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 <dev/random/fenestrasX/fx_rng.h> 30 31 #define FXRNG_BUFRNG_SZ 128 32 33 /* 34 * An object representing a buffered random number generator with forward 35 * secrecy (aka "fast-key-erasure"). 36 * 37 * There is a single static root instance of this object associated with the 38 * entropy harvester, as well as additional instances per CPU, lazily allocated 39 * in NUMA-local memory, seeded from output of the root generator. 40 */ 41 struct fxrng_buffered_rng { 42 struct fxrng_basic_rng brng_rng; 43 #define FXRNG_BRNG_LOCK(brng) mtx_lock(&(brng)->brng_rng.rng_lk) 44 #define FXRNG_BRNG_UNLOCK(brng) mtx_unlock(&(brng)->brng_rng.rng_lk) 45 #define FXRNG_BRNG_ASSERT(brng) mtx_assert(&(brng)->brng_rng.rng_lk, MA_OWNED) 46 #define FXRNG_BRNG_ASSERT_NOT(brng) \ 47 mtx_assert(&(brng)->brng_rng.rng_lk, MA_NOTOWNED) 48 49 /* Entropy reseed generation ("seed version"). */ 50 uint64_t brng_generation; 51 52 /* Buffered output for quick access by small requests. */ 53 uint8_t brng_buffer[FXRNG_BUFRNG_SZ]; 54 uint8_t brng_avail_idx; 55 }; 56 57 void fxrng_brng_init(struct fxrng_buffered_rng *); 58 void fxrng_brng_produce_seed_data_internal(struct fxrng_buffered_rng *, void *, 59 size_t, uint64_t *seed_generation); 60 void fxrng_brng_read(struct fxrng_buffered_rng *, void *, size_t); 61 62 void fxrng_brng_reseed(const void *, size_t); 63 struct harvest_event; 64 void fxrng_brng_src_reseed(const struct harvest_event *); 65