1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Permission is hereby granted, free of charge, to any person
5 * obtaining a copy of this software and associated documentation
6 * files (the "Software"), to deal in the Software without
7 * restriction, including without limitation the rights to use, copy,
8 * modify, merge, publish, distribute, sublicense, and/or sell copies
9 * of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25 #include "avb_slot_verify.h"
26 #include "avb_chain_partition_descriptor.h"
27 #include "avb_cmdline.h"
28 #include "avb_footer.h"
29 #include "avb_hash_descriptor.h"
30 #include "avb_hashtree_descriptor.h"
31 #include "avb_kernel_cmdline_descriptor.h"
32 #include "avb_sha.h"
33 #include "avb_util.h"
34 #include "avb_vbmeta_image.h"
35 #include "avb_version.h"
36
37 /* Maximum number of partitions that can be loaded with avb_slot_verify(). */
38 #define MAX_NUMBER_OF_LOADED_PARTITIONS 32
39
40 /* Maximum number of vbmeta images that can be loaded with avb_slot_verify(). */
41 #define MAX_NUMBER_OF_VBMETA_IMAGES 32
42
43 /* Maximum size of a vbmeta image - 64 KiB. */
44 #define VBMETA_MAX_SIZE (64 * 1024)
45
46 static AvbSlotVerifyResult initialize_persistent_digest(
47 AvbOps* ops,
48 const char* part_name,
49 const char* persistent_value_name,
50 size_t digest_size,
51 const uint8_t* initial_digest,
52 uint8_t* out_digest);
53
54 /* Helper function to see if we should continue with verification in
55 * allow_verification_error=true mode if something goes wrong. See the
56 * comments for the avb_slot_verify() function for more information.
57 */
result_should_continue(AvbSlotVerifyResult result)58 static inline bool result_should_continue(AvbSlotVerifyResult result) {
59 switch (result) {
60 case AVB_SLOT_VERIFY_RESULT_ERROR_OOM:
61 case AVB_SLOT_VERIFY_RESULT_ERROR_IO:
62 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA:
63 case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION:
64 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT:
65 return false;
66
67 case AVB_SLOT_VERIFY_RESULT_OK:
68 case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION:
69 case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX:
70 case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED:
71 return true;
72 }
73
74 return false;
75 }
76
load_full_partition(AvbOps * ops,const char * part_name,uint64_t image_size,uint8_t ** out_image_buf,bool * out_image_preloaded)77 static AvbSlotVerifyResult load_full_partition(AvbOps* ops,
78 const char* part_name,
79 uint64_t image_size,
80 uint8_t** out_image_buf,
81 bool* out_image_preloaded) {
82 size_t part_num_read;
83 AvbIOResult io_ret;
84
85 /* Make sure that we do not overwrite existing data. */
86 avb_assert(*out_image_buf == NULL);
87 avb_assert(!*out_image_preloaded);
88
89 /* We are going to implicitly cast image_size from uint64_t to size_t in the
90 * following code, so we need to make sure that the cast is safe. */
91 if (image_size != (size_t)(image_size)) {
92 avb_errorv(part_name, ": Partition size too large to load.\n", NULL);
93 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
94 }
95
96 /* Try use a preloaded one. */
97 if (ops->get_preloaded_partition != NULL) {
98 io_ret = ops->get_preloaded_partition(
99 ops, part_name, image_size, out_image_buf, &part_num_read);
100 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
101 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
102 } else if (io_ret != AVB_IO_RESULT_OK) {
103 avb_errorv(part_name, ": Error loading data from partition.\n", NULL);
104 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
105 }
106
107 if (*out_image_buf != NULL) {
108 if (part_num_read != image_size) {
109 avb_errorv(part_name, ": Read incorrect number of bytes.\n", NULL);
110 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
111 }
112 *out_image_preloaded = true;
113 }
114 }
115
116 /* Allocate and copy the partition. */
117 if (!*out_image_preloaded) {
118 *out_image_buf = avb_malloc(image_size);
119 if (*out_image_buf == NULL) {
120 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
121 }
122
123 io_ret = ops->read_from_partition(ops,
124 part_name,
125 0 /* offset */,
126 image_size,
127 *out_image_buf,
128 &part_num_read);
129 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
130 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
131 } else if (io_ret != AVB_IO_RESULT_OK) {
132 avb_errorv(part_name, ": Error loading data from partition.\n", NULL);
133 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
134 }
135 if (part_num_read != image_size) {
136 avb_errorv(part_name, ": Read incorrect number of bytes.\n", NULL);
137 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
138 }
139 }
140
141 return AVB_SLOT_VERIFY_RESULT_OK;
142 }
143
144 /* Reads a persistent digest stored as a named persistent value corresponding to
145 * the given |part_name|. The value is returned in |out_digest| which must point
146 * to |expected_digest_size| bytes. If there is no digest stored for |part_name|
147 * it can be initialized by providing a non-NULL |initial_digest| of length
148 * |expected_digest_size|. This automatic initialization will only occur if the
149 * device is currently locked. The |initial_digest| may be NULL.
150 *
151 * Returns AVB_SLOT_VERIFY_RESULT_OK on success, otherwise returns an
152 * AVB_SLOT_VERIFY_RESULT_ERROR_* error code.
153 *
154 * If the value does not exist, is not supported, or is not populated, and
155 * |initial_digest| is NULL, returns
156 * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA. If |expected_digest_size| does
157 * not match the stored digest size, also returns
158 * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA.
159 */
read_persistent_digest(AvbOps * ops,const char * part_name,size_t expected_digest_size,const uint8_t * initial_digest,uint8_t * out_digest)160 static AvbSlotVerifyResult read_persistent_digest(AvbOps* ops,
161 const char* part_name,
162 size_t expected_digest_size,
163 const uint8_t* initial_digest,
164 uint8_t* out_digest) {
165 char* persistent_value_name = NULL;
166 AvbIOResult io_ret = AVB_IO_RESULT_OK;
167 size_t stored_digest_size = 0;
168
169 if (ops->read_persistent_value == NULL) {
170 avb_errorv(part_name, ": Persistent values are not implemented.\n", NULL);
171 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
172 }
173 persistent_value_name =
174 avb_strdupv(AVB_NPV_PERSISTENT_DIGEST_PREFIX, part_name, NULL);
175 if (persistent_value_name == NULL) {
176 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
177 }
178
179 io_ret = ops->read_persistent_value(ops,
180 persistent_value_name,
181 expected_digest_size,
182 out_digest,
183 &stored_digest_size);
184
185 // If no such named persistent value exists and an initial digest value was
186 // given, initialize the named persistent value with the given digest. If
187 // initialized successfully, this will recurse into this function but with a
188 // NULL initial_digest.
189 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE && initial_digest) {
190 AvbSlotVerifyResult ret =
191 initialize_persistent_digest(ops,
192 part_name,
193 persistent_value_name,
194 expected_digest_size,
195 initial_digest,
196 out_digest);
197 avb_free(persistent_value_name);
198 return ret;
199 }
200 avb_free(persistent_value_name);
201
202 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
203 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
204 } else if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE) {
205 // Treat a missing persistent value as a verification error, which is
206 // ignoreable, rather than a metadata error which is not.
