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-rw-r--r--third_party/rust/getrandom/src/macos.rs36
1 files changed, 36 insertions, 0 deletions
diff --git a/third_party/rust/getrandom/src/macos.rs b/third_party/rust/getrandom/src/macos.rs
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+// 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)
+ }
+}