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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" |
36445ace | 26 | #include "block-luks-priv.h" |
3e308f20 DB |
27 | |
28 | #include "crypto/hash.h" | |
29 | #include "crypto/afsplit.h" | |
30 | #include "crypto/pbkdf.h" | |
31 | #include "crypto/secret.h" | |
32 | #include "crypto/random.h" | |
2ef950f9 | 33 | #include "qemu/uuid.h" |
3e308f20 | 34 | |
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; | |
3e308f20 DB |
49 | |
50 | typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap; | |
51 | struct QCryptoBlockLUKSNameMap { | |
52 | const char *name; | |
53 | int id; | |
54 | }; | |
55 | ||
56 | typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap; | |
57 | struct QCryptoBlockLUKSCipherSizeMap { | |
58 | uint32_t key_bytes; | |
59 | int id; | |
60 | }; | |
61 | typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap; | |
62 | struct QCryptoBlockLUKSCipherNameMap { | |
63 | const char *name; | |
64 | const QCryptoBlockLUKSCipherSizeMap *sizes; | |
65 | }; | |
66 | ||
67 | ||
68 | static const QCryptoBlockLUKSCipherSizeMap | |
69 | qcrypto_block_luks_cipher_size_map_aes[] = { | |
70 | { 16, QCRYPTO_CIPHER_ALG_AES_128 }, | |
71 | { 24, QCRYPTO_CIPHER_ALG_AES_192 }, | |
72 | { 32, QCRYPTO_CIPHER_ALG_AES_256 }, | |
73 | { 0, 0 }, | |
74 | }; | |
75 | ||
76 | static const QCryptoBlockLUKSCipherSizeMap | |
77 | qcrypto_block_luks_cipher_size_map_cast5[] = { | |
78 | { 16, QCRYPTO_CIPHER_ALG_CAST5_128 }, | |
79 | { 0, 0 }, | |
80 | }; | |
81 | ||
82 | static const QCryptoBlockLUKSCipherSizeMap | |
83 | qcrypto_block_luks_cipher_size_map_serpent[] = { | |
84 | { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 }, | |
85 | { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 }, | |
86 | { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 }, | |
87 | { 0, 0 }, | |
88 | }; | |
89 | ||
90 | static const QCryptoBlockLUKSCipherSizeMap | |
91 | qcrypto_block_luks_cipher_size_map_twofish[] = { | |
92 | { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 }, | |
93 | { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 }, | |
94 | { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 }, | |
95 | { 0, 0 }, | |
96 | }; | |
97 | ||
52ed9f45 HH |
98 | #ifdef CONFIG_CRYPTO_SM4 |
99 | static const QCryptoBlockLUKSCipherSizeMap | |
100 | qcrypto_block_luks_cipher_size_map_sm4[] = { | |
101 | { 16, QCRYPTO_CIPHER_ALG_SM4}, | |
102 | { 0, 0 }, | |
103 | }; | |
104 | #endif | |
105 | ||
3e308f20 DB |
106 | static const QCryptoBlockLUKSCipherNameMap |
107 | qcrypto_block_luks_cipher_name_map[] = { | |
108 | { "aes", qcrypto_block_luks_cipher_size_map_aes }, | |
109 | { "cast5", qcrypto_block_luks_cipher_size_map_cast5 }, | |
110 | { "serpent", qcrypto_block_luks_cipher_size_map_serpent }, | |
111 | { "twofish", qcrypto_block_luks_cipher_size_map_twofish }, | |
52ed9f45 HH |
112 | #ifdef CONFIG_CRYPTO_SM4 |
113 | { "sm4", qcrypto_block_luks_cipher_size_map_sm4}, | |
114 | #endif | |
3e308f20 DB |
115 | }; |
116 | ||
3e308f20 | 117 | QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48); |
3e308f20 DB |
118 | QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592); |
119 | ||
120 | ||
121 | struct QCryptoBlockLUKS { | |
122 | QCryptoBlockLUKSHeader header; | |
40c85028 | 123 | |
9d80e59d | 124 | /* Main encryption algorithm used for encryption*/ |
40c85028 | 125 | QCryptoCipherAlgorithm cipher_alg; |
9d80e59d ML |
126 | |
127 | /* Mode of encryption for the selected encryption algorithm */ | |
40c85028 | 128 | QCryptoCipherMode cipher_mode; |
9d80e59d ML |
129 | |
130 | /* Initialization vector generation algorithm */ | |
40c85028 | 131 | QCryptoIVGenAlgorithm ivgen_alg; |
9d80e59d ML |
132 | |
133 | /* Hash algorithm used for IV generation*/ | |
40c85028 | 134 | QCryptoHashAlgorithm ivgen_hash_alg; |
9d80e59d ML |
135 | |
136 | /* | |
137 | * Encryption algorithm used for IV generation. | |
138 | * Usually the same as main encryption algorithm | |
139 | */ | |
140 | QCryptoCipherAlgorithm ivgen_cipher_alg; | |
141 | ||
142 | /* Hash algorithm used in pbkdf2 function */ | |
40c85028 | 143 | QCryptoHashAlgorithm hash_alg; |
557d2bdc ML |
144 | |
145 | /* Name of the secret that was used to open the image */ | |
146 | char *secret; | |
3e308f20 DB |
147 | }; |
148 | ||
149 | ||
150 | static int qcrypto_block_luks_cipher_name_lookup(const char *name, | |
151 | QCryptoCipherMode mode, | |
152 | uint32_t key_bytes, | |
153 | Error **errp) | |
154 | { | |
155 | const QCryptoBlockLUKSCipherNameMap *map = | |
156 | qcrypto_block_luks_cipher_name_map; | |
157 | size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); | |
158 | size_t i, j; | |
159 | ||
160 | if (mode == QCRYPTO_CIPHER_MODE_XTS) { | |
161 | key_bytes /= 2; | |
162 | } | |
163 | ||
164 | for (i = 0; i < maplen; i++) { | |
165 | if (!g_str_equal(map[i].name, name)) { | |
166 | continue; | |
167 | } | |
168 | for (j = 0; j < map[i].sizes[j].key_bytes; j++) { | |
169 | if (map[i].sizes[j].key_bytes == key_bytes) { | |
170 | return map[i].sizes[j].id; | |
171 | } | |
172 | } | |
173 | } | |
174 | ||
6c198932 | 175 | error_setg(errp, "Algorithm '%s' with key size %d bytes not supported", |
3e308f20 DB |
176 | name, key_bytes); |
177 | return 0; | |
178 | } | |
179 | ||
180 | static const char * | |
181 | qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg, | |
182 | Error **errp) | |
183 | { | |
184 | const QCryptoBlockLUKSCipherNameMap *map = | |
185 | qcrypto_block_luks_cipher_name_map; | |
186 | size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); | |
187 | size_t i, j; | |
188 | for (i = 0; i < maplen; i++) { | |
189 | for (j = 0; j < map[i].sizes[j].key_bytes; j++) { | |
190 | if (map[i].sizes[j].id == alg) { | |
191 | return map[i].name; | |
192 | } | |
193 | } | |
194 | } | |
195 | ||
196 | error_setg(errp, "Algorithm '%s' not supported", | |
977c736f | 197 | QCryptoCipherAlgorithm_str(alg)); |
3e308f20 DB |
198 | return NULL; |
199 | } | |
200 | ||
201 | /* XXX replace with qapi_enum_parse() in future, when we can | |
202 | * make that function emit a more friendly error message */ | |
203 | static int qcrypto_block_luks_name_lookup(const char *name, | |
f7abe0ec | 204 | const QEnumLookup *map, |
3e308f20 DB |
205 | const char *type, |
206 | Error **errp) | |
207 | { | |
9ae33079 | 208 | int ret = qapi_enum_parse(map, name, -1, NULL); |
3e308f20 | 209 | |
9ae33079 | 210 | if (ret < 0) { |
6c198932 | 211 | error_setg(errp, "%s '%s' not supported", type, name); |
9ae33079 MA |
212 | return 0; |
213 | } | |
214 | return ret; | |
3e308f20 DB |
215 | } |
216 | ||
217 | #define qcrypto_block_luks_cipher_mode_lookup(name, errp) \ | |
218 | qcrypto_block_luks_name_lookup(name, \ | |
f7abe0ec | 219 | &QCryptoCipherMode_lookup, \ |
3e308f20 DB |
220 | "Cipher mode", \ |
221 | errp) | |
222 | ||
223 | #define qcrypto_block_luks_hash_name_lookup(name, errp) \ | |
224 | qcrypto_block_luks_name_lookup(name, \ | |
f7abe0ec | 225 | &QCryptoHashAlgorithm_lookup, \ |
3e308f20 DB |
226 | "Hash algorithm", \ |
227 | errp) | |
228 | ||
229 | #define qcrypto_block_luks_ivgen_name_lookup(name, errp) \ | |
230 | qcrypto_block_luks_name_lookup(name, \ | |
f7abe0ec | 231 | &QCryptoIVGenAlgorithm_lookup, \ |
3e308f20 DB |
232 | "IV generator", \ |
233 | errp) | |
234 | ||
235 | ||
236 | static bool | |
237 | qcrypto_block_luks_has_format(const uint8_t *buf, | |
238 | size_t buf_size) | |
239 | { | |
240 | const QCryptoBlockLUKSHeader *luks_header = (const void *)buf; | |
241 | ||
242 | if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) && | |
243 | memcmp(luks_header->magic, qcrypto_block_luks_magic, | |
244 | QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 && | |
245 | be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) { | |
246 | return true; | |
247 | } else { | |
248 | return false; | |
249 | } | |
250 | } | |
251 | ||
252 | ||
253 | /** | |
254 | * Deal with a quirk of dm-crypt usage of ESSIV. | |
255 | * | |
256 | * When calculating ESSIV IVs, the cipher length used by ESSIV | |
257 | * may be different from the cipher length used for the block | |
0a19d879 | 258 | * encryption, because dm-crypt uses the hash digest length |
3e308f20 DB |
259 | * as the key size. ie, if you have AES 128 as the block cipher |
260 | * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as | |
261 | * the cipher since that gets a key length matching the digest | |
262 | * size, not AES 128 with truncated digest as might be imagined | |
263 | */ | |
264 | static QCryptoCipherAlgorithm | |
265 | qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher, | |
266 | QCryptoHashAlgorithm hash, | |
267 | Error **errp) | |
268 | { | |
269 | size_t digestlen = qcrypto_hash_digest_len(hash); | |