207 avb_errorv(part_name, ": Persistent digest does not exist.\n", NULL);
208 return AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
209 } else if (io_ret == AVB_IO_RESULT_ERROR_INVALID_VALUE_SIZE ||
210 io_ret == AVB_IO_RESULT_ERROR_INSUFFICIENT_SPACE) {
211 avb_errorv(
212 part_name, ": Persistent digest is not of expected size.\n", NULL);
213 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
214 } else if (io_ret != AVB_IO_RESULT_OK) {
215 avb_errorv(part_name, ": Error reading persistent digest.\n", NULL);
216 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
217 } else if (expected_digest_size != stored_digest_size) {
218 avb_errorv(
219 part_name, ": Persistent digest is not of expected size.\n", NULL);
220 return AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
221 }
222 return AVB_SLOT_VERIFY_RESULT_OK;
223 }
224
initialize_persistent_digest(AvbOps * ops,const char * part_name,const char * persistent_value_name,size_t digest_size,const uint8_t * initial_digest,uint8_t * out_digest)225 static AvbSlotVerifyResult initialize_persistent_digest(
226 AvbOps* ops,
227 const char* part_name,
228 const char* persistent_value_name,
229 size_t digest_size,
230 const uint8_t* initial_digest,
231 uint8_t* out_digest) {
232 AvbSlotVerifyResult ret;
233 AvbIOResult io_ret = AVB_IO_RESULT_OK;
234 bool is_device_unlocked = true;
235
236 io_ret = ops->read_is_device_unlocked(ops, &is_device_unlocked);
237 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
238 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
239 } else if (io_ret != AVB_IO_RESULT_OK) {
240 avb_error("Error getting device lock state.\n");
241 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
242 }
243
244 if (is_device_unlocked) {
245 avb_debugv(part_name,
246 ": Digest does not exist, device unlocked so not initializing "
247 "digest.\n",
248 NULL);
249 return AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
250 }
251
252 // Device locked; initialize digest with given initial value.
253 avb_debugv(part_name,
254 ": Digest does not exist, initializing persistent digest.\n",
255 NULL);
256 io_ret = ops->write_persistent_value(
257 ops, persistent_value_name, digest_size, initial_digest);
258 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
259 return AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
260 } else if (io_ret != AVB_IO_RESULT_OK) {
261 avb_errorv(part_name, ": Error initializing persistent digest.\n", NULL);
262 return AVB_SLOT_VERIFY_RESULT_ERROR_IO;
263 }
264
265 // To ensure that the digest value was written successfully - and avoid a
266 // scenario where the digest is simply 'initialized' on every verify - recurse
267 // into read_persistent_digest to read back the written value. The NULL
268 // initial_digest ensures that this will not recurse again.
269 ret = read_persistent_digest(ops, part_name, digest_size, NULL, out_digest);
270 if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
271 avb_errorv(part_name,
272 ": Reading back initialized persistent digest failed!\n",
273 NULL);
274 }
275 return ret;
276 }
277
load_and_verify_hash_partition(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,bool allow_verification_error,const AvbDescriptor * descriptor,AvbSlotVerifyData * slot_data)278 static AvbSlotVerifyResult load_and_verify_hash_partition(
279 AvbOps* ops,
280 const char* const* requested_partitions,
281 const char* ab_suffix,
282 bool allow_verification_error,
283 const AvbDescriptor* descriptor,
284 AvbSlotVerifyData* slot_data) {
285 AvbHashDescriptor hash_desc;
286 const uint8_t* desc_partition_name = NULL;
287 const uint8_t* desc_salt;
288 const uint8_t* desc_digest;
289 char part_name[AVB_PART_NAME_MAX_SIZE];
290 AvbSlotVerifyResult ret;
291 AvbIOResult io_ret;
292 uint8_t* image_buf = NULL;
293 bool image_preloaded = false;
294 uint8_t* digest;
295 size_t digest_len;
296 const char* found;
297 uint64_t image_size;
298 size_t expected_digest_len = 0;
299 uint8_t expected_digest_buf[AVB_SHA512_DIGEST_SIZE];
300 const uint8_t* expected_digest = NULL;
301
302 if (!avb_hash_descriptor_validate_and_byteswap(
303 (const AvbHashDescriptor*)descriptor, &hash_desc)) {
304 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
305 goto out;
306 }
307
308 desc_partition_name =
309 ((const uint8_t*)descriptor) + sizeof(AvbHashDescriptor);
310 desc_salt = desc_partition_name + hash_desc.partition_name_len;
311 desc_digest = desc_salt + hash_desc.salt_len;
312
313 if (!avb_validate_utf8(desc_partition_name, hash_desc.partition_name_len)) {
314 avb_error("Partition name is not valid UTF-8.\n");
315 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
316 goto out;
317 }
318
319 /* Don't bother loading or validating unless the partition was
320 * requested in the first place.
321 */
322 found = avb_strv_find_str(requested_partitions,
323 (const char*)desc_partition_name,
324 hash_desc.partition_name_len);
325 if (found == NULL) {
326 ret = AVB_SLOT_VERIFY_RESULT_OK;
327 goto out;
328 }
329
330 if ((hash_desc.flags & AVB_HASH_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) != 0) {
331 /* No ab_suffix, just copy the partition name as is. */
332 if (hash_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) {
333 avb_error("Partition name does not fit.\n");
334 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
335 goto out;
336 }
337 avb_memcpy(part_name, desc_partition_name, hash_desc.partition_name_len);
338 part_name[hash_desc.partition_name_len] = '\0';
339 } else if (hash_desc.digest_len == 0 && avb_strlen(ab_suffix) != 0) {
340 /* No ab_suffix allowed for partitions without a digest in the descriptor
341 * because these partitions hold data unique to this device and are not
342 * updated using an A/B scheme.
343 */
344 avb_error("Cannot use A/B with a persistent digest.\n");
345 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
346 goto out;
347 } else {
348 /* Add ab_suffix to the partition name. */
349 if (!avb_str_concat(part_name,
350 sizeof part_name,
351 (const char*)desc_partition_name,
352 hash_desc.partition_name_len,
353 ab_suffix,
354 avb_strlen(ab_suffix))) {
355 avb_error("Partition name and suffix does not fit.\n");
356 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
357 goto out;
358 }
359 }
360
361 /* If we're allowing verification errors then hash_desc.image_size
362 * may no longer match what's in the partition... so in this case
363 * just load the entire partition.
364 *
365 * For example, this can happen if a developer does 'fastboot flash
366 * boot /path/to/new/and/bigger/boot.img'. We want this to work
367 * since it's such a common workflow.
368 */
369 image_size = hash_desc.image_size;
370 if (allow_verification_error) {
371 io_ret = ops->get_size_of_partition(ops, part_name, &image_size);
372 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
373 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
374 goto out;
375 } else if (io_ret != AVB_IO_RESULT_OK) {
376 avb_errorv(part_name, ": Error determining partition size.\n", NULL);
377 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
378 goto out;
379 }
380 avb_debugv(part_name, ": Loading entire partition.\n", NULL);
381 }
382
383 ret = load_full_partition(
384 ops, part_name, image_size, &image_buf, &image_preloaded);
385 if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
386 goto out;
387 }
388 // Although only one of the type might be used, we have to defined the
389 // structure here so that they would live outside the 'if/else' scope to be
390 // used later.
391 AvbSHA256Ctx sha256_ctx;
392 AvbSHA512Ctx sha512_ctx;
393 size_t image_size_to_hash = hash_desc.image_size;
394 // If we allow verification error and the whole partition is smaller than
395 // image size in hash descriptor, we just hash the whole partition.
396 if (image_size_to_hash > image_size) {
397 image_size_to_hash = image_size;
398 }
399 if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha256") == 0) {
400 avb_sha256_init(&sha256_ctx);
401 avb_sha256_update(&sha256_ctx, desc_salt, hash_desc.salt_len);
402 avb_sha256_update(&sha256_ctx, image_buf, image_size_to_hash);
403 digest = avb_sha256_final(&sha256_ctx);
404 digest_len = AVB_SHA256_DIGEST_SIZE;
405 } else if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha512") == 0) {
406 avb_sha512_init(&sha512_ctx);
407 avb_sha512_update(&sha512_ctx, desc_salt, hash_desc.salt_len);
408 avb_sha512_update(&sha512_ctx, image_buf, image_size_to_hash);
409 digest = avb_sha512_final(&sha512_ctx);
410 digest_len = AVB_SHA512_DIGEST_SIZE;
411 } else {
412 avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL);
413 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
414 goto out;
415 }
416
417 if (hash_desc.digest_len == 0) {
418 /* Expect a match to a persistent digest. */
419 avb_debugv(part_name, ": No digest, using persistent digest.\n", NULL);
420 expected_digest_len = digest_len;
421 expected_digest = expected_digest_buf;
422 avb_assert(expected_digest_len <= sizeof(expected_digest_buf));
423 /* Pass |digest| as the |initial_digest| so devices not yet initialized get
424 * initialized to the current partition digest.
