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, 123 insertions, 0 deletions

diff --git a/rand/rand_xorshift/src/lib.rs b/rand/rand_xorshift/src/lib.rs
new file mode 100644
index 0000000..aad74e4
--- /dev/null
+++ b/rand/rand_xorshift/src/lib.rs
@@ -0,0 +1,123 @@
+// 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.
+
+//! The xorshift random number generator.
+
+#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk.png",
+       html_favicon_url = "https://www.rust-lang.org/favicon.ico",
+       html_root_url = "https://rust-random.github.io/rand/")]
+
+#![deny(missing_docs)]
+#![deny(missing_debug_implementations)]
+
+#![no_std]
+
+extern crate rand_core;
+
+#[cfg(feature="serde1")] extern crate serde;
+#[cfg(feature="serde1")] #[macro_use] extern crate serde_derive;
+
+use core::num::Wrapping as w;
+use core::{fmt, slice};
+use rand_core::{RngCore, SeedableRng, Error, impls, le};
+
+/// An Xorshift random number generator.
+///
+/// The Xorshift[^1] algorithm is not suitable for cryptographic purposes
+/// but is very fast. If you do not know for sure that it fits your
+/// requirements, use a more secure one such as `StdRng` or `OsRng`.
+///
+/// [^1]: Marsaglia, George (July 2003).
+///       ["Xorshift RNGs"](https://www.jstatsoft.org/v08/i14/paper).
+///       *Journal of Statistical Software*. Vol. 8 (Issue 14).
+#[derive(Clone)]
+#[cfg_attr(feature="serde1", derive(Serialize,Deserialize))]
+pub struct XorShiftRng {
+    x: w<u32>,
+    y: w<u32>,
+    z: w<u32>,
+    w: w<u32>,
+}
+
+// Custom Debug implementation that does not expose the internal state
+impl fmt::Debug for XorShiftRng {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "XorShiftRng {{}}")
+    }
+}
+
+impl RngCore for XorShiftRng {
+    #[inline]
+    fn next_u32(&mut self) -> u32 {
+        let x = self.x;
+        let t = x ^ (x << 11);
+        self.x = self.y;
+        self.y = self.z;
+        self.z = self.w;
+        let w_ = self.w;
+        self.w = w_ ^ (w_ >> 19) ^ (t ^ (t >> 8));
+        self.w.0
+    }
+
+    #[inline]
+    fn next_u64(&mut self) -> u64 {
+        impls::next_u64_via_u32(self)
+    }
+
+    #[inline]
+    fn fill_bytes(&mut self, dest: &mut [u8]) {
+        impls::fill_bytes_via_next(self, dest)
+    }
+
+    fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+        Ok(self.fill_bytes(dest))
+    }
+}
+
+impl SeedableRng for XorShiftRng {
+    type Seed = [u8; 16];
+
+    fn from_seed(seed: Self::Seed) -> Self {
+        let mut seed_u32 = [0u32; 4];
+        le::read_u32_into(&seed, &mut seed_u32);
+
+        // Xorshift cannot be seeded with 0 and we cannot return an Error, but
+        // also do not wish to panic (because a random seed can legitimately be
+        // 0); our only option is therefore to use a preset value.
+        if seed_u32.iter().all(|&x| x == 0) {
+            seed_u32 = [0xBAD_5EED, 0xBAD_5EED, 0xBAD_5EED, 0xBAD_5EED];
+        }
+
+        XorShiftRng {
+            x: w(seed_u32[0]),
+            y: w(seed_u32[1]),
+            z: w(seed_u32[2]),
+            w: w(seed_u32[3]),
+        }
+    }
+
+    fn from_rng<R: RngCore>(mut rng: R) -> Result<Self, Error> {
+        let mut seed_u32 = [0u32; 4];
+        loop {
+            unsafe {
+                let ptr = seed_u32.as_mut_ptr() as *mut u8;
+
+                let slice = slice::from_raw_parts_mut(ptr, 4 * 4);
+                rng.try_fill_bytes(slice)?;
+            }
+            if !seed_u32.iter().all(|&x| x == 0) { break; }
+        }
+
+        Ok(XorShiftRng {
+            x: w(seed_u32[0]),
+            y: w(seed_u32[1]),
+            z: w(seed_u32[2]),
+            w: w(seed_u32[3]),
+        })
+    }
+}