blob: 4d7cf36a8f59dab4e20c597f22ff2c9154d25ba9 [file] [log] [blame]
Daniel P. Berrange7d969012015-10-24 11:44:13 +01001/*
2 * QEMU Crypto block device encryption QCow/QCow2 AES-CBC format
3 *
4 * Copyright (c) 2015-2016 Red Hat, Inc.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
Thomas Huthb7cbb872019-02-13 16:54:59 +01009 * version 2.1 of the License, or (at your option) any later version.
Daniel P. Berrange7d969012015-10-24 11:44:13 +010010 *
11 * This library 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 GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 */
20
21/*
22 * Note that the block encryption implemented in this file is broken
23 * by design. This exists only to allow data to be liberated from
24 * existing qcow[2] images and should not be used in any new areas.
25 */
26
27#include "qemu/osdep.h"
Markus Armbrusterda34e652016-03-14 09:01:28 +010028#include "qapi/error.h"
Daniel P. Berrange7d969012015-10-24 11:44:13 +010029
Michael S. Tsirkin986bc8d2018-05-03 22:50:23 +030030#include "block-qcow.h"
Daniel P. Berrange7d969012015-10-24 11:44:13 +010031#include "crypto/secret.h"
32
33#define QCRYPTO_BLOCK_QCOW_SECTOR_SIZE 512
34
35
36static bool
37qcrypto_block_qcow_has_format(const uint8_t *buf G_GNUC_UNUSED,
38 size_t buf_size G_GNUC_UNUSED)
39{
40 return false;
41}
42
43
44static int
45qcrypto_block_qcow_init(QCryptoBlock *block,
46 const char *keysecret,
Vladimir Sementsov-Ogievskiyc972fa12018-12-07 19:13:51 +030047 size_t n_threads,
Daniel P. Berrange7d969012015-10-24 11:44:13 +010048 Error **errp)
49{
50 char *password;
51 int ret;
52 uint8_t keybuf[16];
53 int len;
54
55 memset(keybuf, 0, 16);
56
57 password = qcrypto_secret_lookup_as_utf8(keysecret, errp);
58 if (!password) {
59 return -1;
60 }
61
62 len = strlen(password);
63 memcpy(keybuf, password, MIN(len, sizeof(keybuf)));
64 g_free(password);
65
66 block->niv = qcrypto_cipher_get_iv_len(QCRYPTO_CIPHER_ALG_AES_128,
67 QCRYPTO_CIPHER_MODE_CBC);
68 block->ivgen = qcrypto_ivgen_new(QCRYPTO_IVGEN_ALG_PLAIN64,
69 0, 0, NULL, 0, errp);
70 if (!block->ivgen) {
71 ret = -ENOTSUP;
72 goto fail;
73 }
74
Vladimir Sementsov-Ogievskiyc972fa12018-12-07 19:13:51 +030075 ret = qcrypto_block_init_cipher(block, QCRYPTO_CIPHER_ALG_AES_128,
76 QCRYPTO_CIPHER_MODE_CBC,
77 keybuf, G_N_ELEMENTS(keybuf),
78 n_threads, errp);
79 if (ret < 0) {
Daniel P. Berrange7d969012015-10-24 11:44:13 +010080 ret = -ENOTSUP;
81 goto fail;
82 }
83
Daniel P. Berrange850f49d2017-09-27 13:53:36 +010084 block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
Daniel P. Berrange7d969012015-10-24 11:44:13 +010085 block->payload_offset = 0;
86
87 return 0;
88
89 fail:
Vladimir Sementsov-Ogievskiyc972fa12018-12-07 19:13:51 +030090 qcrypto_block_free_cipher(block);
Daniel P. Berrange7d969012015-10-24 11:44:13 +010091 qcrypto_ivgen_free(block->ivgen);
92 return ret;
93}
94
95
96static int
97qcrypto_block_qcow_open(QCryptoBlock *block,
98 QCryptoBlockOpenOptions *options,
Daniel P. Berrange1cd9a782017-06-23 17:24:17 +010099 const char *optprefix,
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100100 QCryptoBlockReadFunc readfunc G_GNUC_UNUSED,
101 void *opaque G_GNUC_UNUSED,
102 unsigned int flags,
Vladimir Sementsov-Ogievskiyc972fa12018-12-07 19:13:51 +0300103 size_t n_threads,
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100104 Error **errp)
105{
106 if (flags & QCRYPTO_BLOCK_OPEN_NO_IO) {
