geom_aes.c revision 105551
1185377Ssam/*- 2185377Ssam * Copyright (c) 2002 Poul-Henning Kamp 3185377Ssam * Copyright (c) 2002 Networks Associates Technology, Inc. 4185377Ssam * All rights reserved. 5185377Ssam * 6185377Ssam * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7185377Ssam * and NAI Labs, the Security Research Division of Network Associates, Inc. 8185377Ssam * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9185377Ssam * DARPA CHATS research program. 10185377Ssam * 11185377Ssam * Redistribution and use in source and binary forms, with or without 12185377Ssam * modification, are permitted provided that the following conditions 13185377Ssam * are met: 14185377Ssam * 1. Redistributions of source code must retain the above copyright 15185377Ssam * notice, this list of conditions and the following disclaimer. 16185377Ssam * 2. Redistributions in binary form must reproduce the above copyright 17188773Ssam * notice, this list of conditions and the following disclaimer in the 18185377Ssam * documentation and/or other materials provided with the distribution. 19185377Ssam * 3. The names of the authors may not be used to endorse or promote 20185377Ssam * products derived from this software without specific prior written 21185377Ssam * permission. 22185377Ssam * 23185377Ssam * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24185377Ssam * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25185377Ssam * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26185377Ssam * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27185377Ssam * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28185377Ssam * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29185377Ssam * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30188773Ssam * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31188773Ssam * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32185377Ssam * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33185377Ssam * SUCH DAMAGE. 34185377Ssam * 35185377Ssam * $FreeBSD: head/sys/geom/geom_aes.c 105551 2002-10-20 20:28:24Z phk $ 36185377Ssam * 37185377Ssam * This method provides AES encryption with a compiled in key (default 38185377Ssam * all zeroes). 39185377Ssam * 40185377Ssam * XXX: This could probably save a lot of code by pretending to be a slicer. 41185377Ssam */ 42185377Ssam 43185377Ssam#include <sys/param.h> 44185377Ssam#ifndef _KERNEL 45185377Ssam#include <stdio.h> 46185377Ssam#include <string.h> 47185377Ssam#include <stdlib.h> 48185377Ssam#include <signal.h> 49185377Ssam#include <err.h> 50185380Ssam#else 51185377Ssam#include <sys/systm.h> 52185377Ssam#include <sys/kernel.h> 53185377Ssam#include <sys/conf.h> 54185377Ssam#include <sys/bio.h> 55185377Ssam#include <sys/malloc.h> 56188773Ssam#include <sys/lock.h> 57188773Ssam#include <sys/mutex.h> 58188773Ssam#include <sys/libkern.h> 59188773Ssam#endif 60188773Ssam#include <sys/endian.h> 61188773Ssam#include <sys/md5.h> 62188773Ssam#include <sys/errno.h> 63188773Ssam#include <geom/geom.h> 64185377Ssam 65185377Ssam#include <crypto/rijndael/rijndael.h> 66185377Ssam 67185380Ssam#include <crypto/rijndael/rijndael.h> 68185377Ssam 69185377Ssam#define AES_CLASS_NAME "AES" 