Update nitrokey crate to 0.4.0

This change finally updates the version of the nitrokey crate that we
consume to 0.4.0. Along with that we update rand_core, one of its
dependencies, to 0.5.1. Further more we add cfg-if in version 0.1.10 and
getrandom in version 0.1.13, both of which are now new (non-development)
dependencies.

Import subrepo nitrokey/:nitrokey at e81057037e9b4f370b64c0a030a725bc6bdfb870
Import subrepo cfg-if/:cfg-if at 4484a6faf816ff8058088ad857b0c6bb2f4b02b2
Import subrepo getrandom/:getrandom at d661aa7e1b8cc80b47dabe3d2135b3b47d2858af
Import subrepo rand/:rand at d877ed528248b52d947e0484364a4e1ae59ca502

1 files changed, 32 insertions, 21 deletions

diff --git a/rand/src/rngs/adapter/read.rs b/rand/src/rngs/adapter/read.rs
index 30b6de6..901462e 100644
--- a/rand/src/rngs/adapter/read.rs
+++ b/rand/src/rngs/adapter/read.rs
@@ -10,12 +10,13 @@
 //! A wrapper around any Read to treat it as an RNG.
 
 use std::io::Read;
+use std::fmt;
 
-use rand_core::{RngCore, Error, ErrorKind, impls};
+use rand_core::{RngCore, Error, impls};
 
 
 /// An RNG that reads random bytes straight from any type supporting
-/// `std::io::Read`, for example files.
+/// [`std::io::Read`], for example files.
 ///
 /// This will work best with an infinite reader, but that is not required.
 ///
@@ -24,10 +25,10 @@ use rand_core::{RngCore, Error, ErrorKind, impls};
 ///
 /// # Panics
 ///
-/// `ReadRng` uses `std::io::read_exact`, which retries on interrupts. All other
-/// errors from the underlying reader, including when it does not have enough
-/// data, will only be reported through [`try_fill_bytes`]. The other
-/// [`RngCore`] methods will panic in case of an error.
+/// `ReadRng` uses [`std::io::Read::read_exact`], which retries on interrupts.
+/// All other errors from the underlying reader, including when it does not
+/// have enough data, will only be reported through [`try_fill_bytes`].
+/// The other [`RngCore`] methods will panic in case of an error.
 ///
 /// # Example
 ///
@@ -40,9 +41,8 @@ use rand_core::{RngCore, Error, ErrorKind, impls};
 /// println!("{:x}", rng.gen::<u32>());
 /// ```
 ///
-/// [`OsRng`]: ../struct.OsRng.html
-/// [`RngCore`]: ../../trait.RngCore.html
-/// [`try_fill_bytes`]: ../../trait.RngCore.html#method.tymethod.try_fill_bytes
+/// [`OsRng`]: crate::rngs::OsRng
+/// [`try_fill_bytes`]: RngCore::try_fill_bytes
 #[derive(Debug)]
 pub struct ReadRng<R> {
     reader: R
@@ -72,24 +72,33 @@ impl<R: Read> RngCore for ReadRng<R> {
     }
 
     fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-        if dest.len() == 0 { return Ok(()); }
+        if dest.is_empty() { return Ok(()); }
         // Use `std::io::read_exact`, which retries on `ErrorKind::Interrupted`.
-        self.reader.read_exact(dest).map_err(|err| {
-            match err.kind() {
-                ::std::io::ErrorKind::UnexpectedEof => Error::with_cause(
-                    ErrorKind::Unavailable,
-                    "not enough bytes available, reached end of source", err),
-                _ => Error::with_cause(ErrorKind::Unavailable,
-                    "error reading from Read source", err)
-            }
-        })
+        self.reader.read_exact(dest).map_err(|e| Error::new(ReadError(e)))
     }
 }
 
+/// `ReadRng` error type
+#[derive(Debug)]
+pub struct ReadError(std::io::Error);
+
+impl fmt::Display for ReadError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "ReadError: {}", self.0)
+    }
+}
+
+impl std::error::Error for ReadError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        Some(&self.0)
+    }
+}
+
+
 #[cfg(test)]
 mod test {
     use super::ReadRng;
-    use {RngCore, ErrorKind};
+    use crate::RngCore;
 
     #[test]
     fn test_reader_rng_u64() {
@@ -132,6 +141,8 @@ mod test {
 
         let mut rng = ReadRng::new(&v[..]);
 
-        assert!(rng.try_fill_bytes(&mut w).err().unwrap().kind == ErrorKind::Unavailable);
+        let result = rng.try_fill_bytes(&mut w);
+        assert!(result.is_err());
+        println!("Error: {}", result.unwrap_err());
     }
 }