xref: /openbsd/sbin/mount_vnd/mount_vnd.c (revision d415bd75)
1 /*	$OpenBSD: mount_vnd.c,v 1.22 2019/06/28 13:32:45 deraadt Exp $	*/
2 /*
3  * Copyright (c) 1993 University of Utah.
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * the Systems Programming Group of the University of Utah Computer
9  * Science Department.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
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. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/param.h>	/* DEV_BSIZE */
37 #include <sys/ioctl.h>
38 #include <sys/mount.h>
39 #include <sys/stat.h>
40 #include <sys/disklabel.h>
41 
42 #include <dev/vndioctl.h>
43 
44 #include <blf.h>
45 #include <err.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <readpassphrase.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <limits.h>
54 #include <util.h>
55 
56 __dead void	 usage(void);
57 int		 config(char *, char *, struct disklabel *, char *, size_t);
58 char		*get_pkcs_key(char *, char *);
59 
60 int
61 main(int argc, char **argv)
62 {
63 	int	 ch, rv, opt_k = 0, opt_K = 0;
64 	char	*key = NULL, *mntopts = NULL, *rounds = NULL, *saltopt = NULL;
65 	size_t	 keylen = 0;
66 	struct disklabel *dp = NULL;
67 
68 	while ((ch = getopt(argc, argv, "kK:o:S:t:")) != -1) {
69 		switch (ch) {
70 		case 'k':
71 			opt_k = 1;
72 			break;
73 		case 'K':
74 			opt_K = 1;
75 			rounds = optarg;
76 			break;
77 		case 'o':
78 			mntopts = optarg;
79 			break;
80 		case 'S':
81 			saltopt = optarg;
82 			break;
83 		case 't':
84 			dp = getdiskbyname(optarg);
85 			if (dp == NULL)
86 				errx(1, "unknown disk type: %s", optarg);
87 			break;
88 		default:
89 			usage();
90 			/* NOTREACHED */
91 		}
92 	}
93 	argc -= optind;
94 	argv += optind;
95 
96 	if (saltopt && !opt_K)
97 		errx(1, "-S only makes sense when used with -K");
98 
99 	if (argc != 2)
100 		usage();
101 
102 	if (opt_k || opt_K)
103 		fprintf(stderr, "WARNING: Consider using softraid crypto.\n");
104 	if (opt_k) {
105 		if (opt_K)
106 			errx(1, "-k and -K are mutually exclusive");
107 		key = getpass("Encryption key: ");
108 		if (key == NULL || (keylen = strlen(key)) == 0)
109 			errx(1, "Need an encryption key");
110 	} else if (opt_K) {
111 		key = get_pkcs_key(rounds, saltopt);
112 		keylen = BLF_MAXUTILIZED;
113 	}
114 	rv = config(argv[1], argv[0], dp, key, keylen);
115 
116 	exit(rv);
117 }
118 
119 char *
120 get_pkcs_key(char *arg, char *saltopt)
121 {
122 	char		 passphrase[128] = {'\0'};
123 	char		 saltbuf[128] = {'\0'}, saltfilebuf[PATH_MAX];
124 	char		*key = NULL;
125 	char		*saltfile;
126 	const char	*errstr;
127 	int		 rounds;
128 
129 	rounds = strtonum(arg, 1000, INT_MAX, &errstr);
130 	if (errstr)
131 		err(1, "rounds: %s", errstr);
132 	if (readpassphrase("Encryption key: ", passphrase, sizeof(passphrase),
133 	    RPP_REQUIRE_TTY) == NULL)
134 		errx(1, "Unable to read passphrase");
135 	if (saltopt)
136 		saltfile = saltopt;
137 	else {
138 		printf("Salt file: ");
139 		fflush(stdout);
140 		saltfile = fgets(saltfilebuf, sizeof(saltfilebuf), stdin);
141 		if (saltfile)
142 			saltfile[strcspn(saltfile, "\n")] = '\0';
143 	}
144 	if (!saltfile || saltfile[0] == '\0')
145 		warnx("Skipping salt file, insecure");
146 	else {
147 		int fd;
148 
149 		fd = open(saltfile, O_RDONLY);
150 		if (fd == -1) {
151 			int *s;
152 
153 			fprintf(stderr, "Salt file not found, attempting to "
154 			    "create one\n");
155 			fd = open(saltfile, O_RDWR|O_CREAT|O_EXCL, 0600);
156 			if (fd == -1)
157 				err(1, "Unable to create salt file: '%s'",
158 				    saltfile);
159 			for (s = (int *)saltbuf;
160 			    s < (int *)(saltbuf + sizeof(saltbuf)); s++)
161 				*s = arc4random();
162 			if (write(fd, saltbuf, sizeof(saltbuf))
163 			    != sizeof(saltbuf))
164 				err(1, "Unable to write salt file: '%s'",
165 				    saltfile);
166 			fprintf(stderr, "Salt file created as '%s'\n",
167 			    saltfile);
168 		} else {
169 			if (read(fd, saltbuf, sizeof(saltbuf))
170 			    != sizeof(saltbuf))
171 				err(1, "Unable to read salt file: '%s'",
172 				    saltfile);
173 		}
174 		close(fd);
175 	}
176 	if ((key = calloc(1, BLF_MAXUTILIZED)) == NULL)
177 		err(1, NULL);
178 	if (pkcs5_pbkdf2(passphrase, sizeof(passphrase), saltbuf,
179 	    sizeof (saltbuf), key, BLF_MAXUTILIZED, rounds))
180 		errx(1, "pkcs5_pbkdf2 failed");
181 	explicit_bzero(passphrase, sizeof(passphrase));
182 
183 	return (key);
184 }
185 
186 int
187 config(char *dev, char *file, struct disklabel *dp, char *key, size_t keylen)
188 {
189 	struct vnd_ioctl vndio;
190 	char *rdev;
191 	int fd, rv = -1;
192 
193 	if ((fd = opendev(dev, O_RDONLY, OPENDEV_PART, &rdev)) == -1) {
194 		err(4, "%s", rdev);
195 		goto out;
196 	}
197 
198 	vndio.vnd_file = file;
199 	vndio.vnd_secsize = (dp && dp->d_secsize) ? dp->d_secsize : DEV_BSIZE;
200 	vndio.vnd_nsectors = (dp && dp->d_nsectors) ? dp->d_nsectors : 100;
201 	vndio.vnd_ntracks = (dp && dp->d_ntracks) ? dp->d_ntracks : 1;
202 	vndio.vnd_key = (u_char *)key;
203 	vndio.vnd_keylen = keylen;
204 
205 	/*
206 	 * Configure the device
207 	 */
208 	rv = ioctl(fd, VNDIOCSET, &vndio);
209 	if (rv)
210 		warn("VNDIOCSET");
211 
212 	close(fd);
213 	fflush(stdout);
214  out:
215 	if (key)
216 		explicit_bzero(key, keylen);
217 	return (rv < 0);
218 }
219 
220 __dead void
221 usage(void)
222 {
223 	(void)fprintf(stderr,
224 	    "usage: mount_vnd [-k] [-K rounds] [-o options] "
225 	    "[-S saltfile] [-t disktype]\n"
226 	    "\t\t image vnd_dev\n");
227 	exit(1);
228 }
229