freebsd-dev/sbin/gbde/gbde.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.
 *
 * $FreeBSD$
 */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/mutex.h>
#include <md5.h>
#include <readpassphrase.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <strings.h>
#include <stdlib.h>
#include <err.h>
#include <stdio.h>
#include <libutil.h>
#include <sys/errno.h>
#include <sys/disk.h>
#include <crypto/rijndael/rijndael.h>

#include <geom/geom.h>
#include <geom/bde/g_bde.h>

extern const char template[];

static void __dead2
usage(const char *reason)
{
	const char *p;

	p = getprogname();
	fprintf(stderr, "Usage error: %s", reason);
	fprintf(stderr, "Usage:\n");
	fprintf(stderr, "\t%s attach dest -l filename\n", p);
	fprintf(stderr, "\t%s dettach dest\n", p);
	fprintf(stderr, "\t%s init dest [-i] [-f filename] -l filename\n", p);
	fprintf(stderr, "\t%s setkey dest [-n key] -l filename\n", p);
	fprintf(stderr, "\t%s destroy dest [-n key] -l filename\n", p);
	exit (1);
}

void *
g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
{
	void *p;
	int fd, i;
	off_t o2;

	p = malloc(length);
	if (p == NULL)
		err(1, "malloc");
	fd = *(int *)cp;
	o2 = lseek(fd, offset, SEEK_SET);
	if (o2 != offset)
		err(1, "lseek");
	i = read(fd, p, length);
	if (i != length)
		err(1, "read");
	if (error != NULL)
		error = 0;
	return (p);
}

static void
random_bits(void *p, u_int len)
{
	static int fdr = -1;
	int i;

	if (fdr < 0) {
		fdr = open("/dev/urandom", O_RDONLY);
		if (fdr < 0)
			err(1, "/dev/urandom");
	}
		
	i = read(fdr, p, len);
	if (i != (int)len)
		err(1, "read from /dev/urandom");
}

/* XXX: not nice */
static u_char sbox[256];

static void
reset_passphrase(struct g_bde_softc *sc)
{

	memcpy(sc->arc4_sbox, sbox, 256);
	sc->arc4_i = sc->arc4_j = 0;
}

static void
setup_passphrase(struct g_bde_softc *sc, int sure, const char *input)
{
	char buf1[BUFSIZ], buf2[BUFSIZ], *p;

	if (input != NULL) {
		g_bde_arc4_seed(sc, input, strlen(input));
		memcpy(sbox, sc->arc4_sbox, 256);
		return;
	}
	for (;;) {
		p = readpassphrase(
		    sure ? "Enter new passphrase:" : "Enter passphrase: ",
		    buf1, sizeof buf1,
		    RPP_ECHO_OFF | RPP_REQUIRE_TTY);
		if (p == NULL)
			err(1, "readpassphrase");

		if (sure) {
			p = readpassphrase("Reenter new passphrase: ",
			    buf2, sizeof buf2,
			    RPP_ECHO_OFF | RPP_REQUIRE_TTY);
			if (p == NULL)
				err(1, "readpassphrase");

			if (strcmp(buf1, buf2)) {
				printf("They didn't match.\n");
				continue;
			}
		}
		if (strlen(buf1) < 3) {
			printf("Too short passphrase.\n");
			continue;
		}
		break;
	}
	g_bde_arc4_seed(sc, buf1, strlen(buf1));
	memcpy(sbox, sc->arc4_sbox, 256);
}

static void
encrypt_sector(void *d, int len, void *key)
{
	keyInstance ki;
	cipherInstance ci;
	int error;
	
	error = rijndael_cipherInit(&ci, MODE_CBC, NULL);
	if (error <= 0)
		errx(1, "rijndael_cipherInit=%d", error);
	error = rijndael_makeKey(&ki, DIR_ENCRYPT, 128, key);
	if (error <= 0)
		errx(1, "rijndael_makeKeY=%d", error);
	error = rijndael_blockEncrypt(&ci, &ki, d, len * 8, d);
	if (error <= 0)
		errx(1, "rijndael_blockEncrypt=%d", error);
}

static void
cmd_attach(const struct g_bde_softc *sc, const char *dest, const char *lfile)
{
	int gfd, i, ffd;
	struct geomconfiggeom gcg;
	u_char buf[256 + 16];

