1 // Copyright 2018 Developers of the Rand project.
2 //
3 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4 // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5 // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
6 // option. This file may not be copied, modified, or distributed
7 // except according to those terms.
8
9 //! Implementation for Windows
10 use crate::{error::RTL_GEN_RANDOM_FAILED, Error};
11
12 extern "system" {
13 #[link_name = "SystemFunction036"]
RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: u32) -> u814 fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: u32) -> u8;
15 }
16
getrandom_inner(dest: &mut [u8]) -> Result<(), Error>17 pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
18 // Prevent overflow of u32
19 for chunk in dest.chunks_mut(u32::max_value() as usize) {
20 let ret = unsafe { RtlGenRandom(chunk.as_mut_ptr(), chunk.len() as u32) };
21 if ret == 0 {
22 return Err(RTL_GEN_RANDOM_FAILED);
23 }
24 }
25 Ok(())
26 }
27