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
34 struct 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 */
48 static inline void
fxrng_rng_init(struct fxrng_basic_rng * rng,bool is_root_rng)49 fxrng_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
57 static inline void
fxrng_rng_setkey(struct fxrng_basic_rng * rng,const void * newkey,size_t len)58 fxrng_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
64 void fxrng_rng_genrandom_internal(struct fxrng_basic_rng *, void *, size_t,
65 bool return_unlocked);
66
67 void fxrng_rng_reseed(struct fxrng_basic_rng *, bool seeded, const void *,
68 size_t);
69 void fxrng_rng_src_reseed(struct fxrng_basic_rng *,
70 const struct harvest_event *);
71