	gfd = open("/dev/geom.ctl", O_RDWR);
	if (gfd < 0)
		err(1, "/dev/geom.ctl");
	memset(&gcg, 0, sizeof gcg);
	gcg.class.u.name = "BDE";
	gcg.class.len = strlen(gcg.class.u.name);
	gcg.provider.u.name = dest;
	gcg.provider.len = strlen(gcg.provider.u.name);
	gcg.flag = 0;
	gcg.len = sizeof buf;
	gcg.ptr = buf;
	
	if (lfile != NULL) {
		ffd = open(lfile, O_RDONLY, 0);
		if (ffd < 0)
			err(1, lfile);
		read(ffd, buf + 256, 16);
		close(ffd);
	} else {
		memset(buf + 256, 0, 16);
	}
	memcpy(buf, sc->arc4_sbox, 256);

	i = ioctl(gfd, GEOMCONFIGGEOM, &gcg);
	if (i != 0)
		err(1, "ioctl(GEOMCONFIGGEOM)");
	exit (0);
}

static void
cmd_dettach(const char *dest)
{
	int i, gfd;
	struct geomconfiggeom gcg;

	gfd = open("/dev/geom.ctl", O_RDWR);
	if (gfd < 0)
		err(1, "/dev/geom.ctl");
	memset(&gcg, 0, sizeof gcg);
	gcg.class.u.name = "BDE";
	gcg.class.len = strlen(gcg.class.u.name);
	gcg.provider.u.name = dest;
	gcg.provider.len = strlen(gcg.provider.u.name);
	gcg.flag = 1;
	
	i = ioctl(gfd, GEOMCONFIGGEOM, &gcg);
	if (i != 0)
		err(1, "ioctl(GEOMCONFIGGEOM)");
	exit (0);
}

static void
cmd_open(struct g_bde_softc *sc, int dfd __unused, const char *l_opt, u_int *nkey)
{
	int error;
	int ffd;
	u_char keyloc[16];

	if (l_opt != NULL) {
		ffd = open(l_opt, O_RDONLY, 0);
		if (ffd < 0)
			err(1, l_opt);
		read(ffd, keyloc, sizeof keyloc);
		close(ffd);
	} else {
		memset(keyloc, 0, sizeof keyloc);
	}

	error = g_bde_decrypt_lock(sc, sbox, keyloc, 0xffffffff,
	    512, nkey);
	if (error == ENOENT)
		errx(1, "Lock was destroyed.");
	if (error == ESRCH)
		errx(1, "Lock was nuked.");
	if (error == ENOTDIR)
		errx(1, "Lock not found");
	if (error != 0)
		errx(1, "Error %d decrypting lock", error);
	if (nkey)
		printf("Opened with key %u\n", *nkey);
	return;
}

static void
cmd_nuke(struct g_bde_key *gl, int dfd , int key)
{
	int i;
	u_char *sbuf;
	off_t offset, offset2;

	sbuf = malloc(gl->sectorsize);
	memset(sbuf, 0, gl->sectorsize);
	offset = (gl->lsector[key] & ~(gl->sectorsize - 1));
	offset2 = lseek(dfd, offset, SEEK_SET);
	if (offset2 != offset)
		err(1, "lseek");
	i = write(dfd, sbuf, gl->sectorsize);
	if (i != (int)gl->sectorsize)
		err(1, "write");
	printf("Nuked key %d\n", key);
}

static void
cmd_write(struct g_bde_key *gl, struct g_bde_softc *sc, int dfd , int key, const char *l_opt)
{
	char buf[BUFSIZ];
	int i, ffd;
	uint64_t off[2];
	u_char keyloc[16];
	u_char *sbuf, *q;
	MD5_CTX c;
	off_t offset, offset2;

	sbuf = malloc(gl->sectorsize);
	/*
	 * Find the byte-offset in the lock sector where we will put the lock
	 * data structure.  We can put it any random place as long as the
	 * structure fits.
	 */
	for(;;) {
		random_bits(off, sizeof off);
		off[0] &= (gl->sectorsize - 1);
		if (off[0] + G_BDE_LOCKSIZE > gl->sectorsize)
			continue;
		break;
	}

