geom_aes.c revision 139778
139818Speter/*- 239818Speter * Copyright (c) 2002 Poul-Henning Kamp 339818Speter * Copyright (c) 2002 Networks Associates Technology, Inc. 447719Speter * All rights reserved. 539818Speter * 639818Speter * This software was developed for the FreeBSD Project by Poul-Henning Kamp 739818Speter * and NAI Labs, the Security Research Division of Network Associates, Inc. 844670Sdg * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 939818Speter * DARPA CHATS research program. 1039818Speter * 1139818Speter * Redistribution and use in source and binary forms, with or without 1239818Speter * modification, are permitted provided that the following conditions 1339818Speter * are met: 1439818Speter * 1. Redistributions of source code must retain the above copyright 1539818Speter * notice, this list of conditions and the following disclaimer. 1639818Speter * 2. Redistributions in binary form must reproduce the above copyright 1739818Speter * notice, this list of conditions and the following disclaimer in the 1839818Speter * documentation and/or other materials provided with the distribution. 1939818Speter * 3. The names of the authors may not be used to endorse or promote 2039818Speter * products derived from this software without specific prior written 2139818Speter * permission. 2239818Speter * 2339818Speter * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 2439818Speter * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2539818Speter * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2639818Speter * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 2739818Speter * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2839818Speter * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2939818Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3039818Speter * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3139818Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3239818Speter * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3339818Speter * SUCH DAMAGE. 3439818Speter */ 3539818Speter 3639818Speter/* 3739818Speter * This method provides AES encryption with a compiled in key (default 3839818Speter * all zeroes). 3939818Speter * 4039818Speter * XXX: This could probably save a lot of code by pretending to be a slicer. 4139818Speter */ 4239818Speter 4339818Speter#include <sys/cdefs.h> 4439818Speter__FBSDID("$FreeBSD: head/sys/geom/geom_aes.c 139778 2005-01-06 18:27:30Z imp $"); 4539818Speter 4639818Speter#include <sys/param.h> 4739818Speter#include <sys/systm.h> 4839818Speter#include <sys/kernel.h> 4939818Speter#include <sys/conf.h> 5039818Speter#include <sys/bio.h> 5139818Speter#include <sys/malloc.h> 5239818Speter#include <sys/lock.h> 5339818Speter#include <sys/mutex.h> 5439818Speter#include <sys/libkern.h> 5539818Speter#include <sys/endian.h> 5639818Speter#include <sys/md5.h> 5739818Speter#include <sys/errno.h> 5839818Speter#include <geom/geom.h> 5939818Speter 6039818Speter#include <crypto/rijndael/rijndael.h> 6139818Speter 6239818Speter#include <crypto/rijndael/rijndael.h> 6339818Speter 6439818Speter#define AES_CLASS_NAME "AES" 6539818Speter 6639818Speter#define MASTER_KEY_LENGTH (1024/8) 6739818Speter 6839818Speterstatic const u_char *aes_magic = "<<FreeBSD-GEOM-AES>>"; 6939818Speterstatic const u_char *aes_magic_random = "<<FreeBSD-GEOM-AES-RANDOM>>"; 7039818Speterstatic const u_char *aes_magic_test = "<<FreeBSD-GEOM-AES-TEST>>"; 7139818Speter 7239818Speter 7339818Speterstruct g_aes_softc { 7439818Speter enum { 7539818Speter KEY_ZERO, 7639818Speter KEY_RANDOM, 7739818Speter KEY_TEST 7839818Speter } keying; 7939818Speter u_int sectorsize; 8039818Speter off_t mediasize; 8139818Speter cipherInstance ci; 8239818Speter u_char master_key[MASTER_KEY_LENGTH]; 8339818Speter}; 8439818Speter 8539818Speter/* 8639818Speter * Generate a sectorkey from the masterkey and the offset position. 8739818Speter * 8839818Speter * For KEY_ZERO we just return a key of all zeros. 