70185377Ssam 71185377Ssam#define MASTER_KEY_LENGTH (1024/8) 72185377Ssam 73188773Ssamstatic u_char *aes_magic = "<<FreeBSD-GEOM-AES>>"; 74188773Ssamstatic u_char *aes_magic_random = "<<FreeBSD-GEOM-AES-RANDOM>>"; 75188773Ssamstatic u_char *aes_magic_test = "<<FreeBSD-GEOM-AES-TEST>>"; 76188773Ssam 77188773Ssam 78188773Ssamstruct g_aes_softc { 79188773Ssam enum { 80188773Ssam KEY_ZERO, 81185377Ssam KEY_RANDOM, 82185377Ssam KEY_TEST 83185377Ssam } keying; 84185377Ssam u_int sectorsize; 85185377Ssam off_t mediasize; 86185377Ssam cipherInstance ci; 87185377Ssam u_char master_key[MASTER_KEY_LENGTH]; 88185377Ssam}; 89185377Ssam 90191022Ssam/* 91191022Ssam * Generate a sectorkey from the masterkey and the offset position. 92191022Ssam * 93191022Ssam * For KEY_ZERO we just return a key of all zeros. 94191022Ssam * 95191022Ssam * We feed the sector byte offset, 16 bytes of the master-key and 96191022Ssam * the sector byte offset once more to MD5. 97185377Ssam * The sector byte offset is converted to little-endian format first 98185377Ssam * to support multi-architecture operation. 99185377Ssam * We use 16 bytes from the master-key starting at the logical sector 100185377Ssam * number modulus he length of the master-key. If need be we wrap 101185377Ssam * around to the start of the master-key. 102185377Ssam */ 103185377Ssam 104185377Ssamstatic void 105185377Ssamg_aes_makekey(struct g_aes_softc *sc, off_t off, keyInstance *ki, int dir) 106191022Ssam{ 107191022Ssam MD5_CTX cx; 108191022Ssam u_int64_t u64; 109191022Ssam u_int u, u1; 110191022Ssam u_char *p, buf[16]; 111191022Ssam 112191022Ssam if (sc->keying == KEY_ZERO) { 113191022Ssam rijndael_makeKey(ki, dir, 128, sc->master_key); 114185377Ssam return; 115185377Ssam } 116185377Ssam MD5Init(&cx); 117185377Ssam u64 = htole64(off); 118185377Ssam MD5Update(&cx, (u_char *)&u64, sizeof(u64)); 119185377Ssam u = off / sc->sectorsize; 120185377Ssam u %= sizeof sc->master_key; 121185377Ssam p = sc->master_key + u; 122185377Ssam if (u + 16 <= sizeof(sc->master_key)) { 123185377Ssam MD5Update(&cx, p, 16); 124185377Ssam } else { 125185377Ssam u1 = sizeof sc->master_key - u; 126185377Ssam MD5Update(&cx, p, u1); 127185377Ssam MD5Update(&cx, sc->master_key, 16 - u1); 128185377Ssam u1 = 0; /* destroy evidence */ 129185377Ssam } 130185377Ssam u = 0; /* destroy evidence */ 131185377Ssam MD5Update(&cx, (u_char *)&u64, sizeof(u64)); 132185377Ssam u64 = 0; /* destroy evidence */ 133185377Ssam MD5Final(buf, &cx); 134185377Ssam bzero(&cx, sizeof cx); /* destroy evidence */ 135185377Ssam rijndael_makeKey(ki, dir, 128, buf); 136185377Ssam bzero(buf, sizeof buf); /* destroy evidence */ 137185377Ssam 138185377Ssam} 139185377Ssam 140185377Ssamstatic void 141185377Ssamg_aes_read_done(struct bio *bp) 142185377Ssam{ 143185377Ssam struct g_geom *gp; 144185377Ssam struct g_aes_softc *sc; 145185377Ssam u_char *p, *b, *e, *sb; 146185377Ssam keyInstance dkey; 147185377Ssam off_t o; 148185377Ssam 149185377Ssam gp = bp->bio_from->geom; 150185377Ssam sc = gp->softc; 151185377Ssam sb = g_malloc(sc->sectorsize, M_WAITOK); 152185377Ssam b = bp->bio_data; 153185377Ssam e = bp->bio_data; 154185377Ssam e += bp->bio_length; 155185377Ssam o = bp->bio_offset - sc->sectorsize; 156185377Ssam for (p = b; p < e; p += sc->sectorsize) { 157185377Ssam g_aes_makekey(sc, o, &dkey, DIR_DECRYPT); 158185377Ssam rijndael_blockDecrypt(&sc->ci, &dkey, p, sc->sectorsize * 8, sb); 159185377Ssam bcopy(sb, p, sc->sectorsize); 160185377Ssam o += sc->sectorsize; 161185377Ssam } 162185377Ssam bzero(&dkey, sizeof dkey); /* destroy evidence */ 163185377Ssam bzero(sb, sc->sectorsize); /* destroy evidence */ 164185377Ssam g_free(sb); 165185377Ssam g_std_done(bp); 166185377Ssam} 167185377Ssam 168185377Ssamstatic void 169185377Ssamg_aes_write_done(struct bio *bp) 170185377Ssam{ 171185377Ssam struct g_aes_softc *sc; 172185377Ssam struct g_geom *gp; 173185377Ssam 174185377Ssam gp = bp->bio_to->geom; 175185377Ssam sc = gp->softc; 176185377Ssam bzero(bp->bio_data, bp->bio_length); /* destroy evidence */ 177185377Ssam g_free(bp->bio_data); 178185377Ssam g_std_done(bp); 179185377Ssam} 180185377Ssam 181185377Ssamstatic void 182185377Ssamg_aes_start(struct bio *bp) 183185377Ssam{ 184185377Ssam struct g_geom *gp; 185185377Ssam struct g_consumer *cp; 186185377Ssam struct g_aes_softc *sc; 187185380Ssam struct bio *bp2; 188185380Ssam u_char *p1, *p2, *b, *e; 189185377Ssam keyInstance ekey; 190185377Ssam off_t o; 191185380Ssam 192185380Ssam gp = bp->bio_to->geom; 193185377Ssam cp = LIST_FIRST(&gp->consumer); 194185377Ssam sc = gp->softc; 195185377Ssam switch (bp->bio_cmd) { 196185377Ssam case BIO_READ: 197185377Ssam bp2 = g_clone_bio(bp); 198185377Ssam if (bp2 == NULL) { 199185377Ssam g_io_deliver(bp, ENOMEM); 200185377Ssam return; 201185377Ssam } 202 bp2->bio_done = g_aes_read_done; 203 bp2->bio_offset += sc->sectorsize; 204 g_io_request(bp2, cp); 205 break; 206 case BIO_WRITE: 207 bp2 = g_clone_bio(bp); 208 if (bp2 == NULL) { 209 g_io_deliver(bp, ENOMEM); 210 return; 211 } 212 bp2->bio_done = g_aes_write_done; 213 bp2->bio_offset += sc->sectorsize; 214 bp2->bio_data = g_malloc(bp->bio_length, M_WAITOK); 215 b = bp->bio_data; 216 e = bp->bio_data; 217 e += bp->bio_length; 218 p2 = bp2->bio_data; 219 o = bp->bio_offset; 220 for (p1 = b; p1 < e; p1 += sc->sectorsize) { 221 g_aes_makekey(sc, o, &ekey, DIR_ENCRYPT); 222 rijndael_blockEncrypt(&sc->ci, &ekey, 223 p1, sc->sectorsize * 8, p2); 224 p2 += sc->sectorsize; 225 o += sc->sectorsize; 226 } 227 bzero(&ekey, sizeof ekey); /* destroy evidence */ 228 g_io_request(bp2, cp); 229 break; 230 case BIO_GETATTR: 231 case BIO_SETATTR: 232 bp2 = g_clone_bio(bp); 233 if (bp2 == NULL) { 234 g_io_deliver(bp, ENOMEM); 235 return; 236 } 237 bp2->bio_done = g_std_done; 238 bp2->bio_offset += sc->sectorsize; 239 g_io_request(bp2, cp); 240 break; 241 default: 242 g_io_deliver(bp, EOPNOTSUPP); 243 return; 244 } 245 return; 246} 247 248static void 249g_aes_orphan(struct g_consumer *cp) 250{ 251 struct g_geom *gp; 252 struct g_provider *pp; 253 struct g_aes_softc *sc; 254 int error; 255 256 g_trace(G_T_TOPOLOGY, "g_aes_orphan(%p/%s)", cp, cp->provider->name); 257 g_topology_assert(); 258 KASSERT(cp->provider->error != 0, 259 ("g_aes_orphan with error == 0")); 260 261 gp = cp->geom; 262 sc = gp->softc; 263 gp->flags |= G_GEOM_WITHER; 264 error = cp->provider->error; 265 LIST_FOREACH(pp, &gp->provider, provider) 266 