425 */
426 ret = read_persistent_digest(
427 ops, part_name, digest_len, digest, expected_digest_buf);
428 if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
429 goto out;
430 }
431 } else {
432 /* Expect a match to the digest in the descriptor. */
433 expected_digest_len = hash_desc.digest_len;
434 expected_digest = desc_digest;
435 }
436
437 if (digest_len != expected_digest_len) {
438 avb_errorv(
439 part_name, ": Digest in descriptor not of expected size.\n", NULL);
440 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
441 goto out;
442 }
443
444 if (avb_safe_memcmp(digest, expected_digest, digest_len) != 0) {
445 avb_errorv(part_name,
446 ": Hash of data does not match digest in descriptor.\n",
447 NULL);
448 ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
449 goto out;
450 }
451
452 ret = AVB_SLOT_VERIFY_RESULT_OK;
453
454 out:
455
456 /* If it worked and something was loaded, copy to slot_data. */
457 if ((ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) &&
458 image_buf != NULL) {
459 AvbPartitionData* loaded_partition;
460 if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) {
461 avb_errorv(part_name, ": Too many loaded partitions.\n", NULL);
462 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
463 goto fail;
464 }
465 loaded_partition =
466 &slot_data->loaded_partitions[slot_data->num_loaded_partitions++];
467 loaded_partition->partition_name = avb_strdup(found);
468 loaded_partition->data_size = image_size;
469 loaded_partition->data = image_buf;
470 loaded_partition->preloaded = image_preloaded;
471 image_buf = NULL;
472 }
473
474 fail:
475 if (image_buf != NULL && !image_preloaded) {
476 avb_free(image_buf);
477 }
478 return ret;
479 }
480
load_requested_partitions(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,AvbSlotVerifyData * slot_data)481 static AvbSlotVerifyResult load_requested_partitions(
482 AvbOps* ops,
483 const char* const* requested_partitions,
484 const char* ab_suffix,
485 AvbSlotVerifyData* slot_data) {
486 AvbSlotVerifyResult ret;
487 uint8_t* image_buf = NULL;
488 bool image_preloaded = false;
489 size_t n;
490
491 for (n = 0; requested_partitions[n] != NULL; n++) {
492 char part_name[AVB_PART_NAME_MAX_SIZE];
493 AvbIOResult io_ret;
494 uint64_t image_size;
495 AvbPartitionData* loaded_partition;
496
497 if (!avb_str_concat(part_name,
498 sizeof part_name,
499 requested_partitions[n],
500 avb_strlen(requested_partitions[n]),
501 ab_suffix,
502 avb_strlen(ab_suffix))) {
503 avb_error("Partition name and suffix does not fit.\n");
504 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
505 goto out;
506 }
507
508 io_ret = ops->get_size_of_partition(ops, part_name, &image_size);
509 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
510 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
511 goto out;
512 } else if (io_ret != AVB_IO_RESULT_OK) {
513 avb_errorv(part_name, ": Error determining partition size.\n", NULL);
514 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
515 goto out;
516 }
517 avb_debugv(part_name, ": Loading entire partition.\n", NULL);
518
519 ret = load_full_partition(
520 ops, part_name, image_size, &image_buf, &image_preloaded);
521 if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
522 goto out;
523 }
524
525 /* Move to slot_data. */
526 if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) {
527 avb_errorv(part_name, ": Too many loaded partitions.\n", NULL);
528 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
529 goto out;
530 }
531 loaded_partition =
532 &slot_data->loaded_partitions[slot_data->num_loaded_partitions++];
533 loaded_partition->partition_name = avb_strdup(requested_partitions[n]);
534 if (loaded_partition->partition_name == NULL) {
535 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
536 goto out;
537 }
538 loaded_partition->data_size = image_size;
539 loaded_partition->data = image_buf; /* Transferring the owner. */
540 loaded_partition->preloaded = image_preloaded;
541 image_buf = NULL;
542 image_preloaded = false;
543 }
544
545 ret = AVB_SLOT_VERIFY_RESULT_OK;
546
547 out:
548 /* Free the current buffer if any. */
549 if (image_buf != NULL && !image_preloaded) {
550 avb_free(image_buf);
551 }
552 /* Buffers that are already saved in slot_data will be handled by the caller
553 * even on failure. */
554 return ret;
555 }
556
load_and_verify_vbmeta(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,AvbSlotVerifyFlags flags,bool allow_verification_error,AvbVBMetaImageFlags toplevel_vbmeta_flags,int rollback_index_location,const char * partition_name,size_t partition_name_len,const uint8_t * expected_public_key,size_t expected_public_key_length,AvbSlotVerifyData * slot_data,AvbAlgorithmType * out_algorithm_type,AvbCmdlineSubstList * out_additional_cmdline_subst)557 static AvbSlotVerifyResult load_and_verify_vbmeta(
558 AvbOps* ops,
559 const char* const* requested_partitions,
560 const char* ab_suffix,
561 AvbSlotVerifyFlags flags,
562 bool allow_verification_error,
563 AvbVBMetaImageFlags toplevel_vbmeta_flags,
564 int rollback_index_location,
565 const char* partition_name,
566 size_t partition_name_len,
567 const uint8_t* expected_public_key,
568 size_t expected_public_key_length,
569 AvbSlotVerifyData* slot_data,
570 AvbAlgorithmType* out_algorithm_type,
571 AvbCmdlineSubstList* out_additional_cmdline_subst) {
572 char full_partition_name[AVB_PART_NAME_MAX_SIZE];
573 AvbSlotVerifyResult ret;
574 AvbIOResult io_ret;
575 uint64_t vbmeta_offset;
576 size_t vbmeta_size;
577 uint8_t* vbmeta_buf = NULL;
578 size_t vbmeta_num_read;
579 AvbVBMetaVerifyResult vbmeta_ret;
580 const uint8_t* pk_data;
581 size_t pk_len;
582 AvbVBMetaImageHeader vbmeta_header;
583 uint64_t stored_rollback_index;
584 const AvbDescriptor** descriptors = NULL;
585 size_t num_descriptors;
586 size_t n;
587 bool is_main_vbmeta;
588 bool look_for_vbmeta_footer;
589 AvbVBMetaData* vbmeta_image_data = NULL;
590
591 ret = AVB_SLOT_VERIFY_RESULT_OK;
592
593 avb_assert(slot_data != NULL);
594
595 /* Since we allow top-level vbmeta in 'boot', use
596 * rollback_index_location to determine whether we're the main
597 * vbmeta struct.
598 */
599 is_main_vbmeta = false;
600 if (rollback_index_location == 0) {
601 if ((flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) == 0) {
602 is_main_vbmeta = true;
603 }
604 }
605
606 /* Don't use footers for vbmeta partitions ('vbmeta' or
607 * 'vbmeta_<partition_name>').
608 */
609 look_for_vbmeta_footer = true;
610 if (avb_strncmp(partition_name, "vbmeta", avb_strlen("vbmeta")) == 0) {
611 look_for_vbmeta_footer = false;
612 }
613
614 if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) {
615 avb_error("Partition name is not valid UTF-8.\n");
616 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
617 goto out;
618 }
619
620 /* Construct full partition name e.g. system_a. */
621 if (!avb_str_concat(full_partition_name,
622 sizeof full_partition_name,
623 partition_name,
624 partition_name_len,
625 ab_suffix,
626 avb_strlen(ab_suffix))) {
627 avb_error("Partition name and suffix does not fit.\n");
628 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
629 goto out;
630 }
631
632 /* If we're loading from the main vbmeta partition, the vbmeta struct is in
633 * the beginning. Otherwise we may have to locate it via a footer... if no
634 * footer is found, we look in the beginning to support e.g. vbmeta_<org>
635 * partitions holding data for e.g. super partitions (b/80195851 for
636 * rationale).
