]>
Commit | Line | Data |
---|---|---|
f20569fa XL |
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 the Solaris family | |
10 | //! | |
11 | //! Read from `/dev/random`, with chunks of limited size (256 bytes). | |
12 | //! `/dev/random` uses the Hash_DRBG with SHA512 algorithm from NIST SP 800-90A. | |
13 | //! `/dev/urandom` uses the FIPS 186-2 algorithm, which is considered less | |
14 | //! secure. We choose to read from `/dev/random`. | |
15 | //! | |
16 | //! Since Solaris 11.3 and mid-2015 illumos, the `getrandom` syscall is available. | |
17 | //! To make sure we can compile on both Solaris and its derivatives, as well as | |
18 | //! function, we check for the existence of getrandom(2) in libc by calling | |
19 | //! libc::dlsym. | |
20 | use crate::{ | |
21 | use_file, | |
22 | util_libc::{sys_fill_exact, Weak}, | |
23 | Error, | |
24 | }; | |
25 | use core::mem; | |
26 | ||
27 | #[cfg(target_os = "illumos")] | |
28 | type GetRandomFn = unsafe extern "C" fn(*mut u8, libc::size_t, libc::c_uint) -> libc::ssize_t; | |
29 | #[cfg(target_os = "solaris")] | |
30 | type GetRandomFn = unsafe extern "C" fn(*mut u8, libc::size_t, libc::c_uint) -> libc::c_int; | |
31 | ||
32 | pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> { | |
33 | static GETRANDOM: Weak = unsafe { Weak::new("getrandom\0") }; | |
34 | if let Some(fptr) = GETRANDOM.ptr() { | |
35 | let func: GetRandomFn = unsafe { mem::transmute(fptr) }; | |
36 | // 256 bytes is the lowest common denominator across all the Solaris | |
37 | // derived platforms for atomically obtaining random data. | |
38 | for chunk in dest.chunks_mut(256) { | |
39 | sys_fill_exact(chunk, |buf| unsafe { | |
40 | func(buf.as_mut_ptr(), buf.len(), 0) as libc::ssize_t | |
41 | })? | |
42 | } | |
43 | Ok(()) | |
44 | } else { | |
45 | use_file::getrandom_inner(dest) | |
46 | } | |
47 | } |