1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2019 Conrad Meyer <cem@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27#pragma once
28
29#include <crypto/chacha20/chacha.h>
30#include <dev/random/fenestrasX/fx_priv.h>
31
32#define	FX_CHACHA20_KEYSIZE	32
33
34struct fxrng_basic_rng {
35	struct mtx		rng_lk;
36#define	FXRNG_RNG_LOCK(rng)	mtx_lock(&(rng)->rng_lk)
37#define	FXRNG_RNG_UNLOCK(rng)	mtx_unlock(&(rng)->rng_lk)
38#define	FXRNG_RNG_ASSERT(rng)	mtx_assert(&(rng)->rng_lk, MA_OWNED)
39#define	FXRNG_RNG_ASSERT_NOT(rng)	mtx_assert(&(rng)->rng_lk, MA_NOTOWNED)
40	/* CTR-mode cipher state, including 128-bit embedded counter. */
41	struct chacha_ctx	rng_prf;
42};
43
44/*
45 * Initialize a basic rng instance (half of a buffered FX BRNG).
46 * Memory should be zero initialized before this routine.
47 */
48static inline void
49fxrng_rng_init(struct fxrng_basic_rng *rng, bool is_root_rng)
50{
51	if (is_root_rng)
52		mtx_init(&rng->rng_lk, "fx root brng lk", NULL, MTX_DEF);
53	else
54		mtx_init(&rng->rng_lk, "fx pcpu brng lk", NULL, MTX_DEF);
55}
56
57static inline void
58fxrng_rng_setkey(struct fxrng_basic_rng *rng, const void *newkey, size_t len)
59{
60	ASSERT_DEBUG(len == FX_CHACHA20_KEYSIZE, "chacha20 uses 256 bit keys");
61	chacha_keysetup(&rng->rng_prf, newkey, len * 8);
62}
63
64void fxrng_rng_genrandom_internal(struct fxrng_basic_rng *, void *, size_t,
65    bool return_unlocked);
66
67void fxrng_rng_reseed(struct fxrng_basic_rng *, bool seeded, const void *,
68    size_t);
69void fxrng_rng_src_reseed(struct fxrng_basic_rng *,
70    const struct harvest_event *);
71