qxl: check release info object
[qemu.git] / crypto / block-qcow.c
1 /*
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
9 * version 2 of the License, or (at your option) any later version.
10 *
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"
28 #include "qapi/error.h"
29
30 #include "block-qcow.h"
31 #include "crypto/secret.h"
32
33 #define QCRYPTO_BLOCK_QCOW_SECTOR_SIZE 512
34
35
36 static bool
37 qcrypto_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
44 static int
45 qcrypto_block_qcow_init(QCryptoBlock *block,
46 const char *keysecret,
47 size_t n_threads,
48 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
75 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) {
80 ret = -ENOTSUP;
81 goto fail;
82 }
83
84 block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
85 block->payload_offset = 0;
86
87 return 0;
88
89 fail:
90 qcrypto_block_free_cipher(block);
91 qcrypto_ivgen_free(block->ivgen);
92 return ret;
93 }
94
95
96 static int
97 qcrypto_block_qcow_open(QCryptoBlock *block,
98 QCryptoBlockOpenOptions *options,
99 const char *optprefix,
100 QCryptoBlockReadFunc readfunc G_GNUC_UNUSED,
101 void *opaque G_GNUC_UNUSED,
102 unsigned int flags,
103 size_t n_threads,
104 Error **errp)
105 {
106 if (flags & QCRYPTO_BLOCK_OPEN_NO_IO) {
107 block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
108 block->payload_offset = 0;
109 return 0;
110 } else {
111 if (!options->u.qcow.key_secret) {
112 error_setg(errp,
113 "Parameter '%skey-secret' is required for cipher",
114 optprefix ? optprefix : "");
115 return -1;
116 }
117 return qcrypto_block_qcow_init(block, options->u.qcow.key_secret,
118 n_threads, errp);
119 }
120 }
121
122
123 static int
124 qcrypto_block_qcow_create(QCryptoBlock *block,
125 QCryptoBlockCreateOptions *options,
126 const char *optprefix,
127 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) {
133 error_setg(errp, "Parameter '%skey-secret' is required for cipher",
134 optprefix ? optprefix : "");
135 return -1;
136 }
137 /* QCow2 has no special header, since everything is hardwired */
138 return qcrypto_block_qcow_init(block, options->u.qcow.key_secret, 1, errp);
139 }
140
141
142 static void
143 qcrypto_block_qcow_cleanup(QCryptoBlock *block)
144 {
145 }
146
147
148 static int
149 qcrypto_block_qcow_decrypt(QCryptoBlock *block,
150 uint64_t offset,
151 uint8_t *buf,
152 size_t len,
153 Error **errp)
154 {
155 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
156 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
157 return qcrypto_block_decrypt_helper(block,
158 QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
159 offset, buf, len, errp);
160 }
161
162
163 static int
164 qcrypto_block_qcow_encrypt(QCryptoBlock *block,
165 uint64_t offset,
166 uint8_t *buf,
167 size_t len,
168 Error **errp)
169 {
170 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
171 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_QCOW_SECTOR_SIZE));
172 return qcrypto_block_encrypt_helper(block,
173 QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
174 offset, buf, len, errp);
175 }
176
177
178 const 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 };