637 */
638 vbmeta_offset = 0;
639 vbmeta_size = VBMETA_MAX_SIZE;
640 if (look_for_vbmeta_footer) {
641 uint8_t footer_buf[AVB_FOOTER_SIZE];
642 size_t footer_num_read;
643 AvbFooter footer;
644
645 io_ret = ops->read_from_partition(ops,
646 full_partition_name,
647 -AVB_FOOTER_SIZE,
648 AVB_FOOTER_SIZE,
649 footer_buf,
650 &footer_num_read);
651 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
652 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
653 goto out;
654 } else if (io_ret != AVB_IO_RESULT_OK) {
655 avb_errorv(full_partition_name, ": Error loading footer.\n", NULL);
656 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
657 goto out;
658 }
659 avb_assert(footer_num_read == AVB_FOOTER_SIZE);
660
661 if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf,
662 &footer)) {
663 avb_debugv(full_partition_name, ": No footer detected.\n", NULL);
664 } else {
665 /* Basic footer sanity check since the data is untrusted. */
666 if (footer.vbmeta_size > VBMETA_MAX_SIZE) {
667 avb_errorv(
668 full_partition_name, ": Invalid vbmeta size in footer.\n", NULL);
669 } else {
670 vbmeta_offset = footer.vbmeta_offset;
671 vbmeta_size = footer.vbmeta_size;
672 }
673 }
674 }
675
676 vbmeta_buf = avb_malloc(vbmeta_size);
677 if (vbmeta_buf == NULL) {
678 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
679 goto out;
680 }
681
682 if (vbmeta_offset != 0) {
683 avb_debugv("Loading vbmeta struct in footer from partition '",
684 full_partition_name,
685 "'.\n",
686 NULL);
687 } else {
688 avb_debugv("Loading vbmeta struct from partition '",
689 full_partition_name,
690 "'.\n",
691 NULL);
692 }
693
694 io_ret = ops->read_from_partition(ops,
695 full_partition_name,
696 vbmeta_offset,
697 vbmeta_size,
698 vbmeta_buf,
699 &vbmeta_num_read);
700 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
701 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
702 goto out;
703 } else if (io_ret != AVB_IO_RESULT_OK) {
704 /* If we're looking for 'vbmeta' but there is no such partition,
705 * go try to get it from the boot partition instead.
706 */
707 if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION &&
708 !look_for_vbmeta_footer) {
709 avb_debugv(full_partition_name,
710 ": No such partition. Trying 'boot' instead.\n",
711 NULL);
712 ret = load_and_verify_vbmeta(ops,
713 requested_partitions,
714 ab_suffix,
715 flags,
716 allow_verification_error,
717 0 /* toplevel_vbmeta_flags */,
718 0 /* rollback_index_location */,
719 "boot",
720 avb_strlen("boot"),
721 NULL /* expected_public_key */,
722 0 /* expected_public_key_length */,
723 slot_data,
724 out_algorithm_type,
725 out_additional_cmdline_subst);
726 goto out;
727 } else {
728 avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL);
729 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
730 goto out;
731 }
732 }
733 avb_assert(vbmeta_num_read <= vbmeta_size);
734
735 /* Check if the image is properly signed and get the public key used
736 * to sign the image.
737 */
738 vbmeta_ret =
739 avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len);
740 switch (vbmeta_ret) {
741 case AVB_VBMETA_VERIFY_RESULT_OK:
742 avb_assert(pk_data != NULL && pk_len > 0);
743 break;
744
745 case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED:
746 case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH:
747 case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH:
748 ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
749 avb_errorv(full_partition_name,
750 ": Error verifying vbmeta image: ",
751 avb_vbmeta_verify_result_to_string(vbmeta_ret),
752 "\n",
753 NULL);
754 if (!allow_verification_error) {
755 goto out;
756 }
757 break;
758
759 case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER:
760 /* No way to continue this case. */
761 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
762 avb_errorv(full_partition_name,
763 ": Error verifying vbmeta image: invalid vbmeta header\n",
764 NULL);
765 goto out;
766
767 case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION:
768 /* No way to continue this case. */
769 ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION;
770 avb_errorv(full_partition_name,
771 ": Error verifying vbmeta image: unsupported AVB version\n",
772 NULL);
773 goto out;
774 }
775
776 /* Byteswap the header. */
777 avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf,
778 &vbmeta_header);
779
780 /* If we're the toplevel, assign flags so they'll be passed down. */
781 if (is_main_vbmeta) {
782 toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags;
783 } else {
784 if (vbmeta_header.flags != 0) {
785 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
786 avb_errorv(full_partition_name,
787 ": chained vbmeta image has non-zero flags\n",
788 NULL);
789 goto out;
790 }
791 }
792
793 uint32_t rollback_index_location_to_use = rollback_index_location;
794
795 /* Check if key used to make signature matches what is expected. */
796 if (pk_data != NULL) {
797 if (expected_public_key != NULL) {
798 avb_assert(!is_main_vbmeta);
799 if (expected_public_key_length != pk_len ||
800 avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) {
801 avb_errorv(full_partition_name,
802 ": Public key used to sign data does not match key in chain "
803 "partition descriptor.\n",
804 NULL);
805 ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED;
806 if (!allow_verification_error) {
807 goto out;
808 }
809 }
810 } else {
811 bool key_is_trusted = false;
812 const uint8_t* pk_metadata = NULL;
813 size_t pk_metadata_len = 0;
814
815 if (vbmeta_header.public_key_metadata_size > 0) {
816 pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) +
817 vbmeta_header.authentication_data_block_size +
818 vbmeta_header.public_key_metadata_offset;
819 pk_metadata_len = vbmeta_header.public_key_metadata_size;
820 }
821
822 // If we're not using a vbmeta partition, need to use another AvbOps...
823 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) {
824 io_ret = ops->validate_public_key_for_partition(
825 ops,
826 full_partition_name,
827 pk_data,
828 pk_len,
829 pk_metadata,
830 pk_metadata_len,
831 &key_is_trusted,
832 &rollback_index_location_to_use);
833 } else {
834 avb_assert(is_main_vbmeta);
835 io_ret = ops->validate_vbmeta_public_key(ops,
836 pk_data,
837 pk_len,
838 pk_metadata,
839 pk_metadata_len,
840 &key_is_trusted);
841 }
842
843 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
844 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
845 goto out;
846 } else if (io_ret != AVB_IO_RESULT_OK) {
847 avb_errorv(full_partition_name,
848 ": Error while checking public key used to sign data.\n",
849 NULL);
850 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
851 goto out;
852 }
853 if (!key_is_trusted) {
854 avb_errorv(full_partition_name,
855 ": Public key used to sign data rejected.\n",
856 NULL);
857 ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED;
858 if (!allow_verification_error) {
859 goto out;
860 }
861 }
862 }
863 }
864
865 /* Check rollback index. */
866 io_ret = ops->read_rollback_index(
867 ops, rollback_index_location_to_use, &stored_rollback_index);
868 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
869 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
870 goto out;
871 } else if (io_ret != AVB_IO_RESULT_OK) {
872 avb_errorv(full_partition_name,
873 ": Error getting rollback index for location.\n",
874 NULL);
875 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
876 goto out;
877 }
878 if (vbmeta_header.rollback_index < stored_rollback_index) {
879 avb_errorv(
880 full_partition_name,
881 ": Image rollback index is less than the stored rollback index.\n",
882 NULL);
883 ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX;
884 if (!allow_verification_error) {
885 goto out;
886 }
887 }
888
889 /* Copy vbmeta to vbmeta_images before recursing. */
890 if (is_main_vbmeta) {
891 avb_assert(slot_data->num_vbmeta_images == 0);
892 } else {
893 if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) {
894 avb_assert(slot_data->num_vbmeta_images > 0);
895 }
896 }
897 if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) {
898 avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL);
899 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
900 goto out;
901 }
902 vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++];
903 vbmeta_image_data->partition_name = avb_strdup(partition_name);
904 vbmeta_image_data->vbmeta_data = vbmeta_buf;
905 /* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long
906 * and this includes data past the end of the image. Pass the
907 * actual size of the vbmeta image. Also, no need to use
908 * avb_safe_add() since the header has already been verified.
