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3e308f20 DB |
1 | /* |
2 | * QEMU Crypto block device encryption LUKS 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 | |
b7cbb874 | 9 | * version 2.1 of the License, or (at your option) any later version. |
3e308f20 DB |
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 | #include "qemu/osdep.h" | |
da34e65c | 22 | #include "qapi/error.h" |
58369e22 | 23 | #include "qemu/bswap.h" |
3e308f20 | 24 | |
986bc8de | 25 | #include "block-luks.h" |
3e308f20 DB |
26 | |
27 | #include "crypto/hash.h" | |
28 | #include "crypto/afsplit.h" | |
29 | #include "crypto/pbkdf.h" | |
30 | #include "crypto/secret.h" | |
31 | #include "crypto/random.h" | |
2ef950f9 | 32 | #include "qemu/uuid.h" |
3e308f20 DB |
33 | |
34 | #include "qemu/coroutine.h" | |
557d2bdc | 35 | #include "qemu/bitmap.h" |
3e308f20 DB |
36 | |
37 | /* | |
38 | * Reference for the LUKS format implemented here is | |
39 | * | |
40 | * docs/on-disk-format.pdf | |
41 | * | |
42 | * in 'cryptsetup' package source code | |
43 | * | |
44 | * This file implements the 1.2.1 specification, dated | |
45 | * Oct 16, 2011. | |
46 | */ | |
47 | ||
48 | typedef struct QCryptoBlockLUKS QCryptoBlockLUKS; | |
49 | typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader; | |
50 | typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot; | |
51 | ||
52 | ||
53 | /* The following constants are all defined by the LUKS spec */ | |
54 | #define QCRYPTO_BLOCK_LUKS_VERSION 1 | |
55 | ||
56 | #define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6 | |
57 | #define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32 | |
58 | #define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32 | |
59 | #define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32 | |
60 | #define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20 | |
61 | #define QCRYPTO_BLOCK_LUKS_SALT_LEN 32 | |
62 | #define QCRYPTO_BLOCK_LUKS_UUID_LEN 40 | |
63 | #define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8 | |
64 | #define QCRYPTO_BLOCK_LUKS_STRIPES 4000 | |
65 | #define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000 | |
66 | #define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000 | |
67 | #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096 | |
68 | ||
69 | #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD | |
70 | #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3 | |
71 | ||
72 | #define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL | |
73 | ||
557d2bdc ML |
74 | #define QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS 2000 |
75 | #define QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS 40 | |
76 | ||
3e308f20 DB |
77 | static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = { |
78 | 'L', 'U', 'K', 'S', 0xBA, 0xBE | |
79 | }; | |
80 | ||
81 | typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap; | |
82 | struct QCryptoBlockLUKSNameMap { | |
83 | const char *name; | |
84 | int id; | |
85 | }; | |
86 | ||
87 | typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap; | |
88 | struct QCryptoBlockLUKSCipherSizeMap { | |
89 | uint32_t key_bytes; | |
90 | int id; | |
91 | }; | |
92 | typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap; | |
93 | struct QCryptoBlockLUKSCipherNameMap { | |
94 | const char *name; | |
95 | const QCryptoBlockLUKSCipherSizeMap *sizes; | |
96 | }; | |
97 | ||
98 | ||
99 | static const QCryptoBlockLUKSCipherSizeMap | |
100 | qcrypto_block_luks_cipher_size_map_aes[] = { | |
101 | { 16, QCRYPTO_CIPHER_ALG_AES_128 }, | |
102 | { 24, QCRYPTO_CIPHER_ALG_AES_192 }, | |
103 | { 32, QCRYPTO_CIPHER_ALG_AES_256 }, | |
104 | { 0, 0 }, | |
105 | }; | |
106 | ||
107 | static const QCryptoBlockLUKSCipherSizeMap | |
108 | qcrypto_block_luks_cipher_size_map_cast5[] = { | |
109 | { 16, QCRYPTO_CIPHER_ALG_CAST5_128 }, | |
110 | { 0, 0 }, | |
111 | }; | |
112 | ||
113 | static const QCryptoBlockLUKSCipherSizeMap | |
114 | qcrypto_block_luks_cipher_size_map_serpent[] = { | |
115 | { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 }, | |
116 | { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 }, | |
117 | { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 }, | |
118 | { 0, 0 }, | |
119 | }; | |
120 | ||
121 | static const QCryptoBlockLUKSCipherSizeMap | |
122 | qcrypto_block_luks_cipher_size_map_twofish[] = { | |
123 | { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 }, | |
124 | { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 }, | |
125 | { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 }, | |
126 | { 0, 0 }, | |
127 | }; | |
128 | ||
129 | static const QCryptoBlockLUKSCipherNameMap | |
130 | qcrypto_block_luks_cipher_name_map[] = { | |
131 | { "aes", qcrypto_block_luks_cipher_size_map_aes }, | |
132 | { "cast5", qcrypto_block_luks_cipher_size_map_cast5 }, | |
133 | { "serpent", qcrypto_block_luks_cipher_size_map_serpent }, | |
134 | { "twofish", qcrypto_block_luks_cipher_size_map_twofish }, | |
135 | }; | |
136 | ||
137 | ||
138 | /* | |
139 | * This struct is written to disk in big-endian format, | |
140 | * but operated upon in native-endian format. | |
141 | */ | |
142 | struct QCryptoBlockLUKSKeySlot { | |
143 | /* state of keyslot, enabled/disable */ | |
144 | uint32_t active; | |
145 | /* iterations for PBKDF2 */ | |
146 | uint32_t iterations; | |
147 | /* salt for PBKDF2 */ | |
148 | uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN]; | |
149 | /* start sector of key material */ | |
f0d3c362 | 150 | uint32_t key_offset_sector; |
3e308f20 DB |
151 | /* number of anti-forensic stripes */ |
152 | uint32_t stripes; | |
5993e3be | 153 | }; |
3e308f20 DB |
154 | |
155 | QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48); | |
156 | ||
157 | ||
158 | /* | |
159 | * This struct is written to disk in big-endian format, | |
160 | * but operated upon in native-endian format. | |
161 | */ | |
162 | struct QCryptoBlockLUKSHeader { | |
163 | /* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */ | |
164 | char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN]; | |
165 | ||
166 | /* LUKS version, currently 1 */ | |
167 | uint16_t version; | |
168 | ||
169 | /* cipher name specification (aes, etc) */ | |
170 | char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN]; | |
171 | ||
172 | /* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */ | |
173 | char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN]; | |
174 | ||
175 | /* hash specification (sha256, etc) */ | |
176 | char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN]; | |
177 | ||
178 | /* start offset of the volume data (in 512 byte sectors) */ | |
f0d3c362 | 179 | uint32_t payload_offset_sector; |
3e308f20 DB |
180 | |
181 | /* Number of key bytes */ | |
f0d3c362 | 182 | uint32_t master_key_len; |
3e308f20 DB |
183 | |
184 | /* master key checksum after PBKDF2 */ | |
185 | uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; | |
186 | ||
187 | /* salt for master key PBKDF2 */ | |
188 | uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN]; | |
189 | ||
190 | /* iterations for master key PBKDF2 */ | |
191 | uint32_t master_key_iterations; | |
192 | ||
193 | /* UUID of the partition in standard ASCII representation */ | |
194 | uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN]; | |
195 | ||
196 | /* key slots */ | |
197 | QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS]; | |
5993e3be | 198 | }; |
3e308f20 DB |
199 | |
200 | QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592); | |
201 | ||
202 | ||
203 | struct QCryptoBlockLUKS { | |
204 | QCryptoBlockLUKSHeader header; | |
40c85028 | 205 | |
9d80e59d | 206 | /* Main encryption algorithm used for encryption*/ |
40c85028 | 207 | QCryptoCipherAlgorithm cipher_alg; |
9d80e59d ML |
208 | |
209 | /* Mode of encryption for the selected encryption algorithm */ | |
40c85028 | 210 | QCryptoCipherMode cipher_mode; |
9d80e59d ML |
211 | |
212 | /* Initialization vector generation algorithm */ | |
40c85028 | 213 | QCryptoIVGenAlgorithm ivgen_alg; |
9d80e59d ML |
214 | |
215 | /* Hash algorithm used for IV generation*/ | |
40c85028 | 216 | QCryptoHashAlgorithm ivgen_hash_alg; |
9d80e59d ML |
217 | |
218 | /* | |
219 | * Encryption algorithm used for IV generation. | |
220 | * Usually the same as main encryption algorithm | |
221 | */ | |
222 | QCryptoCipherAlgorithm ivgen_cipher_alg; | |
223 | ||
224 | /* Hash algorithm used in pbkdf2 function */ | |
40c85028 | 225 | QCryptoHashAlgorithm hash_alg; |
557d2bdc ML |
226 | |
227 | /* Name of the secret that was used to open the image */ | |
228 | char *secret; | |
3e308f20 DB |
229 | }; |
230 | ||
231 | ||
232 | static int qcrypto_block_luks_cipher_name_lookup(const char *name, | |
233 | QCryptoCipherMode mode, | |
234 | uint32_t key_bytes, | |
235 | Error **errp) | |
236 | { | |
237 | const QCryptoBlockLUKSCipherNameMap *map = | |
238 | qcrypto_block_luks_cipher_name_map; | |
239 | size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); | |
240 | size_t i, j; | |
241 | ||