	/* Add the sector offset in bytes */
	off[0] += (gl->lsector[key] & ~(gl->sectorsize - 1));
	gl->lsector[key] = off[0];

	i = g_bde_keyloc_encrypt(sc, off, keyloc);
	if (i)
		errx(1, "g_bde_keyloc_encrypt()");
	if (l_opt != NULL) {
		ffd = open(l_opt, O_WRONLY | O_CREAT | O_TRUNC, 0600);
		if (ffd < 0)
			err(1, l_opt);
		write(ffd, keyloc, sizeof keyloc);
		close(ffd);
	} else if (gl->flags & 1) {
		offset2 = lseek(dfd, 0, SEEK_SET);
		if (offset2 != 0)
			err(1, "lseek");
		i = read(dfd, sbuf, gl->sectorsize);
		if (i != (int)gl->sectorsize)
			err(1, "read");
		memcpy(sbuf + key * 16, keyloc, sizeof keyloc);
		offset2 = lseek(dfd, 0, SEEK_SET);
		if (offset2 != 0)
			err(1, "lseek");
		i = write(dfd, sbuf, gl->sectorsize);
		if (i != (int)gl->sectorsize)
			err(1, "write");
	} else {
		errx(1, "No -L option and no space in sector 0 for lockfile");
	}

	/* Allocate a sectorbuffer and fill it with random junk */
	if (sbuf == NULL)
		err(1, "malloc");
	random_bits(sbuf, gl->sectorsize);

	/* Fill in the hash field with something we can recognize again */
	g_bde_arc4_seq(sc, buf, 16);
	MD5Init(&c);
	MD5Update(&c, "0000", 4);	/* XXX: for future versioning */
	MD5Update(&c, buf, 16);
	MD5Final(gl->hash, &c);

	/* Fill random bits in the spare field */
	random_bits(gl->spare, sizeof(gl->spare));

	/* Encode the structure where we want it */
	q = sbuf + (off[0] % gl->sectorsize);
	g_bde_encode_lock(gl, q);

	/*
	 * The encoded structure likely contains long sequences of zeros
	 * which stick out as a sore thumb, so we XOR with key-material
	 * to make it harder to recognize in a brute-force attack
	 */
	g_bde_arc4_seq(sc, buf, G_BDE_LOCKSIZE);
	for (i = 0; i < G_BDE_LOCKSIZE; i++)
		q[i] ^= buf[i];

	g_bde_arc4_seq(sc, buf, 16);

	encrypt_sector(q, G_BDE_LOCKSIZE, buf);
	offset = gl->lsector[key] & ~(gl->sectorsize - 1);
	offset2 = lseek(dfd, offset, SEEK_SET);
	if (offset2 != offset)
		err(1, "lseek");
	i = write(dfd, sbuf, gl->sectorsize);
	if (i != (int)gl->sectorsize)
		err(1, "write");
	printf("Wrote key %d at %jd\n", key, (intmax_t)offset);

}

static void
cmd_destroy(struct g_bde_key *gl, int nkey)
{
	int i;

	bzero(&gl->sector0, sizeof gl->sector0);
	bzero(&gl->sectorN, sizeof gl->sectorN);
	bzero(&gl->keyoffset, sizeof gl->keyoffset);
	bzero(&gl->flags, sizeof gl->flags);
	bzero(gl->key, sizeof gl->key);
	for (i = 0; i < G_BDE_MAXKEYS; i++)
		if (i != nkey)
			gl->lsector[i] = ~0;
}

static void
cmd_init(struct g_bde_key *gl, int dfd, const char *f_opt, int i_opt, const char *l_opt)
{
	int i;
	u_char *buf;
	unsigned sector_size;
	uint64_t	first_sector;
	uint64_t	last_sector;
	uint64_t	total_sectors;
	off_t	off, off2;
	unsigned nkeys;
	const char *p;
	char *q, cbuf[BUFSIZ];
	unsigned u, u2;
	uint64_t o;
	properties	params;

	bzero(gl, sizeof *gl);
	if (f_opt != NULL) {
		i = open(f_opt, O_RDONLY);
		if (i < 0)
			err(1, f_opt);
		params = properties_read(i);
		close (i);
	} else {
		/* XXX: Polish */
		q = strdup("/tmp/temp.XXXXXXXXXX");
		i = mkstemp(q);
		if (i < 0)
			err(1, q);
		write(i, template, strlen(template));
		close (i);
		if (i_opt) {
			p = getenv("EDITOR");
			if (p == NULL)
				p = "vi";
			sprintf(cbuf, "%s %s\n", p, q);
			system(cbuf);
		}
		i = open(q, O_RDONLY);
		if (i < 0)
			err(1, f_opt);
		params = properties_read(i);
		close (i);
		unlink(q);
	}

