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rand_core: Replace transmutes with safe code

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This commit is contained in:
Vinzent Steinberg 2019-07-09 14:12:35 +02:00
parent 1c516ebd66
commit 183fadb81e
1 changed files with 3 additions and 10 deletions
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13
rand_core/src/impls.rs
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@ -17,7 +17,6 @@
//! to/from byte sequences, and since its purpose is reproducibility,
//! non-reproducible sources (e.g. `OsRng`) need not bother with it.
use core::intrinsics::transmute;
use core::ptr::copy_nonoverlapping;
use core::slice;
use core::cmp::min;
@ -44,21 +43,15 @@ pub fn fill_bytes_via_next<R: RngCore + ?Sized>(rng: &mut R, dest: &mut [u8]) {
while left.len() >= 8 {
let (l, r) = {left}.split_at_mut(8);
left = r;
let chunk: [u8; 8] = unsafe {
transmute(rng.next_u64().to_le())
};
let chunk: [u8; 8] = rng.next_u64().to_le_bytes();
l.copy_from_slice(&chunk);
}
let n = left.len();
if n > 4 {
let chunk: [u8; 8] = unsafe {
transmute(rng.next_u64().to_le())
};
let chunk: [u8; 8] = rng.next_u64().to_le_bytes();
left.copy_from_slice(&chunk[..n]);
} else if n > 0 {
let chunk: [u8; 4] = unsafe {
transmute(rng.next_u32().to_le())
};
let chunk: [u8; 4] = rng.next_u32().to_le_bytes();
left.copy_from_slice(&chunk[..n]);
}
}