1 /*
2 * LUKS - Linux Unified Key Setup
3 *
4 * Copyright (C) 2004-2006, Clemens Fruhwirth <clemens@endorphin.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/ioctl.h>
23 #include <netinet/in.h>
24 #include <fcntl.h>
25 #include <errno.h>
26 #include <unistd.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <ctype.h>
31
32 #include "luks.h"
33 #include "af.h"
34 #include "pbkdf.h"
35 #include "random.h"
36 #include <uuid.h>
37 #include <../lib/internal.h>
38
39 #define div_round_up(a,b) ({ \
40 typeof(a) __a = (a); \
41 typeof(b) __b = (b); \
42 (__a - 1) / __b + 1; \
43 })
44
round_up_modulo(int x,int m)45 static inline int round_up_modulo(int x, int m) {
46 return div_round_up(x, m) * m;
47 }
48
LUKS_alloc_masterkey(int keylength,const char * key)49 struct luks_masterkey *LUKS_alloc_masterkey(int keylength, const char *key)
50 {
51 struct luks_masterkey *mk=malloc(sizeof(*mk) + keylength);
52 if(NULL == mk) return NULL;
53 mk->keyLength=keylength;
54 if (key)
55 memcpy(&mk->key, key, keylength);
56 return mk;
57 }
58
LUKS_dealloc_masterkey(struct luks_masterkey * mk)59 void LUKS_dealloc_masterkey(struct luks_masterkey *mk)
60 {
61 if(NULL != mk) {
62 memset(mk->key,0,mk->keyLength);
63 mk->keyLength=0;
64 free(mk);
65 }
66 }
67
LUKS_generate_masterkey(int keylength)68 struct luks_masterkey *LUKS_generate_masterkey(int keylength)
69 {
70 struct luks_masterkey *mk=LUKS_alloc_masterkey(keylength, NULL);
71 if(NULL == mk) return NULL;
72
73 int r = getRandom(mk->key,keylength);
74 if(r < 0) {
75 LUKS_dealloc_masterkey(mk);
76 return NULL;
77 }
78 return mk;
79 }
80
LUKS_hdr_backup(const char * backup_file,const char * device,struct luks_phdr * hdr,struct crypt_device * ctx)81 int LUKS_hdr_backup(
82 const char *backup_file,
83 const char *device,
84 struct luks_phdr *hdr,
85 struct crypt_device *ctx)
86 {
87 int r = 0, devfd = -1;
88 size_t buffer_size;
89 char *buffer = NULL;
90 struct stat st;
91
92 if(stat(backup_file, &st) == 0) {
93 log_err(ctx, _("Requested file %s already exist.\n"), backup_file);
94 return -EINVAL;
95 }
96
97 r = LUKS_read_phdr(device, hdr, 0, ctx);
98 if (r)
99 return r;
100
101 buffer_size = hdr->payloadOffset << SECTOR_SHIFT;
102 buffer = safe_alloc(buffer_size);
103 if (!buffer || buffer_size < LUKS_ALIGN_KEYSLOTS) {
104 r = -ENOMEM;
105 goto out;
106 }
107
108 log_dbg("Storing backup of header (%u bytes) and keyslot area (%u bytes).",
109 sizeof(*hdr), buffer_size - LUKS_ALIGN_KEYSLOTS);
110
111 devfd = open(device, O_RDONLY | O_DIRECT | O_SYNC);
112 if(devfd == -1) {
113 log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device);
114 r = -EINVAL;
115 goto out;
116 }
117
118 if(read_blockwise(devfd, buffer, buffer_size) < buffer_size) {
119 r = -EIO;
120 goto out;
121 }
122 close(devfd);
123
124 /* Wipe unused area, so backup cannot contain old signatures */
125 memset(buffer + sizeof(*hdr), 0, LUKS_ALIGN_KEYSLOTS - sizeof(*hdr));
126
127 devfd = creat(backup_file, S_IRUSR);
128 if(devfd == -1) {
129 r = -EINVAL;
130 goto out;
131 }
132 if(write(devfd, buffer, buffer_size) < buffer_size) {
133 log_err(ctx, _("Cannot write header backup file %s.\n"), backup_file);
134 r = -EIO;
135 goto out;
136 }
137 close(devfd);
138
139 r = 0;
140 out:
141 if (devfd != -1)
142 close(devfd);
143 safe_free(buffer);
144 return r;
145 }
146
LUKS_hdr_restore(const char * backup_file,const char * device,struct luks_phdr * hdr,struct crypt_device * ctx)147 int LUKS_hdr_restore(
