vendor/getrandom-0.1.14/src/windows.rs

   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"]
  14     fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: u32) -> u8;
  15 }
  16
  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 }