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, 297 insertions, 0 deletions

diff --git a/rand/src/rngs/entropy.rs b/rand/src/rngs/entropy.rs
new file mode 100644
index 0000000..8736324
--- /dev/null
+++ b/rand/src/rngs/entropy.rs
@@ -0,0 +1,297 @@
+// 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.
+
+//! Entropy generator, or wrapper around external generators
+
+use rand_core::{RngCore, CryptoRng, Error, ErrorKind, impls};
+#[allow(unused)]
+use rngs;
+
+/// An interface returning random data from external source(s), provided
+/// specifically for securely seeding algorithmic generators (PRNGs).
+///
+/// Where possible, `EntropyRng` retrieves random data from the operating
+/// system's interface for random numbers ([`OsRng`]); if that fails it will
+/// fall back to the [`JitterRng`] entropy collector. In the latter case it will
+/// still try to use [`OsRng`] on the next usage.
+///
+/// If no secure source of entropy is available `EntropyRng` will panic on use;
+/// i.e. it should never output predictable data.
+///
+/// This is either a little slow ([`OsRng`] requires a system call) or extremely
+/// slow ([`JitterRng`] must use significant CPU time to generate sufficient
+/// jitter); for better performance it is common to seed a local PRNG from
+/// external entropy then primarily use the local PRNG ([`thread_rng`] is
+/// provided as a convenient, local, automatically-seeded CSPRNG).
+///
+/// # Panics
+///
+/// On most systems, like Windows, Linux, macOS and *BSD on common hardware, it
+/// is highly unlikely for both [`OsRng`] and [`JitterRng`] to fail. But on
+/// combinations like webassembly without Emscripten or stdweb both sources are
+/// unavailable. If both sources fail, only [`try_fill_bytes`] is able to
+/// report the error, and only the one from `OsRng`. The other [`RngCore`]
+/// methods will panic in case of an error.
+///
+/// [`OsRng`]: struct.OsRng.html
+/// [`JitterRng`]: jitter/struct.JitterRng.html
+/// [`thread_rng`]: ../fn.thread_rng.html
+/// [`RngCore`]: ../trait.RngCore.html
+/// [`try_fill_bytes`]: ../trait.RngCore.html#method.tymethod.try_fill_bytes
+#[derive(Debug)]
+pub struct EntropyRng {
+    source: Source,
+}
+
+#[derive(Debug)]
+enum Source {
+    Os(Os),
+    Custom(Custom),
+    Jitter(Jitter),
+    None,
+}
+
+impl EntropyRng {
+    /// Create a new `EntropyRng`.
+    ///
+    /// This method will do no system calls or other initialization routines,
+    /// those are done on first use. This is done to make `new` infallible,
+    /// and `try_fill_bytes` the only place to report errors.
+    pub fn new() -> Self {
+        EntropyRng { source: Source::None }
+    }
+}
+
+impl Default for EntropyRng {
+    fn default() -> Self {
+        EntropyRng::new()
+    }
+}
+
+impl RngCore for EntropyRng {
+    fn next_u32(&mut self) -> u32 {
+        impls::next_u32_via_fill(self)
+    }
+
+    fn next_u64(&mut self) -> u64 {
+        impls::next_u64_via_fill(self)
+    }
+
+    fn fill_bytes(&mut self, dest: &mut [u8]) {
+        self.try_fill_bytes(dest).unwrap_or_else(|err|
+                panic!("all entropy sources failed; first error: {}", err))
+    }
+
+    fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+        let mut reported_error = None;
+
+        if let Source::Os(ref mut os_rng) = self.source {
+            match os_rng.fill(dest) {
+                Ok(()) => return Ok(()),
+                Err(err) => {
+                    warn!("EntropyRng: OsRng failed \
+                          [trying other entropy sources]: {}", err);
+                    reported_error = Some(err);
+                },
+            }
+        } else if Os::is_supported() {
+            match Os::new_and_fill(dest) {
+                Ok(os_rng) => {
+                    debug!("EntropyRng: using OsRng");
+                    self.source = Source::Os(os_rng);
+                    return Ok(());
+                },
+                Err(err) => { reported_error = reported_error.or(Some(err)) },
+            }
+        }
+
+        if let Source::Custom(ref mut rng) = self.source {
+            match rng.fill(dest) {
+                Ok(()) => return Ok(()),
+                Err(err) => {
+                    warn!("EntropyRng: custom entropy source failed \
+                          [trying other entropy sources]: {}", err);
+                    reported_error = Some(err);
+                },
+            }
+        } else if Custom::is_supported() {
+            match Custom::new_and_fill(dest) {
+                Ok(custom) => {
+                    debug!("EntropyRng: using custom entropy source");
+                    self.source = Source::Custom(custom);
+                    return Ok(());
+                },
+                Err(err) => { reported_error = reported_error.or(Some(err)) },
+            }
+        }
+
+        if let Source::Jitter(ref mut jitter_rng) = self.source {
+            match jitter_rng.fill(dest) {
+                Ok(()) => return Ok(()),