148 const char *backup_file,
149 const char *device,
150 struct luks_phdr *hdr,
151 struct crypt_device *ctx)
152 {
153 int r = 0, devfd = -1, diff_uuid = 0;
154 size_t buffer_size;
155 char *buffer = NULL, msg[200];
156 struct stat st;
157 struct luks_phdr hdr_file;
158
159 if(stat(backup_file, &st) < 0) {
160 log_err(ctx, _("Backup file %s doesn't exist.\n"), backup_file);
161 return -EINVAL;
162 }
163
164 r = LUKS_read_phdr_backup(backup_file, device, &hdr_file, 0, ctx);
165 buffer_size = hdr_file.payloadOffset << SECTOR_SHIFT;
166
167 if (r || buffer_size < LUKS_ALIGN_KEYSLOTS) {
168 log_err(ctx, _("Backup file do not contain valid LUKS header.\n"));
169 r = -EINVAL;
170 goto out;
171 }
172
173 buffer = safe_alloc(buffer_size);
174 if (!buffer) {
175 r = -ENOMEM;
176 goto out;
177 }
178
179 devfd = open(backup_file, O_RDONLY);
180 if(devfd == -1) {
181 log_err(ctx, _("Cannot open header backup file %s.\n"), backup_file);
182 r = -EINVAL;
183 goto out;
184 }
185
186 if(read(devfd, buffer, buffer_size) < buffer_size) {
187 log_err(ctx, _("Cannot read header backup file %s.\n"), backup_file);
188 r = -EIO;
189 goto out;
190 }
191 close(devfd);
192
193 r = LUKS_read_phdr(device, hdr, 0, ctx);
194 if (r == 0) {
195 log_dbg("Device %s already contains LUKS header, checking UUID and offset.", device);
196 if(hdr->payloadOffset != hdr_file.payloadOffset ||
197 hdr->keyBytes != hdr_file.keyBytes) {
198 log_err(ctx, _("Data offset or key size differs on device and backup, restore failed.\n"));
199 r = -EINVAL;
200 goto out;
201 }
202 if (memcmp(hdr->uuid, hdr_file.uuid, UUID_STRING_L))
203 diff_uuid = 1;
204 }
205
206 if (snprintf(msg, sizeof(msg), _("Device %s %s%s"), device,
207 r ? _("does not contain LUKS header. Replacing header can destroy data on that device.") :
208 _("already contains LUKS header. Replacing header will destroy existing keyslots."),
209 diff_uuid ? _("\nWARNING: real device header has different UUID than backup!") : "") < 0) {
210 r = -ENOMEM;
211 goto out;
212 }
213
214 if (!crypt_confirm(ctx, msg)) {
215 r = -EINVAL;
216 goto out;
217 }
218
219 log_dbg("Storing backup of header (%u bytes) and keyslot area (%u bytes) to device %s.",
220 sizeof(*hdr), buffer_size - LUKS_ALIGN_KEYSLOTS, device);
221
222 devfd = open(device, O_WRONLY | O_DIRECT | O_SYNC);
223 if(devfd == -1) {
224 log_err(ctx, _("Cannot open device %s.\n"), device);
225 r = -EINVAL;
226 goto out;
227 }
228
229 if(write_blockwise(devfd, buffer, buffer_size) < buffer_size) {
230 r = -EIO;
231 goto out;
232 }
233 close(devfd);
234
235 /* Be sure to reload new data */
236 r = LUKS_read_phdr(device, hdr, 0, ctx);
237 out:
238 if (devfd != -1)
239 close(devfd);
240 safe_free(buffer);
241 return r;
242 }
243
_check_and_convert_hdr(const char * device,struct luks_phdr * hdr,int require_luks_device,struct crypt_device * ctx)244 static int _check_and_convert_hdr(const char *device,
245 struct luks_phdr *hdr,
246 int require_luks_device,
247 struct crypt_device *ctx)
248 {
249 int r = 0;
250 unsigned int i;
251 char luksMagic[] = LUKS_MAGIC;
252
253 if(memcmp(hdr->magic, luksMagic, LUKS_MAGIC_L)) { /* Check magic */
254 log_dbg("LUKS header not detected.");
255 if (require_luks_device)
256 log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device);
257 else
258 set_error(_("Device %s is not a valid LUKS device."), device);