	/* <sector_size> */
	p = property_find(params, "sector_size");
	i = ioctl(dfd, DIOCGSECTORSIZE, &u);
	if (i == 0)
		sector_size = u;
	else if (p == NULL)
		errx(1, "Missing sector_size property");
	if (p != NULL) {
		sector_size = strtoul(p, &q, 0);
		if (!*p || *q)
			errx(1, "sector_size not a proper number");
	}
	if (sector_size & (sector_size - 1))
		errx(1, "sector_size not a power of 2");
	if (sector_size < 512)
		errx(1, "sector_size is smaller than 512");
	buf = malloc(sector_size);
	if (buf == NULL)
		err(1, "Failed to malloc sector buffer");
	gl->sectorsize = sector_size;

	i = ioctl(dfd, DIOCGMEDIASIZE, &off);
	if (i == 0) {
		first_sector = 0;
		total_sectors = off / sector_size;
		last_sector = total_sectors - 1;
	} else {
		first_sector = 0;
		last_sector = 0;
		total_sectors = 0;
	}

	/* <first_sector> */
	p = property_find(params, "first_sector");
	if (p != NULL) {
		first_sector = strtoul(p, &q, 0);
		if (!*p || *q)
			errx(1, "first_sector not a proper number");
	}
	gl->sector0 = first_sector * gl->sectorsize;

	/* <last_sector> */
	p = property_find(params, "last_sector");
	if (p != NULL) {
		last_sector = strtoul(p, &q, 0);
		if (!*p || *q)
			errx(1, "last_sector not a proper number");
		if (last_sector <= first_sector)
			errx(1, "last_sector not larger than first_sector");
		total_sectors = last_sector + 1;
	}

	/* <total_sectors> */
	p = property_find(params, "total_sectors");
	if (p != NULL) {
		total_sectors = strtoul(p, &q, 0);
		if (!*p || *q)
			errx(1, "total_sectors not a proper number");
		if (last_sector == 0) 
			last_sector = first_sector + total_sectors - 1;
	}

	if (l_opt == NULL && first_sector != 0)
		errx(1, "No -L new-lockfile argument and first_sector != 0");
	else if (l_opt == NULL) {
		first_sector++;
		total_sectors--;
		gl->flags |= 1;
	}

	if (total_sectors != (last_sector - first_sector) + 1)
		errx(1, "total_sectors disagree with first_sector and last_sector");
	if (total_sectors == 0)
		errx(1, "missing last_sector or total_sectors");

	gl->sectorN = (last_sector + 1) * gl->sectorsize;

	/* Find a random keyoffset */
	random_bits(&o, sizeof o);
	o %= (gl->sectorN - gl->sector0);
	o &= ~(gl->sectorsize - 1);
	gl->keyoffset = o;

	/* <number_of_keys> */
	p = property_find(params, "number_of_keys");
	if (p == NULL)
		errx(1, "Missing number_of_keys property");
	nkeys = strtoul(p, &q, 0);
	if (!*p || *q)
		errx(1, "number_of_keys not a proper number");
	if (nkeys < 1 || nkeys > G_BDE_MAXKEYS)
		errx(1, "number_of_keys out of range");
	for (u = 0; u < nkeys; u++) {
		for(;;) {
			do {
				random_bits(&o, sizeof o);
				o %= gl->sectorN;
				o &= ~(gl->sectorsize - 1);
			} while(o < gl->sector0);
			for (u2 = 0; u2 < u; u2++)
				if (o == gl->lsector[u2])
					break;
			if (u2 < u)
				continue;
			break;
		}
		gl->lsector[u] = o;
	}	
	for (; u < G_BDE_MAXKEYS; u++) {
		do 
			random_bits(&o, sizeof o);
		while (o < gl->sectorN);
		gl->lsector[u] = o;
	}

	/* Flush sector zero if we use it for lockfile data */
	if (gl->flags & 1) {
		off2 = lseek(dfd, 0, SEEK_SET);
		if (off2 != 0)
			err(1, "lseek(2) to sector 0");
		random_bits(buf, sector_size);
		i = write(dfd, buf, sector_size);
		if (i != (int)sector_size)
			err(1, "write sector 0");
	}