270 | size_t keylen = qcrypto_cipher_get_key_len(cipher); | |
271 | if (digestlen == keylen) { | |
272 | return cipher; | |
273 | } | |
274 | ||
275 | switch (cipher) { | |
276 | case QCRYPTO_CIPHER_ALG_AES_128: | |
277 | case QCRYPTO_CIPHER_ALG_AES_192: | |
278 | case QCRYPTO_CIPHER_ALG_AES_256: | |
279 | if (digestlen == qcrypto_cipher_get_key_len( | |
280 | QCRYPTO_CIPHER_ALG_AES_128)) { | |
281 | return QCRYPTO_CIPHER_ALG_AES_128; | |
282 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
283 | QCRYPTO_CIPHER_ALG_AES_192)) { | |
284 | return QCRYPTO_CIPHER_ALG_AES_192; | |
285 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
286 | QCRYPTO_CIPHER_ALG_AES_256)) { | |
287 | return QCRYPTO_CIPHER_ALG_AES_256; | |
288 | } else { | |
289 | error_setg(errp, "No AES cipher with key size %zu available", | |
290 | digestlen); | |
291 | return 0; | |
292 | } | |
293 | break; | |
294 | case QCRYPTO_CIPHER_ALG_SERPENT_128: | |
295 | case QCRYPTO_CIPHER_ALG_SERPENT_192: | |
296 | case QCRYPTO_CIPHER_ALG_SERPENT_256: | |
297 | if (digestlen == qcrypto_cipher_get_key_len( | |
298 | QCRYPTO_CIPHER_ALG_SERPENT_128)) { | |
299 | return QCRYPTO_CIPHER_ALG_SERPENT_128; | |
300 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
301 | QCRYPTO_CIPHER_ALG_SERPENT_192)) { | |
302 | return QCRYPTO_CIPHER_ALG_SERPENT_192; | |
303 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
304 | QCRYPTO_CIPHER_ALG_SERPENT_256)) { | |
305 | return QCRYPTO_CIPHER_ALG_SERPENT_256; | |
306 | } else { | |
307 | error_setg(errp, "No Serpent cipher with key size %zu available", | |
308 | digestlen); | |
309 | return 0; | |
310 | } | |
311 | break; | |
312 | case QCRYPTO_CIPHER_ALG_TWOFISH_128: | |
313 | case QCRYPTO_CIPHER_ALG_TWOFISH_192: | |
314 | case QCRYPTO_CIPHER_ALG_TWOFISH_256: | |
315 | if (digestlen == qcrypto_cipher_get_key_len( | |
316 | QCRYPTO_CIPHER_ALG_TWOFISH_128)) { | |
317 | return QCRYPTO_CIPHER_ALG_TWOFISH_128; | |
318 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
319 | QCRYPTO_CIPHER_ALG_TWOFISH_192)) { | |
320 | return QCRYPTO_CIPHER_ALG_TWOFISH_192; | |
321 | } else if (digestlen == qcrypto_cipher_get_key_len( | |
322 | QCRYPTO_CIPHER_ALG_TWOFISH_256)) { | |
323 | return QCRYPTO_CIPHER_ALG_TWOFISH_256; | |
324 | } else { | |
325 | error_setg(errp, "No Twofish cipher with key size %zu available", | |
326 | digestlen); | |
327 | return 0; | |
328 | } | |
329 | break; | |
330 | default: | |
331 | error_setg(errp, "Cipher %s not supported with essiv", | |
977c736f | 332 | QCryptoCipherAlgorithm_str(cipher)); |
3e308f20 DB |
333 | return 0; |
334 | } | |
335 | } | |
336 | ||
bd56a55a ML |
337 | /* |
338 | * Returns number of sectors needed to store the key material | |
339 | * given number of anti forensic stripes | |
340 | */ | |
341 | static int | |
342 | qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks, | |
343 | unsigned int header_sectors, | |
344 | unsigned int stripes) | |
345 | { | |
346 | /* | |
347 | * This calculation doesn't match that shown in the spec, | |
348 | * but instead follows the cryptsetup implementation. | |
349 | */ | |
350 | ||
351 | size_t splitkeylen = luks->header.master_key_len * stripes; | |
352 | ||
353 | /* First align the key material size to block size*/ | |
354 | size_t splitkeylen_sectors = | |
355 | DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE); | |
356 | ||
357 | /* Then also align the key material size to the size of the header */ | |
358 | return ROUND_UP(splitkeylen_sectors, header_sectors); | |
359 | } | |
360 | ||
98c72dfb DB |
361 | |
362 | void | |
363 | qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr) | |
364 | { | |
365 | size_t i; | |
366 | ||
367 | /* | |
368 | * Everything on disk uses Big Endian (tm), so flip header fields | |
369 | * before writing them | |
370 | */ | |
371 | cpu_to_be16s(&hdr->version); | |
372 | cpu_to_be32s(&hdr->payload_offset_sector); | |
373 | cpu_to_be32s(&hdr->master_key_len); | |
374 | cpu_to_be32s(&hdr->master_key_iterations); | |
375 | ||
376 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
377 | cpu_to_be32s(&hdr->key_slots[i].active); | |
378 | cpu_to_be32s(&hdr->key_slots[i].iterations); | |
379 | cpu_to_be32s(&hdr->key_slots[i].key_offset_sector); | |
380 | cpu_to_be32s(&hdr->key_slots[i].stripes); | |
381 | } | |
382 | } | |
383 | ||
384 | void | |
385 | qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr) | |
386 | { | |
387 | size_t i; | |
388 | ||
389 | /* | |
390 | * The header is always stored in big-endian format, so | |
391 | * convert everything to native | |
392 | */ | |
393 | be16_to_cpus(&hdr->version); | |
394 | be32_to_cpus(&hdr->payload_offset_sector); | |
395 | be32_to_cpus(&hdr->master_key_len); | |
396 | be32_to_cpus(&hdr->master_key_iterations); | |
397 | ||
398 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
399 | be32_to_cpus(&hdr->key_slots[i].active); | |
400 | be32_to_cpus(&hdr->key_slots[i].iterations); | |
401 | be32_to_cpus(&hdr->key_slots[i].key_offset_sector); | |
402 | be32_to_cpus(&hdr->key_slots[i].stripes); | |
403 | } | |
404 | } | |
405 | ||
dde2c5af | 406 | /* |
0a19d879 | 407 | * Stores the main LUKS header, taking care of endianness |
dde2c5af ML |
408 | */ |
409 | static int | |
410 | qcrypto_block_luks_store_header(QCryptoBlock *block, | |
411 | QCryptoBlockWriteFunc writefunc, | |
412 | void *opaque, | |
413 | Error **errp) | |
414 | { | |
415 | const QCryptoBlockLUKS *luks = block->opaque; | |
416 | Error *local_err = NULL; | |
dde2c5af ML |
417 | g_autofree QCryptoBlockLUKSHeader *hdr_copy = NULL; |
418 | ||
419 | /* Create a copy of the header */ | |
420 | hdr_copy = g_new0(QCryptoBlockLUKSHeader, 1); | |
421 | memcpy(hdr_copy, &luks->header, sizeof(QCryptoBlockLUKSHeader)); | |
422 | ||
98c72dfb | 423 | qcrypto_block_luks_to_disk_endian(hdr_copy); |
dde2c5af ML |
424 | |
425 | /* Write out the partition header and key slot headers */ | |
426 | writefunc(block, 0, (const uint8_t *)hdr_copy, sizeof(*hdr_copy), | |
427 | opaque, &local_err); | |
428 | ||
429 | if (local_err) { | |
430 | error_propagate(errp, local_err); | |
431 | return -1; | |
432 | } | |
433 | return 0; | |
434 | } | |
435 | ||
436 | /* | |
0a19d879 | 437 | * Loads the main LUKS header, and byteswaps it to native endianness |
dde2c5af ML |
438 | * And run basic sanity checks on it |
439 | */ | |
440 | static int | |
441 | qcrypto_block_luks_load_header(QCryptoBlock *block, | |
442 | QCryptoBlockReadFunc readfunc, | |
443 | void *opaque, | |
444 | Error **errp) | |
445 | { | |
757dda54 | 446 | int rv; |
dde2c5af ML |
447 | QCryptoBlockLUKS *luks = block->opaque; |
448 | ||
449 | /* | |
450 | * Read the entire LUKS header, minus the key material from | |
451 | * the underlying device | |
452 | */ | |
453 | rv = readfunc(block, 0, | |
454 | (uint8_t *)&luks->header, | |
455 | sizeof(luks->header), | |
456 | opaque, | |
457 | errp); | |
458 | if (rv < 0) { | |
459 | return rv; | |
460 | } | |
461 | ||
98c72dfb | 462 | qcrypto_block_luks_from_disk_endian(&luks->header); |
dde2c5af ML |
463 | |
464 | return 0; | |
465 | } | |
466 | ||
9fa9c1c2 ML |
467 | /* |
468 | * Does basic sanity checks on the LUKS header | |
469 | */ | |
470 | static int | |
471 | qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp) | |
472 | { | |
befdba9e ML |
473 | size_t i, j; |
474 | ||
475 | unsigned int header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / | |
476 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; | |
477 | ||
9fa9c1c2 ML |
478 | if (memcmp(luks->header.magic, qcrypto_block_luks_magic, |
479 | QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { | |
480 | error_setg(errp, "Volume is not in LUKS format"); | |
481 | return -1; | |
482 | } | |
483 | ||
484 | if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { | |
485 | error_setg(errp, "LUKS version %" PRIu32 " is not supported", | |
486 | luks->header.version); | |
487 | return -1; | |
488 | } | |
befdba9e | 489 | |
c1d8634c DB |
490 | if (!memchr(luks->header.cipher_name, '\0', |
491 | sizeof(luks->header.cipher_name))) { | |
492 | error_setg(errp, "LUKS header cipher name is not NUL terminated"); | |
493 | return -1; | |
494 | } | |
495 | ||
496 | if (!memchr(luks->header.cipher_mode, '\0', | |
497 | sizeof(luks->header.cipher_mode))) { | |
498 | error_setg(errp, "LUKS header cipher mode is not NUL terminated"); | |
499 | return -1; | |
500 | } | |
501 | ||
502 | if (!memchr(luks->header.hash_spec, '\0', | |
503 | sizeof(luks->header.hash_spec))) { | |
504 | error_setg(errp, "LUKS header hash spec is not NUL terminated"); | |
505 | return -1; | |
506 | } | |
507 | ||
d233fbc3 DB |
508 | if (luks->header.payload_offset_sector < |
509 | DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET, | |
510 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) { | |