259 r = -EINVAL;
260 } else if((hdr->version = ntohs(hdr->version)) != 1) { /* Convert every uint16/32_t item from network byte order */
261 log_err(ctx, _("Unsupported LUKS version %d.\n"), hdr->version);
262 r = -EINVAL;
263 } else if (PBKDF2_HMAC_ready(hdr->hashSpec) < 0) {
264 log_err(ctx, _("Requested LUKS hash %s is not supported.\n"), hdr->hashSpec);
265 r = -EINVAL;
266 } else {
267 hdr->payloadOffset = ntohl(hdr->payloadOffset);
268 hdr->keyBytes = ntohl(hdr->keyBytes);
269 hdr->mkDigestIterations = ntohl(hdr->mkDigestIterations);
270
271 for(i = 0; i < LUKS_NUMKEYS; ++i) {
272 hdr->keyblock[i].active = ntohl(hdr->keyblock[i].active);
273 hdr->keyblock[i].passwordIterations = ntohl(hdr->keyblock[i].passwordIterations);
274 hdr->keyblock[i].keyMaterialOffset = ntohl(hdr->keyblock[i].keyMaterialOffset);
275 hdr->keyblock[i].stripes = ntohl(hdr->keyblock[i].stripes);
276 }
277 }
278
279 return r;
280 }
281
_to_lower(char * str,unsigned max_len)282 static void _to_lower(char *str, unsigned max_len)
283 {
284 for(; *str && max_len; str++, max_len--)
285 if (isupper(*str))
286 *str = tolower(*str);
287 }
288
LUKS_fix_header_compatible(struct luks_phdr * header)289 static void LUKS_fix_header_compatible(struct luks_phdr *header)
290 {
291 /* Old cryptsetup expects "sha1", gcrypt allows case insensistive names,
292 * so always convert hash to lower case in header */
293 _to_lower(header->hashSpec, LUKS_HASHSPEC_L);
294 }
295
LUKS_read_phdr_backup(const char * backup_file,const char * device,struct luks_phdr * hdr,int require_luks_device,struct crypt_device * ctx)296 int LUKS_read_phdr_backup(const char *backup_file,
297 const char *device,
298 struct luks_phdr *hdr,
299 int require_luks_device,
300 struct crypt_device *ctx)
301 {
302 int devfd = 0, r = 0;
303
304 log_dbg("Reading LUKS header of size %d from backup file %s",
305 sizeof(struct luks_phdr), backup_file);
306
307 devfd = open(backup_file, O_RDONLY);
308 if(-1 == devfd) {
309 log_err(ctx, _("Cannot open file %s.\n"), device);
310 return -EINVAL;
311 }
312
313 if(read(devfd, hdr, sizeof(struct luks_phdr)) < sizeof(struct luks_phdr))
314 r = -EIO;
315 else {
316 LUKS_fix_header_compatible(hdr);
317 r = _check_and_convert_hdr(backup_file, hdr, require_luks_device, ctx);
318 }
319
320 close(devfd);
321 return r;
322 }
323
LUKS_read_phdr(const char * device,struct luks_phdr * hdr,int require_luks_device,struct crypt_device * ctx)324 int LUKS_read_phdr(const char *device,
325 struct luks_phdr *hdr,
326 int require_luks_device,
327 struct crypt_device *ctx)
328 {
329 int devfd = 0, r = 0;
330 uint64_t size;
331
332 log_dbg("Reading LUKS header of size %d from device %s",
333 sizeof(struct luks_phdr), device);
334
335 devfd = open(device,O_RDONLY | O_DIRECT | O_SYNC);
336 if(-1 == devfd) {
337 log_err(ctx, _("Cannot open device %s.\n"), device);
338 return -EINVAL;
339 }
340
341 if(read_blockwise(devfd, hdr, sizeof(struct luks_phdr)) < sizeof(struct luks_phdr))
342 r = -EIO;
343 else
344 r = _check_and_convert_hdr(device, hdr, require_luks_device, ctx);
345
346 #ifdef BLKGETSIZE64
347 if (r == 0 && (ioctl(devfd, BLKGETSIZE64, &size) < 0 ||
348 size < (uint64_t)hdr->payloadOffset)) {
349 log_err(ctx, _("LUKS header detected but device %s is too small.\n"), device);
350 r = -EINVAL;
351 }
352 #endif
353 close(devfd);
354
355 return r;
356 }
357
LUKS_write_phdr(const char * device,struct luks_phdr * hdr,struct crypt_device * ctx)358 int LUKS_write_phdr(const char *device,
