37 lines
1.3 KiB
Rust
37 lines
1.3 KiB
Rust
// Copyright 2019 Developers of the Rand project.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
//! Implementation for macOS
|
|
use crate::{
|
|
use_file,
|
|
util_libc::{last_os_error, Weak},
|
|
Error,
|
|
};
|
|
use core::mem;
|
|
|
|
type GetEntropyFn = unsafe extern "C" fn(*mut u8, libc::size_t) -> libc::c_int;
|
|
|
|
pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
|
|
// getentropy(2) was added in 10.12, Rust supports 10.7+
|
|
static GETENTROPY: Weak = unsafe { Weak::new("getentropy\0") };
|
|
if let Some(fptr) = GETENTROPY.ptr() {
|
|
let func: GetEntropyFn = unsafe { mem::transmute(fptr) };
|
|
for chunk in dest.chunks_mut(256) {
|
|
let ret = unsafe { func(chunk.as_mut_ptr(), chunk.len()) };
|
|
if ret != 0 {
|
|
return Err(last_os_error());
|
|
}
|
|
}
|
|
Ok(())
|
|
} else {
|
|
// We fallback to reading from /dev/random instead of SecRandomCopyBytes
|
|
// to avoid high startup costs and linking the Security framework.
|
|
use_file::getrandom_inner(dest)
|
|
}
|
|
}
|