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::util_libc::{sys_fill_exact, Weak};
21 use crate::{use_file, Error};
22 use core::mem;
23
24 #[cfg(target_os = "illumos")]
25 type GetRandomFn = unsafe extern "C" fn(*mut u8, libc::size_t, libc::c_uint) -> libc::ssize_t;
26 #[cfg(target_os = "solaris")]
27 type GetRandomFn = unsafe extern "C" fn(*mut u8, libc::size_t, libc::c_uint) -> libc::c_int;
28
getrandom_inner(dest: &mut [u8]) -> Result<(), Error>29 pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
30 static GETRANDOM: Weak = unsafe { Weak::new("getrandom\0") };
31 if let Some(fptr) = GETRANDOM.ptr() {
32 let func: GetRandomFn = unsafe { mem::transmute(fptr) };
33 // 256 bytes is the lowest common denominator across all the Solaris
34 // derived platforms for atomically obtaining random data.
35 for chunk in dest.chunks_mut(256) {
36 sys_fill_exact(chunk, |buf| unsafe {
37 func(buf.as_mut_ptr(), buf.len(), 0) as libc::ssize_t
38 })?
39 }
40 Ok(())
41 } else {
42 use_file::getrandom_inner(dest)
43 }
44 }
45