242 | if (mode == QCRYPTO_CIPHER_MODE_XTS) { | |
243 | key_bytes /= 2; | |
244 | } | |
245 | ||
246 | for (i = 0; i < maplen; i++) { | |
247 | if (!g_str_equal(map[i].name, name)) { | |
248 | continue; | |
249 | } | |
250 | for (j = 0; j < map[i].sizes[j].key_bytes; j++) { | |
251 | if (map[i].sizes[j].key_bytes == key_bytes) { | |
252 | return map[i].sizes[j].id; | |
253 | } | |
254 | } | |
255 | } | |
256 | ||
257 | error_setg(errp, "Algorithm %s with key size %d bytes not supported", | |
258 | name, key_bytes); | |
259 | return 0; | |
260 | } | |
261 | ||
262 | static const char * | |
263 | qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg, | |
264 | Error **errp) | |
265 | { | |
266 | const QCryptoBlockLUKSCipherNameMap *map = | |
267 | qcrypto_block_luks_cipher_name_map; | |
268 | size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); | |
269 | size_t i, j; | |
270 | for (i = 0; i < maplen; i++) { | |
271 | for (j = 0; j < map[i].sizes[j].key_bytes; j++) { | |
272 | if (map[i].sizes[j].id == alg) { | |
273 | return map[i].name; | |
274 | } | |
275 | } | |
276 | } | |
277 | ||
278 | error_setg(errp, "Algorithm '%s' not supported", | |
977c736f | 279 | QCryptoCipherAlgorithm_str(alg)); |
3e308f20 DB |
280 | return NULL; |
281 | } | |
282 | ||
283 | /* XXX replace with qapi_enum_parse() in future, when we can | |
284 | * make that function emit a more friendly error message */ | |
285 | static int qcrypto_block_luks_name_lookup(const char *name, | |
f7abe0ec | 286 | const QEnumLookup *map, |
3e308f20 DB |
287 | const char *type, |
288 | Error **errp) | |
289 | { | |
9ae33079 | 290 | int ret = qapi_enum_parse(map, name, -1, NULL); |
3e308f20 | 291 | |
9ae33079 MA |
292 | if (ret < 0) { |
293 | error_setg(errp, "%s %s not supported", type, name); | |
294 | return 0; | |
295 | } | |
296 | return ret; | |
3e308f20 DB |
297 | } |
298 | ||
299 | #define qcrypto_block_luks_cipher_mode_lookup(name, errp) \ | |
300 | qcrypto_block_luks_name_lookup(name, \ | |
f7abe0ec | 301 | &QCryptoCipherMode_lookup, \ |
3e308f20 DB |
302 | "Cipher mode", \ |
303 | errp) | |
304 | ||
305 | #define qcrypto_block_luks_hash_name_lookup(name, errp) \ | |
306 | qcrypto_block_luks_name_lookup(name, \ | |
f7abe0ec | 307 | &QCryptoHashAlgorithm_lookup, \ |
3e308f20 DB |
308 | "Hash algorithm", \ |
309 | errp) | |
310 | ||
311 | #define qcrypto_block_luks_ivgen_name_lookup(name, errp) \ | |
312 | qcrypto_block_luks_name_lookup(name, \ | |
f7abe0ec | 313 | &QCryptoIVGenAlgorithm_lookup, \ |
3e308f20 DB |
314 | "IV generator", \ |
315 | errp) | |
316 | ||
317 | ||
318 | static bool | |
319 | qcrypto_block_luks_has_format(const uint8_t *buf, | |
320 | size_t buf_size) | |
321 | { | |
322 | const QCryptoBlockLUKSHeader *luks_header = (const void *)buf; | |
323 | ||
324 | if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) && | |
325 | memcmp(luks_header->magic, qcrypto_block_luks_magic, | |
326 | QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 && | |
327 | be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) { | |
328 | return true; | |
329 | } else { | |
330 | return false; | |
331 | } | |
332 | } | |
333 | ||
334 | ||
335 | /** | |
336 | * Deal with a quirk of dm-crypt usage of ESSIV. | |
337 | * | |
338 | * When calculating ESSIV IVs, the cipher length used by ESSIV | |
339 | * may be different from the cipher length used for the block | |
340 | * encryption, becauses dm-crypt uses the hash digest length | |
341 | * as the key size. ie, if you have AES 128 as the block cipher | |
342 | * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as | |
343 | * the cipher since that gets a key length matching the digest | |
344 | * size, not AES 128 with truncated digest as might be imagined | |
345 | */ | |
346 | static QCryptoCipherAlgorithm | |
347 | qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher, | |
348 | QCryptoHashAlgorithm hash, | |
349 | Error **errp) | |
350 | { | |
351 | size_t digestlen = qcrypto_hash_digest_len(hash); | |
352 | size_t keylen = qcrypto_cipher_get_key_len(cipher); | |
353 | if (digestlen == keylen) { | |
354 | return cipher; | |
355 | } | |
356 | ||
357 | switch (cipher) { | |
358 | case QCRYPTO_CIPHER_ALG_AES_128: | |
359 | case QCRYPTO_CIPHER_ALG_AES_192: | |
360 | case QCRYPTO_CIPHER_ALG_AES_256: | |
361 | if (digestlen == qcrypto_cipher_get_key_len( | |
362 | QCRYPTO_CIPHER_ALG_AES_128)) { | |
363 | return QCRYPTO_CIPHER_ALG_AES_128; | |
364 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
365 | QCRYPTO_CIPHER_ALG_AES_192)) { | |
366 | return QCRYPTO_CIPHER_ALG_AES_192; | |
367 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
368 | QCRYPTO_CIPHER_ALG_AES_256)) { | |
369 | return QCRYPTO_CIPHER_ALG_AES_256; | |
370 | } else { | |
371 | error_setg(errp, "No AES cipher with key size %zu available", | |
372 | digestlen); | |
373 | return 0; | |
374 | } | |
375 | break; | |
376 | case QCRYPTO_CIPHER_ALG_SERPENT_128: | |
377 | case QCRYPTO_CIPHER_ALG_SERPENT_192: | |
378 | case QCRYPTO_CIPHER_ALG_SERPENT_256: | |
379 | if (digestlen == qcrypto_cipher_get_key_len( | |
380 | QCRYPTO_CIPHER_ALG_SERPENT_128)) { | |
381 | return QCRYPTO_CIPHER_ALG_SERPENT_128; | |
382 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
383 | QCRYPTO_CIPHER_ALG_SERPENT_192)) { | |
384 | return QCRYPTO_CIPHER_ALG_SERPENT_192; | |
385 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
386 | QCRYPTO_CIPHER_ALG_SERPENT_256)) { | |
387 | return QCRYPTO_CIPHER_ALG_SERPENT_256; | |
388 | } else { | |
389 | error_setg(errp, "No Serpent cipher with key size %zu available", | |
390 | digestlen); | |
391 | return 0; | |
392 | } | |
393 | break; | |
394 | case QCRYPTO_CIPHER_ALG_TWOFISH_128: | |
395 | case QCRYPTO_CIPHER_ALG_TWOFISH_192: | |
396 | case QCRYPTO_CIPHER_ALG_TWOFISH_256: | |
397 | if (digestlen == qcrypto_cipher_get_key_len( | |
398 | QCRYPTO_CIPHER_ALG_TWOFISH_128)) { | |
399 | return QCRYPTO_CIPHER_ALG_TWOFISH_128; | |
400 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
401 | QCRYPTO_CIPHER_ALG_TWOFISH_192)) { | |
402 | return QCRYPTO_CIPHER_ALG_TWOFISH_192; | |
403 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
404 | QCRYPTO_CIPHER_ALG_TWOFISH_256)) { | |
405 | return QCRYPTO_CIPHER_ALG_TWOFISH_256; | |
406 | } else { | |
407 | error_setg(errp, "No Twofish cipher with key size %zu available", | |
408 | digestlen); | |
409 | return 0; | |
410 | } | |
411 | break; | |
412 | default: | |
413 | error_setg(errp, "Cipher %s not supported with essiv", | |
977c736f | 414 | QCryptoCipherAlgorithm_str(cipher)); |
3e308f20 DB |
415 | return 0; |
416 | } | |
417 | } | |
418 | ||
bd56a55a ML |
419 | /* |
420 | * Returns number of sectors needed to store the key material | |
421 | * given number of anti forensic stripes | |
422 | */ | |
423 | static int | |
424 | qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks, | |
425 | unsigned int header_sectors, | |
426 | unsigned int stripes) | |
427 | { | |
428 | /* | |
429 | * This calculation doesn't match that shown in the spec, | |
430 | * but instead follows the cryptsetup implementation. | |
431 | */ | |
432 | ||
433 | size_t splitkeylen = luks->header.master_key_len * stripes; | |
434 | ||
435 | /* First align the key material size to block size*/ | |
436 | size_t splitkeylen_sectors = | |
437 | DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE); | |
438 | ||
439 | /* Then also align the key material size to the size of the header */ | |
440 | return ROUND_UP(splitkeylen_sectors, header_sectors); | |
441 | } | |
442 | ||
dde2c5af ML |
443 | /* |
444 | * Stores the main LUKS header, taking care of endianess | |
445 | */ | |
446 | static int | |
447 | qcrypto_block_luks_store_header(QCryptoBlock *block, | |
448 | QCryptoBlockWriteFunc writefunc, | |
449 | void *opaque, | |
450 | Error **errp) | |
451 | { | |
452 | const QCryptoBlockLUKS *luks = block->opaque; | |
453 | Error *local_err = NULL; | |
454 | size_t i; | |
455 | g_autofree QCryptoBlockLUKSHeader *hdr_copy = NULL; | |
456 | ||
457 | /* Create a copy of the header */ | |
458 | hdr_copy = g_new0(QCryptoBlockLUKSHeader, 1); | |
459 | memcpy(hdr_copy, &luks->header, sizeof(QCryptoBlockLUKSHeader)); | |
460 | ||
461 | /* | |
462 | * Everything on disk uses Big Endian (tm), so flip header fields | |
463 | * before writing them | |
464 | */ | |
465 | cpu_to_be16s(&hdr_copy->version); | |
466 | cpu_to_be32s(&hdr_copy->payload_offset_sector); | |
467 | cpu_to_be32s(&hdr_copy->master_key_len); | |
468 | cpu_to_be32s(&hdr_copy->master_key_iterations); | |
469 | ||
470 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
471 | cpu_to_be32s(&hdr_copy->key_slots[i].active); | |
472 | cpu_to_be32s(&hdr_copy->key_slots[i].iterations); | |
473 | cpu_to_be32s(&hdr_copy->key_slots[i].key_offset_sector); | |
474 | cpu_to_be32s(&hdr_copy->key_slots[i].stripes); | |
475 | } | |
476 | ||
477 | /* Write out the partition header and key slot headers */ | |
478 | writefunc(block, 0, (const uint8_t *)hdr_copy, sizeof(*hdr_copy), | |
479 | opaque, &local_err); | |