511 | error_setg(errp, "LUKS payload is overlapping with the header"); | |
512 | return -1; | |
513 | } | |
514 | ||
b57151ac DB |
515 | if (luks->header.master_key_iterations == 0) { |
516 | error_setg(errp, "LUKS key iteration count is zero"); | |
517 | return -1; | |
518 | } | |
519 | ||
befdba9e ML |
520 | /* Check all keyslots for corruption */ |
521 | for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; i++) { | |
522 | ||
523 | const QCryptoBlockLUKSKeySlot *slot1 = &luks->header.key_slots[i]; | |
524 | unsigned int start1 = slot1->key_offset_sector; | |
525 | unsigned int len1 = | |
526 | qcrypto_block_luks_splitkeylen_sectors(luks, | |
527 | header_sectors, | |
528 | slot1->stripes); | |
529 | ||
f1195961 DB |
530 | if (slot1->stripes != QCRYPTO_BLOCK_LUKS_STRIPES) { |
531 | error_setg(errp, "Keyslot %zu is corrupted (stripes %d != %d)", | |
532 | i, slot1->stripes, QCRYPTO_BLOCK_LUKS_STRIPES); | |
befdba9e ML |
533 | return -1; |
534 | } | |
535 | ||
536 | if (slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED && | |
537 | slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { | |
538 | error_setg(errp, | |
539 | "Keyslot %zu state (active/disable) is corrupted", i); | |
540 | return -1; | |
541 | } | |
542 | ||
b57151ac DB |
543 | if (slot1->active == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED && |
544 | slot1->iterations == 0) { | |
545 | error_setg(errp, "Keyslot %zu iteration count is zero", i); | |
546 | return -1; | |
547 | } | |
548 | ||
c5f69628 | 549 | if (start1 < DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET, |
93569c37 DB |
550 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) { |
551 | error_setg(errp, | |
552 | "Keyslot %zu is overlapping with the LUKS header", | |
553 | i); | |
554 | return -1; | |
555 | } | |
556 | ||
befdba9e ML |
557 | if (start1 + len1 > luks->header.payload_offset_sector) { |
558 | error_setg(errp, | |
559 | "Keyslot %zu is overlapping with the encrypted payload", | |
560 | i); | |
561 | return -1; | |
562 | } | |
563 | ||
564 | for (j = i + 1 ; j < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; j++) { | |
565 | const QCryptoBlockLUKSKeySlot *slot2 = &luks->header.key_slots[j]; | |
566 | unsigned int start2 = slot2->key_offset_sector; | |
567 | unsigned int len2 = | |
568 | qcrypto_block_luks_splitkeylen_sectors(luks, | |
569 | header_sectors, | |
570 | slot2->stripes); | |
571 | ||
572 | if (start1 + len1 > start2 && start2 + len2 > start1) { | |
573 | error_setg(errp, | |
574 | "Keyslots %zu and %zu are overlapping in the header", | |
575 | i, j); | |
576 | return -1; | |
577 | } | |
578 | } | |
579 | ||
580 | } | |
9fa9c1c2 ML |
581 | return 0; |
582 | } | |
583 | ||
584 | /* | |
585 | * Parses the crypto parameters that are stored in the LUKS header | |
586 | */ | |
587 | ||
588 | static int | |
589 | qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp) | |
590 | { | |
591 | g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode); | |
592 | char *ivgen_name, *ivhash_name; | |
593 | Error *local_err = NULL; | |
594 | ||
595 | /* | |
596 | * The cipher_mode header contains a string that we have | |
597 | * to further parse, of the format | |
598 | * | |
599 | * <cipher-mode>-<iv-generator>[:<iv-hash>] | |
600 | * | |
601 | * eg cbc-essiv:sha256, cbc-plain64 | |
602 | */ | |
603 | ivgen_name = strchr(cipher_mode, '-'); | |
604 | if (!ivgen_name) { | |
6c198932 | 605 | error_setg(errp, "Unexpected cipher mode string format '%s'", |
9fa9c1c2 ML |
606 | luks->header.cipher_mode); |
607 | return -1; | |
608 | } | |
609 | *ivgen_name = '\0'; | |
610 | ivgen_name++; | |
611 | ||
612 | ivhash_name = strchr(ivgen_name, ':'); | |
613 | if (!ivhash_name) { | |
614 | luks->ivgen_hash_alg = 0; | |
615 | } else { | |
616 | *ivhash_name = '\0'; | |
617 | ivhash_name++; | |
618 | ||
619 | luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name, | |
620 | &local_err); | |
621 | if (local_err) { | |
622 | error_propagate(errp, local_err); | |
623 | return -1; | |
624 | } | |
625 | } | |
626 | ||
627 | luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode, | |
628 | &local_err); | |
629 | if (local_err) { | |
630 | error_propagate(errp, local_err); | |
631 | return -1; | |
632 | } | |
633 | ||
634 | luks->cipher_alg = | |
635 | qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, | |
636 | luks->cipher_mode, | |
637 | luks->header.master_key_len, | |
638 | &local_err); | |
639 | if (local_err) { | |
640 | error_propagate(errp, local_err); | |
641 | return -1; | |
642 | } | |
643 | ||
644 | luks->hash_alg = | |
645 | qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, | |
646 | &local_err); | |
647 | if (local_err) { | |
648 | error_propagate(errp, local_err); | |
649 | return -1; | |
650 | } | |
651 | ||
652 | luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, | |
653 | &local_err); | |
654 | if (local_err) { | |
655 | error_propagate(errp, local_err); | |
656 | return -1; | |
657 | } | |
658 | ||
659 | if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { | |
660 | if (!ivhash_name) { | |
661 | error_setg(errp, "Missing IV generator hash specification"); | |
662 | return -1; | |
663 | } | |
664 | luks->ivgen_cipher_alg = | |
665 | qcrypto_block_luks_essiv_cipher(luks->cipher_alg, | |
666 | luks->ivgen_hash_alg, | |
667 | &local_err); | |
668 | if (local_err) { | |
669 | error_propagate(errp, local_err); | |
670 | return -1; | |
671 | } | |
672 | } else { | |
673 | ||
674 | /* | |
675 | * Note we parsed the ivhash_name earlier in the cipher_mode | |
676 | * spec string even with plain/plain64 ivgens, but we | |
677 | * will ignore it, since it is irrelevant for these ivgens. | |
678 | * This is for compat with dm-crypt which will silently | |
679 | * ignore hash names with these ivgens rather than report | |
680 | * an error about the invalid usage | |
681 | */ | |
682 | luks->ivgen_cipher_alg = luks->cipher_alg; | |
683 | } | |
684 | return 0; | |
685 | } | |
686 | ||
3994a7c9 ML |
687 | /* |
688 | * Given a key slot, user password, and the master key, | |
689 | * will store the encrypted master key there, and update the | |
690 | * in-memory header. User must then write the in-memory header | |
691 | * | |
692 | * Returns: | |
693 | * 0 if the keyslot was written successfully | |
694 | * with the provided password | |
695 | * -1 if a fatal error occurred while storing the key | |
696 | */ | |
697 | static int | |
698 | qcrypto_block_luks_store_key(QCryptoBlock *block, | |
699 | unsigned int slot_idx, | |
700 | const char *password, | |
701 | uint8_t *masterkey, | |
702 | uint64_t iter_time, | |
703 | QCryptoBlockWriteFunc writefunc, | |
704 | void *opaque, | |
705 | Error **errp) | |
706 | { | |
707 | QCryptoBlockLUKS *luks = block->opaque; | |
557d2bdc | 708 | QCryptoBlockLUKSKeySlot *slot; |
3994a7c9 ML |
709 | g_autofree uint8_t *splitkey = NULL; |
710 | size_t splitkeylen; | |
711 | g_autofree uint8_t *slotkey = NULL; | |
712 | g_autoptr(QCryptoCipher) cipher = NULL; | |
713 | g_autoptr(QCryptoIVGen) ivgen = NULL; | |
714 | Error *local_err = NULL; | |
715 | uint64_t iters; | |
716 | int ret = -1; | |
717 | ||
557d2bdc ML |
718 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); |
719 | slot = &luks->header.key_slots[slot_idx]; | |
55a01cab AO |
720 | splitkeylen = luks->header.master_key_len * slot->stripes; |
721 | ||
3994a7c9 ML |
722 | if (qcrypto_random_bytes(slot->salt, |
723 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
724 | errp) < 0) { | |
725 | goto cleanup; | |
726 | } | |
727 | ||
3994a7c9 ML |
728 | /* |
729 | * Determine how many iterations are required to | |
730 | * hash the user password while consuming 1 second of compute | |
731 | * time | |
732 | */ | |
733 | iters = qcrypto_pbkdf2_count_iters(luks->hash_alg, | |
734 | (uint8_t *)password, strlen(password), | |
735 | slot->salt, | |
736 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
737 | luks->header.master_key_len, | |
738 | &local_err); | |
739 | if (local_err) { | |
740 | error_propagate(errp, local_err); | |
741 | goto cleanup; | |
742 | } | |
743 | ||
744 | if (iters > (ULLONG_MAX / iter_time)) { | |
745 | error_setg_errno(errp, ERANGE, | |
746 | "PBKDF iterations %llu too large to scale", | |
747 | (unsigned long long)iters); | |
748 | goto cleanup; | |
749 | } | |
750 | ||
751 | /* iter_time was in millis, but count_iters reported for secs */ | |
752 | iters = iters * iter_time / 1000; | |
753 | ||
754 | if (iters > UINT32_MAX) { | |
755 | error_setg_errno(errp, ERANGE, | |
756 | "PBKDF iterations %llu larger than %u", | |
757 | (unsigned long long)iters, UINT32_MAX); | |
758 | goto cleanup; | |
759 | } | |
760 | ||
761 | slot->iterations = | |
762 | MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); | |
763 | ||