g_orphan_provider(pp, error); 267 bzero(sc, sizeof(struct g_aes_softc)); /* destroy evidence */ 268 return; 269} 270 271static int 272g_aes_access(struct g_provider *pp, int dr, int dw, int de) 273{ 274 struct g_geom *gp; 275 struct g_consumer *cp; 276 277 gp = pp->geom; 278 cp = LIST_FIRST(&gp->consumer); 279 /* On first open, grab an extra "exclusive" bit */ 280 if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0) 281 de++; 282 /* ... and let go of it on last close */ 283 if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1) 284 de--; 285 return (g_access_rel(cp, dr, dw, de)); 286} 287 288static struct g_geom * 289g_aes_taste(struct g_class *mp, struct g_provider *pp, int flags __unused) 290{ 291 struct g_geom *gp; 292 struct g_consumer *cp; 293 struct g_aes_softc *sc; 294 int error; 295 u_int sectorsize; 296 off_t mediasize; 297 u_char *buf; 298 299 g_trace(G_T_TOPOLOGY, "aes_taste(%s,%s)", mp->name, pp->name); 300 g_topology_assert(); 301 gp = g_new_geomf(mp, "%s.aes", pp->name); 302 gp->start = g_aes_start; 303 gp->orphan = g_aes_orphan; 304 gp->spoiled = g_std_spoiled; 305 cp = g_new_consumer(gp); 306 g_attach(cp, pp); 307 error = g_access_rel(cp, 1, 0, 0); 308 if (error) { 309 g_detach(cp); 310 g_destroy_consumer(cp); 311 g_destroy_geom(gp); 312 return (NULL); 313 } 314 buf = NULL; 315 g_topology_unlock(); 316 while (1) { 317 if (gp->rank != 2) 318 break; 319 sectorsize = cp->provider->sectorsize; 320 mediasize = cp->provider->mediasize; 321 buf = g_read_data(cp, 0, sectorsize, &error); 322 if (buf == NULL || error != 0) { 323 break; 324 } 325 sc = g_malloc(sizeof(struct g_aes_softc), M_WAITOK | M_ZERO); 326 if (!memcmp(buf, aes_magic, strlen(aes_magic))) { 327 sc->keying = KEY_ZERO; 328 } else if (!memcmp(buf, aes_magic_random, 329 strlen(aes_magic_random))) { 330 sc->keying = KEY_RANDOM; 331 } else if (!memcmp(buf, aes_magic_test, 332 strlen(aes_magic_test))) { 333 sc->keying = KEY_TEST; 334 } else { 335 g_free(sc); 336 break; 337 } 338 gp->softc = sc; 339 gp->access = g_aes_access; 340 sc->sectorsize = sectorsize; 341 sc->mediasize = mediasize - sectorsize; 342 rijndael_cipherInit(&sc->ci, MODE_CBC, NULL); 343 if (sc->keying == KEY_TEST) { 344 int i; 345 u_char *p; 346 347 p = sc->master_key; 348 for (i = 0; i < (int)sizeof sc->master_key; i ++) 349 *p++ = i; 350 } 351 if (sc->keying == KEY_RANDOM) { 352 int i; 353 u_int32_t u; 354 u_char *p; 355 356 p = sc->master_key; 357 for (i = 0; i < (int)sizeof sc->master_key; i += sizeof u) { 358 u = arc4random(); 359 *p++ = u; 360 *p++ = u >> 8; 361 *p++ = u >> 16; 362 *p++ = u >> 24; 363 } 364 } 365 g_topology_lock(); 366 pp = g_new_providerf(gp, gp->name); 367 pp->mediasize = mediasize - sectorsize; 368 pp->sectorsize = sectorsize; 369 g_error_provider(pp, 0); 370 g_topology_unlock(); 371 break; 372 } 373 g_topology_lock(); 374 if (buf) 375 g_free(buf); 376 g_access_rel(cp, -1, 0, 0); 377 if (gp->softc != NULL) 378 return (gp); 379 g_detach(cp); 380 g_destroy_consumer(cp); 381 g_destroy_geom(gp); 382 return (NULL); 383} 384 385static struct g_class g_aes_class = { 386 AES_CLASS_NAME, 387 g_aes_taste, 388 NULL, 389 G_CLASS_INITIALIZER 390}; 391 392DECLARE_GEOM_CLASS(g_aes_class, g_aes); 393