8939818Speter * 9039818Speter * We feed the sector byte offset, 16 bytes of the master-key and 9139818Speter * the sector byte offset once more to MD5. 9239818Speter * The sector byte offset is converted to little-endian format first 9339818Speter * to support multi-architecture operation. 9439818Speter * We use 16 bytes from the master-key starting at the logical sector 9539818Speter * number modulus he length of the master-key. If need be we wrap 9639818Speter * around to the start of the master-key. 9739818Speter */ 9839818Speter 9939818Speterstatic void 10039818Speterg_aes_makekey(struct g_aes_softc *sc, off_t off, keyInstance *ki, int dir) 10139818Speter{ 10239818Speter MD5_CTX cx; 10339818Speter u_int64_t u64; 10439818Speter u_int u, u1; 10539818Speter u_char *p, buf[16]; 10639818Speter 10739818Speter if (sc->keying == KEY_ZERO) { 10839818Speter rijndael_makeKey(ki, dir, 128, sc->master_key); 10939818Speter return; 11039818Speter } 11139818Speter MD5Init(&cx); 11239818Speter u64 = htole64(off); 11339818Speter MD5Update(&cx, (u_char *)&u64, sizeof(u64)); 11439818Speter u = off / sc->sectorsize; 11539818Speter u %= sizeof sc->master_key; 11639818Speter p = sc->master_key + u; 11739818Speter if (u + 16 <= sizeof(sc->master_key)) { 11839818Speter MD5Update(&cx, p, 16); 11939818Speter } else { 12039818Speter u1 = sizeof sc->master_key - u; 12139818Speter MD5Update(&cx, p, u1); 12239818Speter MD5Update(&cx, sc->master_key, 16 - u1); 12339818Speter u1 = 0; /* destroy evidence */ 12439818Speter } 12539818Speter u = 0; /* destroy evidence */ 12639818Speter MD5Update(&cx, (u_char *)&u64, sizeof(u64)); 12739818Speter u64 = 0; /* destroy evidence */ 12839818Speter MD5Final(buf, &cx); 129 bzero(&cx, sizeof cx); /* destroy evidence */ 130 rijndael_makeKey(ki, dir, 128, buf); 131 bzero(buf, sizeof buf); /* destroy evidence */ 132 133} 134 135static void 136g_aes_read_done(struct bio *bp) 137{ 138 struct g_geom *gp; 139 struct g_aes_softc *sc; 140 u_char *p, *b, *e, *sb; 141 keyInstance dkey; 142 off_t o; 143 144 gp = bp->bio_from->geom; 145 sc = gp->softc; 146 sb = g_malloc(sc->sectorsize, M_WAITOK); 147 b = bp->bio_data; 148 e = bp->bio_data; 149 e += bp->bio_length; 150 o = bp->bio_offset - sc->sectorsize; 151 for (p = b; p < e; p += sc->sectorsize) { 152 g_aes_makekey(sc, o, &dkey, DIR_DECRYPT); 153 rijndael_blockDecrypt(&sc->ci, &dkey, p, sc->sectorsize * 8, sb); 154 bcopy(sb, p, sc->sectorsize); 155 o += sc->sectorsize; 156 } 157 bzero(&dkey, sizeof dkey); /* destroy evidence */ 158 bzero(sb, sc->sectorsize); /* destroy evidence */ 159 g_free(sb); 160 g_std_done(bp); 161} 162 163static void 164g_aes_write_done(struct bio *bp) 165{ 166 167 bzero(bp->bio_data, bp->bio_length); /* destroy evidence */ 168 g_free(bp->bio_data); 169 g_std_done(bp); 170} 171 172static void 173g_aes_start(struct bio *bp) 174{ 175 struct g_geom *gp; 176 struct g_consumer *cp; 177 struct g_aes_softc *sc; 178 struct bio *bp2; 179 u_char *p1, *p2, *b, *e; 180 keyInstance ekey; 181 off_t o; 182 183 gp = bp->bio_to->geom; 184 cp = LIST_FIRST(&gp->consumer); 185 sc = gp->softc; 186 switch (bp->bio_cmd) { 187 case BIO_READ: 188 bp2 = g_clone_bio(bp); 189 if (bp2 == NULL) { 190 g_io_deliver(bp, ENOMEM); 191 return; 192 } 193 bp2->bio_done = g_aes_read_done; 194 bp2->bio_offset += sc->sectorsize; 195 g_io_request(bp2, cp); 196 break; 197 case BIO_WRITE: 198 bp2 = g_clone_bio(bp); 199 if (bp2 == NULL) { 200 g_io_deliver(bp, ENOMEM); 201 return; 202 } 203 bp2->bio_done = g_aes_write_done; 204 bp2->bio_offset += sc->sectorsize; 205 bp2->bio_data = g_malloc(bp->bio_length, M_WAITOK); 206 b = bp->bio_data; 207 e = bp->bio_data; 208 e += bp->bio_length; 209 p2 = bp2->bio_data; 210 o = bp->bio_offset; 211 for (p1 = b; p1 < e; p1 += sc->sectorsize) { 212 g_aes_makekey(sc, o, &ekey, DIR_ENCRYPT); 213 rijndael_blockEncrypt(&sc->ci, &ekey, 214 p1, sc->sectorsize * 8, p2); 215 p2 += sc->sectorsize; 216 o += sc->sectorsize; 217 } 218 