909 */
910 vbmeta_image_data->vbmeta_size =
911 sizeof(AvbVBMetaImageHeader) +
912 vbmeta_header.authentication_data_block_size +
913 vbmeta_header.auxiliary_data_block_size;
914 vbmeta_image_data->verify_result = vbmeta_ret;
915
916 /* If verification has been disabled by setting a bit in the image,
917 * we're done... except that we need to load the entirety of the
918 * requested partitions.
919 */
920 if (vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) {
921 AvbSlotVerifyResult sub_ret;
922 avb_debugv(
923 full_partition_name, ": VERIFICATION_DISABLED bit is set.\n", NULL);
924 /* If load_requested_partitions() fail it is always a fatal
925 * failure (e.g. ERROR_INVALID_ARGUMENT, ERROR_OOM, etc.) rather
926 * than recoverable (e.g. one where result_should_continue()
927 * returns true) and we want to convey that error.
928 */
929 sub_ret = load_requested_partitions(
930 ops, requested_partitions, ab_suffix, slot_data);
931 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
932 ret = sub_ret;
933 }
934 goto out;
935 }
936
937 /* Now go through all descriptors and take the appropriate action:
938 *
939 * - hash descriptor: Load data from partition, calculate hash, and
940 * checks that it matches what's in the hash descriptor.
941 *
942 * - hashtree descriptor: Do nothing since verification happens
943 * on-the-fly from within the OS. (Unless the descriptor uses a
944 * persistent digest, in which case we need to find it).
945 *
946 * - chained partition descriptor: Load the footer, load the vbmeta
947 * image, verify vbmeta image (includes rollback checks, hash
948 * checks, bail on chained partitions).
949 */
950 descriptors =
951 avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors);
952 for (n = 0; n < num_descriptors; n++) {
953 AvbDescriptor desc;
954
955 if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) {
956 avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL);
957 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
958 goto out;
959 }
960
961 switch (desc.tag) {
962 case AVB_DESCRIPTOR_TAG_HASH: {
963 AvbSlotVerifyResult sub_ret;
964 sub_ret = load_and_verify_hash_partition(ops,
965 requested_partitions,
966 ab_suffix,
967 allow_verification_error,
968 descriptors[n],
969 slot_data);
970 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
971 ret = sub_ret;
972 if (!allow_verification_error || !result_should_continue(ret)) {
973 goto out;
974 }
975 }
976 } break;
977
978 case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: {
979 AvbSlotVerifyResult sub_ret;
980 AvbChainPartitionDescriptor chain_desc;
981 const uint8_t* chain_partition_name;
982 const uint8_t* chain_public_key;
983
984 /* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */
985 if (!is_main_vbmeta) {
986 avb_errorv(full_partition_name,
987 ": Encountered chain descriptor not in main image.\n",
988 NULL);
989 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
990 goto out;
991 }
992
993 if (!avb_chain_partition_descriptor_validate_and_byteswap(
994 (AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) {
995 avb_errorv(full_partition_name,
996 ": Chain partition descriptor is invalid.\n",
997 NULL);
998 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
999 goto out;
1000 }
1001
1002 if (chain_desc.rollback_index_location == 0) {
1003 avb_errorv(full_partition_name,
1004 ": Chain partition has invalid "
1005 "rollback_index_location field.\n",
1006 NULL);
1007 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1008 goto out;
1009 }
1010
1011 chain_partition_name = ((const uint8_t*)descriptors[n]) +
1012 sizeof(AvbChainPartitionDescriptor);
1013 chain_public_key = chain_partition_name + chain_desc.partition_name_len;
1014
1015 sub_ret =
1016 load_and_verify_vbmeta(ops,
1017 requested_partitions,
1018 ab_suffix,
1019 flags,
1020 allow_verification_error,
1021 toplevel_vbmeta_flags,
1022 chain_desc.rollback_index_location,
1023 (const char*)chain_partition_name,
1024 chain_desc.partition_name_len,
1025 chain_public_key,
1026 chain_desc.public_key_len,
1027 slot_data,
1028 NULL, /* out_algorithm_type */
1029 NULL /* out_additional_cmdline_subst */);
1030 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
1031 ret = sub_ret;
1032 if (!result_should_continue(ret)) {
1033 goto out;
1034 }
1035 }
1036 } break;
1037
1038 case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: {
1039 const uint8_t* kernel_cmdline;
1040 AvbKernelCmdlineDescriptor kernel_cmdline_desc;
1041 bool apply_cmdline;
1042
1043 if (!avb_kernel_cmdline_descriptor_validate_and_byteswap(
1044 (AvbKernelCmdlineDescriptor*)descriptors[n],
1045 &kernel_cmdline_desc)) {
1046 avb_errorv(full_partition_name,
1047 ": Kernel cmdline descriptor is invalid.\n",
1048 NULL);
1049 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1050 goto out;
1051 }
1052
1053 kernel_cmdline = ((const uint8_t*)descriptors[n]) +
1054 sizeof(AvbKernelCmdlineDescriptor);
1055
1056 if (!avb_validate_utf8(kernel_cmdline,
1057 kernel_cmdline_desc.kernel_cmdline_length)) {
1058 avb_errorv(full_partition_name,
1059 ": Kernel cmdline is not valid UTF-8.\n",
1060 NULL);
1061 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1062 goto out;
1063 }
1064
1065 /* Compare the flags for top-level VBMeta struct with flags in
1066 * the command-line descriptor so command-line snippets only
1067 * intended for a certain mode (dm-verity enabled/disabled)
1068 * are skipped if applicable.
1069 */
1070 apply_cmdline = true;
1071 if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) {
1072 if (kernel_cmdline_desc.flags &
1073 AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) {
1074 apply_cmdline = false;
1075 }
1076 } else {
1077 if (kernel_cmdline_desc.flags &
1078 AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) {
1079 apply_cmdline = false;
1080 }
1081 }
1082
1083 if (apply_cmdline) {
1084 if (slot_data->cmdline == NULL) {
1085 slot_data->cmdline =
1086 avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1);
1087 if (slot_data->cmdline == NULL) {
1088 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1089 goto out;
1090 }
1091 avb_memcpy(slot_data->cmdline,
1092 kernel_cmdline,
1093 kernel_cmdline_desc.kernel_cmdline_length);
1094 } else {
1095 /* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */
1096 size_t orig_size = avb_strlen(slot_data->cmdline);
1097 size_t new_size =
1098 orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1;
1099 char* new_cmdline = avb_calloc(new_size);
1100 if (new_cmdline == NULL) {
1101 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1102 goto out;
1103 }
1104 avb_memcpy(new_cmdline, slot_data->cmdline, orig_size);
1105 new_cmdline[orig_size] = ' ';
1106 avb_memcpy(new_cmdline + orig_size + 1,
1107 kernel_cmdline,
1108 kernel_cmdline_desc.kernel_cmdline_length);
1109 avb_free(slot_data->cmdline);
1110 slot_data->cmdline = new_cmdline;
1111 }
1112 }
1113 } break;
1114
1115 case AVB_DESCRIPTOR_TAG_HASHTREE: {
1116 AvbHashtreeDescriptor hashtree_desc;
1117
1118 if (!avb_hashtree_descriptor_validate_and_byteswap(
1119 (AvbHashtreeDescriptor*)descriptors[n], &hashtree_desc)) {
1120 avb_errorv(
1121 full_partition_name, ": Hashtree descriptor is invalid.\n", NULL);
1122 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1123 goto out;
1124 }
1125
1126 /* We only need to continue when there is no digest in the descriptor.
1127 * This is because the only processing here is to find the digest and
1128 * make it available on the kernel command line.