764 | ||
765 | /* | |
766 | * Generate a key that we'll use to encrypt the master | |
767 | * key, from the user's password | |
768 | */ | |
769 | slotkey = g_new0(uint8_t, luks->header.master_key_len); | |
770 | if (qcrypto_pbkdf2(luks->hash_alg, | |
771 | (uint8_t *)password, strlen(password), | |
772 | slot->salt, | |
773 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
774 | slot->iterations, | |
775 | slotkey, luks->header.master_key_len, | |
776 | errp) < 0) { | |
777 | goto cleanup; | |
778 | } | |
779 | ||
780 | ||
781 | /* | |
782 | * Setup the encryption objects needed to encrypt the | |
783 | * master key material | |
784 | */ | |
785 | cipher = qcrypto_cipher_new(luks->cipher_alg, | |
786 | luks->cipher_mode, | |
787 | slotkey, luks->header.master_key_len, | |
788 | errp); | |
789 | if (!cipher) { | |
790 | goto cleanup; | |
791 | } | |
792 | ||
793 | ivgen = qcrypto_ivgen_new(luks->ivgen_alg, | |
794 | luks->ivgen_cipher_alg, | |
795 | luks->ivgen_hash_alg, | |
796 | slotkey, luks->header.master_key_len, | |
797 | errp); | |
798 | if (!ivgen) { | |
799 | goto cleanup; | |
800 | } | |
801 | ||
802 | /* | |
803 | * Before storing the master key, we need to vastly | |
804 | * increase its size, as protection against forensic | |
805 | * disk data recovery | |
806 | */ | |
807 | splitkey = g_new0(uint8_t, splitkeylen); | |
808 | ||
809 | if (qcrypto_afsplit_encode(luks->hash_alg, | |
810 | luks->header.master_key_len, | |
811 | slot->stripes, | |
812 | masterkey, | |
813 | splitkey, | |
814 | errp) < 0) { | |
815 | goto cleanup; | |
816 | } | |
817 | ||
818 | /* | |
819 | * Now we encrypt the split master key with the key generated | |
820 | * from the user's password, before storing it | |
821 | */ | |
822 | if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen, | |
823 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
824 | 0, | |
825 | splitkey, | |
826 | splitkeylen, | |
827 | errp) < 0) { | |
828 | goto cleanup; | |
829 | } | |
830 | ||
831 | /* Write out the slot's master key material. */ | |
832 | if (writefunc(block, | |
833 | slot->key_offset_sector * | |
834 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
835 | splitkey, splitkeylen, | |
836 | opaque, | |
757dda54 | 837 | errp) < 0) { |
3994a7c9 ML |
838 | goto cleanup; |
839 | } | |
840 | ||
841 | slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; | |
842 | ||
843 | if (qcrypto_block_luks_store_header(block, writefunc, opaque, errp) < 0) { | |
844 | goto cleanup; | |
845 | } | |
846 | ||
847 | ret = 0; | |
848 | ||
849 | cleanup: | |
850 | if (slotkey) { | |
851 | memset(slotkey, 0, luks->header.master_key_len); | |
852 | } | |
853 | if (splitkey) { | |
854 | memset(splitkey, 0, splitkeylen); | |
855 | } | |
856 | return ret; | |
857 | } | |
858 | ||
3e308f20 DB |
859 | /* |
860 | * Given a key slot, and user password, this will attempt to unlock | |
861 | * the master encryption key from the key slot. | |
862 | * | |
863 | * Returns: | |
864 | * 0 if the key slot is disabled, or key could not be decrypted | |
865 | * with the provided password | |
866 | * 1 if the key slot is enabled, and key decrypted successfully | |
867 | * with the provided password | |
868 | * -1 if a fatal error occurred loading the key | |
869 | */ | |
870 | static int | |
871 | qcrypto_block_luks_load_key(QCryptoBlock *block, | |
7e60a6f5 | 872 | size_t slot_idx, |
3e308f20 | 873 | const char *password, |
3e308f20 | 874 | uint8_t *masterkey, |
3e308f20 DB |
875 | QCryptoBlockReadFunc readfunc, |
876 | void *opaque, | |
877 | Error **errp) | |
878 | { | |
879 | QCryptoBlockLUKS *luks = block->opaque; | |
557d2bdc | 880 | const QCryptoBlockLUKSKeySlot *slot; |
57b9f113 | 881 | g_autofree uint8_t *splitkey = NULL; |
3e308f20 | 882 | size_t splitkeylen; |
57b9f113 | 883 | g_autofree uint8_t *possiblekey = NULL; |
757dda54 | 884 | int rv; |
57b9f113 | 885 | g_autoptr(QCryptoCipher) cipher = NULL; |
3e308f20 | 886 | uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; |
57b9f113 | 887 | g_autoptr(QCryptoIVGen) ivgen = NULL; |
3e308f20 DB |
888 | size_t niv; |
889 | ||
557d2bdc ML |
890 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); |
891 | slot = &luks->header.key_slots[slot_idx]; | |
3e308f20 DB |
892 | if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { |
893 | return 0; | |
894 | } | |
895 | ||
1ddd52e4 | 896 | splitkeylen = luks->header.master_key_len * slot->stripes; |
3e308f20 | 897 | splitkey = g_new0(uint8_t, splitkeylen); |
1ddd52e4 | 898 | possiblekey = g_new0(uint8_t, luks->header.master_key_len); |
3e308f20 DB |
899 | |
900 | /* | |
901 | * The user password is used to generate a (possible) | |
902 | * decryption key. This may or may not successfully | |
903 | * decrypt the master key - we just blindly assume | |
904 | * the key is correct and validate the results of | |
905 | * decryption later. | |
906 | */ | |
9d80e59d | 907 | if (qcrypto_pbkdf2(luks->hash_alg, |
3e308f20 DB |
908 | (const uint8_t *)password, strlen(password), |
909 | slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
910 | slot->iterations, | |
1ddd52e4 | 911 | possiblekey, luks->header.master_key_len, |
3e308f20 | 912 | errp) < 0) { |
57b9f113 | 913 | return -1; |
3e308f20 DB |
914 | } |
915 | ||
916 | /* | |
917 | * We need to read the master key material from the | |
918 | * LUKS key material header. What we're reading is | |
919 | * not the raw master key, but rather the data after | |
920 | * it has been passed through AFSplit and the result | |
921 | * then encrypted. | |
922 | */ | |
923 | rv = readfunc(block, | |
f0d3c362 | 924 | slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, |
3e308f20 | 925 | splitkey, splitkeylen, |
e4a3507e | 926 | opaque, |
37509233 | 927 | errp); |
3e308f20 | 928 | if (rv < 0) { |
57b9f113 | 929 | return -1; |
3e308f20 DB |
930 | } |
931 | ||
932 | ||
933 | /* Setup the cipher/ivgen that we'll use to try to decrypt | |
934 | * the split master key material */ | |
9d80e59d ML |
935 | cipher = qcrypto_cipher_new(luks->cipher_alg, |
936 | luks->cipher_mode, | |
937 | possiblekey, | |
938 | luks->header.master_key_len, | |
3e308f20 DB |
939 | errp); |
940 | if (!cipher) { | |
57b9f113 | 941 | return -1; |
3e308f20 DB |
942 | } |
943 | ||
9d80e59d ML |
944 | niv = qcrypto_cipher_get_iv_len(luks->cipher_alg, |
945 | luks->cipher_mode); | |
946 | ||
947 | ivgen = qcrypto_ivgen_new(luks->ivgen_alg, | |
948 | luks->ivgen_cipher_alg, | |
949 | luks->ivgen_hash_alg, | |
950 | possiblekey, | |
951 | luks->header.master_key_len, | |
3e308f20 DB |
952 | errp); |
953 | if (!ivgen) { | |
57b9f113 | 954 | return -1; |
3e308f20 DB |
955 | } |
956 | ||
957 | ||
958 | /* | |
959 | * The master key needs to be decrypted in the same | |
960 | * way that the block device payload will be decrypted | |
961 | * later. In particular we'll be using the IV generator | |
962 | * to reset the encryption cipher every time the master | |
963 | * key crosses a sector boundary. | |
964 | */ | |
0270417c VSO |
965 | if (qcrypto_block_cipher_decrypt_helper(cipher, |
966 | niv, | |
967 | ivgen, | |
968 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
969 | 0, | |
970 | splitkey, | |
971 | splitkeylen, | |
972 | errp) < 0) { | |
57b9f113 | 973 | return -1; |
3e308f20 DB |
974 | } |
975 | ||
976 | /* | |
977 | * Now we've decrypted the split master key, join | |
978 | * it back together to get the actual master key. | |
979 | */ | |
9d80e59d | 980 | if (qcrypto_afsplit_decode(luks->hash_alg, |
1ddd52e4 | 981 | luks->header.master_key_len, |
3e308f20 DB |
982 | slot->stripes, |
983 | splitkey, | |
984 | masterkey, | |
985 | errp) < 0) { | |
57b9f113 | 986 | return -1; |
3e308f20 DB |
987 | } |
988 | ||
989 | ||
990 | /* | |
991 | * We still don't know that the masterkey we got is valid, | |
992 | * because we just blindly assumed the user's password | |
993 | * was correct. This is where we now verify it. We are | |
994 | * creating a hash of the master key using PBKDF and | |
995 | * then comparing that to the hash stored in the key slot | |
996 | * header | |
997 | */ | |
9d80e59d | 998 | if (qcrypto_pbkdf2(luks->hash_alg, |
1ddd52e4 ML |
999 | masterkey, |
1000 | luks->header.master_key_len, | |
3e308f20 DB |
1001 | luks->header.master_key_salt, |
1002 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
1003 | luks->header.master_key_iterations, | |
1ddd52e4 ML |
1004 | keydigest, |
1005 | G_N_ELEMENTS(keydigest), | |
3e308f20 | 1006 | errp) < 0) { |
57b9f113 | 1007 | return -1; |
3e308f20 DB |
1008 | } |
1009 | ||
1010 | if (memcmp(keydigest, luks->header.master_key_digest, | |
1011 | QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) { | |
1012 | /* Success, we got the right master key */ | |
57b9f113 | 1013 | return 1; |
3e308f20 DB |
1014 | } |
