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, long limit);
40
41 #define PADLOCK_RNDBYTES 32
42
43 static void
padlock_rng_harvest(void * arg)44 padlock_rng_harvest(void *arg)
45 {
46 struct padlock_softc *sc = arg;
47 uint8_t randomness[PADLOCK_RNDBYTES + 32];
48 uint8_t *arandomness; /* randomness aligned */
49 int cnt;
50
51 arandomness = PADLOCK_ALIGN(randomness);
52 cnt = padlock_rng(arandomness, PADLOCK_RNDBYTES);
53
54 add_buffer_randomness_src(arandomness, cnt, RAND_SRC_PADLOCK);
55
56 callout_reset(&sc->sc_rng_co, sc->sc_rng_ticks,
57 padlock_rng_harvest, sc);
58 }
59
60 void
padlock_rng_init(struct padlock_softc * sc)61 padlock_rng_init(struct padlock_softc *sc)
62 {
63 if (hz > 100)
64 sc->sc_rng_ticks = hz/100;
65 else
66 sc->sc_rng_ticks = 1;
67
68 callout_init_mp(&sc->sc_rng_co);
69 callout_reset(&sc->sc_rng_co, sc->sc_rng_ticks,
70 padlock_rng_harvest, sc);
71 }
72
73 void
padlock_rng_uninit(struct padlock_softc * sc)74 padlock_rng_uninit(struct padlock_softc *sc)
75 {
76 callout_stop(&sc->sc_rng_co);
77 }
78
79