359 struct luks_phdr *hdr,
360 struct crypt_device *ctx)
361 {
362 int devfd = 0;
363 unsigned int i;
364 struct luks_phdr convHdr;
365 int r;
366
367 log_dbg("Updating LUKS header of size %d on device %s",
368 sizeof(struct luks_phdr), device);
369
370 devfd = open(device,O_RDWR | O_DIRECT | O_SYNC);
371 if(-1 == devfd) {
372 log_err(ctx, _("Cannot open device %s.\n"), device);
373 return -EINVAL;
374 }
375
376 memcpy(&convHdr, hdr, sizeof(struct luks_phdr));
377 memset(&convHdr._padding, 0, sizeof(convHdr._padding));
378
379 /* Convert every uint16/32_t item to network byte order */
380 convHdr.version = htons(hdr->version);
381 convHdr.payloadOffset = htonl(hdr->payloadOffset);
382 convHdr.keyBytes = htonl(hdr->keyBytes);
383 convHdr.mkDigestIterations = htonl(hdr->mkDigestIterations);
384 for(i = 0; i < LUKS_NUMKEYS; ++i) {
385 convHdr.keyblock[i].active = htonl(hdr->keyblock[i].active);
386 convHdr.keyblock[i].passwordIterations = htonl(hdr->keyblock[i].passwordIterations);
387 convHdr.keyblock[i].keyMaterialOffset = htonl(hdr->keyblock[i].keyMaterialOffset);
388 convHdr.keyblock[i].stripes = htonl(hdr->keyblock[i].stripes);
389 }
390
391 r = write_blockwise(devfd, &convHdr, sizeof(struct luks_phdr)) < sizeof(struct luks_phdr) ? -EIO : 0;
392 if (r)
393 log_err(ctx, _("Error during update of LUKS header on device %s.\n"), device);
394 close(devfd);
395
396 /* Re-read header from disk to be sure that in-memory and on-disk data are the same. */
397 if (!r) {
398 r = LUKS_read_phdr(device, hdr, 1, ctx);
399 if (r)
400 log_err(ctx, _("Error re-reading LUKS header after update on device %s.\n"), device);
401 }
402
403 return r;
404 }
405
LUKS_PBKDF2_performance_check(const char * hashSpec,uint64_t * PBKDF2_per_sec,struct crypt_device * ctx)406 static int LUKS_PBKDF2_performance_check(const char *hashSpec,
407 uint64_t *PBKDF2_per_sec,
408 struct crypt_device *ctx)
409 {
410 if (!*PBKDF2_per_sec) {
411 if (PBKDF2_performance_check(hashSpec, PBKDF2_per_sec) < 0) {
412 log_err(ctx, _("Not compatible PBKDF2 options (using hash algorithm %s).\n"), hashSpec);
413 return -EINVAL;
414 }
415 log_dbg("PBKDF2: %" PRIu64 " iterations per second using hash %s.", *PBKDF2_per_sec, hashSpec);
416 }
417
418 return 0;
419 }
420
LUKS_generate_phdr(struct luks_phdr * header,const struct luks_masterkey * mk,const char * cipherName,const char * cipherMode,const char * hashSpec,const char * uuid,unsigned int stripes,unsigned int alignPayload,unsigned int alignOffset,uint32_t iteration_time_ms,uint64_t * PBKDF2_per_sec,struct crypt_device * ctx)421 int LUKS_generate_phdr(struct luks_phdr *header,
422 const struct luks_masterkey *mk,
423 const char *cipherName, const char *cipherMode, const char *hashSpec,
424 const char *uuid, unsigned int stripes,
425 unsigned int alignPayload,
426 unsigned int alignOffset,
427 uint32_t iteration_time_ms,
428 uint64_t *PBKDF2_per_sec,
429 struct crypt_device *ctx)
430 {
431 unsigned int i=0;
432 unsigned int blocksPerStripeSet = div_round_up(mk->keyLength*stripes,SECTOR_SIZE);
433 int r;
434 uint32_t ret;
435 char luksMagic[] = LUKS_MAGIC;
436 char *uu;
437 uuid_t partitionUuid;
438 int currentSector;
439 int alignSectors = LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE;
440 if (alignPayload == 0)
441 alignPayload = alignSectors;
442
443 memset(header,0,sizeof(struct luks_phdr));