1015 | ||
1016 | /* Fail, user's password was not valid for this key slot, | |
1017 | * tell caller to try another slot */ | |
57b9f113 | 1018 | return 0; |
3e308f20 DB |
1019 | } |
1020 | ||
1021 | ||
1022 | /* | |
1023 | * Given a user password, this will iterate over all key | |
1024 | * slots and try to unlock each active key slot using the | |
1025 | * password until it successfully obtains a master key. | |
1026 | * | |
1027 | * Returns 0 if a key was loaded, -1 if no keys could be loaded | |
1028 | */ | |
1029 | static int | |
1030 | qcrypto_block_luks_find_key(QCryptoBlock *block, | |
1031 | const char *password, | |
1ddd52e4 | 1032 | uint8_t *masterkey, |
3e308f20 DB |
1033 | QCryptoBlockReadFunc readfunc, |
1034 | void *opaque, | |
1035 | Error **errp) | |
1036 | { | |
3e308f20 DB |
1037 | size_t i; |
1038 | int rv; | |
1039 | ||
3e308f20 DB |
1040 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { |
1041 | rv = qcrypto_block_luks_load_key(block, | |
7e60a6f5 | 1042 | i, |
3e308f20 | 1043 | password, |
1ddd52e4 | 1044 | masterkey, |
3e308f20 DB |
1045 | readfunc, |
1046 | opaque, | |
1047 | errp); | |
1048 | if (rv < 0) { | |
1049 | goto error; | |
1050 | } | |
1051 | if (rv == 1) { | |
1052 | return 0; | |
1053 | } | |
1054 | } | |
1055 | ||
1056 | error_setg(errp, "Invalid password, cannot unlock any keyslot"); | |
3e308f20 | 1057 | error: |
3e308f20 DB |
1058 | return -1; |
1059 | } | |
1060 | ||
557d2bdc ML |
1061 | /* |
1062 | * Returns true if a slot i is marked as active | |
1063 | * (contains encrypted copy of the master key) | |
1064 | */ | |
1065 | static bool | |
1066 | qcrypto_block_luks_slot_active(const QCryptoBlockLUKS *luks, | |
1067 | unsigned int slot_idx) | |
1068 | { | |
1069 | uint32_t val; | |
1070 | ||
1071 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); | |
1072 | val = luks->header.key_slots[slot_idx].active; | |
1073 | return val == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * Returns the number of slots that are marked as active | |
1078 | * (slots that contain encrypted copy of the master key) | |
1079 | */ | |
1080 | static unsigned int | |
1081 | qcrypto_block_luks_count_active_slots(const QCryptoBlockLUKS *luks) | |
1082 | { | |
1083 | size_t i = 0; | |
1084 | unsigned int ret = 0; | |
1085 | ||
1086 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1087 | if (qcrypto_block_luks_slot_active(luks, i)) { | |
1088 | ret++; | |
1089 | } | |
1090 | } | |
1091 | return ret; | |
1092 | } | |
1093 | ||
1094 | /* | |
1095 | * Finds first key slot which is not active | |
1096 | * Returns the key slot index, or -1 if it doesn't exist | |
1097 | */ | |
1098 | static int | |
1099 | qcrypto_block_luks_find_free_keyslot(const QCryptoBlockLUKS *luks) | |
1100 | { | |
1101 | size_t i; | |
1102 | ||
1103 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1104 | if (!qcrypto_block_luks_slot_active(luks, i)) { | |
1105 | return i; | |
1106 | } | |
1107 | } | |
1108 | return -1; | |
1109 | } | |
1110 | ||
1111 | /* | |
1112 | * Erases an keyslot given its index | |
1113 | * Returns: | |
1114 | * 0 if the keyslot was erased successfully | |
1115 | * -1 if a error occurred while erasing the keyslot | |
1116 | * | |
1117 | */ | |
1118 | static int | |
1119 | qcrypto_block_luks_erase_key(QCryptoBlock *block, | |
1120 | unsigned int slot_idx, | |
1121 | QCryptoBlockWriteFunc writefunc, | |
1122 | void *opaque, | |
1123 | Error **errp) | |
1124 | { | |
1125 | QCryptoBlockLUKS *luks = block->opaque; | |
1126 | QCryptoBlockLUKSKeySlot *slot; | |
1127 | g_autofree uint8_t *garbagesplitkey = NULL; | |
1128 | size_t splitkeylen; | |
1129 | size_t i; | |
1130 | Error *local_err = NULL; | |
1131 | int ret; | |
1132 | ||
1133 | assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); | |
1134 | slot = &luks->header.key_slots[slot_idx]; | |
1135 | ||
1136 | splitkeylen = luks->header.master_key_len * slot->stripes; | |
1137 | assert(splitkeylen > 0); | |
1138 | ||
1139 | garbagesplitkey = g_new0(uint8_t, splitkeylen); | |
1140 | ||
1141 | /* Reset the key slot header */ | |
1142 | memset(slot->salt, 0, QCRYPTO_BLOCK_LUKS_SALT_LEN); | |
1143 | slot->iterations = 0; | |
1144 | slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; | |
1145 | ||
1146 | ret = qcrypto_block_luks_store_header(block, writefunc, | |
1147 | opaque, &local_err); | |
1148 | ||
1149 | if (ret < 0) { | |
1150 | error_propagate(errp, local_err); | |
1151 | } | |
1152 | /* | |
1153 | * Now try to erase the key material, even if the header | |
1154 | * update failed | |
1155 | */ | |
1156 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS; i++) { | |
1157 | if (qcrypto_random_bytes(garbagesplitkey, | |
1158 | splitkeylen, &local_err) < 0) { | |
1159 | /* | |
1160 | * If we failed to get the random data, still write | |
1161 | * at least zeros to the key slot at least once | |
1162 | */ | |
1163 | error_propagate(errp, local_err); | |
1164 | ||
1165 | if (i > 0) { | |
1166 | return -1; | |
1167 | } | |
1168 | } | |
1169 | if (writefunc(block, | |
1170 | slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
1171 | garbagesplitkey, | |
1172 | splitkeylen, | |
1173 | opaque, | |
757dda54 | 1174 | &local_err) < 0) { |
557d2bdc ML |
1175 | error_propagate(errp, local_err); |
1176 | return -1; | |
1177 | } | |
1178 | } | |
1179 | return ret; | |
1180 | } | |
3e308f20 DB |
1181 | |
1182 | static int | |
1183 | qcrypto_block_luks_open(QCryptoBlock *block, | |
1184 | QCryptoBlockOpenOptions *options, | |
1cd9a787 | 1185 | const char *optprefix, |
3e308f20 DB |
1186 | QCryptoBlockReadFunc readfunc, |
1187 | void *opaque, | |
1188 | unsigned int flags, | |
c972fa12 | 1189 | size_t n_threads, |
3e308f20 DB |
1190 | Error **errp) |
1191 | { | |
9d80e59d | 1192 | QCryptoBlockLUKS *luks = NULL; |
57b9f113 | 1193 | g_autofree uint8_t *masterkey = NULL; |
57b9f113 | 1194 | g_autofree char *password = NULL; |
3e308f20 DB |
1195 | |
1196 | if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { | |
1197 | if (!options->u.luks.key_secret) { | |
1cd9a787 DB |
1198 | error_setg(errp, "Parameter '%skey-secret' is required for cipher", |
1199 | optprefix ? optprefix : ""); | |
3e308f20 DB |
1200 | return -1; |
1201 | } | |
1202 | password = qcrypto_secret_lookup_as_utf8( | |
1203 | options->u.luks.key_secret, errp); | |
1204 | if (!password) { | |
1205 | return -1; | |
1206 | } | |
1207 | } | |
1208 | ||
1209 | luks = g_new0(QCryptoBlockLUKS, 1); | |
1210 | block->opaque = luks; | |
557d2bdc | 1211 | luks->secret = g_strdup(options->u.luks.key_secret); |
3e308f20 | 1212 | |
dde2c5af | 1213 | if (qcrypto_block_luks_load_header(block, readfunc, opaque, errp) < 0) { |
3e308f20 DB |
1214 | goto fail; |
1215 | } | |
1216 | ||
9fa9c1c2 | 1217 | if (qcrypto_block_luks_check_header(luks, errp) < 0) { |
3e308f20 DB |
1218 | goto fail; |
1219 | } | |
1220 | ||
9fa9c1c2 | 1221 | if (qcrypto_block_luks_parse_header(luks, errp) < 0) { |
3e308f20 DB |
1222 | goto fail; |
1223 | } | |
3e308f20 DB |
1224 | |
1225 | if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { | |
1226 | /* Try to find which key slot our password is valid for | |
1227 | * and unlock the master key from that slot. | |
1228 | */ | |
1ddd52e4 ML |
1229 | |
1230 | masterkey = g_new0(uint8_t, luks->header.master_key_len); | |
1231 | ||
3e308f20 DB |
1232 | if (qcrypto_block_luks_find_key(block, |
1233 | password, | |
1ddd52e4 | 1234 | masterkey, |
3e308f20 DB |
1235 | readfunc, opaque, |
1236 | errp) < 0) { | |
3e308f20 DB |
1237 | goto fail; |
1238 | } | |
1239 | ||
1240 | /* We have a valid master key now, so can setup the | |
1241 | * block device payload decryption objects | |
1242 | */ | |
9d80e59d ML |
1243 | block->kdfhash = luks->hash_alg; |
1244 | block->niv = qcrypto_cipher_get_iv_len(luks->cipher_alg, | |
1245 | luks->cipher_mode); | |
1246 | ||
1247 | block->ivgen = qcrypto_ivgen_new(luks->ivgen_alg, | |
1248 | luks->ivgen_cipher_alg, | |
1249 | luks->ivgen_hash_alg, | |
1ddd52e4 ML |
1250 | masterkey, |
1251 | luks->header.master_key_len, | |
3e308f20 DB |
1252 | errp); |
1253 | if (!block->ivgen) { | |
3e308f20 DB |
1254 | goto fail; |
1255 | } | |
1256 | ||
61dd8a9a ML |
1257 | if (qcrypto_block_init_cipher(block, |
1258 | luks->cipher_alg, | |
1259 | luks->cipher_mode, | |
1260 | masterkey, | |
1261 | luks->header.master_key_len, | |
1262 | n_threads, | |
1263 | errp) < 0) { | |
3e308f20 DB |
1264 | goto fail; |
1265 | } | |
1266 | } | |
1267 | ||
850f49de | 1268 | block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; |
f0d3c362 | 1269 | block->payload_offset = luks->header.payload_offset_sector * |
850f49de | 1270 | block->sector_size; |
3e308f20 | 1271 | |
3e308f20 DB |
1272 | return 0; |
1273 | ||
1274 | fail: | |
c972fa12 | 1275 | qcrypto_block_free_cipher(block); |