480 | ||
481 | if (local_err) { | |
482 | error_propagate(errp, local_err); | |
483 | return -1; | |
484 | } | |
485 | return 0; | |
486 | } | |
487 | ||
488 | /* | |
489 | * Loads the main LUKS header,and byteswaps it to native endianess | |
490 | * And run basic sanity checks on it | |
491 | */ | |
492 | static int | |
493 | qcrypto_block_luks_load_header(QCryptoBlock *block, | |
494 | QCryptoBlockReadFunc readfunc, | |
495 | void *opaque, | |
496 | Error **errp) | |
497 | { | |
498 | ssize_t rv; | |
499 | size_t i; | |
500 | QCryptoBlockLUKS *luks = block->opaque; | |
501 | ||
502 | /* | |
503 | * Read the entire LUKS header, minus the key material from | |
504 | * the underlying device | |
505 | */ | |
506 | rv = readfunc(block, 0, | |
507 | (uint8_t *)&luks->header, | |
508 | sizeof(luks->header), | |
509 | opaque, | |
510 | errp); | |
511 | if (rv < 0) { | |
512 | return rv; | |
513 | } | |
514 | ||
515 | /* | |
516 | * The header is always stored in big-endian format, so | |
517 | * convert everything to native | |
518 | */ | |
519 | be16_to_cpus(&luks->header.version); | |
520 | be32_to_cpus(&luks->header.payload_offset_sector); | |
521 | be32_to_cpus(&luks->header.master_key_len); | |
522 | be32_to_cpus(&luks->header.master_key_iterations); | |
523 | ||
524 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
525 | be32_to_cpus(&luks->header.key_slots[i].active); | |
526 | be32_to_cpus(&luks->header.key_slots[i].iterations); | |
527 | be32_to_cpus(&luks->header.key_slots[i].key_offset_sector); | |
528 | be32_to_cpus(&luks->header.key_slots[i].stripes); | |
529 | } | |
530 | ||
531 | return 0; | |
532 | } | |
533 | ||
9fa9c1c2 ML |
534 | /* |
535 | * Does basic sanity checks on the LUKS header | |
536 | */ | |
537 | static int | |
538 | qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp) | |
539 | { | |
befdba9e ML |
540 | size_t i, j; |
541 | ||
542 | unsigned int header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / | |
543 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; | |
544 | ||
9fa9c1c2 ML |
545 | if (memcmp(luks->header.magic, qcrypto_block_luks_magic, |
546 | QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { | |
547 | error_setg(errp, "Volume is not in LUKS format"); | |
548 | return -1; | |
549 | } | |
550 | ||
551 | if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { | |
552 | error_setg(errp, "LUKS version %" PRIu32 " is not supported", | |
553 | luks->header.version); | |
554 | return -1; | |
555 | } | |
befdba9e ML |
556 | |
557 | /* Check all keyslots for corruption */ | |
558 | for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; i++) { | |
559 | ||
560 | const QCryptoBlockLUKSKeySlot *slot1 = &luks->header.key_slots[i]; | |
561 | unsigned int start1 = slot1->key_offset_sector; | |
562 | unsigned int len1 = | |
563 | qcrypto_block_luks_splitkeylen_sectors(luks, | |
564 | header_sectors, | |
565 | slot1->stripes); | |
566 | ||
567 | if (slot1->stripes == 0) { | |
568 | error_setg(errp, "Keyslot %zu is corrupted (stripes == 0)", i); | |
569 | return -1; | |
570 | } | |
571 | ||
572 | if (slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED && | |
573 | slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { | |
574 | error_setg(errp, | |
575 | "Keyslot %zu state (active/disable) is corrupted", i); | |
576 | return -1; | |
577 | } | |
578 | ||
579 | if (start1 + len1 > luks->header.payload_offset_sector) { | |
580 | error_setg(errp, | |
581 | "Keyslot %zu is overlapping with the encrypted payload", | |
582 | i); | |
583 | return -1; | |
584 | } | |
585 | ||
586 | for (j = i + 1 ; j < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; j++) { | |
587 | const QCryptoBlockLUKSKeySlot *slot2 = &luks->header.key_slots[j]; | |
588 | unsigned int start2 = slot2->key_offset_sector; | |
589 | unsigned int len2 = | |
590 | qcrypto_block_luks_splitkeylen_sectors(luks, | |
591 | header_sectors, | |
592 | slot2->stripes); | |
593 | ||
594 | if (start1 + len1 > start2 && start2 + len2 > start1) { | |
595 | error_setg(errp, | |
596 | "Keyslots %zu and %zu are overlapping in the header", | |
597 | i, j); | |
598 | return -1; | |
599 | } | |
600 | } | |
601 | ||
602 | } | |
9fa9c1c2 ML |
603 | return 0; |
604 | } | |
605 | ||
606 | /* | |
607 | * Parses the crypto parameters that are stored in the LUKS header | |
608 | */ | |
609 | ||
610 | static int | |
611 | qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp) | |
612 | { | |
613 | g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode); | |
614 | char *ivgen_name, *ivhash_name; | |
615 | Error *local_err = NULL; | |
616 | ||
617 | /* | |
618 | * The cipher_mode header contains a string that we have | |
619 | * to further parse, of the format | |
620 | * | |
621 | * <cipher-mode>-<iv-generator>[:<iv-hash>] | |
622 | * | |
623 | * eg cbc-essiv:sha256, cbc-plain64 | |
624 | */ | |
625 | ivgen_name = strchr(cipher_mode, '-'); | |
626 | if (!ivgen_name) { | |
627 | error_setg(errp, "Unexpected cipher mode string format %s", | |
628 | luks->header.cipher_mode); | |
629 | return -1; | |
630 | } | |
631 | *ivgen_name = '\0'; | |
632 | ivgen_name++; | |
633 | ||
634 | ivhash_name = strchr(ivgen_name, ':'); | |
635 | if (!ivhash_name) { | |
636 | luks->ivgen_hash_alg = 0; | |
637 | } else { | |
638 | *ivhash_name = '\0'; | |
639 | ivhash_name++; | |
640 | ||
641 | luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name, | |
642 | &local_err); | |
643 | if (local_err) { | |
644 | error_propagate(errp, local_err); | |
645 | return -1; | |
646 | } | |
647 | } | |
648 | ||
649 | luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode, | |
650 | &local_err); | |
651 | if (local_err) { | |
652 | error_propagate(errp, local_err); | |
653 | return -1; | |
654 | } | |
655 | ||
656 | luks->cipher_alg = | |
657 | qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, | |
658 | luks->cipher_mode, | |
659 | luks->header.master_key_len, | |
660 | &local_err); | |
661 | if (local_err) { | |
662 | error_propagate(errp, local_err); | |
663 | return -1; | |
664 | } | |
665 | ||
666 | luks->hash_alg = | |
667 | qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, | |
668 | &local_err); | |
669 | if (local_err) { | |
670 | error_propagate(errp, local_err); | |
671 | return -1; | |
672 | } | |
673 | ||
674 | luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, | |
675 | &local_err); | |
676 | if (local_err) { | |
677 | error_propagate(errp, local_err); | |
678 | return -1; | |
679 | } | |
680 | ||
681 | if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { | |
682 | if (!ivhash_name) { | |
683 | error_setg(errp, "Missing IV generator hash specification"); | |
684 | return -1; | |
685 | } | |
686 | luks->ivgen_cipher_alg = | |
687 | qcrypto_block_luks_essiv_cipher(luks->cipher_alg, | |
688 | luks->ivgen_hash_alg, | |
689 | &local_err); | |
690 | if (local_err) { | |
691 | error_propagate(errp, local_err); | |
692 | return -1; | |
693 | } | |
694 | } else { | |
695 | ||
696 | /* | |
697 | * Note we parsed the ivhash_name earlier in the cipher_mode | |
698 | * spec string even with plain/plain64 ivgens, but we | |
699 | * will ignore it, since it is irrelevant for these ivgens. | |
700 | * This is for compat with dm-crypt which will silently | |
701 | * ignore hash names with these ivgens rather than report | |
702 | * an error about the invalid usage | |
703 | */ | |
704 | luks->ivgen_cipher_alg = luks->cipher_alg; | |
705 | } | |
706 | return 0; | |
707 | } | |
708 | ||
3994a7c9 ML |
709 | /* |
710 | * Given a key slot, user password, and the master key, | |
711 | * will store the encrypted master key there, and update the | |
712 | * in-memory header. User must then write the in-memory header | |
713 | * | |
714 | * Returns: | |
715 | * 0 if the keyslot was written successfully | |
716 | * with the provided password | |
717 | * -1 if a fatal error occurred while storing the key | |
718 | */ | |
719 | static int | |
720 | qcrypto_block_luks_store_key(QCryptoBlock *block, | |
721 | unsigned int slot_idx, | |
722 | const char *password, | |
723 | uint8_t *masterkey, | |
724 | uint64_t iter_time, | |
725 | QCryptoBlockWriteFunc writefunc, | |
726 | void *opaque, | |
727 | Error **errp) | |
728 | { | |
729 | QCryptoBlockLUKS *luks = block->opaque; | |
557d2bdc | 730 | QCryptoBlockLUKSKeySlot *slot; |
3994a7c9 ML |
731 | g_autofree uint8_t *splitkey = NULL; |
732 | size_t splitkeylen; | |
733 | g_autofree uint8_t *slotkey = NULL; | |
734 | g_autoptr(QCryptoCipher) cipher = NULL; | |
735 | g_autoptr(QCryptoIVGen) ivgen = NULL; | |
736 | Error *local_err = NULL; | |
737 | uint64_t iters; | |
738 | int ret = -1; | |
739 | ||
557d2bdc ML |
740 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); |
741 | slot = &luks->header.key_slots[slot_idx]; | |
3994a7c9 ML |
742 | if (qcrypto_random_bytes(slot->salt, |
743 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
744 | errp) < 0) { | |
745 | goto cleanup; | |
746 | } | |
747 | ||
748 | splitkeylen = luks->header.master_key_len * slot->stripes; | |