1129 */
1130 if (hashtree_desc.root_digest_len == 0) {
1131 char part_name[AVB_PART_NAME_MAX_SIZE];
1132 size_t digest_len = 0;
1133 uint8_t digest_buf[AVB_SHA512_DIGEST_SIZE];
1134 const uint8_t* desc_partition_name =
1135 ((const uint8_t*)descriptors[n]) + sizeof(AvbHashtreeDescriptor);
1136
1137 if (!avb_validate_utf8(desc_partition_name,
1138 hashtree_desc.partition_name_len)) {
1139 avb_error("Partition name is not valid UTF-8.\n");
1140 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1141 goto out;
1142 }
1143
1144 /* No ab_suffix for partitions without a digest in the descriptor
1145 * because these partitions hold data unique to this device and are
1146 * not updated using an A/B scheme.
1147 */
1148 if ((hashtree_desc.flags &
1149 AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB) == 0 &&
1150 avb_strlen(ab_suffix) != 0) {
1151 avb_error("Cannot use A/B with a persistent root digest.\n");
1152 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1153 goto out;
1154 }
1155 if (hashtree_desc.partition_name_len >= AVB_PART_NAME_MAX_SIZE) {
1156 avb_error("Partition name does not fit.\n");
1157 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1158 goto out;
1159 }
1160 avb_memcpy(
1161 part_name, desc_partition_name, hashtree_desc.partition_name_len);
1162 part_name[hashtree_desc.partition_name_len] = '\0';
1163
1164 /* Determine the expected digest size from the hash algorithm. */
1165 if (avb_strcmp((const char*)hashtree_desc.hash_algorithm, "sha1") ==
1166 0) {
1167 digest_len = AVB_SHA1_DIGEST_SIZE;
1168 } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm,
1169 "sha256") == 0) {
1170 digest_len = AVB_SHA256_DIGEST_SIZE;
1171 } else if (avb_strcmp((const char*)hashtree_desc.hash_algorithm,
1172 "sha512") == 0) {
1173 digest_len = AVB_SHA512_DIGEST_SIZE;
1174 } else {
1175 avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL);
1176 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1177 goto out;
1178 }
1179
1180 ret = read_persistent_digest(ops,
1181 part_name,
1182 digest_len,
1183 NULL /* initial_digest */,
1184 digest_buf);
1185 if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
1186 goto out;
1187 }
1188
1189 if (out_additional_cmdline_subst) {
1190 ret =
1191 avb_add_root_digest_substitution(part_name,
1192 digest_buf,
1193 digest_len,
1194 out_additional_cmdline_subst);
1195 if (ret != AVB_SLOT_VERIFY_RESULT_OK) {
1196 goto out;
1197 }
1198 }
1199 }
1200 } break;
1201
1202 case AVB_DESCRIPTOR_TAG_PROPERTY:
1203 /* Do nothing. */
1204 break;
1205 }
1206 }
1207
1208 if (rollback_index_location < 0 ||
1209 rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) {
1210 avb_errorv(
1211 full_partition_name, ": Invalid rollback_index_location.\n", NULL);
1212 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
1213 goto out;
1214 }
1215
1216 slot_data->rollback_indexes[rollback_index_location] =
1217 vbmeta_header.rollback_index;
1218
1219 if (out_algorithm_type != NULL) {
1220 *out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type;
1221 }
1222
1223 out:
1224 /* If |vbmeta_image_data| isn't NULL it means that it adopted
1225 * |vbmeta_buf| so in that case don't free it here.
1226 */
1227 if (vbmeta_image_data == NULL) {
1228 if (vbmeta_buf != NULL) {
1229 avb_free(vbmeta_buf);
1230 }
1231 }
1232 if (descriptors != NULL) {
1233 avb_free(descriptors);
1234 }
1235 return ret;
1236 }
1237
avb_manage_hashtree_error_mode(AvbOps * ops,AvbSlotVerifyFlags flags,AvbSlotVerifyData * data,AvbHashtreeErrorMode * out_hashtree_error_mode)1238 static AvbIOResult avb_manage_hashtree_error_mode(
1239 AvbOps* ops,
1240 AvbSlotVerifyFlags flags,
1241 AvbSlotVerifyData* data,
1242 AvbHashtreeErrorMode* out_hashtree_error_mode) {
1243 AvbHashtreeErrorMode ret = AVB_HASHTREE_ERROR_MODE_RESTART;
1244 AvbIOResult io_ret = AVB_IO_RESULT_OK;
1245 uint8_t vbmeta_digest_sha256[AVB_SHA256_DIGEST_SIZE];
1246 uint8_t stored_vbmeta_digest_sha256[AVB_SHA256_DIGEST_SIZE];
1247 size_t num_bytes_read;
1248
1249 avb_assert(out_hashtree_error_mode != NULL);
1250 avb_assert(ops->read_persistent_value != NULL);
1251 avb_assert(ops->write_persistent_value != NULL);
1252
1253 // If we're rebooting because of dm-verity corruption, make a note of
1254 // the vbmeta hash so we can stay in 'eio' mode until things change.
1255 if (flags & AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION) {
1256 avb_debug(
1257 "Rebooting because of dm-verity corruption - "
1258 "recording OS instance and using 'eio' mode.\n");
1259 avb_slot_verify_data_calculate_vbmeta_digest(
1260 data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest_sha256);
1261 io_ret = ops->write_persistent_value(ops,
1262 AVB_NPV_MANAGED_VERITY_MODE,
1263 AVB_SHA256_DIGEST_SIZE,
1264 vbmeta_digest_sha256);
1265 if (io_ret != AVB_IO_RESULT_OK) {
1266 avb_error("Error writing to " AVB_NPV_MANAGED_VERITY_MODE ".\n");
1267 goto out;
1268 }
1269 ret = AVB_HASHTREE_ERROR_MODE_EIO;
1270 io_ret = AVB_IO_RESULT_OK;
1271 goto out;
1272 }
1273
1274 // See if we're in 'eio' mode.
1275 io_ret = ops->read_persistent_value(ops,
1276 AVB_NPV_MANAGED_VERITY_MODE,
1277 AVB_SHA256_DIGEST_SIZE,
1278 stored_vbmeta_digest_sha256,
1279 &num_bytes_read);
1280 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_VALUE ||
1281 (io_ret == AVB_IO_RESULT_OK && num_bytes_read == 0)) {
1282 // This is the usual case ('eio' mode not set).
1283 avb_debug("No dm-verity corruption - using in 'restart' mode.\n");
1284 ret = AVB_HASHTREE_ERROR_MODE_RESTART;
1285 io_ret = AVB_IO_RESULT_OK;
1286 goto out;
1287 } else if (io_ret != AVB_IO_RESULT_OK) {
1288 avb_error("Error reading from " AVB_NPV_MANAGED_VERITY_MODE ".\n");
1289 goto out;
1290 }
1291 if (num_bytes_read != AVB_SHA256_DIGEST_SIZE) {
1292 avb_error(
1293 "Unexpected number of bytes read from " AVB_NPV_MANAGED_VERITY_MODE
1294 ".\n");
1295 io_ret = AVB_IO_RESULT_ERROR_IO;
1296 goto out;
1297 }
1298
1299 // OK, so we're currently in 'eio' mode and the vbmeta digest of the OS
1300 // that caused this is in |stored_vbmeta_digest_sha256| ... now see if
1301 // the OS we're dealing with now is the same.
1302 avb_slot_verify_data_calculate_vbmeta_digest(
1303 data, AVB_DIGEST_TYPE_SHA256, vbmeta_digest_sha256);
1304 if (avb_memcmp(vbmeta_digest_sha256,
1305 stored_vbmeta_digest_sha256,
1306 AVB_SHA256_DIGEST_SIZE) == 0) {
1307 // It's the same so we're still in 'eio' mode.
1308 avb_debug("Same OS instance detected - staying in 'eio' mode.\n");
1309 ret = AVB_HASHTREE_ERROR_MODE_EIO;
1310 io_ret = AVB_IO_RESULT_OK;
1311 } else {
1312 // It did change!
1313 avb_debug(
1314 "New OS instance detected - changing from 'eio' to 'restart' mode.\n");
1315 io_ret =
1316 ops->write_persistent_value(ops,
1317 AVB_NPV_MANAGED_VERITY_MODE,
1318 0, // This clears the persistent property.