	/* <random_flush> */
	p = property_find(params, "random_flush");
	if (p != NULL) {
		off = first_sector * sector_size;
		off2 = lseek(dfd, off, SEEK_SET);
		if (off2 != off)
			err(1, "lseek(2) to first_sector");
		off2 = last_sector * sector_size;
		while (off <= off2) {
			random_bits(buf, sector_size);
			i = write(dfd, buf, sector_size);
			if (i != (int)sector_size)
				err(1, "write to $device_name");
			off += sector_size;
		}
	}

	random_bits(gl->key, sizeof gl->key);
	
	return;
}

static enum action {
	ACT_HUH,
	ACT_ATTACH, ACT_DETTACH,
	ACT_INIT, ACT_SETKEY, ACT_DESTROY, ACT_NUKE
} action;

int
main(int argc, char **argv)
{
	const char *opts;
	const char *l_opt, *L_opt;
	const char *p_opt, *P_opt;
	const char *f_opt;
	const char *dest;
	int i_opt, n_opt, ch, dfd, nkey, doopen;
	int i;
	char *q;
	struct g_bde_key *gl;
	struct g_bde_softc sc;

	if (argc < 3)
		usage("Too few arguments\n");

	doopen = 0;
	if (!strcmp(argv[1], "attach")) {
		action = ACT_ATTACH;
		opts = "l:p:";
	} else if (!strcmp(argv[1], "dettach")) {
		action = ACT_DETTACH;
		opts = "";
	} else if (!strcmp(argv[1], "init")) {
		action = ACT_INIT;
		doopen = 1;
		opts = "f:iL:P:";
	} else if (!strcmp(argv[1], "setkey")) {
		action = ACT_SETKEY;
		doopen = 1;
		opts = "n:l:L:p:P:";
	} else if (!strcmp(argv[1], "destroy")) {
		action = ACT_DESTROY;
		doopen = 1;
		opts = "l:p:";
	} else if (!strcmp(argv[1], "nuke")) {
		action = ACT_NUKE;
		doopen = 1;
		opts = "l:p:n:";
	} else {
		usage("Unknown sub command\n");
	}
	argc--;
	argv++;

	dest = argv[1];
	argc--;
	argv++;

	p_opt = NULL;
	P_opt = NULL;
	l_opt = NULL;
	L_opt = NULL;
	f_opt = NULL;
	n_opt = 0;
	i_opt = 0;

	while((ch = getopt(argc, argv, opts)) != -1)
		switch (ch) {
		case 'f':
			f_opt = optarg;
			break;
		case 'i':
			i_opt = !i_opt;
		case 'l':
			l_opt = optarg;
			break;
		case 'L':
			L_opt = optarg;
			break;
		case 'p':
			p_opt = optarg;
			break;
		case 'P':
			P_opt = optarg;
			break;
		case 'n':
			n_opt = strtoul(optarg, &q, 0);
			if (!*optarg || *q)
				usage("-n argument not numeric\n");
			if (n_opt < -1 || n_opt > G_BDE_MAXKEYS)
				usage("-n argument out of range\n");
			break;
		default:
			usage("Invalid option\n");
		}

	if (doopen) {
		dfd = open(dest, O_RDWR | O_CREAT, 0644);
		if (dfd < 0)
			err(1, dest);
	}

	memset(&sc, 0, sizeof sc);
	sc.consumer = (struct g_consumer *)&dfd;
	gl = &sc.key;
	switch(action) {
	case ACT_ATTACH:
		setup_passphrase(&sc, 0, p_opt);
		cmd_attach(&sc, dest, l_opt);
		break;
	case ACT_DETTACH:
		cmd_dettach(dest);
		break;
	case ACT_INIT:
		cmd_init(gl, dfd, f_opt, i_opt, L_opt);
		setup_passphrase(&sc, 1, P_opt);
		cmd_write(gl, &sc, dfd, 0, L_opt);
		break;
	case ACT_SETKEY:
		setup_passphrase(&sc, 0, p_opt);
		cmd_open(&sc, dfd, l_opt, &nkey);
		if (n_opt == 0)
			n_opt = nkey + 1;
		setup_passphrase(&sc, 1, P_opt);
		cmd_write(gl, &sc, dfd, n_opt - 1, L_opt);
		break;
	case ACT_DESTROY:
		setup_passphrase(&sc, 0, p_opt);
		cmd_open(&sc, dfd, l_opt, &nkey);
		cmd_destroy(gl, nkey);
		reset_passphrase(&sc);
		cmd_write(gl, &sc, dfd, nkey, l_opt);
		break;
	case ACT_NUKE:
		setup_passphrase(&sc, 0, p_opt);
		cmd_open(&sc, dfd, l_opt, &nkey);
		if (n_opt == 0)
			n_opt = nkey + 1;
		if (n_opt == -1) {
			for(i = 0; i < G_BDE_MAXKEYS; i++)
				cmd_nuke(gl, dfd, i);
		} else {
				cmd_nuke(gl, dfd, n_opt - 1);
		}
		break;
	default:
		usage("Internal error\n");
	}

	return(0);
}