+                Err(err) => {
+                    warn!("EntropyRng: JitterRng failed: {}", err);
+                    reported_error = Some(err);
+                },
+            }
+        } else if Jitter::is_supported() {
+            match Jitter::new_and_fill(dest) {
+                Ok(jitter_rng) => {
+                    debug!("EntropyRng: using JitterRng");
+                    self.source = Source::Jitter(jitter_rng);
+                    return Ok(());
+                },
+                Err(err) => { reported_error = reported_error.or(Some(err)) },
+            }
+        }
+
+        if let Some(err) = reported_error {
+            Err(Error::with_cause(ErrorKind::Unavailable,
+                                  "All entropy sources failed",
+                                  err))
+        } else {
+            Err(Error::new(ErrorKind::Unavailable,
+                           "No entropy sources available"))
+        }
+    }
+}
+
+impl CryptoRng for EntropyRng {}
+
+
+
+trait EntropySource {
+    fn new_and_fill(dest: &mut [u8]) -> Result<Self, Error>
+        where Self: Sized;
+
+    fn fill(&mut self, dest: &mut [u8]) -> Result<(), Error>;
+
+    fn is_supported() -> bool { true }
+}
+
+#[allow(unused)]
+#[derive(Clone, Debug)]
+struct NoSource;
+
+#[allow(unused)]
+impl EntropySource for NoSource {
+    fn new_and_fill(dest: &mut [u8]) -> Result<Self, Error> {
+        Err(Error::new(ErrorKind::Unavailable, "Source not supported"))
+    }
+
+    fn fill(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+        unreachable!()
+    }
+
+    fn is_supported() -> bool { false }
+}
+
+
+#[cfg(all(feature="std",
+          any(target_os = "linux", target_os = "android",
+              target_os = "netbsd",
+              target_os = "dragonfly",
+              target_os = "haiku",
+              target_os = "emscripten",
+              target_os = "solaris",
+              target_os = "cloudabi",
+              target_os = "macos", target_os = "ios",
+              target_os = "freebsd",
+              target_os = "openbsd", target_os = "bitrig",
+              target_os = "redox",
+              target_os = "fuchsia",
+              windows,
+              all(target_arch = "wasm32", feature = "stdweb"),
+              all(target_arch = "wasm32", feature = "wasm-bindgen"),
+)))]
+#[derive(Clone, Debug)]
+pub struct Os(rngs::OsRng);
+
+#[cfg(all(feature="std",
+          any(target_os = "linux", target_os = "android",
+              target_os = "netbsd",
+              target_os = "dragonfly",
+              target_os = "haiku",
+              target_os = "emscripten",
+              target_os = "solaris",
+              target_os = "cloudabi",
+              target_os = "macos", target_os = "ios",
+              target_os = "freebsd",
+              target_os = "openbsd", target_os = "bitrig",
+              target_os = "redox",
+              target_os = "fuchsia",
+              windows,
+              all(target_arch = "wasm32", feature = "stdweb"),
+              all(target_arch = "wasm32", feature = "wasm-bindgen"),
+)))]
+impl EntropySource for Os {
+    fn new_and_fill(dest: &mut [u8]) -> Result<Self, Error> {
+        let mut rng = rngs::OsRng::new()?;
+        rng.try_fill_bytes(dest)?;
+        Ok(Os(rng))
+    }
+
+    fn fill(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+        self.0.try_fill_bytes(dest)
+    }
+}
+
+#[cfg(not(all(feature="std",
+              any(target_os = "linux", target_os = "android",
+                  target_os = "netbsd",
+                  target_os = "dragonfly",
+                  target_os = "haiku",
+                  target_os = "emscripten",
+                  target_os = "solaris",
+                  target_os = "cloudabi",
+                  target_os = "macos", target_os = "ios",
+                  target_os = "freebsd",
+                  target_os = "openbsd", target_os = "bitrig",
+                  target_os = "redox",
+                  target_os = "fuchsia",
+                  windows,
+                  all(target_arch = "wasm32", feature = "stdweb"),
+                  all(target_arch = "wasm32", feature = "wasm-bindgen"),
+))))]
+type Os = NoSource;
+
+
+type Custom = NoSource;
+
+
+#[cfg(not(target_arch = "wasm32"))]
+#[derive(Clone, Debug)]
+pub struct Jitter(rngs::JitterRng);
+
+#[cfg(not(target_arch = "wasm32"))]
+impl EntropySource for Jitter {
+    fn new_and_fill(dest: &mut [u8]) -> Result<Self, Error> {
+        let mut rng = rngs::JitterRng::new()?;
+        rng.try_fill_bytes(dest)?;
+        Ok(Jitter(rng))
+    }
+
+    fn fill(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+        self.0.try_fill_bytes(dest)
+    }
+}
+
+#[cfg(target_arch = "wasm32")]
+type Jitter = NoSource;
+
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_entropy() {
+        let mut rng = EntropyRng::new();
+        let n = (rng.next_u32() ^ rng.next_u32()).count_ones();
+        assert!(n >= 2);    // p(failure) approx 1e-7
+    }
+}