Daniel P. Berrangé07809a72018-10-16 11:31:05 +0100107 block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
108 block->payload_offset = 0;
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100109 return 0;
110 } else {
111 if (!options->u.qcow.key_secret) {
112 error_setg(errp,
Daniel P. Berrange1cd9a782017-06-23 17:24:17 +0100113 "Parameter '%skey-secret' is required for cipher",
114 optprefix ? optprefix : "");
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100115 return -1;
116 }
Vladimir Sementsov-Ogievskiyc972fa12018-12-07 19:13:51 +0300117 return qcrypto_block_qcow_init(block, options->u.qcow.key_secret,
118 n_threads, errp);
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100119 }
120}
121
122
123static int
124qcrypto_block_qcow_create(QCryptoBlock *block,
125 QCryptoBlockCreateOptions *options,
Daniel P. Berrange1cd9a782017-06-23 17:24:17 +0100126 const char *optprefix,
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100127 QCryptoBlockInitFunc initfunc G_GNUC_UNUSED,
128 QCryptoBlockWriteFunc writefunc G_GNUC_UNUSED,
129 void *opaque G_GNUC_UNUSED,
130 Error **errp)
131{
132 if (!options->u.qcow.key_secret) {
Daniel P. Berrange1cd9a782017-06-23 17:24:17 +0100133 error_setg(errp, "Parameter '%skey-secret' is required for cipher",
134 optprefix ? optprefix : "");
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100135 return -1;
136 }
137 /* QCow2 has no special header, since everything is hardwired */
Vladimir Sementsov-Ogievskiyc972fa12018-12-07 19:13:51 +0300138 return qcrypto_block_qcow_init(block, options->u.qcow.key_secret, 1, errp);
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100139}
140
141
142static void
143qcrypto_block_qcow_cleanup(QCryptoBlock *block)
144{
145}
146
147
148static int
149qcrypto_block_qcow_decrypt(QCryptoBlock *block,
Daniel P. Berrange46097422017-09-27 13:53:39 +0100150 uint64_t offset,
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100151 uint8_t *buf,
152 size_t len,
153 Error **errp)
154{
Daniel P. Berrange46097422017-09-27 13:53:39 +0100155 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
156 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
Vladimir Sementsov-Ogievskiy0f0d5962018-12-07 19:13:50 +0300157 return qcrypto_block_decrypt_helper(block,
158 QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
159 offset, buf, len, errp);
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100160}
161
162
163static int
164qcrypto_block_qcow_encrypt(QCryptoBlock *block,
Daniel P. Berrange46097422017-09-27 13:53:39 +0100165 uint64_t offset,
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100166 uint8_t *buf,
167 size_t len,
168 Error **errp)
169{
Daniel P. Berrange46097422017-09-27 13:53:39 +0100170 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
171 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
Vladimir Sementsov-Ogievskiy0f0d5962018-12-07 19:13:50 +0300172 return qcrypto_block_encrypt_helper(block,
173 QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
174 offset, buf, len, errp);
Daniel P. Berrange7d969012015-10-24 11:44:13 +0100175}
176
177
178const QCryptoBlockDriver qcrypto_block_driver_qcow = {
179 .open = qcrypto_block_qcow_open,
180 .create = qcrypto_block_qcow_create,
181 .cleanup = qcrypto_block_qcow_cleanup,
182 .decrypt = qcrypto_block_qcow_decrypt,
183 .encrypt = qcrypto_block_qcow_encrypt,
184 .has_format = qcrypto_block_qcow_has_format,
185};