2 * LUKS - Linux Unified Key Setup v2, digest handling
4 * Copyright (C) 2015-2021 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2015-2021 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 if (snprintf(num, sizeof(num), "%d", keyslot) < 0)
226 jobj1 = LUKS2_array_jobj(jobj_digest_keyslots, num);
228 json_object_array_add(jobj_digest_keyslots, json_object_new_string(num));
230 jobj1 = LUKS2_array_remove(jobj_digest_keyslots, num);
232 json_object_object_add(jobj_digest, "keyslots", jobj1);
238 int LUKS2_digest_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
239 int keyslot, int digest, int assign, int commit)
241 json_object *jobj_digests;
244 if (digest == CRYPT_ANY_DIGEST) {
245 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
247 json_object_object_foreach(jobj_digests, key, val) {
249 r = assign_one_digest(cd, hdr, keyslot, atoi(key), assign);
254 r = assign_one_digest(cd, hdr, keyslot, digest, assign);
259 // FIXME: do not write header in nothing changed
260 return commit ? LUKS2_hdr_write(cd, hdr) : 0;
263 static int assign_all_segments(struct crypt_device *cd, struct luks2_hdr *hdr,
264 int digest, int assign)
266 json_object *jobj1, *jobj_digest, *jobj_digest_segments;
268 jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
272 json_object_object_get_ex(jobj_digest, "segments", &jobj_digest_segments);
273 if (!jobj_digest_segments)
277 json_object_object_foreach(LUKS2_get_segments_jobj(hdr), key, value) {
279 jobj1 = LUKS2_array_jobj(jobj_digest_segments, key);
281 json_object_array_add(jobj_digest_segments, json_object_new_string(key));
284 jobj1 = json_object_new_array();
287 json_object_object_add(jobj_digest, "segments", jobj1);
293 static int assign_one_segment(struct crypt_device *cd, struct luks2_hdr *hdr,
294 int segment, int digest, int assign)
296 json_object *jobj1, *jobj_digest, *jobj_digest_segments;
299 log_dbg(cd, "Segment %i %s digest %i.", segment, assign ? "assigned to" : "unassigned from", digest);
301 jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
305 json_object_object_get_ex(jobj_digest, "segments", &jobj_digest_segments);
306 if (!jobj_digest_segments)
309 if (snprintf(num, sizeof(num), "%d", segment) < 0)
313 jobj1 = LUKS2_array_jobj(jobj_digest_segments, num);
315 json_object_array_add(jobj_digest_segments, json_object_new_string(num));
317 jobj1 = LUKS2_array_remove(jobj_digest_segments, num);
319 json_object_object_add(jobj_digest, "segments", jobj1);
325 int LUKS2_digest_segment_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
326 int segment, int digest, int assign, int commit)
328 json_object *jobj_digests;
331 if (segment == CRYPT_DEFAULT_SEGMENT)
332 segment = LUKS2_get_default_segment(hdr);
334 if (digest == CRYPT_ANY_DIGEST) {
335 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
337 json_object_object_foreach(jobj_digests, key, val) {
339 if (segment == CRYPT_ANY_SEGMENT)
340 r = assign_all_segments(cd, hdr, atoi(key), assign);
342 r = assign_one_segment(cd, hdr, segment, atoi(key), assign);
347 if (segment == CRYPT_ANY_SEGMENT)
348 r = assign_all_segments(cd, hdr, digest, assign);
350 r = assign_one_segment(cd, hdr, segment, digest, assign);
356 // FIXME: do not write header in nothing changed
357 return commit ? LUKS2_hdr_write(cd, hdr) : 0;
360 static int digest_unused(json_object *jobj_digest)
364 json_object_object_get_ex(jobj_digest, "segments", &jobj);
365 if (!jobj || !json_object_is_type(jobj, json_type_array) || json_object_array_length(jobj) > 0)
368 json_object_object_get_ex(jobj_digest, "keyslots", &jobj);
369 if (!jobj || !json_object_is_type(jobj, json_type_array))
372 return json_object_array_length(jobj) > 0 ? 0 : 1;
375 void LUKS2_digests_erase_unused(struct crypt_device *cd,
376 struct luks2_hdr *hdr)
378 json_object *jobj_digests;
380 json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
381 if (!jobj_digests || !json_object_is_type(jobj_digests, json_type_object))
384 json_object_object_foreach(jobj_digests, key, val) {
385 if (digest_unused(val)) {
386 log_dbg(cd, "Erasing unused digest %d.", atoi(key));
387 json_object_object_del(jobj_digests, key);
392 /* Key description helpers */
393 static char *get_key_description_by_digest(struct crypt_device *cd, int digest)
395 char *desc, digest_str[3];
399 if (!crypt_get_uuid(cd))
402 r = snprintf(digest_str, sizeof(digest_str), "d%u", digest);
403 if (r < 0 || (size_t)r >= sizeof(digest_str))
406 /* "cryptsetup:<uuid>-<digest_str>" + \0 */
407 len = strlen(crypt_get_uuid(cd)) + strlen(digest_str) + 13;
413 r = snprintf(desc, len, "%s:%s-%s", "cryptsetup", crypt_get_uuid(cd), digest_str);
414 if (r < 0 || (size_t)r >= len) {
422 int LUKS2_key_description_by_segment(struct crypt_device *cd,
423 struct luks2_hdr *hdr, struct volume_key *vk, int segment)
425 char *desc = get_key_description_by_digest(cd, LUKS2_digest_by_segment(hdr, segment));
428 r = crypt_volume_key_set_description(vk, desc);
433 int LUKS2_volume_key_load_in_keyring_by_keyslot(struct crypt_device *cd,
434 struct luks2_hdr *hdr, struct volume_key *vk, int keyslot)
436 char *desc = get_key_description_by_digest(cd, LUKS2_digest_by_keyslot(hdr, keyslot));
439 r = crypt_volume_key_set_description(vk, desc);
441 r = crypt_volume_key_load_in_keyring(cd, vk);
447 int LUKS2_volume_key_load_in_keyring_by_digest(struct crypt_device *cd,
448 struct luks2_hdr *hdr, struct volume_key *vk, int digest)
450 char *desc = get_key_description_by_digest(cd, digest);
453 r = crypt_volume_key_set_description(vk, desc);
455 r = crypt_volume_key_load_in_keyring(cd, vk);