749 | ||
750 | /* | |
751 | * Determine how many iterations are required to | |
752 | * hash the user password while consuming 1 second of compute | |
753 | * time | |
754 | */ | |
755 | iters = qcrypto_pbkdf2_count_iters(luks->hash_alg, | |
756 | (uint8_t *)password, strlen(password), | |
757 | slot->salt, | |
758 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
759 | luks->header.master_key_len, | |
760 | &local_err); | |
761 | if (local_err) { | |
762 | error_propagate(errp, local_err); | |
763 | goto cleanup; | |
764 | } | |
765 | ||
766 | if (iters > (ULLONG_MAX / iter_time)) { | |
767 | error_setg_errno(errp, ERANGE, | |
768 | "PBKDF iterations %llu too large to scale", | |
769 | (unsigned long long)iters); | |
770 | goto cleanup; | |
771 | } | |
772 | ||
773 | /* iter_time was in millis, but count_iters reported for secs */ | |
774 | iters = iters * iter_time / 1000; | |
775 | ||
776 | if (iters > UINT32_MAX) { | |
777 | error_setg_errno(errp, ERANGE, | |
778 | "PBKDF iterations %llu larger than %u", | |
779 | (unsigned long long)iters, UINT32_MAX); | |
780 | goto cleanup; | |
781 | } | |
782 | ||
783 | slot->iterations = | |
784 | MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); | |
785 | ||
786 | ||
787 | /* | |
788 | * Generate a key that we'll use to encrypt the master | |
789 | * key, from the user's password | |
790 | */ | |
791 | slotkey = g_new0(uint8_t, luks->header.master_key_len); | |
792 | if (qcrypto_pbkdf2(luks->hash_alg, | |
793 | (uint8_t *)password, strlen(password), | |
794 | slot->salt, | |
795 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
796 | slot->iterations, | |
797 | slotkey, luks->header.master_key_len, | |
798 | errp) < 0) { | |
799 | goto cleanup; | |
800 | } | |
801 | ||
802 | ||
803 | /* | |
804 | * Setup the encryption objects needed to encrypt the | |
805 | * master key material | |
806 | */ | |
807 | cipher = qcrypto_cipher_new(luks->cipher_alg, | |
808 | luks->cipher_mode, | |
809 | slotkey, luks->header.master_key_len, | |
810 | errp); | |
811 | if (!cipher) { | |
812 | goto cleanup; | |
813 | } | |
814 | ||
815 | ivgen = qcrypto_ivgen_new(luks->ivgen_alg, | |
816 | luks->ivgen_cipher_alg, | |
817 | luks->ivgen_hash_alg, | |
818 | slotkey, luks->header.master_key_len, | |
819 | errp); | |
820 | if (!ivgen) { | |
821 | goto cleanup; | |
822 | } | |
823 | ||
824 | /* | |
825 | * Before storing the master key, we need to vastly | |
826 | * increase its size, as protection against forensic | |
827 | * disk data recovery | |
828 | */ | |
829 | splitkey = g_new0(uint8_t, splitkeylen); | |
830 | ||
831 | if (qcrypto_afsplit_encode(luks->hash_alg, | |
832 | luks->header.master_key_len, | |
833 | slot->stripes, | |
834 | masterkey, | |
835 | splitkey, | |
836 | errp) < 0) { | |
837 | goto cleanup; | |
838 | } | |
839 | ||
840 | /* | |
841 | * Now we encrypt the split master key with the key generated | |
842 | * from the user's password, before storing it | |
843 | */ | |
844 | if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen, | |
845 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
846 | 0, | |
847 | splitkey, | |
848 | splitkeylen, | |
849 | errp) < 0) { | |
850 | goto cleanup; | |
851 | } | |
852 | ||
853 | /* Write out the slot's master key material. */ | |
854 | if (writefunc(block, | |
855 | slot->key_offset_sector * | |
856 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
857 | splitkey, splitkeylen, | |
858 | opaque, | |
859 | errp) != splitkeylen) { | |
860 | goto cleanup; | |
861 | } | |
862 | ||
863 | slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; | |
864 | ||
865 | if (qcrypto_block_luks_store_header(block, writefunc, opaque, errp) < 0) { | |
866 | goto cleanup; | |
867 | } | |
868 | ||
869 | ret = 0; | |
870 | ||
871 | cleanup: | |
872 | if (slotkey) { | |
873 | memset(slotkey, 0, luks->header.master_key_len); | |
874 | } | |
875 | if (splitkey) { | |
876 | memset(splitkey, 0, splitkeylen); | |
877 | } | |
878 | return ret; | |
879 | } | |
880 | ||
3e308f20 DB |
881 | /* |
882 | * Given a key slot, and user password, this will attempt to unlock | |
883 | * the master encryption key from the key slot. | |
884 | * | |
885 | * Returns: | |
886 | * 0 if the key slot is disabled, or key could not be decrypted | |
887 | * with the provided password | |
888 | * 1 if the key slot is enabled, and key decrypted successfully | |
889 | * with the provided password | |
890 | * -1 if a fatal error occurred loading the key | |
891 | */ | |
892 | static int | |
893 | qcrypto_block_luks_load_key(QCryptoBlock *block, | |
7e60a6f5 | 894 | size_t slot_idx, |
3e308f20 | 895 | const char *password, |
3e308f20 | 896 | uint8_t *masterkey, |
3e308f20 DB |
897 | QCryptoBlockReadFunc readfunc, |
898 | void *opaque, | |
899 | Error **errp) | |
900 | { | |
901 | QCryptoBlockLUKS *luks = block->opaque; | |
557d2bdc | 902 | const QCryptoBlockLUKSKeySlot *slot; |
57b9f113 | 903 | g_autofree uint8_t *splitkey = NULL; |
3e308f20 | 904 | size_t splitkeylen; |
57b9f113 | 905 | g_autofree uint8_t *possiblekey = NULL; |
3e308f20 | 906 | ssize_t rv; |
57b9f113 | 907 | g_autoptr(QCryptoCipher) cipher = NULL; |
3e308f20 | 908 | uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; |
57b9f113 | 909 | g_autoptr(QCryptoIVGen) ivgen = NULL; |
3e308f20 DB |
910 | size_t niv; |
911 | ||
557d2bdc ML |
912 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); |
913 | slot = &luks->header.key_slots[slot_idx]; | |
3e308f20 DB |
914 | if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { |
915 | return 0; | |
916 | } | |
917 | ||
1ddd52e4 | 918 | splitkeylen = luks->header.master_key_len * slot->stripes; |
3e308f20 | 919 | splitkey = g_new0(uint8_t, splitkeylen); |
1ddd52e4 | 920 | possiblekey = g_new0(uint8_t, luks->header.master_key_len); |
3e308f20 DB |
921 | |
922 | /* | |
923 | * The user password is used to generate a (possible) | |
924 | * decryption key. This may or may not successfully | |
925 | * decrypt the master key - we just blindly assume | |
926 | * the key is correct and validate the results of | |
927 | * decryption later. | |
928 | */ | |
9d80e59d | 929 | if (qcrypto_pbkdf2(luks->hash_alg, |
3e308f20 DB |
930 | (const uint8_t *)password, strlen(password), |
931 | slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
932 | slot->iterations, | |
1ddd52e4 | 933 | possiblekey, luks->header.master_key_len, |
3e308f20 | 934 | errp) < 0) { |
57b9f113 | 935 | return -1; |
3e308f20 DB |
936 | } |
937 | ||
938 | /* | |
939 | * We need to read the master key material from the | |
940 | * LUKS key material header. What we're reading is | |
941 | * not the raw master key, but rather the data after | |
942 | * it has been passed through AFSplit and the result | |
943 | * then encrypted. | |
944 | */ | |
945 | rv = readfunc(block, | |
f0d3c362 | 946 | slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, |
3e308f20 | 947 | splitkey, splitkeylen, |
e4a3507e | 948 | opaque, |
37509233 | 949 | errp); |
3e308f20 | 950 | if (rv < 0) { |
57b9f113 | 951 | return -1; |
3e308f20 DB |
952 | } |
953 | ||
954 | ||
955 | /* Setup the cipher/ivgen that we'll use to try to decrypt | |
956 | * the split master key material */ | |
9d80e59d ML |
957 | cipher = qcrypto_cipher_new(luks->cipher_alg, |
958 | luks->cipher_mode, | |
959 | possiblekey, | |
960 | luks->header.master_key_len, | |
3e308f20 DB |
961 | errp); |
962 | if (!cipher) { | |
57b9f113 | 963 | return -1; |
3e308f20 DB |
964 | } |
965 | ||
9d80e59d ML |
966 | niv = qcrypto_cipher_get_iv_len(luks->cipher_alg, |
967 | luks->cipher_mode); | |
968 | ||
969 | ivgen = qcrypto_ivgen_new(luks->ivgen_alg, | |
970 | luks->ivgen_cipher_alg, | |
971 | luks->ivgen_hash_alg, | |
972 | possiblekey, | |
973 | luks->header.master_key_len, | |
3e308f20 DB |
974 | errp); |
975 | if (!ivgen) { | |
57b9f113 | 976 | return -1; |
3e308f20 DB |
977 | } |
978 | ||
979 | ||
980 | /* | |
981 | * The master key needs to be decrypted in the same | |
982 | * way that the block device payload will be decrypted | |
983 | * later. In particular we'll be using the IV generator | |
984 | * to reset the encryption cipher every time the master | |
985 | * key crosses a sector boundary. | |
986 | */ | |
0270417c VSO |
987 | if (qcrypto_block_cipher_decrypt_helper(cipher, |
988 | niv, | |
989 | ivgen, | |
990 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
991 | 0, | |
992 | splitkey, | |
993 | splitkeylen, | |
994 | errp) < 0) { | |
57b9f113 | 995 | return -1; |
3e308f20 DB |
996 | } |
997 | ||
998 | /* | |
999 | * Now we've decrypted the split master key, join | |
1000 | * it back together to get the actual master key. | |
1001 | */ | |
9d80e59d | 1002 | if (qcrypto_afsplit_decode(luks->hash_alg, |
1ddd52e4 | 1003 | luks->header.master_key_len, |
3e308f20 DB |
1004 | slot->stripes, |
1005 | splitkey, | |
1006 | masterkey, | |
1007 | errp) < 0) { | |
57b9f113 | 1008 | return -1; |
3e308f20 DB |
1009 | } |
1010 | ||
1011 | ||
1012 | /* | |