3e308f20 | 1276 | qcrypto_ivgen_free(block->ivgen); |
557d2bdc | 1277 | g_free(luks->secret); |
3e308f20 | 1278 | g_free(luks); |
61dd8a9a | 1279 | return -1; |
3e308f20 DB |
1280 | } |
1281 | ||
1282 | ||
2ef950f9 FZ |
1283 | static void |
1284 | qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) | |
3e308f20 | 1285 | { |
2ef950f9 FZ |
1286 | QemuUUID uuid; |
1287 | qemu_uuid_generate(&uuid); | |
1288 | qemu_uuid_unparse(&uuid, (char *)uuidstr); | |
3e308f20 DB |
1289 | } |
1290 | ||
1291 | static int | |
1292 | qcrypto_block_luks_create(QCryptoBlock *block, | |
1293 | QCryptoBlockCreateOptions *options, | |
1cd9a787 | 1294 | const char *optprefix, |
3e308f20 DB |
1295 | QCryptoBlockInitFunc initfunc, |
1296 | QCryptoBlockWriteFunc writefunc, | |
1297 | void *opaque, | |
1298 | Error **errp) | |
1299 | { | |
1300 | QCryptoBlockLUKS *luks; | |
1301 | QCryptoBlockCreateOptionsLUKS luks_opts; | |
1302 | Error *local_err = NULL; | |
57b9f113 | 1303 | g_autofree uint8_t *masterkey = NULL; |
bd56a55a ML |
1304 | size_t header_sectors; |
1305 | size_t split_key_sectors; | |
3e308f20 | 1306 | size_t i; |
57b9f113 | 1307 | g_autofree char *password = NULL; |
3e308f20 DB |
1308 | const char *cipher_alg; |
1309 | const char *cipher_mode; | |
1310 | const char *ivgen_alg; | |
1311 | const char *ivgen_hash_alg = NULL; | |
1312 | const char *hash_alg; | |
57b9f113 | 1313 | g_autofree char *cipher_mode_spec = NULL; |
59b060be | 1314 | uint64_t iters; |
3e308f20 DB |
1315 | |
1316 | memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); | |
3bd18890 | 1317 | if (!luks_opts.has_iter_time) { |
557d2bdc | 1318 | luks_opts.iter_time = QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS; |
3bd18890 | 1319 | } |
3e308f20 DB |
1320 | if (!luks_opts.has_cipher_alg) { |
1321 | luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; | |
1322 | } | |
1323 | if (!luks_opts.has_cipher_mode) { | |
1324 | luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; | |
1325 | } | |
1326 | if (!luks_opts.has_ivgen_alg) { | |
1327 | luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; | |
1328 | } | |
1329 | if (!luks_opts.has_hash_alg) { | |
1330 | luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; | |
1331 | } | |
8b7cdba3 DB |
1332 | if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { |
1333 | if (!luks_opts.has_ivgen_hash_alg) { | |
1334 | luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; | |
1335 | luks_opts.has_ivgen_hash_alg = true; | |
1336 | } | |
1337 | } | |
9d80e59d ML |
1338 | |
1339 | luks = g_new0(QCryptoBlockLUKS, 1); | |
1340 | block->opaque = luks; | |
1341 | ||
1342 | luks->cipher_alg = luks_opts.cipher_alg; | |
1343 | luks->cipher_mode = luks_opts.cipher_mode; | |
1344 | luks->ivgen_alg = luks_opts.ivgen_alg; | |
1345 | luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; | |
1346 | luks->hash_alg = luks_opts.hash_alg; | |
1347 | ||
1348 | ||
8b7cdba3 DB |
1349 | /* Note we're allowing ivgen_hash_alg to be set even for |
1350 | * non-essiv iv generators that don't need a hash. It will | |
1351 | * be silently ignored, for compatibility with dm-crypt */ | |
3e308f20 DB |
1352 | |
1353 | if (!options->u.luks.key_secret) { | |
1cd9a787 DB |
1354 | error_setg(errp, "Parameter '%skey-secret' is required for cipher", |
1355 | optprefix ? optprefix : ""); | |
9d80e59d | 1356 | goto error; |
3e308f20 | 1357 | } |
557d2bdc ML |
1358 | luks->secret = g_strdup(options->u.luks.key_secret); |
1359 | ||
3e308f20 DB |
1360 | password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp); |
1361 | if (!password) { | |
9d80e59d | 1362 | goto error; |
3e308f20 DB |
1363 | } |
1364 | ||
3e308f20 DB |
1365 | |
1366 | memcpy(luks->header.magic, qcrypto_block_luks_magic, | |
1367 | QCRYPTO_BLOCK_LUKS_MAGIC_LEN); | |
1368 | ||
1369 | /* We populate the header in native endianness initially and | |
1370 | * then convert everything to big endian just before writing | |
1371 | * it out to disk | |
1372 | */ | |
1373 | luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION; | |
2ef950f9 | 1374 | qcrypto_block_luks_uuid_gen(luks->header.uuid); |
3e308f20 DB |
1375 | |
1376 | cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg, | |
1377 | errp); | |
1378 | if (!cipher_alg) { | |
1379 | goto error; | |
1380 | } | |
1381 | ||
977c736f MA |
1382 | cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode); |
1383 | ivgen_alg = QCryptoIVGenAlgorithm_str(luks_opts.ivgen_alg); | |
3e308f20 | 1384 | if (luks_opts.has_ivgen_hash_alg) { |
977c736f | 1385 | ivgen_hash_alg = QCryptoHashAlgorithm_str(luks_opts.ivgen_hash_alg); |
3e308f20 DB |
1386 | cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg, |
1387 | ivgen_hash_alg); | |
1388 | } else { | |
1389 | cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg); | |
1390 | } | |
977c736f | 1391 | hash_alg = QCryptoHashAlgorithm_str(luks_opts.hash_alg); |
3e308f20 DB |
1392 | |
1393 | ||
1394 | if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) { | |
1395 | error_setg(errp, "Cipher name '%s' is too long for LUKS header", | |
1396 | cipher_alg); | |
1397 | goto error; | |
1398 | } | |
1399 | if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) { | |
1400 | error_setg(errp, "Cipher mode '%s' is too long for LUKS header", | |
1401 | cipher_mode_spec); | |
1402 | goto error; | |
1403 | } | |
1404 | if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) { | |
1405 | error_setg(errp, "Hash name '%s' is too long for LUKS header", | |
1406 | hash_alg); | |
1407 | goto error; | |
1408 | } | |
1409 | ||
1410 | if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { | |
9d80e59d ML |
1411 | luks->ivgen_cipher_alg = |
1412 | qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg, | |
1413 | luks_opts.ivgen_hash_alg, | |
1414 | &local_err); | |
3e308f20 DB |
1415 | if (local_err) { |
1416 | error_propagate(errp, local_err); | |
1417 | goto error; | |
1418 | } | |
1419 | } else { | |
9d80e59d | 1420 | luks->ivgen_cipher_alg = luks_opts.cipher_alg; |
3e308f20 DB |
1421 | } |
1422 | ||
1423 | strcpy(luks->header.cipher_name, cipher_alg); | |
1424 | strcpy(luks->header.cipher_mode, cipher_mode_spec); | |
1425 | strcpy(luks->header.hash_spec, hash_alg); | |
1426 | ||
f0d3c362 ML |
1427 | luks->header.master_key_len = |
1428 | qcrypto_cipher_get_key_len(luks_opts.cipher_alg); | |
1429 | ||
3e308f20 | 1430 | if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) { |
f0d3c362 | 1431 | luks->header.master_key_len *= 2; |
3e308f20 DB |
1432 | } |
1433 | ||
1434 | /* Generate the salt used for hashing the master key | |
1435 | * with PBKDF later | |
1436 | */ | |
1437 | if (qcrypto_random_bytes(luks->header.master_key_salt, | |
1438 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
1439 | errp) < 0) { | |
1440 | goto error; | |
1441 | } | |
1442 | ||
1443 | /* Generate random master key */ | |
f0d3c362 | 1444 | masterkey = g_new0(uint8_t, luks->header.master_key_len); |
3e308f20 | 1445 | if (qcrypto_random_bytes(masterkey, |
f0d3c362 | 1446 | luks->header.master_key_len, errp) < 0) { |
3e308f20 DB |
1447 | goto error; |
1448 | } | |
1449 | ||
1450 | ||
1451 | /* Setup the block device payload encryption objects */ | |
c972fa12 VSO |
1452 | if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg, |
1453 | luks_opts.cipher_mode, masterkey, | |
f0d3c362 | 1454 | luks->header.master_key_len, 1, errp) < 0) { |
3e308f20 DB |
1455 | goto error; |
1456 | } | |
1457 | ||
1458 | block->kdfhash = luks_opts.hash_alg; | |
1459 | block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, | |
1460 | luks_opts.cipher_mode); | |
1461 | block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, | |
9d80e59d | 1462 | luks->ivgen_cipher_alg, |
3e308f20 | 1463 | luks_opts.ivgen_hash_alg, |
f0d3c362 | 1464 | masterkey, luks->header.master_key_len, |
3e308f20 DB |
1465 | errp); |
1466 | ||
1467 | if (!block->ivgen) { | |
1468 | goto error; | |
1469 | } | |
1470 | ||
1471 | ||
1472 | /* Determine how many iterations we need to hash the master | |
1473 | * key, in order to have 1 second of compute time used | |
1474 | */ | |
59b060be | 1475 | iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, |
f0d3c362 | 1476 | masterkey, luks->header.master_key_len, |
59b060be DB |
1477 | luks->header.master_key_salt, |
1478 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
e74aabcf | 1479 | QCRYPTO_BLOCK_LUKS_DIGEST_LEN, |
59b060be | 1480 | &local_err); |
3e308f20 DB |
1481 | if (local_err) { |
1482 | error_propagate(errp, local_err); | |
1483 | goto error; | |
1484 | } | |
1485 | ||
3bd18890 DB |
1486 | if (iters > (ULLONG_MAX / luks_opts.iter_time)) { |
1487 | error_setg_errno(errp, ERANGE, | |
1488 | "PBKDF iterations %llu too large to scale", | |
1489 | (unsigned long long)iters); | |
1490 | goto error; | |