444
445 /* Set Magic */
446 memcpy(header->magic,luksMagic,LUKS_MAGIC_L);
447 header->version=1;
448 strncpy(header->cipherName,cipherName,LUKS_CIPHERNAME_L);
449 strncpy(header->cipherMode,cipherMode,LUKS_CIPHERMODE_L);
450 strncpy(header->hashSpec,hashSpec,LUKS_HASHSPEC_L);
451
452 header->keyBytes=mk->keyLength;
453
454 LUKS_fix_header_compatible(header);
455
456 log_dbg("Generating LUKS header version %d using hash %s, %s, %s, MK %d bytes",
457 header->version, header->hashSpec ,header->cipherName, header->cipherMode,
458 header->keyBytes);
459
460 r = getRandom(header->mkDigestSalt,LUKS_SALTSIZE);
461 if(r < 0) {
462 log_err(ctx, _("Cannot create LUKS header: reading random salt failed.\n"));
463 return r;
464 }
465
466 if ((r = LUKS_PBKDF2_performance_check(header->hashSpec, PBKDF2_per_sec, ctx)))
467 return r;
468
469 /* Compute master key digest */
470 iteration_time_ms /= 8;
471 header->mkDigestIterations = at_least((uint32_t)(*PBKDF2_per_sec/1024) * iteration_time_ms,
472 LUKS_MKD_ITERATIONS_MIN);
473
474 r = PBKDF2_HMAC(header->hashSpec,mk->key,mk->keyLength,
475 header->mkDigestSalt,LUKS_SALTSIZE,
476 header->mkDigestIterations,
477 header->mkDigest,LUKS_DIGESTSIZE);
478 if(r < 0) {
479 log_err(ctx, _("Cannot create LUKS header: header digest failed (using hash %s).\n"),
480 header->hashSpec);
481 return r;
482 }
483
484 currentSector = round_up_modulo(LUKS_PHDR_SIZE, alignSectors);
485 for(i = 0; i < LUKS_NUMKEYS; ++i) {
486 header->keyblock[i].active = LUKS_KEY_DISABLED;
487 header->keyblock[i].keyMaterialOffset = currentSector;
488 header->keyblock[i].stripes = stripes;
489 currentSector = round_up_modulo(currentSector + blocksPerStripeSet, alignSectors);
490 }
491 currentSector = round_up_modulo(currentSector, alignPayload);
492
493 /* alignOffset - offset from natural device alignment provided by topology info */
494 header->payloadOffset = currentSector + alignOffset;
495
496 uuid_from_string(uuid, &partitionUuid, &ret);
497 if (uuid && ret != uuid_s_ok) {
498 log_err(ctx, _("Wrong UUID format provided, generating new one.\n"));
499 uuid = NULL;
500 }
501 if (!uuid)
502 uuid_create(&partitionUuid, &ret);
503 uuid_to_string(&partitionUuid, &uu, &ret);
504 if (uu == NULL) {
505 log_err(ctx, _("Cannot allocate memory in uuid_to_string()\n"));
506 return -1;
507 }
508 memcpy(header->uuid, uu, UUID_STRING_L);
509 free(uu);
510
511 log_dbg("Data offset %d, UUID %s, digest iterations %" PRIu32,
512 header->payloadOffset, header->uuid, header->mkDigestIterations);
513
514 return 0;
515 }
516
LUKS_set_key(const char * device,unsigned int keyIndex,const char * password,size_t passwordLen,struct luks_phdr * hdr,struct luks_masterkey * mk,uint32_t iteration_time_ms,uint64_t * PBKDF2_per_sec,struct crypt_device * ctx)517 int LUKS_set_key(const char *device, unsigned int keyIndex,
518 const char *password, size_t passwordLen,
519 struct luks_phdr *hdr, struct luks_masterkey *mk,
520 uint32_t iteration_time_ms,
521 uint64_t *PBKDF2_per_sec,
522 struct crypt_device *ctx)
523 {
524 char derivedKey[hdr->keyBytes];
525 char *AfKey;
526 unsigned int AFEKSize;
527 uint64_t PBKDF2_temp;
528 int r;
529
530 if(hdr->keyblock[keyIndex].active != LUKS_KEY_DISABLED) {
531 log_err(ctx, _("Key slot %d active, purge first.\n"), keyIndex);
532 return -EINVAL;
533 }
534
535 if(hdr->keyblock[keyIndex].stripes < LUKS_STRIPES) {
