2 * utils_wipe - wipe a device
4 * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
5 * Copyright (C) 2011-2012, Red Hat, Inc. All rights reserved.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 #include <sys/types.h>
27 #include <sys/types.h>
29 #include <sys/ioctl.h>
32 #include "libcryptsetup.h"
35 #define MAXIMUM_WIPE_BYTES 1024 * 1024 * 32 /* 32 MiB */
37 static ssize_t _crypt_wipe_zero(int fd, char *buffer, uint64_t offset, uint64_t size)
39 memset(buffer, 0, size);
40 return write_lseek_blockwise(fd, buffer, size, offset);
43 static ssize_t _crypt_wipe_random(int fd, char *buffer, uint64_t offset, uint64_t size)
45 if (crypt_random_get(NULL, buffer, size, CRYPT_RND_NORMAL) < 0)
48 return write_lseek_blockwise(fd, buffer, size, offset);
52 * Wipe using Peter Gutmann method described in
53 * http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html
55 static void wipeSpecial(char *buffer, size_t buffer_size, unsigned int turn)
59 unsigned char write_modes[][3] = {
60 {"\x55\x55\x55"}, {"\xaa\xaa\xaa"}, {"\x92\x49\x24"},
61 {"\x49\x24\x92"}, {"\x24\x92\x49"}, {"\x00\x00\x00"},
62 {"\x11\x11\x11"}, {"\x22\x22\x22"}, {"\x33\x33\x33"},
63 {"\x44\x44\x44"}, {"\x55\x55\x55"}, {"\x66\x66\x66"},
64 {"\x77\x77\x77"}, {"\x88\x88\x88"}, {"\x99\x99\x99"},
65 {"\xaa\xaa\xaa"}, {"\xbb\xbb\xbb"}, {"\xcc\xcc\xcc"},
66 {"\xdd\xdd\xdd"}, {"\xee\xee\xee"}, {"\xff\xff\xff"},
67 {"\x92\x49\x24"}, {"\x49\x24\x92"}, {"\x24\x92\x49"},
68 {"\x6d\xb6\xdb"}, {"\xb6\xdb\x6d"}, {"\xdb\x6d\xb6"}
71 for(i = 0; i < buffer_size / 3; ++i) {
72 memcpy(buffer, write_modes[turn], 3);
77 static ssize_t _crypt_wipe_disk(int fd, char *buffer, uint64_t offset, uint64_t size)
83 for(i = 0; i < 39; ++i) {
85 r = crypt_random_get(NULL, buffer, size, CRYPT_RND_NORMAL);
86 } else if(i >= 5 && i < 32) {
87 wipeSpecial(buffer, size, i - 5);
89 } else if(i >= 32 && i < 38) {
90 r = crypt_random_get(NULL, buffer, size, CRYPT_RND_NORMAL);
91 } else if(i >= 38 && i < 39) {
92 memset(buffer, 0xFF, size);
98 written = write_lseek_blockwise(fd, buffer, size, offset);
99 if (written < 0 || written != (ssize_t)size)
103 /* Rewrite it finally with random */
104 return _crypt_wipe_random(fd, buffer, offset, size);
107 static ssize_t _crypt_wipe_ssd(int fd, char *buffer, uint64_t offset, uint64_t size)
109 // FIXME: for now just rewrite it by random
110 return _crypt_wipe_random(fd, buffer, offset, size);
113 int crypt_wipe(const char *device,
116 crypt_wipe_type type,
121 int devfd, flags, rotational;
124 if (!size || size % SECTOR_SIZE || (size > MAXIMUM_WIPE_BYTES)) {
125 log_dbg("Unsuported wipe size for device %s: %ld.",
126 device, (unsigned long)size);
130 if (stat(device, &st) < 0) {
131 log_dbg("Device %s not found.", device);
135 if (type == CRYPT_WIPE_DISK) {
136 if (!crypt_sysfs_get_rotational(major(st.st_rdev),
140 log_dbg("Rotational flag is %d.", rotational);
142 type = CRYPT_WIPE_SSD;
145 buffer = malloc(size);
149 flags = O_RDWR | O_DIRECT | O_SYNC;
151 /* use O_EXCL only for block devices */
152 if (exclusive && S_ISBLK(st.st_mode))
155 devfd = open(device, flags);
158 return errno == EBUSY ? -EBUSY : -EINVAL;
161 // FIXME: use fixed block size and loop here
163 case CRYPT_WIPE_ZERO:
164 written = _crypt_wipe_zero(devfd, buffer, offset, size);
166 case CRYPT_WIPE_DISK:
167 written = _crypt_wipe_disk(devfd, buffer, offset, size);
170 written = _crypt_wipe_ssd(devfd, buffer, offset, size);
172 case CRYPT_WIPE_RANDOM:
173 written = _crypt_wipe_random(devfd, buffer, offset, size);
176 log_dbg("Unsuported wipe type requested: (%d)", type);
183 if (written != (ssize_t)size || written < 0)