1 /* 2 * Copyright (c) 2011 Alex Hornung <alex@alexhornung.com>. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 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 13 * the documentation and/or other materials provided with the 14 * distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 20 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 #include <sys/module.h> 33 #include <sys/malloc.h> 34 #include <sys/libkern.h> 35 #include <sys/random.h> 36 37 #include <dev/crypto/padlock/padlock.h> 38 39 int padlock_rng(uint8_t *out, int limit); 40 41 static int random_count = 32; 42 43 static void 44 padlock_rng_harvest(void *arg) 45 { 46 struct padlock_softc *sc = arg; 47 uint8_t randomness[128]; 48 uint8_t *arandomness; /* randomness aligned */ 49 int i, cnt; 50 51 arandomness = PADLOCK_ALIGN(randomness); 52 cnt = padlock_rng(arandomness, random_count); 53 54 for (i = 0; i < cnt; i++) 55 add_true_randomness((int)arandomness[i]); 56 57 callout_reset(&sc->sc_rng_co, sc->sc_rng_ticks, 58 padlock_rng_harvest, sc); 59 } 60 61 void 62 padlock_rng_init(struct padlock_softc *sc) 63 { 64 if (hz > 100) 65 sc->sc_rng_ticks = hz/100; 66 else 67 sc->sc_rng_ticks = 1; 68 69 callout_init_mp(&sc->sc_rng_co); 70 callout_reset(&sc->sc_rng_co, sc->sc_rng_ticks, 71 padlock_rng_harvest, sc); 72 } 73 74 void 75 padlock_rng_uninit(struct padlock_softc *sc) 76 { 77 callout_stop(&sc->sc_rng_co); 78 } 79 80