2 * LUKS - Linux Unified Key Setup v2, digest handling
4 * Copyright (C) 2015-2020 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2015-2020 Milan Broz
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include "luks2_internal.h"
24 extern const digest_handler PBKDF2_digest;
26 static const digest_handler *digest_handlers[LUKS2_DIGEST_MAX] = {
31 static const digest_handler *LUKS2_digest_handler_type(struct crypt_device *cd, const char *type)
35 for (i = 0; i < LUKS2_DIGEST_MAX && digest_handlers[i]; i++) {
36 if (!strcmp(digest_handlers[i]->name, type))
37 return digest_handlers[i];
43 static const digest_handler *LUKS2_digest_handler(struct crypt_device *cd, int digest)
45 struct luks2_hdr *hdr;
46 json_object *jobj1, *jobj2;
51 if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
54 if (!(jobj1 = LUKS2_get_digest_jobj(hdr, digest)))
57 if (!json_object_object_get_ex(jobj1, "type", &jobj2))
60 return LUKS2_digest_handler_type(cd, json_object_get_string(jobj2));
63 static int LUKS2_digest_find_free(struct crypt_device *cd, struct luks2_hdr *hdr)
67 while (LUKS2_get_digest_jobj(hdr, digest) && digest < LUKS2_DIGEST_MAX)
70 return digest < LUKS2_DIGEST_MAX ? digest : -1;
73 int LUKS2_digest_create(struct crypt_device *cd,
75 struct luks2_hdr *hdr,
76 const struct volume_key *vk)
79 const digest_handler *dh;
81 dh = LUKS2_digest_handler_type(cd, type);
85 digest = LUKS2_digest_find_free(cd, hdr);
89 log_dbg(cd, "Creating new digest %d (%s).", digest, type);
91 return dh->store(cd, digest, vk->key, vk->keylength) ?: digest;
94 int LUKS2_digest_by_keyslot(struct luks2_hdr *hdr, int keyslot)
96 char keyslot_name[16];
97 json_object *jobj_digests, *jobj_digest_keyslots;
99 if (snprintf(keyslot_name, sizeof(keyslot_name), "%u", keyslot) < 1)
102 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
104 json_object_object_foreach(jobj_digests, key, val) {
105 json_object_object_get_ex(val, "keyslots", &jobj_digest_keyslots);
106 if (LUKS2_array_jobj(jobj_digest_keyslots, keyslot_name))
113 int LUKS2_digest_verify_by_digest(struct crypt_device *cd,
114 struct luks2_hdr *hdr,
116 const struct volume_key *vk)
118 const digest_handler *h;
121 h = LUKS2_digest_handler(cd, digest);
125 r = h->verify(cd, digest, vk->key, vk->keylength);
127 log_dbg(cd, "Digest %d (%s) verify failed with %d.", digest, h->name, r);
134 int LUKS2_digest_verify(struct crypt_device *cd,
135 struct luks2_hdr *hdr,
136 const struct volume_key *vk,
141 digest = LUKS2_digest_by_keyslot(hdr, keyslot);
145 log_dbg(cd, "Verifying key from keyslot %d, digest %d.", keyslot, digest);
147 return LUKS2_digest_verify_by_digest(cd, hdr, digest, vk);
150 int LUKS2_digest_dump(struct crypt_device *cd, int digest)
152 const digest_handler *h;
154 if (!(h = LUKS2_digest_handler(cd, digest)))
157 return h->dump(cd, digest);
160 int LUKS2_digest_any_matching(struct crypt_device *cd,
161 struct luks2_hdr *hdr,
162 const struct volume_key *vk)
166 for (digest = 0; digest < LUKS2_DIGEST_MAX; digest++)
167 if (LUKS2_digest_verify_by_digest(cd, hdr, digest, vk) == digest)
173 int LUKS2_digest_verify_by_segment(struct crypt_device *cd,
174 struct luks2_hdr *hdr,
176 const struct volume_key *vk)
178 return LUKS2_digest_verify_by_digest(cd, hdr, LUKS2_digest_by_segment(hdr, segment), vk);
181 /* FIXME: segment can have more digests */
182 int LUKS2_digest_by_segment(struct luks2_hdr *hdr, int segment)
184 char segment_name[16];
185 json_object *jobj_digests, *jobj_digest_segments;
187 if (segment == CRYPT_DEFAULT_SEGMENT)
188 segment = LUKS2_get_default_segment(hdr);
190 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
192 if (snprintf(segment_name, sizeof(segment_name), "%u", segment) < 1)
195 json_object_object_foreach(jobj_digests, key, val) {
196 json_object_object_get_ex(val, "segments", &jobj_digest_segments);
197 if (!LUKS2_array_jobj(jobj_digest_segments, segment_name))
206 static int assign_one_digest(struct crypt_device *cd, struct luks2_hdr *hdr,
207 int keyslot, int digest, int assign)
209 json_object *jobj1, *jobj_digest, *jobj_digest_keyslots;
212 log_dbg(cd, "Keyslot %i %s digest %i.", keyslot, assign ? "assigned to" : "unassigned from", digest);
214 jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
218 json_object_object_get_ex(jobj_digest, "keyslots", &jobj_digest_keyslots);
219 if (!jobj_digest_keyslots)
222 snprintf(num, sizeof(num), "%d", keyslot);
224 jobj1 = LUKS2_array_jobj(jobj_digest_keyslots, num);
226 json_object_array_add(jobj_digest_keyslots, json_object_new_string(num));
228 jobj1 = LUKS2_array_remove(jobj_digest_keyslots, num);
230 json_object_object_add(jobj_digest, "keyslots", jobj1);
236 int LUKS2_digest_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
237 int keyslot, int digest, int assign, int commit)
239 json_object *jobj_digests;
242 if (digest == CRYPT_ANY_DIGEST) {
