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