at 7cf747d56ddc0b7eeedc3caf36dcc909907a171c
Import subrepo rand/:rand at 4336232dda03323634b10ec72ddf27914aebc3a2

1 files changed, 96 insertions, 0 deletions

diff --git a/rand/rand_xoshiro/src/xoroshiro64starstar.rs b/rand/rand_xoshiro/src/xoroshiro64starstar.rs
new file mode 100644
index 0000000..a40baee
--- /dev/null
+++ b/rand/rand_xoshiro/src/xoroshiro64starstar.rs
@@ -0,0 +1,96 @@
+// 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 byteorder::{ByteOrder, LittleEndian};
+use rand_core;
+use rand_core::le::read_u32_into;
+use rand_core::impls::{fill_bytes_via_next, next_u64_via_u32};
+use rand_core::{RngCore, SeedableRng};
+
+/// A Xoroshiro64** random number generator.
+///
+/// The xoshiro64** algorithm is not suitable for cryptographic purposes, but
+/// is very fast and has excellent statistical properties.
+///
+/// The algorithm used here is translated from [the `xoroshiro64starstar.c`
+/// reference source code](http://xoshiro.di.unimi.it/xoroshiro64starstar.c) by
+/// David Blackman and Sebastiano Vigna.
+#[allow(missing_copy_implementations)]
+#[derive(Debug, Clone)]
+pub struct Xoroshiro64StarStar {
+    s0: u32,
+    s1: u32,
+}
+
+impl RngCore for Xoroshiro64StarStar {
+    #[inline]
+    fn next_u32(&mut self) -> u32 {
+        let r = starstar_u32!(self.s0);
+        impl_xoroshiro_u32!(self);
+        r
+    }
+
+    #[inline]
+    fn next_u64(&mut self) -> u64 {
+        next_u64_via_u32(self)
+    }
+
+    #[inline]
+    fn fill_bytes(&mut self, dest: &mut [u8]) {
+        fill_bytes_via_next(self, dest);
+    }
+
+    #[inline]
+    fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), rand_core::Error> {
+        self.fill_bytes(dest);
+        Ok(())
+    }
+}
+
+impl SeedableRng for Xoroshiro64StarStar {
+    type Seed = [u8; 8];
+
+    /// Create a new `Xoroshiro64StarStar`.  If `seed` is entirely 0, it will be
+    /// mapped to a different seed.
+    fn from_seed(seed: [u8; 8]) -> Xoroshiro64StarStar {
+        deal_with_zero_seed!(seed, Self);
+        let mut s = [0; 2];
+        read_u32_into(&seed, &mut s);
+
+        Xoroshiro64StarStar {
+            s0: s[0],
+            s1: s[1],
+        }
+    }
+
+    /// Seed a `Xoroshiro64StarStar` from a `u64`.
+    fn seed_from_u64(seed: u64) -> Xoroshiro64StarStar {
+        let mut s = [0; 8];
+        LittleEndian::write_u64(&mut s, seed);
+        Xoroshiro64StarStar::from_seed(s)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn reference() {
+        let mut rng = Xoroshiro64StarStar::from_seed([1, 0, 0, 0, 2, 0, 0, 0]);
+        // These values were produced with the reference implementation:
+        // http://xoshiro.di.unimi.it/xoshiro64starstar.c
+        let expected = [
+            3802928447, 813792938, 1618621494, 2955957307, 3252880261,
+            1129983909, 2539651700, 1327610908, 1757650787, 2763843748,
+        ];
+        for &e in &expected {
+            assert_eq!(rng.next_u32(), e);
+        }
+    }
+}