1491 | } | |
1492 | ||
1493 | /* iter_time was in millis, but count_iters reported for secs */ | |
1494 | iters = iters * luks_opts.iter_time / 1000; | |
1495 | ||
3e308f20 DB |
1496 | /* Why /= 8 ? That matches cryptsetup, but there's no |
1497 | * explanation why they chose /= 8... Probably so that | |
1498 | * if all 8 keyslots are active we only spend 1 second | |
1499 | * in total time to check all keys */ | |
59b060be DB |
1500 | iters /= 8; |
1501 | if (iters > UINT32_MAX) { | |
1502 | error_setg_errno(errp, ERANGE, | |
1503 | "PBKDF iterations %llu larger than %u", | |
1504 | (unsigned long long)iters, UINT32_MAX); | |
1505 | goto error; | |
1506 | } | |
1507 | iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); | |
1508 | luks->header.master_key_iterations = iters; | |
3e308f20 DB |
1509 | |
1510 | /* Hash the master key, saving the result in the LUKS | |
1511 | * header. This hash is used when opening the encrypted | |
1512 | * device to verify that the user password unlocked a | |
1513 | * valid master key | |
1514 | */ | |
1515 | if (qcrypto_pbkdf2(luks_opts.hash_alg, | |
f0d3c362 | 1516 | masterkey, luks->header.master_key_len, |
3e308f20 DB |
1517 | luks->header.master_key_salt, |
1518 | QCRYPTO_BLOCK_LUKS_SALT_LEN, | |
1519 | luks->header.master_key_iterations, | |
1520 | luks->header.master_key_digest, | |
1521 | QCRYPTO_BLOCK_LUKS_DIGEST_LEN, | |
1522 | errp) < 0) { | |
1523 | goto error; | |
1524 | } | |
1525 | ||
bd56a55a ML |
1526 | /* start with the sector that follows the header*/ |
1527 | header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / | |
1528 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; | |
1529 | ||
1530 | split_key_sectors = | |
1531 | qcrypto_block_luks_splitkeylen_sectors(luks, | |
1532 | header_sectors, | |
1533 | QCRYPTO_BLOCK_LUKS_STRIPES); | |
3e308f20 | 1534 | |
3e308f20 | 1535 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { |
bd56a55a ML |
1536 | QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; |
1537 | slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; | |
3e308f20 | 1538 | |
bd56a55a ML |
1539 | slot->key_offset_sector = header_sectors + i * split_key_sectors; |
1540 | slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; | |
3e308f20 DB |
1541 | } |
1542 | ||
3e308f20 DB |
1543 | /* The total size of the LUKS headers is the partition header + key |
1544 | * slot headers, rounded up to the nearest sector, combined with | |
1545 | * the size of each master key material region, also rounded up | |
1546 | * to the nearest sector */ | |
bd56a55a ML |
1547 | luks->header.payload_offset_sector = header_sectors + |
1548 | QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors; | |
3e308f20 | 1549 | |
850f49de | 1550 | block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; |
f0d3c362 | 1551 | block->payload_offset = luks->header.payload_offset_sector * |
850f49de | 1552 | block->sector_size; |
3e308f20 DB |
1553 | |
1554 | /* Reserve header space to match payload offset */ | |
e4a3507e | 1555 | initfunc(block, block->payload_offset, opaque, &local_err); |
3e308f20 DB |
1556 | if (local_err) { |
1557 | error_propagate(errp, local_err); | |
1558 | goto error; | |
1559 | } | |
1560 | ||
3e308f20 | 1561 | |
3994a7c9 ML |
1562 | /* populate the slot 0 with the password encrypted master key*/ |
1563 | /* This will also store the header */ | |
1564 | if (qcrypto_block_luks_store_key(block, | |
1565 | 0, | |
1566 | password, | |
1567 | masterkey, | |
1568 | luks_opts.iter_time, | |
1569 | writefunc, | |
1570 | opaque, | |
1571 | errp) < 0) { | |
3e308f20 DB |
1572 | goto error; |
1573 | } | |
1574 | ||
f0d3c362 | 1575 | memset(masterkey, 0, luks->header.master_key_len); |
3e308f20 DB |
1576 | |
1577 | return 0; | |
1578 | ||
1579 | error: | |
1580 | if (masterkey) { | |
f0d3c362 | 1581 | memset(masterkey, 0, luks->header.master_key_len); |
3e308f20 | 1582 | } |
3e308f20 | 1583 | |
c972fa12 | 1584 | qcrypto_block_free_cipher(block); |
b640adca VSO |
1585 | qcrypto_ivgen_free(block->ivgen); |
1586 | ||
557d2bdc | 1587 | g_free(luks->secret); |
3e308f20 DB |
1588 | g_free(luks); |
1589 | return -1; | |
1590 | } | |
1591 | ||
557d2bdc ML |
1592 | static int |
1593 | qcrypto_block_luks_amend_add_keyslot(QCryptoBlock *block, | |
1594 | QCryptoBlockReadFunc readfunc, | |
1595 | QCryptoBlockWriteFunc writefunc, | |
1596 | void *opaque, | |
1597 | QCryptoBlockAmendOptionsLUKS *opts_luks, | |
1598 | bool force, | |
1599 | Error **errp) | |
1600 | { | |
1601 | QCryptoBlockLUKS *luks = block->opaque; | |
1602 | uint64_t iter_time = opts_luks->has_iter_time ? | |
1603 | opts_luks->iter_time : | |
1604 | QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS; | |
1605 | int keyslot; | |
1606 | g_autofree char *old_password = NULL; | |
1607 | g_autofree char *new_password = NULL; | |
1608 | g_autofree uint8_t *master_key = NULL; | |
1609 | ||
16110c8b | 1610 | char *secret = opts_luks->secret ?: luks->secret; |
557d2bdc | 1611 | |
16110c8b | 1612 | if (!opts_luks->new_secret) { |
557d2bdc ML |
1613 | error_setg(errp, "'new-secret' is required to activate a keyslot"); |
1614 | return -1; | |
1615 | } | |
16110c8b | 1616 | if (opts_luks->old_secret) { |
557d2bdc ML |
1617 | error_setg(errp, |
1618 | "'old-secret' must not be given when activating keyslots"); | |
1619 | return -1; | |
1620 | } | |
1621 | ||
1622 | if (opts_luks->has_keyslot) { | |
1623 | keyslot = opts_luks->keyslot; | |
1624 | if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) { | |
1625 | error_setg(errp, | |
1626 | "Invalid keyslot %u specified, must be between 0 and %u", | |
1627 | keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1); | |
1628 | return -1; | |
1629 | } | |
1630 | } else { | |
1631 | keyslot = qcrypto_block_luks_find_free_keyslot(luks); | |
1632 | if (keyslot == -1) { | |
1633 | error_setg(errp, | |
1634 | "Can't add a keyslot - all keyslots are in use"); | |
1635 | return -1; | |
1636 | } | |
1637 | } | |
1638 | ||
1639 | if (!force && qcrypto_block_luks_slot_active(luks, keyslot)) { | |
1640 | error_setg(errp, | |
1641 | "Refusing to overwrite active keyslot %i - " | |
1642 | "please erase it first", | |
1643 | keyslot); | |
1644 | return -1; | |
1645 | } | |
1646 | ||
1647 | /* Locate the password that will be used to retrieve the master key */ | |
1648 | old_password = qcrypto_secret_lookup_as_utf8(secret, errp); | |
1649 | if (!old_password) { | |
1650 | return -1; | |
1651 | } | |
1652 | ||
1653 | /* Retrieve the master key */ | |
1654 | master_key = g_new0(uint8_t, luks->header.master_key_len); | |
1655 | ||
1656 | if (qcrypto_block_luks_find_key(block, old_password, master_key, | |
1657 | readfunc, opaque, errp) < 0) { | |
1658 | error_append_hint(errp, "Failed to retrieve the master key"); | |
1659 | return -1; | |
1660 | } | |
1661 | ||
1662 | /* Locate the new password*/ | |
1663 | new_password = qcrypto_secret_lookup_as_utf8(opts_luks->new_secret, errp); | |
1664 | if (!new_password) { | |
1665 | return -1; | |
1666 | } | |
1667 | ||
1668 | /* Now set the new keyslots */ | |
1669 | if (qcrypto_block_luks_store_key(block, keyslot, new_password, master_key, | |
1670 | iter_time, writefunc, opaque, errp)) { | |
1671 | error_append_hint(errp, "Failed to write to keyslot %i", keyslot); | |
1672 | return -1; | |
1673 | } | |
1674 | return 0; | |
1675 | } | |
1676 | ||
1677 | static int | |
1678 | qcrypto_block_luks_amend_erase_keyslots(QCryptoBlock *block, | |
1679 | QCryptoBlockReadFunc readfunc, | |
1680 | QCryptoBlockWriteFunc writefunc, | |
1681 | void *opaque, | |
1682 | QCryptoBlockAmendOptionsLUKS *opts_luks, | |
1683 | bool force, | |
1684 | Error **errp) | |
1685 | { | |
1686 | QCryptoBlockLUKS *luks = block->opaque; | |
1687 | g_autofree uint8_t *tmpkey = NULL; | |
1688 | g_autofree char *old_password = NULL; | |
1689 | ||
16110c8b | 1690 | if (opts_luks->new_secret) { |
557d2bdc ML |
1691 | error_setg(errp, |
1692 | "'new-secret' must not be given when erasing keyslots"); | |
1693 | return -1; | |
1694 | } | |
1695 | if (opts_luks->has_iter_time) { | |
1696 | error_setg(errp, | |
1697 | "'iter-time' must not be given when erasing keyslots"); | |
1698 | return -1; | |
1699 | } | |
16110c8b | 1700 | if (opts_luks->secret) { |
557d2bdc ML |
1701 | error_setg(errp, |
1702 | "'secret' must not be given when erasing keyslots"); | |
1703 | return -1; | |
1704 | } | |
1705 | ||
1706 | /* Load the old password if given */ | |
16110c8b | 1707 | if (opts_luks->old_secret) { |
557d2bdc ML |
1708 | old_password = qcrypto_secret_lookup_as_utf8(opts_luks->old_secret, |
1709 | errp); | |
1710 | if (!old_password) { | |
1711 | return -1; | |
1712 | } | |
1713 | ||
1714 | /* | |
1715 | * Allocate a temporary key buffer that we will need when | |