1319 vbmeta_digest_sha256);
1320 if (io_ret != AVB_IO_RESULT_OK) {
1321 avb_error("Error clearing " AVB_NPV_MANAGED_VERITY_MODE ".\n");
1322 goto out;
1323 }
1324 ret = AVB_HASHTREE_ERROR_MODE_RESTART;
1325 io_ret = AVB_IO_RESULT_OK;
1326 }
1327
1328 out:
1329 *out_hashtree_error_mode = ret;
1330 return io_ret;
1331 }
1332
has_system_partition(AvbOps * ops,const char * ab_suffix)1333 static bool has_system_partition(AvbOps* ops, const char* ab_suffix) {
1334 char part_name[AVB_PART_NAME_MAX_SIZE];
1335 char* system_part_name = "system";
1336 char guid_buf[37];
1337 AvbIOResult io_ret;
1338
1339 if (!avb_str_concat(part_name,
1340 sizeof part_name,
1341 system_part_name,
1342 avb_strlen(system_part_name),
1343 ab_suffix,
1344 avb_strlen(ab_suffix))) {
1345 avb_error("System partition name and suffix does not fit.\n");
1346 return false;
1347 }
1348
1349 io_ret = ops->get_unique_guid_for_partition(
1350 ops, part_name, guid_buf, sizeof guid_buf);
1351 if (io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION) {
1352 avb_debug("No system partition.\n");
1353 return false;
1354 } else if (io_ret != AVB_IO_RESULT_OK) {
1355 avb_error("Error getting unique GUID for system partition.\n");
1356 return false;
1357 }
1358
1359 return true;
1360 }
1361
avb_slot_verify(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,AvbSlotVerifyFlags flags,AvbHashtreeErrorMode hashtree_error_mode,AvbSlotVerifyData ** out_data)1362 AvbSlotVerifyResult avb_slot_verify(AvbOps* ops,
1363 const char* const* requested_partitions,
1364 const char* ab_suffix,
1365 AvbSlotVerifyFlags flags,
1366 AvbHashtreeErrorMode hashtree_error_mode,
1367 AvbSlotVerifyData** out_data) {
1368 AvbSlotVerifyResult ret;
1369 AvbSlotVerifyData* slot_data = NULL;
1370 AvbAlgorithmType algorithm_type = AVB_ALGORITHM_TYPE_NONE;
1371 bool using_boot_for_vbmeta = false;
1372 AvbVBMetaImageHeader toplevel_vbmeta;
1373 bool allow_verification_error =
1374 (flags & AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR);
1375 AvbCmdlineSubstList* additional_cmdline_subst = NULL;
1376
1377 /* Fail early if we're missing the AvbOps needed for slot verification. */
1378 avb_assert(ops->read_is_device_unlocked != NULL);
1379 avb_assert(ops->read_from_partition != NULL);
1380 avb_assert(ops->get_size_of_partition != NULL);
1381 avb_assert(ops->read_rollback_index != NULL);
1382 avb_assert(ops->get_unique_guid_for_partition != NULL);
1383
1384 if (out_data != NULL) {
1385 *out_data = NULL;
1386 }
1387
1388 /* Allowing dm-verity errors defeats the purpose of verified boot so
1389 * only allow this if set up to allow verification errors
1390 * (e.g. typically only UNLOCKED mode).
1391 */
1392 if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_LOGGING &&
1393 !allow_verification_error) {
1394 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT;
1395 goto fail;
1396 }
1397
1398 /* Make sure passed-in AvbOps support persistent values if
1399 * asking for libavb to manage verity state.
1400 */
1401 if (hashtree_error_mode == AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO) {
1402 if (ops->read_persistent_value == NULL ||
1403 ops->write_persistent_value == NULL) {
1404 avb_error(
1405 "Persistent values required for "
1406 "AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO "
1407 "but are not implemented in given AvbOps.\n");
1408 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT;
1409 goto fail;
1410 }
1411 }
1412
1413 /* Make sure passed-in AvbOps support verifying public keys and getting
1414 * rollback index location if not using a vbmeta partition.
1415 */
1416 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) {
1417 if (ops->validate_public_key_for_partition == NULL) {
1418 avb_error(
1419 "AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION was passed but the "
1420 "validate_public_key_for_partition() operation isn't implemented.\n");
1421 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT;
1422 goto fail;
1423 }
1424 } else {
1425 avb_assert(ops->validate_vbmeta_public_key != NULL);
1426 }
1427
1428 slot_data = avb_calloc(sizeof(AvbSlotVerifyData));
1429 if (slot_data == NULL) {
1430 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1431 goto fail;
1432 }
1433 slot_data->vbmeta_images =
1434 avb_calloc(sizeof(AvbVBMetaData) * MAX_NUMBER_OF_VBMETA_IMAGES);
1435 if (slot_data->vbmeta_images == NULL) {
1436 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1437 goto fail;
1438 }
1439 slot_data->loaded_partitions =
1440 avb_calloc(sizeof(AvbPartitionData) * MAX_NUMBER_OF_LOADED_PARTITIONS);
1441 if (slot_data->loaded_partitions == NULL) {
1442 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1443 goto fail;
1444 }
1445
1446 additional_cmdline_subst = avb_new_cmdline_subst_list();
1447 if (additional_cmdline_subst == NULL) {
1448 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1449 goto fail;
1450 }
1451
1452 if (flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION) {
1453 if (requested_partitions == NULL || requested_partitions[0] == NULL) {
1454 avb_fatal(
1455 "Requested partitions cannot be empty when using "
1456 "AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION");
1457 ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT;
1458 goto fail;
1459 }
1460
1461 /* No vbmeta partition, go through each of the requested partitions... */
1462 for (size_t n = 0; requested_partitions[n] != NULL; n++) {
1463 ret = load_and_verify_vbmeta(ops,
1464 requested_partitions,
1465 ab_suffix,
1466 flags,
1467 allow_verification_error,
1468 0 /* toplevel_vbmeta_flags */,
1469 0 /* rollback_index_location */,
1470 requested_partitions[n],
1471 avb_strlen(requested_partitions[n]),
1472 NULL /* expected_public_key */,
1473 0 /* expected_public_key_length */,
1474 slot_data,
1475 &algorithm_type,
1476 additional_cmdline_subst);
1477 if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) {
1478 goto fail;
1479 }
1480 }
1481
1482 } else {
1483 /* Usual path, load "vbmeta"... */
1484 ret = load_and_verify_vbmeta(ops,
1485 requested_partitions,
1486 ab_suffix,
1487 flags,
1488 allow_verification_error,
1489 0 /* toplevel_vbmeta_flags */,
1490 0 /* rollback_index_location */,
1491 "vbmeta",
1492 avb_strlen("vbmeta"),
1493 NULL /* expected_public_key */,
1494 0 /* expected_public_key_length */,
1495 slot_data,
1496 &algorithm_type,
1497 additional_cmdline_subst);
1498 if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) {
1499 goto fail;
1500 }
1501 }
1502
1503 if (!result_should_continue(ret)) {
1504 goto fail;
1505 }
1506
1507 /* If things check out, mangle the kernel command-line as needed. */
1508 if (!(flags & AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION)) {
1509 if (avb_strcmp(slot_data->vbmeta_images[0].partition_name, "vbmeta") != 0) {
1510 avb_assert(
1511 avb_strcmp(slot_data->vbmeta_images[0].partition_name, "boot") == 0);
1512 using_boot_for_vbmeta = true;
1513 }
1514 }
1515
1516 /* Byteswap top-level vbmeta header since we'll need it below. */
1517 avb_vbmeta_image_header_to_host_byte_order(
1518 (const AvbVBMetaImageHeader*)slot_data->vbmeta_images[0].vbmeta_data,
1519 &toplevel_vbmeta);
1520
1521 /* Fill in |ab_suffix| field. */
1522 slot_data->ab_suffix = avb_strdup(ab_suffix);
1523 if (slot_data->ab_suffix == NULL) {
1524 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1525 goto fail;
1526 }
1527
1528 /* If verification is disabled, we are done ... we specifically
1529 * don't want to add any androidboot.* options since verification
1530 * is disabled.
