xref: /src/lib/libc/include/arc4random.h

/*	$NetBSD: arc4random.h,v 1.4 2025/03/09 18:11:55 riastradh Exp $	*/

/*-
 * Copyright (c) 2014 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Taylor R. Campbell.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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	_LIBC_GEN_ARC4RANDOM_H_
#define	_LIBC_GEN_ARC4RANDOM_H_

#include <stdbool.h>
#include <stdint.h>

#include "reentrant.h"

struct crypto_prng {
	uint8_t		state[32];
};

struct arc4random_prng {
	struct crypto_prng	arc4_prng;
	unsigned		arc4_epoch;
};

struct arc4random_global_state {
	mutex_t			lock;
	thread_key_t		thread_key;
	struct arc4random_prng	prng;
	once_t			once;
	bool			initialized;
	bool			forksafe;
	bool			per_thread;
};

#define	arc4random_global	__arc4random_global /* libc private symbol */

extern struct arc4random_global_state arc4random_global;

#endif	/* _LIBC_GEN_ARC4RANDOM_H_ */