std\sys\random/
windows.rs

1use crate::sys::c;
2
3#[cfg(not(target_vendor = "win7"))]
4#[inline]
5pub fn fill_bytes(bytes: &mut [u8]) {
6    let ret = unsafe { c::ProcessPrng(bytes.as_mut_ptr(), bytes.len()) };
7    // ProcessPrng is documented as always returning `TRUE`.
8    // https://learn.microsoft.com/en-us/windows/win32/seccng/processprng#return-value
9    debug_assert_eq!(ret, c::TRUE);
10}
11
12#[cfg(target_vendor = "win7")]
13pub fn fill_bytes(mut bytes: &mut [u8]) {
14    while !bytes.is_empty() {
15        let len = bytes.len().try_into().unwrap_or(u32::MAX);
16        let ret = unsafe { c::RtlGenRandom(bytes.as_mut_ptr().cast(), len) };
17        assert!(ret, "failed to generate random data");
18        bytes = &mut bytes[len as usize..];
19    }
20}