1013 | * We still don't know that the masterkey we got is valid, | |
1014 | * because we just blindly assumed the user's password | |
1015 | * was correct. This is where we now verify it. We are | |
1016 | * creating a hash of the master key using PBKDF and | |
1017 | * then comparing that to the hash stored in the key slot | |
1018 | * header | |
1019 | */ | |
9d80e59d | 1020 | if (qcrypto_pbkdf2(luks->hash_alg, |
1ddd52e4 ML |
1021 | masterkey, |
1022 | luks->header.master_key_len, | |
3e308f20 DB |
1023 | luks->header.master_key_salt, |
1024 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
1025 | luks->header.master_key_iterations, | |
1ddd52e4 ML |
1026 | keydigest, |
1027 | G_N_ELEMENTS(keydigest), | |
3e308f20 | 1028 | errp) < 0) { |
57b9f113 | 1029 | return -1; |
3e308f20 DB |
1030 | } |
1031 | ||
1032 | if (memcmp(keydigest, luks->header.master_key_digest, | |
1033 | QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) { | |
1034 | /* Success, we got the right master key */ | |
57b9f113 | 1035 | return 1; |
3e308f20 DB |
1036 | } |
1037 | ||
1038 | /* Fail, user's password was not valid for this key slot, | |
1039 | * tell caller to try another slot */ | |
57b9f113 | 1040 | return 0; |
3e308f20 DB |
1041 | } |
1042 | ||
1043 | ||
1044 | /* | |
1045 | * Given a user password, this will iterate over all key | |
1046 | * slots and try to unlock each active key slot using the | |
1047 | * password until it successfully obtains a master key. | |
1048 | * | |
1049 | * Returns 0 if a key was loaded, -1 if no keys could be loaded | |
1050 | */ | |
1051 | static int | |
1052 | qcrypto_block_luks_find_key(QCryptoBlock *block, | |
1053 | const char *password, | |
1ddd52e4 | 1054 | uint8_t *masterkey, |
3e308f20 DB |
1055 | QCryptoBlockReadFunc readfunc, |
1056 | void *opaque, | |
1057 | Error **errp) | |
1058 | { | |
3e308f20 DB |
1059 | size_t i; |
1060 | int rv; | |
1061 | ||
3e308f20 DB |
1062 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { |
1063 | rv = qcrypto_block_luks_load_key(block, | |
7e60a6f5 | 1064 | i, |
3e308f20 | 1065 | password, |
1ddd52e4 | 1066 | masterkey, |
3e308f20 DB |
1067 | readfunc, |
1068 | opaque, | |
1069 | errp); | |
1070 | if (rv < 0) { | |
1071 | goto error; | |
1072 | } | |
1073 | if (rv == 1) { | |
1074 | return 0; | |
1075 | } | |
1076 | } | |
1077 | ||
1078 | error_setg(errp, "Invalid password, cannot unlock any keyslot"); | |
3e308f20 | 1079 | error: |
3e308f20 DB |
1080 | return -1; |
1081 | } | |
1082 | ||
557d2bdc ML |
1083 | /* |
1084 | * Returns true if a slot i is marked as active | |
1085 | * (contains encrypted copy of the master key) | |
1086 | */ | |
1087 | static bool | |
1088 | qcrypto_block_luks_slot_active(const QCryptoBlockLUKS *luks, | |
1089 | unsigned int slot_idx) | |
1090 | { | |
1091 | uint32_t val; | |
1092 | ||
1093 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); | |
1094 | val = luks->header.key_slots[slot_idx].active; | |
1095 | return val == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; | |
1096 | } | |
1097 | ||
1098 | /* | |
1099 | * Returns the number of slots that are marked as active | |
1100 | * (slots that contain encrypted copy of the master key) | |
1101 | */ | |
1102 | static unsigned int | |
1103 | qcrypto_block_luks_count_active_slots(const QCryptoBlockLUKS *luks) | |
1104 | { | |
1105 | size_t i = 0; | |
1106 | unsigned int ret = 0; | |
1107 | ||
1108 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1109 | if (qcrypto_block_luks_slot_active(luks, i)) { | |
1110 | ret++; | |
1111 | } | |
1112 | } | |
1113 | return ret; | |
1114 | } | |
1115 | ||
1116 | /* | |
1117 | * Finds first key slot which is not active | |
1118 | * Returns the key slot index, or -1 if it doesn't exist | |
1119 | */ | |
1120 | static int | |
1121 | qcrypto_block_luks_find_free_keyslot(const QCryptoBlockLUKS *luks) | |
1122 | { | |
1123 | size_t i; | |
1124 | ||
1125 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1126 | if (!qcrypto_block_luks_slot_active(luks, i)) { | |
1127 | return i; | |
1128 | } | |
1129 | } | |
1130 | return -1; | |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * Erases an keyslot given its index | |
1135 | * Returns: | |
1136 | * 0 if the keyslot was erased successfully | |
1137 | * -1 if a error occurred while erasing the keyslot | |
1138 | * | |
1139 | */ | |
1140 | static int | |
1141 | qcrypto_block_luks_erase_key(QCryptoBlock *block, | |
1142 | unsigned int slot_idx, | |
1143 | QCryptoBlockWriteFunc writefunc, | |
1144 | void *opaque, | |
1145 | Error **errp) | |
1146 | { | |
1147 | QCryptoBlockLUKS *luks = block->opaque; | |
1148 | QCryptoBlockLUKSKeySlot *slot; | |
1149 | g_autofree uint8_t *garbagesplitkey = NULL; | |
1150 | size_t splitkeylen; | |
1151 | size_t i; | |
1152 | Error *local_err = NULL; | |
1153 | int ret; | |
1154 | ||
1155 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); | |
1156 | slot = &luks->header.key_slots[slot_idx]; | |
1157 | ||
1158 | splitkeylen = luks->header.master_key_len * slot->stripes; | |
1159 | assert(splitkeylen > 0); | |
1160 | ||
1161 | garbagesplitkey = g_new0(uint8_t, splitkeylen); | |
1162 | ||
1163 | /* Reset the key slot header */ | |
1164 | memset(slot->salt, 0, QCRYPTO_BLOCK_LUKS_SALT_LEN); | |
1165 | slot->iterations = 0; | |
1166 | slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; | |
1167 | ||
1168 | ret = qcrypto_block_luks_store_header(block, writefunc, | |
1169 | opaque, &local_err); | |
1170 | ||
1171 | if (ret < 0) { | |
1172 | error_propagate(errp, local_err); | |
1173 | } | |
1174 | /* | |
1175 | * Now try to erase the key material, even if the header | |
1176 | * update failed | |
1177 | */ | |
1178 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS; i++) { | |
1179 | if (qcrypto_random_bytes(garbagesplitkey, | |
1180 | splitkeylen, &local_err) < 0) { | |
1181 | /* | |
1182 | * If we failed to get the random data, still write | |
1183 | * at least zeros to the key slot at least once | |
1184 | */ | |
1185 | error_propagate(errp, local_err); | |
1186 | ||
1187 | if (i > 0) { | |
1188 | return -1; | |
1189 | } | |
1190 | } | |
1191 | if (writefunc(block, | |
1192 | slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
1193 | garbagesplitkey, | |
1194 | splitkeylen, | |
1195 | opaque, | |
1196 | &local_err) != splitkeylen) { | |
1197 | error_propagate(errp, local_err); | |
1198 | return -1; | |
1199 | } | |
1200 | } | |
1201 | return ret; | |
1202 | } | |
3e308f20 DB |
1203 | |
1204 | static int | |
1205 | qcrypto_block_luks_open(QCryptoBlock *block, | |
1206 | QCryptoBlockOpenOptions *options, | |
1cd9a787 | 1207 | const char *optprefix, |
3e308f20 DB |
1208 | QCryptoBlockReadFunc readfunc, |
1209 | void *opaque, | |
1210 | unsigned int flags, | |
c972fa12 | 1211 | size_t n_threads, |
3e308f20 DB |
1212 | Error **errp) |
1213 | { | |
9d80e59d | 1214 | QCryptoBlockLUKS *luks = NULL; |
57b9f113 | 1215 | g_autofree uint8_t *masterkey = NULL; |
57b9f113 | 1216 | g_autofree char *password = NULL; |
3e308f20 DB |
1217 | |
1218 | if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { | |
1219 | if (!options->u.luks.key_secret) { | |
1cd9a787 DB |
1220 | error_setg(errp, "Parameter '%skey-secret' is required for cipher", |
1221 | optprefix ? optprefix : ""); | |
3e308f20 DB |
1222 | return -1; |
1223 | } | |
1224 | password = qcrypto_secret_lookup_as_utf8( | |
1225 | options->u.luks.key_secret, errp); | |
1226 | if (!password) { | |
1227 | return -1; | |
1228 | } | |
1229 | } | |
1230 | ||
1231 | luks = g_new0(QCryptoBlockLUKS, 1); | |
1232 | block->opaque = luks; | |
557d2bdc | 1233 | luks->secret = g_strdup(options->u.luks.key_secret); |
3e308f20 | 1234 | |
dde2c5af | 1235 | if (qcrypto_block_luks_load_header(block, readfunc, opaque, errp) < 0) { |
3e308f20 DB |
1236 | goto fail; |
1237 | } | |
1238 | ||
9fa9c1c2 | 1239 | if (qcrypto_block_luks_check_header(luks, errp) < 0) { |
3e308f20 DB |
1240 | goto fail; |
1241 | } | |
1242 | ||
9fa9c1c2 | 1243 | if (qcrypto_block_luks_parse_header(luks, errp) < 0) { |
3e308f20 DB |
1244 | goto fail; |
1245 | } | |
3e308f20 DB |
1246 | |
1247 | if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { | |
1248 | /* Try to find which key slot our password is valid for | |
1249 | * and unlock the master key from that slot. | |
1250 | */ | |
1ddd52e4 ML |
1251 | |
1252 | masterkey = g_new0(uint8_t, luks->header.master_key_len); | |
1253 | ||
3e308f20 DB |
1254 | if (qcrypto_block_luks_find_key(block, |
1255 | password, | |
1ddd52e4 | 1256 | masterkey, |
3e308f20 DB |
1257 | readfunc, opaque, |
1258 | errp) < 0) { | |
3e308f20 DB |
1259 | goto fail; |
1260 | } | |
1261 | ||
1262 | /* We have a valid master key now, so can setup the | |
1263 | * block device payload decryption objects | |
1264 | */ | |
9d80e59d ML |
1265 | block->kdfhash = luks->hash_alg; |
1266 | block->niv = qcrypto_cipher_get_iv_len(luks->cipher_alg, | |
1267 | luks->cipher_mode); | |
1268 | ||
1269 | block->ivgen = qcrypto_ivgen_new(luks->ivgen_alg, | |
1270 | luks->ivgen_cipher_alg, | |
