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, 31 insertions, 0 deletions

diff --git a/getrandom/src/ios.rs b/getrandom/src/ios.rs
new file mode 100644
index 0000000..30c008c
--- /dev/null
+++ b/getrandom/src/ios.rs
@@ -0,0 +1,31 @@
+// 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.
+
+//! Implementation for iOS
+use crate::{error::SEC_RANDOM_FAILED, Error};
+
+// TODO: Make extern once extern_types feature is stabilized. See:
+//   https://github.com/rust-lang/rust/issues/43467
+#[repr(C)]
+struct SecRandom([u8; 0]);
+
+#[link(name = "Security", kind = "framework")]
+extern "C" {
+    static kSecRandomDefault: *const SecRandom;
+
+    fn SecRandomCopyBytes(rnd: *const SecRandom, count: usize, bytes: *mut u8) -> i32;
+}
+
+pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
+    let ret = unsafe { SecRandomCopyBytes(kSecRandomDefault, dest.len(), dest.as_mut_ptr()) };
+    if ret == -1 {
+        Err(SEC_RANDOM_FAILED)
+    } else {
+        Ok(())
+    }
+}