2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7 * and NAI Labs, the Security Research Division of Network Associates, Inc.
8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9 * DARPA CHATS research program.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. The names of the authors may not be used to endorse or promote
20 * products derived from this software without specific prior written
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * This method provides AES encryption with a compiled in key (default
40 * XXX: This could probably save a lot of code by pretending to be a slicer.
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
51 #include <sys/malloc.h>
53 #include <sys/mutex.h>
54 #include <sys/libkern.h>
55 #include <sys/endian.h>
57 #include <sys/errno.h>
58 #include <geom/geom.h>
60 #include <crypto/rijndael/rijndael-api-fst.h>
62 #define AES_CLASS_NAME "AES"
64 #define MASTER_KEY_LENGTH (1024/8)
66 static const u_char *aes_magic = "<<FreeBSD-GEOM-AES>>";
67 static const u_char *aes_magic_random = "<<FreeBSD-GEOM-AES-RANDOM>>";
68 static const u_char *aes_magic_test = "<<FreeBSD-GEOM-AES-TEST>>";
70 static int g_aes_once;
81 u_char master_key[MASTER_KEY_LENGTH];
85 * Generate a sectorkey from the masterkey and the offset position.
87 * For KEY_ZERO we just return a key of all zeros.
89 * We feed the sector byte offset, 16 bytes of the master-key and
90 * the sector byte offset once more to MD5.
91 * The sector byte offset is converted to little-endian format first
92 * to support multi-architecture operation.
93 * We use 16 bytes from the master-key starting at the logical sector
94 * number modulus he length of the master-key. If need be we wrap
95 * around to the start of the master-key.
99 g_aes_makekey(struct g_aes_softc *sc, off_t off, keyInstance *ki, int dir)
106 if (sc->keying == KEY_ZERO) {
107 rijndael_makeKey(ki, dir, 128, sc->master_key);
112 MD5Update(&cx, (u_char *)&u64, sizeof(u64));
113 u = off / sc->sectorsize;
114 u %= sizeof sc->master_key;
115 p = sc->master_key + u;
116 if (u + 16 <= sizeof(sc->master_key)) {
117 MD5Update(&cx, p, 16);
119 u1 = sizeof sc->master_key - u;
120 MD5Update(&cx, p, u1);
121 MD5Update(&cx, sc->master_key, 16 - u1);
122 u1 = 0; /* destroy evidence */
124 u = 0; /* destroy evidence */
125 MD5Update(&cx, (u_char *)&u64, sizeof(u64));
126 u64 = 0; /* destroy evidence */
128 bzero(&cx, sizeof cx); /* destroy evidence */
129 rijndael_makeKey(ki, dir, 128, buf);
130 bzero(buf, sizeof buf); /* destroy evidence */
135 g_aes_read_done(struct bio *bp)
138 struct g_aes_softc *sc;
139 u_char *p, *b, *e, *sb;
143 gp = bp->bio_from->geom;
145 sb = g_malloc(sc->sectorsize, M_WAITOK);
149 o = bp->bio_offset - sc->sectorsize;
150 for (p = b; p < e; p += sc->sectorsize) {
151 g_aes_makekey(sc, o, &dkey, DIR_DECRYPT);
152 rijndael_blockDecrypt(&sc->ci, &dkey, p, sc->sectorsize * 8, sb);
153 bcopy(sb, p, sc->sectorsize);
156 bzero(&dkey, sizeof dkey); /* destroy evidence */
157 bzero(sb, sc->sectorsize); /* destroy evidence */
163 g_aes_write_done(struct bio *bp)
166 bzero(bp->bio_data, bp->bio_length); /* destroy evidence */
167 g_free(bp->bio_data);
172 g_aes_start(struct bio *bp)
175 struct g_consumer *cp;
176 struct g_aes_softc *sc;
178 u_char *p1, *p2, *b, *e;