1271 | luks->ivgen_hash_alg, | |
1ddd52e4 ML |
1272 | masterkey, |
1273 | luks->header.master_key_len, | |
3e308f20 DB |
1274 | errp); |
1275 | if (!block->ivgen) { | |
3e308f20 DB |
1276 | goto fail; |
1277 | } | |
1278 | ||
61dd8a9a ML |
1279 | if (qcrypto_block_init_cipher(block, |
1280 | luks->cipher_alg, | |
1281 | luks->cipher_mode, | |
1282 | masterkey, | |
1283 | luks->header.master_key_len, | |
1284 | n_threads, | |
1285 | errp) < 0) { | |
3e308f20 DB |
1286 | goto fail; |
1287 | } | |
1288 | } | |
1289 | ||
850f49de | 1290 | block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; |
f0d3c362 | 1291 | block->payload_offset = luks->header.payload_offset_sector * |
850f49de | 1292 | block->sector_size; |
3e308f20 | 1293 | |
3e308f20 DB |
1294 | return 0; |
1295 | ||
1296 | fail: | |
c972fa12 | 1297 | qcrypto_block_free_cipher(block); |
3e308f20 | 1298 | qcrypto_ivgen_free(block->ivgen); |
557d2bdc | 1299 | g_free(luks->secret); |
3e308f20 | 1300 | g_free(luks); |
61dd8a9a | 1301 | return -1; |
3e308f20 DB |
1302 | } |
1303 | ||
1304 | ||
2ef950f9 FZ |
1305 | static void |
1306 | qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) | |
3e308f20 | 1307 | { |
2ef950f9 FZ |
1308 | QemuUUID uuid; |
1309 | qemu_uuid_generate(&uuid); | |
1310 | qemu_uuid_unparse(&uuid, (char *)uuidstr); | |
3e308f20 DB |
1311 | } |
1312 | ||
1313 | static int | |
1314 | qcrypto_block_luks_create(QCryptoBlock *block, | |
1315 | QCryptoBlockCreateOptions *options, | |
1cd9a787 | 1316 | const char *optprefix, |
3e308f20 DB |
1317 | QCryptoBlockInitFunc initfunc, |
1318 | QCryptoBlockWriteFunc writefunc, | |
1319 | void *opaque, | |
1320 | Error **errp) | |
1321 | { | |
1322 | QCryptoBlockLUKS *luks; | |
1323 | QCryptoBlockCreateOptionsLUKS luks_opts; | |
1324 | Error *local_err = NULL; | |
57b9f113 | 1325 | g_autofree uint8_t *masterkey = NULL; |
bd56a55a ML |
1326 | size_t header_sectors; |
1327 | size_t split_key_sectors; | |
3e308f20 | 1328 | size_t i; |
57b9f113 | 1329 | g_autofree char *password = NULL; |
3e308f20 DB |
1330 | const char *cipher_alg; |
1331 | const char *cipher_mode; | |
1332 | const char *ivgen_alg; | |
1333 | const char *ivgen_hash_alg = NULL; | |
1334 | const char *hash_alg; | |
57b9f113 | 1335 | g_autofree char *cipher_mode_spec = NULL; |
59b060be | 1336 | uint64_t iters; |
3e308f20 DB |
1337 | |
1338 | memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); | |
3bd18890 | 1339 | if (!luks_opts.has_iter_time) { |
557d2bdc | 1340 | luks_opts.iter_time = QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS; |
3bd18890 | 1341 | } |
3e308f20 DB |
1342 | if (!luks_opts.has_cipher_alg) { |
1343 | luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; | |
1344 | } | |
1345 | if (!luks_opts.has_cipher_mode) { | |
1346 | luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; | |
1347 | } | |
1348 | if (!luks_opts.has_ivgen_alg) { | |
1349 | luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; | |
1350 | } | |
1351 | if (!luks_opts.has_hash_alg) { | |
1352 | luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; | |
1353 | } | |
8b7cdba3 DB |
1354 | if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { |
1355 | if (!luks_opts.has_ivgen_hash_alg) { | |
1356 | luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; | |
1357 | luks_opts.has_ivgen_hash_alg = true; | |
1358 | } | |
1359 | } | |
9d80e59d ML |
1360 | |
1361 | luks = g_new0(QCryptoBlockLUKS, 1); | |
1362 | block->opaque = luks; | |
1363 | ||
1364 | luks->cipher_alg = luks_opts.cipher_alg; | |
1365 | luks->cipher_mode = luks_opts.cipher_mode; | |
1366 | luks->ivgen_alg = luks_opts.ivgen_alg; | |
1367 | luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; | |
1368 | luks->hash_alg = luks_opts.hash_alg; | |
1369 | ||
1370 | ||
8b7cdba3 DB |
1371 | /* Note we're allowing ivgen_hash_alg to be set even for |
1372 | * non-essiv iv generators that don't need a hash. It will | |
1373 | * be silently ignored, for compatibility with dm-crypt */ | |
3e308f20 DB |
1374 | |
1375 | if (!options->u.luks.key_secret) { | |
1cd9a787 DB |
1376 | error_setg(errp, "Parameter '%skey-secret' is required for cipher", |
1377 | optprefix ? optprefix : ""); | |
9d80e59d | 1378 | goto error; |
3e308f20 | 1379 | } |
557d2bdc ML |
1380 | luks->secret = g_strdup(options->u.luks.key_secret); |
1381 | ||
3e308f20 DB |
1382 | password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp); |
1383 | if (!password) { | |
9d80e59d | 1384 | goto error; |
3e308f20 DB |
1385 | } |
1386 | ||
3e308f20 DB |
1387 | |
1388 | memcpy(luks->header.magic, qcrypto_block_luks_magic, | |
1389 | QCRYPTO_BLOCK_LUKS_MAGIC_LEN); | |
1390 | ||
1391 | /* We populate the header in native endianness initially and | |
1392 | * then convert everything to big endian just before writing | |
1393 | * it out to disk | |
1394 | */ | |
1395 | luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION; | |
2ef950f9 | 1396 | qcrypto_block_luks_uuid_gen(luks->header.uuid); |
3e308f20 DB |
1397 | |
1398 | cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg, | |
1399 | errp); | |
1400 | if (!cipher_alg) { | |
1401 | goto error; | |
1402 | } | |
1403 | ||
977c736f MA |
1404 | cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode); |
1405 | ivgen_alg = QCryptoIVGenAlgorithm_str(luks_opts.ivgen_alg); | |
3e308f20 | 1406 | if (luks_opts.has_ivgen_hash_alg) { |
977c736f | 1407 | ivgen_hash_alg = QCryptoHashAlgorithm_str(luks_opts.ivgen_hash_alg); |
3e308f20 DB |
1408 | cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg, |
1409 | ivgen_hash_alg); | |
1410 | } else { | |
1411 | cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg); | |
1412 | } | |
977c736f | 1413 | hash_alg = QCryptoHashAlgorithm_str(luks_opts.hash_alg); |
3e308f20 DB |
1414 | |
1415 | ||
1416 | if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) { | |
1417 | error_setg(errp, "Cipher name '%s' is too long for LUKS header", | |
1418 | cipher_alg); | |
1419 | goto error; | |
1420 | } | |
1421 | if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) { | |
1422 | error_setg(errp, "Cipher mode '%s' is too long for LUKS header", | |
1423 | cipher_mode_spec); | |
1424 | goto error; | |
1425 | } | |
1426 | if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) { | |
1427 | error_setg(errp, "Hash name '%s' is too long for LUKS header", | |
1428 | hash_alg); | |
1429 | goto error; | |
1430 | } | |
1431 | ||
1432 | if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { | |
9d80e59d ML |
1433 | luks->ivgen_cipher_alg = |
1434 | qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg, | |
1435 | luks_opts.ivgen_hash_alg, | |
1436 | &local_err); | |
3e308f20 DB |
1437 | if (local_err) { |
1438 | error_propagate(errp, local_err); | |
1439 | goto error; | |
1440 | } | |
1441 | } else { | |
9d80e59d | 1442 | luks->ivgen_cipher_alg = luks_opts.cipher_alg; |
3e308f20 DB |
1443 | } |
1444 | ||
1445 | strcpy(luks->header.cipher_name, cipher_alg); | |
1446 | strcpy(luks->header.cipher_mode, cipher_mode_spec); | |
1447 | strcpy(luks->header.hash_spec, hash_alg); | |
1448 | ||
f0d3c362 ML |
1449 | luks->header.master_key_len = |
1450 | qcrypto_cipher_get_key_len(luks_opts.cipher_alg); | |
1451 | ||
3e308f20 | 1452 | if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) { |
f0d3c362 | 1453 | luks->header.master_key_len *= 2; |
3e308f20 DB |
1454 | } |
1455 | ||
1456 | /* Generate the salt used for hashing the master key | |
1457 | * with PBKDF later | |
1458 | */ | |
1459 | if (qcrypto_random_bytes(luks->header.master_key_salt, | |
1460 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
1461 | errp) < 0) { | |
1462 | goto error; | |
1463 | } | |
1464 | ||
1465 | /* Generate random master key */ | |
f0d3c362 | 1466 | masterkey = g_new0(uint8_t, luks->header.master_key_len); |
3e308f20 | 1467 | if (qcrypto_random_bytes(masterkey, |
f0d3c362 | 1468 | luks->header.master_key_len, errp) < 0) { |
3e308f20 DB |
1469 | goto error; |
1470 | } | |
1471 | ||
1472 | ||
1473 | /* Setup the block device payload encryption objects */ | |
c972fa12 VSO |
1474 | if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg, |
1475 | luks_opts.cipher_mode, masterkey, | |
f0d3c362 | 1476 | luks->header.master_key_len, 1, errp) < 0) { |
3e308f20 DB |
1477 | goto error; |
1478 | } | |
1479 | ||
1480 | block->kdfhash = luks_opts.hash_alg; | |
1481 | block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, | |
1482 | luks_opts.cipher_mode); | |
1483 | block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, | |
9d80e59d | 1484 | luks->ivgen_cipher_alg, |
3e308f20 | 1485 | luks_opts.ivgen_hash_alg, |
f0d3c362 | 1486 | masterkey, luks->header.master_key_len, |
3e308f20 DB |
1487 | errp); |
1488 | ||
1489 | if (!block->ivgen) { | |
1490 | goto error; | |
1491 | } | |
1492 | ||
1493 | ||
1494 | /* Determine how many iterations we need to hash the master | |
1495 | * key, in order to have 1 second of compute time used | |
1496 | */ | |
59b060be | 1497 | iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, |
