50 lines
1.9 KiB
Rust
50 lines
1.9 KiB
Rust
// Copyright 2018 Developers of the Rand project.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Implementation for the Solaris family
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//!
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//! `/dev/random` uses the Hash_DRBG with SHA512 algorithm from NIST SP 800-90A.
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//! `/dev/urandom` uses the FIPS 186-2 algorithm, which is considered less
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//! secure. We choose to read from `/dev/random` (and use GRND_RANDOM).
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//!
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//! Solaris 11.3 and late-2018 illumos added the getrandom(2) libc function.
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//! To make sure we can compile on both Solaris and its derivatives, as well as
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//! function, we check for the existence of getrandom(2) in libc by calling
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//! libc::dlsym.
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use crate::{
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use_file,
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util_libc::{sys_fill_exact, Weak},
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Error,
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};
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use core::mem::{self, MaybeUninit};
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static GETRANDOM: Weak = unsafe { Weak::new("getrandom\0") };
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type GetRandomFn =
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unsafe extern "C" fn(*mut libc::c_void, libc::size_t, libc::c_uint) -> libc::ssize_t;
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pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
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if let Some(fptr) = GETRANDOM.ptr() {
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let func: GetRandomFn = unsafe { mem::transmute(fptr) };
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// 256 bytes is the lowest common denominator across all the Solaris
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// derived platforms for atomically obtaining random data.
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for chunk in dest.chunks_mut(256) {
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sys_fill_exact(chunk, |buf| unsafe {
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// A cast is needed for the flags as libc uses the wrong type.
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func(
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buf.as_mut_ptr() as *mut libc::c_void,
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buf.len(),
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libc::GRND_RANDOM as libc::c_uint,
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)
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})?
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}
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Ok(())
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} else {
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use_file::getrandom_inner(dest)
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}
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}
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