536 log_err(ctx, _("Key slot %d material includes too few stripes. Header manipulation?\n"),
537 keyIndex);
538 return -EINVAL;
539 }
540
541 log_dbg("Calculating data for key slot %d", keyIndex);
542
543 if ((r = LUKS_PBKDF2_performance_check(hdr->hashSpec, PBKDF2_per_sec, ctx)))
544 return r;
545
546 /*
547 * Avoid floating point operation
548 * Final iteration count is at least LUKS_SLOT_ITERATIONS_MIN
549 */
550 PBKDF2_temp = (*PBKDF2_per_sec / 2) * (uint64_t)iteration_time_ms;
551 PBKDF2_temp /= 1024;
552 if (PBKDF2_temp > UINT32_MAX)
553 PBKDF2_temp = UINT32_MAX;
554 hdr->keyblock[keyIndex].passwordIterations = at_least((uint32_t)PBKDF2_temp,
555 LUKS_SLOT_ITERATIONS_MIN);
556
557 log_dbg("Key slot %d use %d password iterations.", keyIndex, hdr->keyblock[keyIndex].passwordIterations);
558
559 r = getRandom(hdr->keyblock[keyIndex].passwordSalt, LUKS_SALTSIZE);
560 if(r < 0) return r;
561
562 // assert((mk->keyLength % TWOFISH_BLOCKSIZE) == 0); FIXME
563
564 r = PBKDF2_HMAC(hdr->hashSpec, password,passwordLen,
565 hdr->keyblock[keyIndex].passwordSalt,LUKS_SALTSIZE,
566 hdr->keyblock[keyIndex].passwordIterations,
567 derivedKey, hdr->keyBytes);
568 if(r < 0) return r;
569
570 /*
571 * AF splitting, the masterkey stored in mk->key is splitted to AfMK
572 */
573 AFEKSize = hdr->keyblock[keyIndex].stripes*mk->keyLength;
574 AfKey = (char *)malloc(AFEKSize);
575 if(AfKey == NULL) return -ENOMEM;
576
577 log_dbg("Using hash %s for AF in key slot %d, %d stripes",
578 hdr->hashSpec, keyIndex, hdr->keyblock[keyIndex].stripes);
579 r = AF_split(mk->key,AfKey,mk->keyLength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
580 if(r < 0) goto out;
581
582 log_dbg("Updating key slot %d [0x%04x] area on device %s.", keyIndex,
583 hdr->keyblock[keyIndex].keyMaterialOffset << 9, device);
584 /* Encryption via dm */
585 r = LUKS_encrypt_to_storage(AfKey,
586 AFEKSize,
587 hdr,
588 derivedKey,
589 hdr->keyBytes,
590 device,
591 hdr->keyblock[keyIndex].keyMaterialOffset,
592 ctx);
593 if(r < 0) {
594 if(!get_error())
595 log_err(ctx, _("Failed to write to key storage.\n"));
596 goto out;
597 }
598
599 /* Mark the key as active in phdr */
600 r = LUKS_keyslot_set(hdr, (int)keyIndex, 1);
601 if(r < 0) goto out;
602
603 r = LUKS_write_phdr(device, hdr, ctx);
604 if(r < 0) goto out;
605
606 r = 0;
607 out:
608 free(AfKey);
609 return r;
610 }
611
612 /* Check whether a master key is invalid. */
LUKS_verify_master_key(const struct luks_phdr * hdr,const struct luks_masterkey * mk)613 int LUKS_verify_master_key(const struct luks_phdr *hdr,
614 const struct luks_masterkey *mk)
615 {
616 char checkHashBuf[LUKS_DIGESTSIZE];
617
618 if (PBKDF2_HMAC(hdr->hashSpec, mk->key, mk->keyLength,
619 hdr->mkDigestSalt, LUKS_SALTSIZE,
620 hdr->mkDigestIterations, checkHashBuf,
621 LUKS_DIGESTSIZE) < 0)
622 return -EINVAL;
623
624 if (memcmp(checkHashBuf, hdr->mkDigest, LUKS_DIGESTSIZE))
625 return -EPERM;
626
627 return 0;
628 }
629
630 /* Try to open a particular key slot */
LUKS_open_key(const char * device,unsigned int keyIndex,const char * password,size_t passwordLen,struct luks_phdr * hdr,struct luks_masterkey * mk,struct crypt_device * ctx)631 static int LUKS_open_key(const char *device,
632 unsigned int keyIndex,
633 const char *password,
634 size_t passwordLen,
635 struct luks_phdr *hdr,
636 struct luks_masterkey *mk,
637 struct crypt_device *ctx)
638 {
639 crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyIndex);