1531 */
1532 if (toplevel_vbmeta.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) {
1533 /* Since verification is disabled we didn't process any
1534 * descriptors and thus there's no cmdline... so set root= such
1535 * that the system partition is mounted.
1536 */
1537 avb_assert(slot_data->cmdline == NULL);
1538 // Devices with dynamic partitions won't have system partition.
1539 // Instead, it has a large super partition to accommodate *.img files.
1540 // See b/119551429 for details.
1541 if (has_system_partition(ops, ab_suffix)) {
1542 slot_data->cmdline =
1543 avb_strdup("root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)");
1544 } else {
1545 // The |cmdline| field should be a NUL-terminated string.
1546 slot_data->cmdline = avb_strdup("");
1547 }
1548 if (slot_data->cmdline == NULL) {
1549 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1550 goto fail;
1551 }
1552 } else {
1553 /* If requested, manage dm-verity mode... */
1554 AvbHashtreeErrorMode resolved_hashtree_error_mode = hashtree_error_mode;
1555 if (hashtree_error_mode ==
1556 AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO) {
1557 AvbIOResult io_ret;
1558 io_ret = avb_manage_hashtree_error_mode(
1559 ops, flags, slot_data, &resolved_hashtree_error_mode);
1560 if (io_ret != AVB_IO_RESULT_OK) {
1561 ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
1562 if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
1563 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1564 }
1565 goto fail;
1566 }
1567 }
1568 slot_data->resolved_hashtree_error_mode = resolved_hashtree_error_mode;
1569
1570 /* Add options... */
1571 AvbSlotVerifyResult sub_ret;
1572 sub_ret = avb_append_options(ops,
1573 flags,
1574 slot_data,
1575 &toplevel_vbmeta,
1576 algorithm_type,
1577 hashtree_error_mode,
1578 resolved_hashtree_error_mode);
1579 if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
1580 ret = sub_ret;
1581 goto fail;
1582 }
1583 }
1584
1585 /* Substitute $(ANDROID_SYSTEM_PARTUUID) and friends. */
1586 if (slot_data->cmdline != NULL && avb_strlen(slot_data->cmdline) != 0) {
1587 char* new_cmdline;
1588 new_cmdline = avb_sub_cmdline(ops,
1589 slot_data->cmdline,
1590 ab_suffix,
1591 using_boot_for_vbmeta,
1592 additional_cmdline_subst);
1593 if (new_cmdline != slot_data->cmdline) {
1594 if (new_cmdline == NULL) {
1595 ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1596 goto fail;
1597 }
1598 avb_free(slot_data->cmdline);
1599 slot_data->cmdline = new_cmdline;
1600 }
1601 }
1602
1603 if (out_data != NULL) {
1604 *out_data = slot_data;
1605 } else {
1606 avb_slot_verify_data_free(slot_data);
1607 }
1608
1609 avb_free_cmdline_subst_list(additional_cmdline_subst);
1610 additional_cmdline_subst = NULL;
1611
1612 if (!allow_verification_error) {
1613 avb_assert(ret == AVB_SLOT_VERIFY_RESULT_OK);
1614 }
1615
1616 return ret;
1617
1618 fail:
1619 if (slot_data != NULL) {
1620 avb_slot_verify_data_free(slot_data);
1621 }
1622 if (additional_cmdline_subst != NULL) {
1623 avb_free_cmdline_subst_list(additional_cmdline_subst);
1624 }
1625 return ret;
1626 }
1627
avb_slot_verify_data_free(AvbSlotVerifyData * data)1628 void avb_slot_verify_data_free(AvbSlotVerifyData* data) {
1629 if (data->ab_suffix != NULL) {
1630 avb_free(data->ab_suffix);
1631 }
1632 if (data->cmdline != NULL) {
1633 avb_free(data->cmdline);
1634 }
1635 if (data->vbmeta_images != NULL) {
1636 size_t n;
1637 for (n = 0; n < data->num_vbmeta_images; n++) {
1638 AvbVBMetaData* vbmeta_image = &data->vbmeta_images[n];
1639 if (vbmeta_image->partition_name != NULL) {
1640 avb_free(vbmeta_image->partition_name);
1641 }
1642 if (vbmeta_image->vbmeta_data != NULL) {
1643 avb_free(vbmeta_image->vbmeta_data);
1644 }
1645 }
1646 avb_free(data->vbmeta_images);
1647 }
1648 if (data->loaded_partitions != NULL) {
1649 size_t n;
1650 for (n = 0; n < data->num_loaded_partitions; n++) {
1651 AvbPartitionData* loaded_partition = &data->loaded_partitions[n];
1652 if (loaded_partition->partition_name != NULL) {
1653 avb_free(loaded_partition->partition_name);
1654 }
1655 if (loaded_partition->data != NULL && !loaded_partition->preloaded) {
1656 avb_free(loaded_partition->data);
1657 }
1658 }
1659 avb_free(data->loaded_partitions);
1660 }
1661 avb_free(data);
1662 }
1663
avb_slot_verify_result_to_string(AvbSlotVerifyResult result)1664 const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result) {
1665 const char* ret = NULL;
1666
1667 switch (result) {
1668 case AVB_SLOT_VERIFY_RESULT_OK:
1669 ret = "OK";
1670 break;
1671 case AVB_SLOT_VERIFY_RESULT_ERROR_OOM:
1672 ret = "ERROR_OOM";
1673 break;
1674 case AVB_SLOT_VERIFY_RESULT_ERROR_IO:
1675 ret = "ERROR_IO";
1676 break;
1677 case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION:
1678 ret = "ERROR_VERIFICATION";
1679 break;
1680 case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX:
1681 ret = "ERROR_ROLLBACK_INDEX";
1682 break;
1683 case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED:
1684 ret = "ERROR_PUBLIC_KEY_REJECTED";
1685 break;
1686 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA:
1687 ret = "ERROR_INVALID_METADATA";
1688 break;
1689 case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION:
1690 ret = "ERROR_UNSUPPORTED_VERSION";
1691 break;
1692 case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT:
1693 ret = "ERROR_INVALID_ARGUMENT";
1694 break;
1695 /* Do not add a 'default:' case here because of -Wswitch. */
1696 }
1697
1698 if (ret == NULL) {
1699 avb_error("Unknown AvbSlotVerifyResult value.\n");
1700 ret = "(unknown)";
1701 }
1702
1703 return ret;
1704 }
1705
avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData * data,AvbDigestType digest_type,uint8_t * out_digest)1706 void avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData* data,
1707 AvbDigestType digest_type,
1708 uint8_t* out_digest) {
1709 bool ret = false;
1710 size_t n;
1711
1712 switch (digest_type) {
1713 case AVB_DIGEST_TYPE_SHA256: {
1714 AvbSHA256Ctx ctx;
1715 avb_sha256_init(&ctx);
1716 for (n = 0; n < data->num_vbmeta_images; n++) {
1717 avb_sha256_update(&ctx,
1718 data->vbmeta_images[n].vbmeta_data,
1719 data->vbmeta_images[n].vbmeta_size);
1720 }
1721 avb_memcpy(out_digest, avb_sha256_final(&ctx), AVB_SHA256_DIGEST_SIZE);
1722 ret = true;
1723 } break;
1724
1725 case AVB_DIGEST_TYPE_SHA512: {
1726 AvbSHA512Ctx ctx;
1727 avb_sha512_init(&ctx);
1728 for (n = 0; n < data->num_vbmeta_images; n++) {
1729 avb_sha512_update(&ctx,
1730 data->vbmeta_images[n].vbmeta_data,
1731 data->vbmeta_images[n].vbmeta_size);
1732 }
1733 avb_memcpy(out_digest, avb_sha512_final(&ctx), AVB_SHA512_DIGEST_SIZE);
1734 ret = true;
1735 } break;
1736
1737 /* Do not add a 'default:' case here because of -Wswitch. */
1738 }
1739
1740 if (!ret) {
1741 avb_fatal("Unknown digest type");
1742 }
1743 }
1744