182 gp = bp->bio_to->geom;
183 cp = LIST_FIRST(&gp->consumer);
185 switch (bp->bio_cmd) {
187 bp2 = g_clone_bio(bp);
189 g_io_deliver(bp, ENOMEM);
192 bp2->bio_done = g_aes_read_done;
193 bp2->bio_offset += sc->sectorsize;
194 g_io_request(bp2, cp);
197 bp2 = g_clone_bio(bp);
199 g_io_deliver(bp, ENOMEM);
202 bp2->bio_done = g_aes_write_done;
203 bp2->bio_offset += sc->sectorsize;
204 bp2->bio_data = g_malloc(bp->bio_length, M_WAITOK);
210 for (p1 = b; p1 < e; p1 += sc->sectorsize) {
211 g_aes_makekey(sc, o, &ekey, DIR_ENCRYPT);
212 rijndael_blockEncrypt(&sc->ci, &ekey,
213 p1, sc->sectorsize * 8, p2);
214 p2 += sc->sectorsize;
217 bzero(&ekey, sizeof ekey); /* destroy evidence */
218 g_io_request(bp2, cp);
221 bp2 = g_clone_bio(bp);
223 g_io_deliver(bp, ENOMEM);
226 bp2->bio_done = g_std_done;
227 bp2->bio_offset += sc->sectorsize;
228 g_io_request(bp2, cp);
231 g_io_deliver(bp, EOPNOTSUPP);
238 g_aes_orphan(struct g_consumer *cp)
241 struct g_aes_softc *sc;
243 g_trace(G_T_TOPOLOGY, "g_aes_orphan(%p/%s)", cp, cp->provider->name);
248 g_wither_geom(gp, ENXIO);
249 bzero(sc, sizeof(struct g_aes_softc)); /* destroy evidence */
255 g_aes_access(struct g_provider *pp, int dr, int dw, int de)
258 struct g_consumer *cp;
261 cp = LIST_FIRST(&gp->consumer);
262 /* On first open, grab an extra "exclusive" bit */
263 if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
265 /* ... and let go of it on last close */
266 if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
268 return (g_access(cp, dr, dw, de));
271 static struct g_geom *
272 g_aes_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
275 struct g_consumer *cp;
276 struct g_aes_softc *sc;
282 g_trace(G_T_TOPOLOGY, "aes_taste(%s,%s)", mp->name, pp->name);
284 gp = g_new_geomf(mp, "%s.aes", pp->name);
285 cp = g_new_consumer(gp);
287 error = g_access(cp, 1, 0, 0);
290 g_destroy_consumer(cp);
299 sectorsize = cp->provider->sectorsize;
300 mediasize = cp->provider->mediasize;
301 buf = g_read_data(cp, 0, sectorsize, NULL);
305 sc = g_malloc(sizeof(struct g_aes_softc), M_WAITOK | M_ZERO);
306 if (!memcmp(buf, aes_magic, strlen(aes_magic))) {
307 sc->keying = KEY_ZERO;
308 } else if (!memcmp(buf, aes_magic_random,
309 strlen(aes_magic_random))) {
310 sc->keying = KEY_RANDOM;
311 } else if (!memcmp(buf, aes_magic_test,
312 strlen(aes_magic_test))) {
313 sc->keying = KEY_TEST;
320 sc->sectorsize = sectorsize;
321 sc->mediasize = mediasize - sectorsize;
322 rijndael_cipherInit(&sc->ci, MODE_CBC, NULL);
323 if (sc->keying == KEY_TEST) {
328 for (i = 0; i < (int)sizeof sc->master_key; i ++)
331 if (sc->keying == KEY_RANDOM) {
337 for (i = 0; i < (int)sizeof sc->master_key; i += sizeof u) {
346 pp = g_new_providerf(gp, "%s", gp->name);
347 pp->mediasize = mediasize - sectorsize;
348 pp->sectorsize = sectorsize;
349 g_error_provider(pp, 0);
355 g_access(cp, -1, 0, 0);
356 if (gp->softc != NULL) {
359 printf("WARNING: geom_aes (geom %s) is deprecated.",
365 g_destroy_consumer(cp);
370 static struct g_class g_aes_class = {
371 .name = AES_CLASS_NAME,
372 .version = G_VERSION,
373 .taste = g_aes_taste,
374 .start = g_aes_start,
375 .orphan = g_aes_orphan,
376 .spoiled = g_std_spoiled,
377 .access = g_aes_access,
380 DECLARE_GEOM_CLASS(g_aes_class, g_aes);