640 char derivedKey[hdr->keyBytes];
641 char *AfKey;
642 size_t AFEKSize;
643 int r;
644
645 log_dbg("Trying to open key slot %d [%d].", keyIndex, (int)ki);
646
647 if (ki < CRYPT_SLOT_ACTIVE)
648 return -ENOENT;
649
650 // assert((mk->keyLength % TWOFISH_BLOCKSIZE) == 0); FIXME
651
652 AFEKSize = hdr->keyblock[keyIndex].stripes*mk->keyLength;
653 AfKey = (char *)malloc(AFEKSize);
654 if(AfKey == NULL) return -ENOMEM;
655
656 r = PBKDF2_HMAC(hdr->hashSpec, password,passwordLen,
657 hdr->keyblock[keyIndex].passwordSalt,LUKS_SALTSIZE,
658 hdr->keyblock[keyIndex].passwordIterations,
659 derivedKey, hdr->keyBytes);
660 if(r < 0) goto out;
661
662 log_dbg("Reading key slot %d area.", keyIndex);
663 r = LUKS_decrypt_from_storage(AfKey,
664 AFEKSize,
665 hdr,
666 derivedKey,
667 hdr->keyBytes,
668 device,
669 hdr->keyblock[keyIndex].keyMaterialOffset,
670 ctx);
671 if(r < 0) {
672 log_err(ctx, _("Failed to read from key storage.\n"));
673 goto out;
674 }
675
676 r = AF_merge(AfKey,mk->key,mk->keyLength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
677 if(r < 0) goto out;
678
679 r = LUKS_verify_master_key(hdr, mk);
680 if (r >= 0)
681 log_verbose(ctx, _("Key slot %d unlocked.\n"), keyIndex);
682 out:
683 free(AfKey);
684 return r;
685 }
686
LUKS_open_key_with_hdr(const char * device,int keyIndex,const char * password,size_t passwordLen,struct luks_phdr * hdr,struct luks_masterkey ** mk,struct crypt_device * ctx)687 int LUKS_open_key_with_hdr(const char *device,
688 int keyIndex,
689 const char *password,
690 size_t passwordLen,
691 struct luks_phdr *hdr,
692 struct luks_masterkey **mk,
693 struct crypt_device *ctx)
694 {
695 unsigned int i;
696 int r;
697
698 *mk = LUKS_alloc_masterkey(hdr->keyBytes, NULL);
699
700 if (keyIndex >= 0)
701 return LUKS_open_key(device, keyIndex, password, passwordLen, hdr, *mk, ctx);
702
703 for(i = 0; i < LUKS_NUMKEYS; i++) {
704 r = LUKS_open_key(device, i, password, passwordLen, hdr, *mk, ctx);
705 if(r == 0)
706 return i;
707
708 /* Do not retry for errors that are no -EPERM or -ENOENT,
709 former meaning password wrong, latter key slot inactive */
710 if ((r != -EPERM) && (r != -ENOENT))
711 return r;
712 }
713 /* Warning, early returns above */
714 log_err(ctx, _("No key available with this passphrase.\n"));
715 return -EPERM;
716 }
717
718 /*
719 * Wipe patterns according to Gutmann's Paper
720 */
721
wipeSpecial(char * buffer,size_t buffer_size,unsigned int turn)722 static void wipeSpecial(char *buffer, size_t buffer_size, unsigned int turn)
723 {
724 unsigned int i;
725
726 unsigned char write_modes[][3] = {
727 {"\x55\x55\x55"}, {"\xaa\xaa\xaa"}, {"\x92\x49\x24"},
728 {"\x49\x24\x92"}, {"\x24\x92\x49"}, {"\x00\x00\x00"},
729 {"\x11\x11\x11"}, {"\x22\x22\x22"}, {"\x33\x33\x33"},
730 {"\x44\x44\x44"}, {"\x55\x55\x55"}, {"\x66\x66\x66"},
731 {"\x77\x77\x77"}, {"\x88\x88\x88"}, {"\x99\x99\x99"},
732 {"\xaa\xaa\xaa"}, {"\xbb\xbb\xbb"}, {"\xcc\xcc\xcc"},
733 {"\xdd\xdd\xdd"}, {"\xee\xee\xee"}, {"\xff\xff\xff"},
734 {"\x92\x49\x24"}, {"\x49\x24\x92"}, {"\x24\x92\x49"},
735 {"\x6d\xb6\xdb"}, {"\xb6\xdb\x6d"}, {"\xdb\x6d\xb6"}
736 };
737
738 for(i = 0; i < buffer_size / 3; ++i) {
739 memcpy(buffer, write_modes[turn], 3);
740 buffer += 3;
741 }
742 }
743
wipe(const char * device,unsigned int from,unsigned int to)744 static int wipe(const char *device, unsigned int from, unsigned int to)
745 {
746 int devfd;