1716 | * checking if slot matches the given old password | |
1717 | */ | |
1718 | tmpkey = g_new0(uint8_t, luks->header.master_key_len); | |
1719 | } | |
1720 | ||
1721 | /* Erase an explicitly given keyslot */ | |
1722 | if (opts_luks->has_keyslot) { | |
1723 | int keyslot = opts_luks->keyslot; | |
1724 | ||
1725 | if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) { | |
1726 | error_setg(errp, | |
1727 | "Invalid keyslot %i specified, must be between 0 and %i", | |
1728 | keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1); | |
1729 | return -1; | |
1730 | } | |
1731 | ||
16110c8b | 1732 | if (opts_luks->old_secret) { |
557d2bdc ML |
1733 | int rv = qcrypto_block_luks_load_key(block, |
1734 | keyslot, | |
1735 | old_password, | |
1736 | tmpkey, | |
1737 | readfunc, | |
1738 | opaque, | |
1739 | errp); | |
1740 | if (rv == -1) { | |
1741 | return -1; | |
1742 | } else if (rv == 0) { | |
1743 | error_setg(errp, | |
1744 | "Given keyslot %i doesn't contain the given " | |
1745 | "old password for erase operation", | |
1746 | keyslot); | |
1747 | return -1; | |
1748 | } | |
1749 | } | |
1750 | ||
1751 | if (!force && !qcrypto_block_luks_slot_active(luks, keyslot)) { | |
1752 | error_setg(errp, | |
1753 | "Given keyslot %i is already erased (inactive) ", | |
1754 | keyslot); | |
1755 | return -1; | |
1756 | } | |
1757 | ||
1758 | if (!force && qcrypto_block_luks_count_active_slots(luks) == 1) { | |
1759 | error_setg(errp, | |
1760 | "Attempt to erase the only active keyslot %i " | |
1761 | "which will erase all the data in the image " | |
1762 | "irreversibly - refusing operation", | |
1763 | keyslot); | |
1764 | return -1; | |
1765 | } | |
1766 | ||
1767 | if (qcrypto_block_luks_erase_key(block, keyslot, | |
1768 | writefunc, opaque, errp)) { | |
1769 | error_append_hint(errp, "Failed to erase keyslot %i", keyslot); | |
1770 | return -1; | |
1771 | } | |
1772 | ||
1773 | /* Erase all keyslots that match the given old password */ | |
16110c8b | 1774 | } else if (opts_luks->old_secret) { |
557d2bdc ML |
1775 | |
1776 | unsigned long slots_to_erase_bitmap = 0; | |
1777 | size_t i; | |
1778 | int slot_count; | |
1779 | ||
1780 | assert(QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS <= | |
1781 | sizeof(slots_to_erase_bitmap) * 8); | |
1782 | ||
1783 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1784 | int rv = qcrypto_block_luks_load_key(block, | |
1785 | i, | |
1786 | old_password, | |
1787 | tmpkey, | |
1788 | readfunc, | |
1789 | opaque, | |
1790 | errp); | |
1791 | if (rv == -1) { | |
1792 | return -1; | |
1793 | } else if (rv == 1) { | |
1794 | bitmap_set(&slots_to_erase_bitmap, i, 1); | |
1795 | } | |
1796 | } | |
1797 | ||
1798 | slot_count = bitmap_count_one(&slots_to_erase_bitmap, | |
1799 | QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); | |
1800 | if (slot_count == 0) { | |
1801 | error_setg(errp, | |
1802 | "No keyslots match given (old) password for erase operation"); | |
1803 | return -1; | |
1804 | } | |
1805 | ||
1806 | if (!force && | |
1807 | slot_count == qcrypto_block_luks_count_active_slots(luks)) { | |
1808 | error_setg(errp, | |
1809 | "All the active keyslots match the (old) password that " | |
1810 | "was given and erasing them will erase all the data in " | |
1811 | "the image irreversibly - refusing operation"); | |
1812 | return -1; | |
1813 | } | |
1814 | ||
1815 | /* Now apply the update */ | |
1816 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
1817 | if (!test_bit(i, &slots_to_erase_bitmap)) { | |
1818 | continue; | |
1819 | } | |
1820 | if (qcrypto_block_luks_erase_key(block, i, writefunc, | |
1821 | opaque, errp)) { | |
1822 | error_append_hint(errp, "Failed to erase keyslot %zu", i); | |
1823 | return -1; | |
1824 | } | |
1825 | } | |
1826 | } else { | |
1827 | error_setg(errp, | |
1828 | "To erase keyslot(s), either explicit keyslot index " | |
1829 | "or the password currently contained in them must be given"); | |
1830 | return -1; | |
1831 | } | |
1832 | return 0; | |
1833 | } | |
1834 | ||
1835 | static int | |
1836 | qcrypto_block_luks_amend_options(QCryptoBlock *block, | |
1837 | QCryptoBlockReadFunc readfunc, | |
1838 | QCryptoBlockWriteFunc writefunc, | |
1839 | void *opaque, | |
1840 | QCryptoBlockAmendOptions *options, | |
1841 | bool force, | |
1842 | Error **errp) | |
1843 | { | |
1844 | QCryptoBlockAmendOptionsLUKS *opts_luks = &options->u.luks; | |
1845 | ||
1846 | switch (opts_luks->state) { | |
1847 | case Q_CRYPTO_BLOCKLUKS_KEYSLOT_STATE_ACTIVE: | |
1848 | return qcrypto_block_luks_amend_add_keyslot(block, readfunc, | |
1849 | writefunc, opaque, | |
1850 | opts_luks, force, errp); | |
1851 | case Q_CRYPTO_BLOCKLUKS_KEYSLOT_STATE_INACTIVE: | |
1852 | return qcrypto_block_luks_amend_erase_keyslots(block, readfunc, | |
1853 | writefunc, opaque, | |
1854 | opts_luks, force, errp); | |
1855 | default: | |
1856 | g_assert_not_reached(); | |
1857 | } | |
1858 | } | |
3e308f20 | 1859 | |
40c85028 DB |
1860 | static int qcrypto_block_luks_get_info(QCryptoBlock *block, |
1861 | QCryptoBlockInfo *info, | |
1862 | Error **errp) | |
1863 | { | |
1864 | QCryptoBlockLUKS *luks = block->opaque; | |
1865 | QCryptoBlockInfoLUKSSlot *slot; | |
c3033fd3 | 1866 | QCryptoBlockInfoLUKSSlotList **tail = &info->u.luks.slots; |
40c85028 DB |
1867 | size_t i; |
1868 | ||
1869 | info->u.luks.cipher_alg = luks->cipher_alg; | |
1870 | info->u.luks.cipher_mode = luks->cipher_mode; | |
1871 | info->u.luks.ivgen_alg = luks->ivgen_alg; | |
1872 | if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { | |
1873 | info->u.luks.has_ivgen_hash_alg = true; | |
1874 | info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; | |
1875 | } | |
1876 | info->u.luks.hash_alg = luks->hash_alg; | |
1877 | info->u.luks.payload_offset = block->payload_offset; | |
1878 | info->u.luks.master_key_iters = luks->header.master_key_iterations; | |
1879 | info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, | |
1880 | sizeof(luks->header.uuid)); | |
1881 | ||
1882 | for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { | |
c3033fd3 | 1883 | slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); |
40c85028 DB |
1884 | slot->active = luks->header.key_slots[i].active == |
1885 | QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; | |
f0d3c362 | 1886 | slot->key_offset = luks->header.key_slots[i].key_offset_sector |
40c85028 DB |
1887 | * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; |
1888 | if (slot->active) { | |
1889 | slot->has_iters = true; | |
1890 | slot->iters = luks->header.key_slots[i].iterations; | |
1891 | slot->has_stripes = true; | |
1892 | slot->stripes = luks->header.key_slots[i].stripes; | |
1893 | } | |
1894 | ||
c3033fd3 | 1895 | QAPI_LIST_APPEND(tail, slot); |
40c85028 DB |
1896 | } |
1897 | ||
1898 | return 0; | |
1899 | } | |
1900 | ||
1901 | ||
3e308f20 DB |
1902 | static void qcrypto_block_luks_cleanup(QCryptoBlock *block) |
1903 | { | |
557d2bdc ML |
1904 | QCryptoBlockLUKS *luks = block->opaque; |
1905 | if (luks) { | |
1906 | g_free(luks->secret); | |
1907 | g_free(luks); | |
1908 | } | |
3e308f20 DB |
1909 | } |
1910 | ||
1911 | ||
1912 | static int | |
1913 | qcrypto_block_luks_decrypt(QCryptoBlock *block, | |
4609742a | 1914 | uint64_t offset, |
3e308f20 DB |
1915 | uint8_t *buf, |
1916 | size_t len, | |
1917 | Error **errp) | |
1918 | { | |
4609742a DB |
1919 | assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); |
1920 | assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); | |
0f0d596c VSO |
1921 | return qcrypto_block_decrypt_helper(block, |
1922 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
1923 | offset, buf, len, errp); | |
3e308f20 DB |
1924 | } |
1925 | ||
1926 | ||
1927 | static int | |
1928 | qcrypto_block_luks_encrypt(QCryptoBlock *block, | |
4609742a | 1929 | uint64_t offset, |
3e308f20 DB |
1930 | uint8_t *buf, |
1931 | size_t len, | |
1932 | Error **errp) | |
1933 | { | |
4609742a DB |
1934 | assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); |
1935 | assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); | |
0f0d596c VSO |
1936 | return qcrypto_block_encrypt_helper(block, |
1937 | QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, | |
1938 | offset, buf, len, errp); | |
3e308f20 DB |
1939 | } |
1940 | ||
1941 | ||
1942 | const QCryptoBlockDriver qcrypto_block_driver_luks = { | |
1943 | .open = qcrypto_block_luks_open, | |
1944 | .create = qcrypto_block_luks_create, | |
557d2bdc | 1945 | .amend = qcrypto_block_luks_amend_options, |
40c85028 | 1946 | .get_info = qcrypto_block_luks_get_info, |
3e308f20 DB |
1947 | .cleanup = qcrypto_block_luks_cleanup, |
1948 | .decrypt = qcrypto_block_luks_decrypt, | |
1949 | .encrypt = qcrypto_block_luks_encrypt, | |
1950 | .has_format = qcrypto_block_luks_has_format, | |
1951 | }; |