243 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
245 json_object_object_foreach(jobj_digests, key, val) {
247 r = assign_one_digest(cd, hdr, keyslot, atoi(key), assign);
252 r = assign_one_digest(cd, hdr, keyslot, digest, assign);
257 // FIXME: do not write header in nothing changed
258 return commit ? LUKS2_hdr_write(cd, hdr) : 0;
261 static int assign_all_segments(struct crypt_device *cd, struct luks2_hdr *hdr,
262 int digest, int assign)
264 json_object *jobj1, *jobj_digest, *jobj_digest_segments;
266 jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
270 json_object_object_get_ex(jobj_digest, "segments", &jobj_digest_segments);
271 if (!jobj_digest_segments)
275 json_object_object_foreach(LUKS2_get_segments_jobj(hdr), key, value) {
277 jobj1 = LUKS2_array_jobj(jobj_digest_segments, key);
279 json_object_array_add(jobj_digest_segments, json_object_new_string(key));
282 jobj1 = json_object_new_array();
285 json_object_object_add(jobj_digest, "segments", jobj1);
291 static int assign_one_segment(struct crypt_device *cd, struct luks2_hdr *hdr,
292 int segment, int digest, int assign)
294 json_object *jobj1, *jobj_digest, *jobj_digest_segments;
297 log_dbg(cd, "Segment %i %s digest %i.", segment, assign ? "assigned to" : "unassigned from", digest);
299 jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
303 json_object_object_get_ex(jobj_digest, "segments", &jobj_digest_segments);
304 if (!jobj_digest_segments)
307 snprintf(num, sizeof(num), "%d", segment);
309 jobj1 = LUKS2_array_jobj(jobj_digest_segments, num);
311 json_object_array_add(jobj_digest_segments, json_object_new_string(num));
313 jobj1 = LUKS2_array_remove(jobj_digest_segments, num);
315 json_object_object_add(jobj_digest, "segments", jobj1);
321 int LUKS2_digest_segment_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
322 int segment, int digest, int assign, int commit)
324 json_object *jobj_digests;
327 if (segment == CRYPT_DEFAULT_SEGMENT)
328 segment = LUKS2_get_default_segment(hdr);
330 if (digest == CRYPT_ANY_DIGEST) {
331 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
333 json_object_object_foreach(jobj_digests, key, val) {
335 if (segment == CRYPT_ANY_SEGMENT)
336 r = assign_all_segments(cd, hdr, atoi(key), assign);
338 r = assign_one_segment(cd, hdr, segment, atoi(key), assign);
343 if (segment == CRYPT_ANY_SEGMENT)
344 r = assign_all_segments(cd, hdr, digest, assign);
346 r = assign_one_segment(cd, hdr, segment, digest, assign);
352 // FIXME: do not write header in nothing changed
353 return commit ? LUKS2_hdr_write(cd, hdr) : 0;
356 static int digest_unused(json_object *jobj_digest)
360 json_object_object_get_ex(jobj_digest, "segments", &jobj);
361 if (!jobj || !json_object_is_type(jobj, json_type_array) || json_object_array_length(jobj) > 0)
364 json_object_object_get_ex(jobj_digest, "keyslots", &jobj);
365 if (!jobj || !json_object_is_type(jobj, json_type_array))
368 return json_object_array_length(jobj) > 0 ? 0 : 1;
371 void LUKS2_digests_erase_unused(struct crypt_device *cd,
372 struct luks2_hdr *hdr)
374 json_object *jobj_digests;
376 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
377 if (!jobj_digests || !json_object_is_type(jobj_digests, json_type_object))
380 json_object_object_foreach(jobj_digests, key, val) {
381 if (digest_unused(val)) {
382 log_dbg(cd, "Erasing unused digest %d.", atoi(key));
383 json_object_object_del(jobj_digests, key);
388 /* Key description helpers */
389 static char *get_key_description_by_digest(struct crypt_device *cd, int digest)
391 char *desc, digest_str[3];
395 if (!crypt_get_uuid(cd))
398 r = snprintf(digest_str, sizeof(digest_str), "d%u", digest);
399 if (r < 0 || (size_t)r >= sizeof(digest_str))
402 /* "cryptsetup:<uuid>-<digest_str>" + \0 */
403 len = strlen(crypt_get_uuid(cd)) + strlen(digest_str) + 13;
409 r = snprintf(desc, len, "%s:%s-%s", "cryptsetup", crypt_get_uuid(cd), digest_str);
410 if (r < 0 || (size_t)r >= len) {
418 int LUKS2_key_description_by_segment(struct crypt_device *cd,
419 struct luks2_hdr *hdr, struct volume_key *vk, int segment)
421 char *desc = get_key_description_by_digest(cd, LUKS2_digest_by_segment(hdr, segment));
424 r = crypt_volume_key_set_description(vk, desc);
429 int LUKS2_volume_key_load_in_keyring_by_keyslot(struct crypt_device *cd,
430 struct luks2_hdr *hdr, struct volume_key *vk, int keyslot)
432 char *desc = get_key_description_by_digest(cd, LUKS2_digest_by_keyslot(hdr, keyslot));
435 r = crypt_volume_key_set_description(vk, desc);
437 r = crypt_volume_key_load_in_keyring(cd, vk);
443 int LUKS2_volume_key_load_in_keyring_by_digest(struct crypt_device *cd,
444 struct luks2_hdr *hdr, struct volume_key *vk, int digest)
446 char *desc = get_key_description_by_digest(cd, digest);
449 r = crypt_volume_key_set_description(vk, desc);
451 r = crypt_volume_key_load_in_keyring(cd, vk);