747 char *buffer;
748 unsigned int i;
749 unsigned int bufLen = (to - from) * SECTOR_SIZE;
750 int r = 0;
751
752 devfd = open(device, O_RDWR | O_DIRECT | O_SYNC);
753 if(devfd == -1)
754 return -EINVAL;
755
756 buffer = (char *) malloc(bufLen);
757 if(!buffer) return -ENOMEM;
758
759 for(i = 0; i < 39; ++i) {
760 if (i >= 0 && i < 5) getRandom(buffer, bufLen);
761 else if(i >= 5 && i < 32) wipeSpecial(buffer, bufLen, i - 5);
762 else if(i >= 32 && i < 38) getRandom(buffer, bufLen);
763 else if(i >= 38 && i < 39) memset(buffer, 0xFF, bufLen);
764
765 if(write_lseek_blockwise(devfd, buffer, bufLen, from * SECTOR_SIZE) < 0) {
766 r = -EIO;
767 break;
768 }
769 }
770
771 free(buffer);
772 close(devfd);
773
774 return r;
775 }
776
LUKS_del_key(const char * device,unsigned int keyIndex,struct luks_phdr * hdr,struct crypt_device * ctx)777 int LUKS_del_key(const char *device,
778 unsigned int keyIndex,
779 struct luks_phdr *hdr,
780 struct crypt_device *ctx)
781 {
782 unsigned int startOffset, endOffset, stripesLen;
783 int r;
784
785 r = LUKS_read_phdr(device, hdr, 1, ctx);
786 if (r)
787 return r;
788
789 r = LUKS_keyslot_set(hdr, keyIndex, 0);
790 if (r) {
791 log_err(ctx, _("Key slot %d is invalid, please select keyslot between 0 and %d.\n"),
792 keyIndex, LUKS_NUMKEYS - 1);
793 return r;
794 }
795
796 /* secure deletion of key material */
797 startOffset = hdr->keyblock[keyIndex].keyMaterialOffset;
798 stripesLen = hdr->keyBytes * hdr->keyblock[keyIndex].stripes;
799 endOffset = startOffset + div_round_up(stripesLen, SECTOR_SIZE);
800
801 r = wipe(device, startOffset, endOffset);
802 if (r) {
803 log_err(ctx, _("Cannot wipe device %s.\n"), device);
804 return r;
805 }
806
807 r = LUKS_write_phdr(device, hdr, ctx);
808
809 return r;
810 }
811
LUKS_keyslot_info(struct luks_phdr * hdr,int keyslot)812 crypt_keyslot_info LUKS_keyslot_info(struct luks_phdr *hdr, int keyslot)
813 {
814 int i;
815
816 if(keyslot >= LUKS_NUMKEYS || keyslot < 0)
817 return CRYPT_SLOT_INVALID;
818
819 if (hdr->keyblock[keyslot].active == LUKS_KEY_DISABLED)
820 return CRYPT_SLOT_INACTIVE;
821
822 if (hdr->keyblock[keyslot].active != LUKS_KEY_ENABLED)
823 return CRYPT_SLOT_INVALID;
824
825 for(i = 0; i < LUKS_NUMKEYS; i++)
826 if(i != keyslot && hdr->keyblock[i].active == LUKS_KEY_ENABLED)
827 return CRYPT_SLOT_ACTIVE;
828
829 return CRYPT_SLOT_ACTIVE_LAST;
830 }
831
LUKS_keyslot_find_empty(struct luks_phdr * hdr)832 int LUKS_keyslot_find_empty(struct luks_phdr *hdr)
833 {
834 int i;
835
836 for (i = 0; i < LUKS_NUMKEYS; i++)
837 if(hdr->keyblock[i].active == LUKS_KEY_DISABLED)
838 break;
839
840 if (i == LUKS_NUMKEYS)
841 return -EINVAL;
842
843 return i;
844 }
845
LUKS_keyslot_active_count(struct luks_phdr * hdr)846 int LUKS_keyslot_active_count(struct luks_phdr *hdr)
847 {
848 int i, num = 0;
849
850 for (i = 0; i < LUKS_NUMKEYS; i++)
851 if(hdr->keyblock[i].active == LUKS_KEY_ENABLED)
852 num++;
853
854 return num;
855 }
856
LUKS_keyslot_set(struct luks_phdr * hdr,int keyslot,int enable)857 int LUKS_keyslot_set(struct luks_phdr *hdr, int keyslot, int enable)
858 {
859 crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyslot);
860
861 if (ki == CRYPT_SLOT_INVALID)
862 return -EINVAL;
863
864 hdr->keyblock[keyslot].active = enable ? LUKS_KEY_ENABLED : LUKS_KEY_DISABLED;
865 log_dbg("Key slot %d was %s in LUKS header.", keyslot, enable ? "enabled" : "disabled");
866 return 0;
867 }
868