platform_bionic/libc/private/bionic_arc4random.h
Elliott Hughes c11fb66739 Inline __libc_arc4random_has_unlimited_entropy.
The name is misleading anyway.

Bug: http://b/67015565
Test: boots
Change-Id: Ic765e376d84e1ca474d3324eab32e14ea1ae9712
2018-02-06 15:35:15 -08:00

43 lines
1.9 KiB
C

/*
* Copyright (C) 2016 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _PRIVATE_BIONIC_ARC4RANDOM_H_
#define _PRIVATE_BIONIC_ARC4RANDOM_H_
#include <stddef.h>
#include "private/KernelArgumentBlock.h"
// arc4random(3) aborts if it's unable to fetch entropy, which is always
// the case for init on devices. GCE kernels have a workaround to ensure
// sufficient entropy during early boot, but no device kernels do. This
// wrapper falls back to AT_RANDOM if the kernel doesn't have enough
// entropy for getrandom(2) or /dev/urandom.
void __libc_safe_arc4random_buf(void* buf, size_t n, KernelArgumentBlock& args);
#endif