bzero(&ekey, sizeof ekey); /* destroy evidence */ 219 g_io_request(bp2, cp); 220 break; 221 case BIO_GETATTR: 222 bp2 = g_clone_bio(bp); 223 if (bp2 == NULL) { 224 g_io_deliver(bp, ENOMEM); 225 return; 226 } 227 bp2->bio_done = g_std_done; 228 bp2->bio_offset += sc->sectorsize; 229 g_io_request(bp2, cp); 230 break; 231 default: 232 g_io_deliver(bp, EOPNOTSUPP); 233 return; 234 } 235 return; 236} 237 238static void 239g_aes_orphan(struct g_consumer *cp) 240{ 241 struct g_geom *gp; 242 struct g_aes_softc *sc; 243 244 g_trace(G_T_TOPOLOGY, "g_aes_orphan(%p/%s)", cp, cp->provider->name); 245 g_topology_assert(); 246 KASSERT(cp->provider->error != 0, 247 ("g_aes_orphan with error == 0")); 248 249 gp = cp->geom; 250 sc = gp->softc; 251 g_wither_geom(gp, cp->provider->error); 252 bzero(sc, sizeof(struct g_aes_softc)); /* destroy evidence */ 253 g_free(sc); 254 return; 255} 256 257static int 258g_aes_access(struct g_provider *pp, int dr, int dw, int de) 259{ 260 struct g_geom *gp; 261 struct g_consumer *cp; 262 263 gp = pp->geom; 264 cp = LIST_FIRST(&gp->consumer); 265 /* On first open, grab an extra "exclusive" bit */ 266 if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0) 267 de++; 268 /* ... and let go of it on last close */ 269 if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1) 270 de--; 271 return (g_access(cp, dr, dw, de)); 272} 273 274static struct g_geom * 275g_aes_taste(struct g_class *mp, struct g_provider *pp, int flags __unused) 276{ 277 struct g_geom *gp; 278 struct g_consumer *cp; 279 struct g_aes_softc *sc; 280 int error; 281 u_int sectorsize; 282 off_t mediasize; 283 u_char *buf; 284 285 g_trace(G_T_TOPOLOGY, "aes_taste(%s,%s)", mp->name, pp->name); 286 g_topology_assert(); 287 gp = g_new_geomf(mp, "%s.aes", pp->name); 288 cp = g_new_consumer(gp); 289 g_attach(cp, pp); 290 error = g_access(cp, 1, 0, 0); 291 if (error) { 292 g_detach(cp); 293 g_destroy_consumer(cp); 294 g_destroy_geom(gp); 295 return (NULL); 296 } 297 buf = NULL; 298 g_topology_unlock(); 299 do { 300 if (gp->rank != 2) 301 break; 302 sectorsize = cp->provider->sectorsize; 303 mediasize = cp->provider->mediasize; 304 buf = g_read_data(cp, 0, sectorsize, &error); 305 if (buf == NULL || error != 0) { 306 break; 307 } 308 sc = g_malloc(sizeof(struct g_aes_softc), M_WAITOK | M_ZERO); 309 if (!memcmp(buf, aes_magic, strlen(aes_magic))) { 310 sc->keying = KEY_ZERO; 311 } else if (!memcmp(buf, aes_magic_random, 312 strlen(aes_magic_random))) { 313 sc->keying = KEY_RANDOM; 314 } else if (!memcmp(buf, aes_magic_test, 315 strlen(aes_magic_test))) { 316 sc->keying = KEY_TEST; 317 } else { 318 g_free(sc); 319 break; 320 } 321 g_free(buf); 322 gp->softc = sc; 323 sc->sectorsize = sectorsize; 324 sc->mediasize = mediasize - sectorsize; 325 rijndael_cipherInit(&sc->ci, MODE_CBC, NULL); 326 if (sc->keying == KEY_TEST) { 327 int i; 328 u_char *p; 329 330 p = sc->master_key; 331 for (i = 0; i < (int)sizeof sc->master_key; i ++) 332 *p++ = i; 333 } 334 if (sc->keying == KEY_RANDOM) { 335 int i; 336 u_int32_t u; 337 u_char *p; 338 339 p = sc->master_key; 340 for (i = 0; i < (int)sizeof sc->master_key; i += sizeof u) { 341 u = arc4random(); 342 *p++ = u; 343 *p++ = u >> 8; 344 *p++ = u >> 16; 345 *p++ = u >> 24; 346 } 347 } 348 g_topology_lock(); 349 pp = g_new_providerf(gp, gp->name); 350 pp->mediasize = mediasize - sectorsize; 351 pp->sectorsize = sectorsize; 352 g_error_provider(pp, 0); 353 g_topology_unlock(); 354 } while(0); 355 g_topology_lock(); 356 if (buf) 357 g_free(buf); 358 g_access(cp, -1, 0, 0); 359 if (gp->softc != NULL) 360 return (gp); 361 g_detach(cp); 362 g_destroy_consumer(cp); 363 g_destroy_geom(gp); 364 return (NULL); 365} 366 367static struct g_class g_aes_class = { 368 .name = AES_CLASS_NAME, 369 .version = G_VERSION, 370 .taste = g_aes_taste, 371 .start = g_aes_start, 372 .orphan = g_aes_orphan, 373 .spoiled = g_std_spoiled, 374 .access = g_aes_access, 375}; 376 377DECLARE_GEOM_CLASS(g_aes_class, g_aes); 378