f0d3c362 | 1498 | masterkey, luks->header.master_key_len, |
59b060be DB |
1499 | luks->header.master_key_salt, |
1500 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
e74aabcf | 1501 | QCRYPTO_BLOCK_LUKS_DIGEST_LEN, |
59b060be | 1502 | &local_err); |
3e308f20 DB |
1503 | if (local_err) { |
1504 | error_propagate(errp, local_err); | |
1505 | goto error; | |
1506 | } | |
1507 | ||
3bd18890 DB |
1508 | if (iters > (ULLONG_MAX / luks_opts.iter_time)) { |
1509 | error_setg_errno(errp, ERANGE, | |
1510 | "PBKDF iterations %llu too large to scale", | |
1511 | (unsigned long long)iters); | |
1512 | goto error; | |
1513 | } | |
1514 | ||
1515 | /* iter_time was in millis, but count_iters reported for secs */ | |
1516 | iters = iters * luks_opts.iter_time / 1000; | |
1517 | ||
3e308f20 DB |
1518 | /* Why /= 8 ? That matches cryptsetup, but there's no |
1519 | * explanation why they chose /= 8... Probably so that | |
1520 | * if all 8 keyslots are active we only spend 1 second | |
1521 | * in total time to check all keys */ | |
59b060be DB |
1522 | iters /= 8; |
1523 | if (iters > UINT32_MAX) { | |
1524 | error_setg_errno(errp, ERANGE, | |
1525 | "PBKDF iterations %llu larger than %u", | |
1526 | (unsigned long long)iters, UINT32_MAX); | |
1527 | goto error; | |
1528 | } | |
1529 | iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); | |
1530 | luks->header.master_key_iterations = iters; | |
3e308f20 DB |
1531 | |
1532 | /* Hash the master key, saving the result in the LUKS | |
1533 | * header. This hash is used when opening the encrypted | |
1534 | * device to verify that the user password unlocked a | |
1535 | * valid master key | |
1536 | */ | |
1537 | if (qcrypto_pbkdf2(luks_opts.hash_alg, | |
f0d3c362 | 1538 | masterkey, luks->header.master_key_len, |
3e308f20 DB |
1539 | luks->header.master_key_salt, |
1540 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
1541 | luks->header.master_key_iterations, | |
1542 | luks->header.master_key_digest, | |
1543 | QCRYPTO_BLOCK_LUKS_DIGEST_LEN, | |
1544 | errp) < 0) { | |
1545 | goto error; | |
1546 | } | |
1547 | ||
bd56a55a ML |
1548 | /* start with the sector that follows the header*/ |
1549 | header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / | |
1550 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; | |
1551 | ||
1552 | split_key_sectors = | |
1553 | qcrypto_block_luks_splitkeylen_sectors(luks, | |
1554 | header_sectors, | |
1555 | QCRYPTO_BLOCK_LUKS_STRIPES); | |
3e308f20 | 1556 | |
3e308f20 | 1557 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { |
bd56a55a ML |
1558 | QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; |
1559 | slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; | |
3e308f20 | 1560 | |
bd56a55a ML |
1561 | slot->key_offset_sector = header_sectors + i * split_key_sectors; |
1562 | slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; | |
3e308f20 DB |
1563 | } |
1564 | ||
3e308f20 DB |
1565 | /* The total size of the LUKS headers is the partition header + key |
1566 | * slot headers, rounded up to the nearest sector, combined with | |
1567 | * the size of each master key material region, also rounded up | |
1568 | * to the nearest sector */ | |
bd56a55a ML |
1569 | luks->header.payload_offset_sector = header_sectors + |
1570 | QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors; | |
3e308f20 | 1571 | |
850f49de | 1572 | block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; |
f0d3c362 | 1573 | block->payload_offset = luks->header.payload_offset_sector * |
850f49de | 1574 | block->sector_size; |
3e308f20 DB |
1575 | |
1576 | /* Reserve header space to match payload offset */ | |
e4a3507e | 1577 | initfunc(block, block->payload_offset, opaque, &local_err); |
3e308f20 DB |
1578 | if (local_err) { |
1579 | error_propagate(errp, local_err); | |
1580 | goto error; | |
1581 | } | |
1582 | ||
3e308f20 | 1583 | |
3994a7c9 ML |
1584 | /* populate the slot 0 with the password encrypted master key*/ |
1585 | /* This will also store the header */ | |
1586 | if (qcrypto_block_luks_store_key(block, | |
1587 | 0, | |
1588 | password, | |
1589 | masterkey, | |
1590 | luks_opts.iter_time, | |
1591 | writefunc, | |
1592 | opaque, | |
1593 | errp) < 0) { | |
3e308f20 DB |
1594 | goto error; |
1595 | } | |
1596 | ||
f0d3c362 | 1597 | memset(masterkey, 0, luks->header.master_key_len); |
3e308f20 DB |
1598 | |
1599 | return 0; | |
1600 | ||
1601 | error: | |
1602 | if (masterkey) { | |
f0d3c362 | 1603 | memset(masterkey, 0, luks->header.master_key_len); |
3e308f20 | 1604 | } |
3e308f20 | 1605 | |
c972fa12 | 1606 | qcrypto_block_free_cipher(block); |
b640adca VSO |
1607 | qcrypto_ivgen_free(block->ivgen); |
1608 | ||
557d2bdc | 1609 | g_free(luks->secret); |
3e308f20 DB |
1610 | g_free(luks); |
1611 | return -1; | |
1612 | } | |
1613 | ||
557d2bdc ML |
1614 | static int |
1615 | qcrypto_block_luks_amend_add_keyslot(QCryptoBlock *block, | |
1616 | QCryptoBlockReadFunc readfunc, | |
1617 | QCryptoBlockWriteFunc writefunc, | |
1618 | void *opaque, | |
1619 | QCryptoBlockAmendOptionsLUKS *opts_luks, | |
1620 | bool force, | |
1621 | Error **errp) | |
1622 | { | |
1623 | QCryptoBlockLUKS *luks = block->opaque; | |
1624 | uint64_t iter_time = opts_luks->has_iter_time ? | |
1625 | opts_luks->iter_time : | |
1626 | QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS; | |
1627 | int keyslot; | |
1628 | g_autofree char *old_password = NULL; | |
1629 | g_autofree char *new_password = NULL; | |
1630 | g_autofree uint8_t *master_key = NULL; | |
1631 | ||
1632 | char *secret = opts_luks->has_secret ? opts_luks->secret : luks->secret; | |
1633 | ||
1634 | if (!opts_luks->has_new_secret) { | |
1635 | error_setg(errp, "'new-secret' is required to activate a keyslot"); | |
1636 | return -1; | |
1637 | } | |
1638 | if (opts_luks->has_old_secret) { | |
1639 | error_setg(errp, | |
1640 | "'old-secret' must not be given when activating keyslots"); | |
1641 | return -1; | |
1642 | } | |
1643 | ||
1644 | if (opts_luks->has_keyslot) { | |
1645 | keyslot = opts_luks->keyslot; | |
1646 | if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) { | |
1647 | error_setg(errp, | |
1648 | "Invalid keyslot %u specified, must be between 0 and %u", | |
1649 | keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1); | |
1650 | return -1; | |
1651 | } | |
1652 | } else { | |
1653 | keyslot = qcrypto_block_luks_find_free_keyslot(luks); | |
1654 | if (keyslot == -1) { | |
1655 | error_setg(errp, | |
1656 | "Can't add a keyslot - all keyslots are in use"); | |
1657 | return -1; | |
1658 | } | |
1659 | } | |
1660 | ||
1661 | if (!force && qcrypto_block_luks_slot_active(luks, keyslot)) { | |
1662 | error_setg(errp, | |
1663 | "Refusing to overwrite active keyslot %i - " | |
1664 | "please erase it first", | |
1665 | keyslot); | |
1666 | return -1; | |
1667 | } | |
1668 | ||
1669 | /* Locate the password that will be used to retrieve the master key */ | |
1670 | old_password = qcrypto_secret_lookup_as_utf8(secret, errp); | |
1671 | if (!old_password) { | |
1672 | return -1; | |
1673 | } | |
1674 | ||
1675 | /* Retrieve the master key */ | |
1676 | master_key = g_new0(uint8_t, luks->header.master_key_len); | |
1677 | ||
1678 | if (qcrypto_block_luks_find_key(block, old_password, master_key, | |
1679 | readfunc, opaque, errp) < 0) { | |
1680 | error_append_hint(errp, "Failed to retrieve the master key"); | |
1681 | return -1; | |
1682 | } | |
1683 | ||
1684 | /* Locate the new password*/ | |
1685 | new_password = qcrypto_secret_lookup_as_utf8(opts_luks->new_secret, errp); | |
1686 | if (!new_password) { | |
1687 | return -1; | |
1688 | } | |
1689 | ||
1690 | /* Now set the new keyslots */ | |
1691 | if (qcrypto_block_luks_store_key(block, keyslot, new_password, master_key, | |
1692 | iter_time, writefunc, opaque, errp)) { | |
1693 | error_append_hint(errp, "Failed to write to keyslot %i", keyslot); | |
1694 | return -1; | |
1695 | } | |
1696 | return 0; | |
1697 | } | |
1698 | ||
1699 | static int | |
1700 | qcrypto_block_luks_amend_erase_keyslots(QCryptoBlock *block, | |
1701 | QCryptoBlockReadFunc readfunc, | |
1702 | QCryptoBlockWriteFunc writefunc, | |
1703 | void *opaque, | |
1704 | QCryptoBlockAmendOptionsLUKS *opts_luks, | |
1705 | bool force, | |
1706 | Error **errp) | |
1707 | { | |
1708 | QCryptoBlockLUKS *luks = block->opaque; | |
1709 | g_autofree uint8_t *tmpkey = NULL; | |
1710 | g_autofree char *old_password = NULL; | |
1711 | ||
1712 | if (opts_luks->has_new_secret) { | |
1713 | error_setg(errp, | |
1714 | "'new-secret' must not be given when erasing keyslots"); | |
1715 | return -1; | |
1716 | } | |
1717 | if (opts_luks->has_iter_time) { | |
1718 | error_setg(errp, | |
1719 | "'iter-time' must not be given when erasing keyslots"); | |
1720 | return -1; | |
1721 | } | |
1722 | if (opts_luks->has_secret) { | |
1723 | error_setg(errp, | |
1724 | "'secret' must not be given when erasing keyslots"); | |
1725 | return -1; | |
1726 | } | |
1727 | ||
1728 | /* Load the old password if given */ | |
1729 | if (opts_luks->has_old_secret) { | |
