1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
/*
* QEMU Crypto block device encryption QCow/QCow2 AES-CBC format
*
* Copyright (c) 2015-2016 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
/*
* Note that the block encryption implemented in this file is broken
* by design. This exists only to allow data to be liberated from
* existing qcow[2] images and should not be used in any new areas.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "block-qcow.h"
#include "crypto/secret.h"
#define QCRYPTO_BLOCK_QCOW_SECTOR_SIZE 512
static bool
qcrypto_block_qcow_has_format(const uint8_t *buf G_GNUC_UNUSED,
size_t buf_size G_GNUC_UNUSED)
{
return false;
}
static int
qcrypto_block_qcow_init(QCryptoBlock *block,
const char *keysecret,
Error **errp)
{
char *password;
int ret;
uint8_t keybuf[16];
int len;
memset(keybuf, 0, 16);
password = qcrypto_secret_lookup_as_utf8(keysecret, errp);
if (!password) {
return -1;
}
len = strlen(password);
memcpy(keybuf, password, MIN(len, sizeof(keybuf)));
g_free(password);
block->niv = qcrypto_cipher_get_iv_len(QCRYPTO_CIPHER_ALG_AES_128,
QCRYPTO_CIPHER_MODE_CBC);
block->ivgen = qcrypto_ivgen_new(QCRYPTO_IVGEN_ALG_PLAIN64,
0, 0, NULL, 0, errp);
if (!block->ivgen) {
ret = -ENOTSUP;
goto fail;
}
block->cipher = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_128,
QCRYPTO_CIPHER_MODE_CBC,
keybuf, G_N_ELEMENTS(keybuf),
errp);
if (!block->cipher) {
ret = -ENOTSUP;
goto fail;
}
block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
block->payload_offset = 0;
return 0;
fail:
qcrypto_cipher_free(block->cipher);
qcrypto_ivgen_free(block->ivgen);
return ret;
}
static int
qcrypto_block_qcow_open(QCryptoBlock *block,
QCryptoBlockOpenOptions *options,
const char *optprefix,
QCryptoBlockReadFunc readfunc G_GNUC_UNUSED,
void *opaque G_GNUC_UNUSED,
unsigned int flags,
Error **errp)
{
if (flags & QCRYPTO_BLOCK_OPEN_NO_IO) {
block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
block->payload_offset = 0;
return 0;
} else {
if (!options->u.qcow.key_secret) {
error_setg(errp,
"Parameter '%skey-secret' is required for cipher",
optprefix ? optprefix : "");
return -1;
}
return qcrypto_block_qcow_init(block,
options->u.qcow.key_secret, errp);
}
}
static int
qcrypto_block_qcow_create(QCryptoBlock *block,
QCryptoBlockCreateOptions *options,
const char *optprefix,
QCryptoBlockInitFunc initfunc G_GNUC_UNUSED,
QCryptoBlockWriteFunc writefunc G_GNUC_UNUSED,
void *opaque G_GNUC_UNUSED,
Error **errp)
{
if (!options->u.qcow.key_secret) {
error_setg(errp, "Parameter '%skey-secret' is required for cipher",
optprefix ? optprefix : "");
return -1;
}
/* QCow2 has no special header, since everything is hardwired */
return qcrypto_block_qcow_init(block, options->u.qcow.key_secret, errp);
}
static void
qcrypto_block_qcow_cleanup(QCryptoBlock *block)
{
}
static int
qcrypto_block_qcow_decrypt(QCryptoBlock *block,
uint64_t offset,
uint8_t *buf,
size_t len,
Error **errp)
{
assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
return qcrypto_block_decrypt_helper(block->cipher,
block->niv, block->ivgen,
QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
offset, buf, len, errp);
}
static int
qcrypto_block_qcow_encrypt(QCryptoBlock *block,
uint64_t offset,
uint8_t *buf,
size_t len,
Error **errp)
{
assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
return qcrypto_block_encrypt_helper(block->cipher,
block->niv, block->ivgen,
QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
offset, buf, len, errp);
}
const QCryptoBlockDriver qcrypto_block_driver_qcow = {
.open = qcrypto_block_qcow_open,
.create = qcrypto_block_qcow_create,
.cleanup = qcrypto_block_qcow_cleanup,
.decrypt = qcrypto_block_qcow_decrypt,
.encrypt = qcrypto_block_qcow_encrypt,
.has_format = qcrypto_block_qcow_has_format,
};
|
