585fc3e554
Let the caller know when libc has an entropy source and arc4random is safe. This is useful for the callers that want entropy, but don't absolutely need it. Bug: http://b/27729263 Test: booted angler-userdebug w/ safestack Change-Id: Iab3050bd19f23518e1676629573eebc656ba1090
50 lines
2.1 KiB
C
50 lines
2.1 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 aborts if it's unable to fetch entropy, which is always the case
|
|
* for init on devices without getrandom(2), since /dev/random hasn't been
|
|
* created yet. Provide a wrapper function that falls back to AT_RANDOM if
|
|
* we don't have getrandom and /dev/urandom is missing.
|
|
*/
|
|
void __libc_safe_arc4random_buf(void* buf, size_t n, KernelArgumentBlock& args);
|
|
|
|
/*
|
|
* Return true if libc has an unlimited entropy source (something other than
|
|
* AT_RANDOM), and arc4random* calls will always succeed.
|
|
*/
|
|
bool __libc_arc4random_has_unlimited_entropy();
|
|
|
|
#endif
|