1730 | old_password = qcrypto_secret_lookup_as_utf8(opts_luks->old_secret, | |
1731 | errp); | |
1732 | if (!old_password) { | |
1733 | return -1; | |
1734 | } | |
1735 | ||
1736 | /* | |
1737 | * Allocate a temporary key buffer that we will need when | |
1738 | * checking if slot matches the given old password | |
1739 | */ | |
1740 | tmpkey = g_new0(uint8_t, luks->header.master_key_len); | |
1741 | } | |
1742 | ||
1743 | /* Erase an explicitly given keyslot */ | |
1744 | if (opts_luks->has_keyslot) { | |
1745 | int keyslot = opts_luks->keyslot; | |
1746 | ||
1747 | if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) { | |
1748 | error_setg(errp, | |
1749 | "Invalid keyslot %i specified, must be between 0 and %i", | |
1750 | keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1); | |
1751 | return -1; | |
1752 | } | |
1753 | ||
1754 | if (opts_luks->has_old_secret) { | |
1755 | int rv = qcrypto_block_luks_load_key(block, | |
1756 | keyslot, | |
1757 | old_password, | |
1758 | tmpkey, | |
1759 | readfunc, | |
1760 | opaque, | |
1761 | errp); | |
1762 | if (rv == -1) { | |
1763 | return -1; | |
1764 | } else if (rv == 0) { | |
1765 | error_setg(errp, | |
1766 | "Given keyslot %i doesn't contain the given " | |
1767 | "old password for erase operation", | |
1768 | keyslot); | |
1769 | return -1; | |
1770 | } | |
1771 | } | |
1772 | ||
1773 | if (!force && !qcrypto_block_luks_slot_active(luks, keyslot)) { | |
1774 | error_setg(errp, | |
1775 | "Given keyslot %i is already erased (inactive) ", | |
1776 | keyslot); | |
1777 | return -1; | |
1778 | } | |
1779 | ||
1780 | if (!force && qcrypto_block_luks_count_active_slots(luks) == 1) { | |
1781 | error_setg(errp, | |
1782 | "Attempt to erase the only active keyslot %i " | |
1783 | "which will erase all the data in the image " | |
1784 | "irreversibly - refusing operation", | |
1785 | keyslot); | |
1786 | return -1; | |
1787 | } | |
1788 | ||
1789 | if (qcrypto_block_luks_erase_key(block, keyslot, | |
1790 | writefunc, opaque, errp)) { | |
1791 | error_append_hint(errp, "Failed to erase keyslot %i", keyslot); | |
1792 | return -1; | |
1793 | } | |
1794 | ||
1795 | /* Erase all keyslots that match the given old password */ | |
1796 | } else if (opts_luks->has_old_secret) { | |
1797 | ||
1798 | unsigned long slots_to_erase_bitmap = 0; | |
1799 | size_t i; | |
1800 | int slot_count; | |
1801 | ||
1802 | assert(QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS <= | |
1803 | sizeof(slots_to_erase_bitmap) * 8); | |
1804 | ||
1805 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1806 | int rv = qcrypto_block_luks_load_key(block, | |
1807 | i, | |
1808 | old_password, | |
1809 | tmpkey, | |
1810 | readfunc, | |
1811 | opaque, | |
1812 | errp); | |
1813 | if (rv == -1) { | |
1814 | return -1; | |
1815 | } else if (rv == 1) { | |
1816 | bitmap_set(&slots_to_erase_bitmap, i, 1); | |
1817 | } | |
1818 | } | |
1819 | ||
1820 | slot_count = bitmap_count_one(&slots_to_erase_bitmap, | |
1821 | QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); | |
1822 | if (slot_count == 0) { | |
1823 | error_setg(errp, | |
1824 | "No keyslots match given (old) password for erase operation"); | |
1825 | return -1; | |
1826 | } | |
1827 | ||
1828 | if (!force && | |
1829 | slot_count == qcrypto_block_luks_count_active_slots(luks)) { | |
1830 | error_setg(errp, | |
1831 | "All the active keyslots match the (old) password that " | |
1832 | "was given and erasing them will erase all the data in " | |
1833 | "the image irreversibly - refusing operation"); | |
1834 | return -1; | |
1835 | } | |
1836 | ||
1837 | /* Now apply the update */ | |
1838 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1839 | if (!test_bit(i, &slots_to_erase_bitmap)) { | |
1840 | continue; | |
1841 | } | |
1842 | if (qcrypto_block_luks_erase_key(block, i, writefunc, | |
1843 | opaque, errp)) { | |
1844 | error_append_hint(errp, "Failed to erase keyslot %zu", i); | |
1845 | return -1; | |
1846 | } | |
1847 | } | |
1848 | } else { | |
1849 | error_setg(errp, | |
1850 | "To erase keyslot(s), either explicit keyslot index " | |
1851 | "or the password currently contained in them must be given"); | |
1852 | return -1; | |
1853 | } | |
1854 | return 0; | |
1855 | } | |
1856 | ||
1857 | static int | |
1858 | qcrypto_block_luks_amend_options(QCryptoBlock *block, | |
1859 | QCryptoBlockReadFunc readfunc, | |
1860 | QCryptoBlockWriteFunc writefunc, | |
1861 | void *opaque, | |
1862 | QCryptoBlockAmendOptions *options, | |
1863 | bool force, | |
1864 | Error **errp) | |
1865 | { | |
1866 | QCryptoBlockAmendOptionsLUKS *opts_luks = &options->u.luks; | |
1867 | ||
1868 | switch (opts_luks->state) { | |
1869 | case Q_CRYPTO_BLOCKLUKS_KEYSLOT_STATE_ACTIVE: | |
1870 | return qcrypto_block_luks_amend_add_keyslot(block, readfunc, | |
1871 | writefunc, opaque, | |
1872 | opts_luks, force, errp); | |
1873 | case Q_CRYPTO_BLOCKLUKS_KEYSLOT_STATE_INACTIVE: | |
1874 | return qcrypto_block_luks_amend_erase_keyslots(block, readfunc, | |
1875 | writefunc, opaque, | |
1876 | opts_luks, force, errp); | |
1877 | default: | |
1878 | g_assert_not_reached(); | |
1879 | } | |
1880 | } | |
3e308f20 | 1881 | |
40c85028 DB |
1882 | static int qcrypto_block_luks_get_info(QCryptoBlock *block, |
1883 | QCryptoBlockInfo *info, | |
1884 | Error **errp) | |
1885 | { | |
1886 | QCryptoBlockLUKS *luks = block->opaque; | |
1887 | QCryptoBlockInfoLUKSSlot *slot; | |
c3033fd3 | 1888 | QCryptoBlockInfoLUKSSlotList **tail = &info->u.luks.slots; |
40c85028 DB |
1889 | size_t i; |
1890 | ||
1891 | info->u.luks.cipher_alg = luks->cipher_alg; | |
1892 | info->u.luks.cipher_mode = luks->cipher_mode; | |
1893 | info->u.luks.ivgen_alg = luks->ivgen_alg; | |
1894 | if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { | |
1895 | info->u.luks.has_ivgen_hash_alg = true; | |
1896 | info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; | |
1897 | } | |
1898 | info->u.luks.hash_alg = luks->hash_alg; | |
1899 | info->u.luks.payload_offset = block->payload_offset; | |
1900 | info->u.luks.master_key_iters = luks->header.master_key_iterations; | |
1901 | info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, | |
1902 | sizeof(luks->header.uuid)); | |
1903 | ||
1904 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
c3033fd3 | 1905 | slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); |
40c85028 DB |
1906 | slot->active = luks->header.key_slots[i].active == |
1907 | QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; | |
f0d3c362 | 1908 | slot->key_offset = luks->header.key_slots[i].key_offset_sector |
40c85028 DB |
1909 | * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; |
1910 | if (slot->active) { | |
1911 | slot->has_iters = true; | |
1912 | slot->iters = luks->header.key_slots[i].iterations; | |
1913 | slot->has_stripes = true; | |
1914 | slot->stripes = luks->header.key_slots[i].stripes; | |
1915 | } | |
1916 | ||
c3033fd3 | 1917 | QAPI_LIST_APPEND(tail, slot); |
40c85028 DB |
1918 | } |
1919 | ||
1920 | return 0; | |
1921 | } | |
1922 | ||
1923 | ||
3e308f20 DB |
1924 | static void qcrypto_block_luks_cleanup(QCryptoBlock *block) |
1925 | { | |
557d2bdc ML |
1926 | QCryptoBlockLUKS *luks = block->opaque; |
1927 | if (luks) { | |
1928 | g_free(luks->secret); | |
1929 | g_free(luks); | |
1930 | } | |
3e308f20 DB |
1931 | } |
1932 | ||
1933 | ||
1934 | static int | |
1935 | qcrypto_block_luks_decrypt(QCryptoBlock *block, | |
4609742a | 1936 | uint64_t offset, |
3e308f20 DB |
1937 | uint8_t *buf, |
1938 | size_t len, | |
1939 | Error **errp) | |
1940 | { | |
4609742a DB |
1941 | assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); |
1942 | assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); | |
0f0d596c VSO |
1943 | return qcrypto_block_decrypt_helper(block, |
1944 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
1945 | offset, buf, len, errp); | |
3e308f20 DB |
1946 | } |
1947 | ||
1948 | ||
1949 | static int | |
1950 | qcrypto_block_luks_encrypt(QCryptoBlock *block, | |
4609742a | 1951 | uint64_t offset, |
3e308f20 DB |
1952 | uint8_t *buf, |
1953 | size_t len, | |
1954 | Error **errp) | |
1955 | { | |
4609742a DB |
1956 | assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); |
1957 | assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); | |
0f0d596c VSO |
1958 | return qcrypto_block_encrypt_helper(block, |
1959 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
1960 | offset, buf, len, errp); | |
3e308f20 DB |
1961 | } |
1962 | ||
1963 | ||
1964 | const QCryptoBlockDriver qcrypto_block_driver_luks = { | |
1965 | .open = qcrypto_block_luks_open, | |
1966 | .create = qcrypto_block_luks_create, | |
557d2bdc | 1967 | .amend = qcrypto_block_luks_amend_options, |
40c85028 | 1968 | .get_info = qcrypto_block_luks_get_info, |
3e308f20 DB |
1969 | .cleanup = qcrypto_block_luks_cleanup, |
1970 | .decrypt = qcrypto_block_luks_decrypt, | |
1971 | .encrypt = qcrypto_block_luks_encrypt, | |
1972 | .has_format = qcrypto_block_luks_has_format, | |
1973 | }; |