Current Path : /sys/geom/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/geom/geom_aes.c |
/*- * Copyright (c) 2002 Poul-Henning Kamp * Copyright (c) 2002 Networks Associates Technology, Inc. * All rights reserved. * * This software was developed for the FreeBSD Project by Poul-Henning Kamp * and NAI Labs, the Security Research Division of Network Associates, Inc. * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the * DARPA CHATS research program. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The names of the authors may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * This method provides AES encryption with a compiled in key (default * all zeroes). * * XXX: This could probably save a lot of code by pretending to be a slicer. */ #include <sys/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/geom/geom_aes.c 152971 2005-11-30 22:15:00Z sobomax $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/conf.h> #include <sys/bio.h> #include <sys/malloc.h> #include <sys/lock.h> #include <sys/mutex.h> #include <sys/libkern.h> #include <sys/endian.h> #include <sys/md5.h> #include <sys/errno.h> #include <geom/geom.h> #include <crypto/rijndael/rijndael-api-fst.h> #define AES_CLASS_NAME "AES" #define MASTER_KEY_LENGTH (1024/8) static const u_char *aes_magic = "<<FreeBSD-GEOM-AES>>"; static const u_char *aes_magic_random = "<<FreeBSD-GEOM-AES-RANDOM>>"; static const u_char *aes_magic_test = "<<FreeBSD-GEOM-AES-TEST>>"; struct g_aes_softc { enum { KEY_ZERO, KEY_RANDOM, KEY_TEST } keying; u_int sectorsize; off_t mediasize; cipherInstance ci; u_char master_key[MASTER_KEY_LENGTH]; }; /* * Generate a sectorkey from the masterkey and the offset position. * * For KEY_ZERO we just return a key of all zeros. * * We feed the sector byte offset, 16 bytes of the master-key and * the sector byte offset once more to MD5. * The sector byte offset is converted to little-endian format first * to support multi-architecture operation. * We use 16 bytes from the master-key starting at the logical sector * number modulus he length of the master-key. If need be we wrap * around to the start of the master-key. */ static void g_aes_makekey(struct g_aes_softc *sc, off_t off, keyInstance *ki, int dir) { MD5_CTX cx; u_int64_t u64; u_int u, u1; u_char *p, buf[16]; if (sc->keying == KEY_ZERO) { rijndael_makeKey(ki, dir, 128, sc->master_key); return; } MD5Init(&cx); u64 = htole64(off); MD5Update(&cx, (u_char *)&u64, sizeof(u64)); u = off / sc->sectorsize; u %= sizeof sc->master_key; p = sc->master_key + u; if (u + 16 <= sizeof(sc->master_key)) { MD5Update(&cx, p, 16); } else { u1 = sizeof sc->master_key - u; MD5Update(&cx, p, u1); MD5Update(&cx, sc->master_key, 16 - u1); u1 = 0; /* destroy evidence */ } u = 0; /* destroy evidence */ MD5Update(&cx, (u_char *)&u64, sizeof(u64)); u64 = 0; /* destroy evidence */ MD5Final(buf, &cx); bzero(&cx, sizeof cx); /* destroy evidence */ rijndael_makeKey(ki, dir, 128, buf); bzero(buf, sizeof buf); /* destroy evidence */ } static void g_aes_read_done(struct bio *bp) { struct g_geom *gp; struct g_aes_softc *sc; u_char *p, *b, *e, *sb; keyInstance dkey; off_t o; gp = bp->bio_from->geom; sc = gp->softc; sb = g_malloc(sc->sectorsize, M_WAITOK); b = bp->bio_data; e = bp->bio_data; e += bp->bio_length; o = bp->bio_offset - sc->sectorsize; for (p = b; p < e; p += sc->sectorsize) { g_aes_makekey(sc, o, &dkey, DIR_DECRYPT); rijndael_blockDecrypt(&sc->ci, &dkey, p, sc->sectorsize * 8, sb); bcopy(sb, p, sc->sectorsize); o += sc->sectorsize; } bzero(&dkey, sizeof dkey); /* destroy evidence */ bzero(sb, sc->sectorsize); /* destroy evidence */ g_free(sb); g_std_done(bp); } static void g_aes_write_done(struct bio *bp) { bzero(bp->bio_data, bp->bio_length); /* destroy evidence */ g_free(bp->bio_data); g_std_done(bp); } static void g_aes_start(struct bio *bp) { struct g_geom *gp; struct g_consumer *cp; struct g_aes_softc *sc; struct bio *bp2; u_char *p1, *p2, *b, *e; keyInstance ekey; off_t o; gp = bp->bio_to->geom; cp = LIST_FIRST(&gp->consumer); sc = gp->softc; switch (bp->bio_cmd) { case BIO_READ: bp2 = g_clone_bio(bp); if (bp2 == NULL) { g_io_deliver(bp, ENOMEM); return; } bp2->bio_done = g_aes_read_done; bp2->bio_offset += sc->sectorsize; g_io_request(bp2, cp); break; case BIO_WRITE: bp2 = g_clone_bio(bp); if (bp2 == NULL) { g_io_deliver(bp, ENOMEM); return; } bp2->bio_done = g_aes_write_done; bp2->bio_offset += sc->sectorsize; bp2->bio_data = g_malloc(bp->bio_length, M_WAITOK); b = bp->bio_data; e = bp->bio_data; e += bp->bio_length; p2 = bp2->bio_data; o = bp->bio_offset; for (p1 = b; p1 < e; p1 += sc->sectorsize) { g_aes_makekey(sc, o, &ekey, DIR_ENCRYPT); rijndael_blockEncrypt(&sc->ci, &ekey, p1, sc->sectorsize * 8, p2); p2 += sc->sectorsize; o += sc->sectorsize; } bzero(&ekey, sizeof ekey); /* destroy evidence */ g_io_request(bp2, cp); break; case BIO_GETATTR: bp2 = g_clone_bio(bp); if (bp2 == NULL) { g_io_deliver(bp, ENOMEM); return; } bp2->bio_done = g_std_done; bp2->bio_offset += sc->sectorsize; g_io_request(bp2, cp); break; default: g_io_deliver(bp, EOPNOTSUPP); return; } return; } static void g_aes_orphan(struct g_consumer *cp) { struct g_geom *gp; struct g_aes_softc *sc; g_trace(G_T_TOPOLOGY, "g_aes_orphan(%p/%s)", cp, cp->provider->name); g_topology_assert(); KASSERT(cp->provider->error != 0, ("g_aes_orphan with error == 0")); gp = cp->geom; sc = gp->softc; g_wither_geom(gp, cp->provider->error); bzero(sc, sizeof(struct g_aes_softc)); /* destroy evidence */ g_free(sc); return; } static int g_aes_access(struct g_provider *pp, int dr, int dw, int de) { struct g_geom *gp; struct g_consumer *cp; gp = pp->geom; cp = LIST_FIRST(&gp->consumer); /* On first open, grab an extra "exclusive" bit */ if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0) de++; /* ... and let go of it on last close */ if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1) de--; return (g_access(cp, dr, dw, de)); } static struct g_geom * g_aes_taste(struct g_class *mp, struct g_provider *pp, int flags __unused) { struct g_geom *gp; struct g_consumer *cp; struct g_aes_softc *sc; int error; u_int sectorsize; off_t mediasize; u_char *buf; g_trace(G_T_TOPOLOGY, "aes_taste(%s,%s)", mp->name, pp->name); g_topology_assert(); gp = g_new_geomf(mp, "%s.aes", pp->name); cp = g_new_consumer(gp); g_attach(cp, pp); error = g_access(cp, 1, 0, 0); if (error) { g_detach(cp); g_destroy_consumer(cp); g_destroy_geom(gp); return (NULL); } buf = NULL; g_topology_unlock(); do { if (gp->rank != 2) break; sectorsize = cp->provider->sectorsize; mediasize = cp->provider->mediasize; buf = g_read_data(cp, 0, sectorsize, NULL); if (buf == NULL) { break; } sc = g_malloc(sizeof(struct g_aes_softc), M_WAITOK | M_ZERO); if (!memcmp(buf, aes_magic, strlen(aes_magic))) { sc->keying = KEY_ZERO; } else if (!memcmp(buf, aes_magic_random, strlen(aes_magic_random))) { sc->keying = KEY_RANDOM; } else if (!memcmp(buf, aes_magic_test, strlen(aes_magic_test))) { sc->keying = KEY_TEST; } else { g_free(sc); break; } g_free(buf); gp->softc = sc; sc->sectorsize = sectorsize; sc->mediasize = mediasize - sectorsize; rijndael_cipherInit(&sc->ci, MODE_CBC, NULL); if (sc->keying == KEY_TEST) { int i; u_char *p; p = sc->master_key; for (i = 0; i < (int)sizeof sc->master_key; i ++) *p++ = i; } if (sc->keying == KEY_RANDOM) { int i; u_int32_t u; u_char *p; p = sc->master_key; for (i = 0; i < (int)sizeof sc->master_key; i += sizeof u) { u = arc4random(); *p++ = u; *p++ = u >> 8; *p++ = u >> 16; *p++ = u >> 24; } } g_topology_lock(); pp = g_new_providerf(gp, gp->name); pp->mediasize = mediasize - sectorsize; pp->sectorsize = sectorsize; g_error_provider(pp, 0); g_topology_unlock(); } while(0); g_topology_lock(); if (buf) g_free(buf); g_access(cp, -1, 0, 0); if (gp->softc != NULL) return (gp); g_detach(cp); g_destroy_consumer(cp); g_destroy_geom(gp); return (NULL); } static struct g_class g_aes_class = { .name = AES_CLASS_NAME, .version = G_VERSION, .taste = g_aes_taste, .start = g_aes_start, .orphan = g_aes_orphan, .spoiled = g_std_spoiled, .access = g_aes_access, }; DECLARE_GEOM_CLASS(g_aes_class, g_aes);