1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright (C) 2016 The Android Open Source Project
4 */
5
6 #include "avb_hashtree_descriptor.h"
7 #include "avb_util.h"
8
avb_hashtree_descriptor_validate_and_byteswap(const AvbHashtreeDescriptor * src,AvbHashtreeDescriptor * dest)9 bool avb_hashtree_descriptor_validate_and_byteswap(
10 const AvbHashtreeDescriptor* src, AvbHashtreeDescriptor* dest) {
11 uint64_t expected_size;
12
13 avb_memcpy(dest, src, sizeof(AvbHashtreeDescriptor));
14
15 if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src,
16 (AvbDescriptor*)dest))
17 return false;
18
19 if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_HASHTREE) {
20 avb_error("Invalid tag for hashtree descriptor.\n");
21 return false;
22 }
23
24 dest->dm_verity_version = avb_be32toh(dest->dm_verity_version);
25 dest->image_size = avb_be64toh(dest->image_size);
26 dest->tree_offset = avb_be64toh(dest->tree_offset);
27 dest->tree_size = avb_be64toh(dest->tree_size);
28 dest->data_block_size = avb_be32toh(dest->data_block_size);
29 dest->hash_block_size = avb_be32toh(dest->hash_block_size);
30 dest->fec_num_roots = avb_be32toh(dest->fec_num_roots);
31 dest->fec_offset = avb_be64toh(dest->fec_offset);
32 dest->fec_size = avb_be64toh(dest->fec_size);
33 dest->partition_name_len = avb_be32toh(dest->partition_name_len);
34 dest->salt_len = avb_be32toh(dest->salt_len);
35 dest->root_digest_len = avb_be32toh(dest->root_digest_len);
36 dest->flags = avb_be32toh(dest->flags);
37
38 /* Check that partition_name, salt, and root_digest are fully contained. */
39 expected_size = sizeof(AvbHashtreeDescriptor) - sizeof(AvbDescriptor);
40 if (!avb_safe_add_to(&expected_size, dest->partition_name_len) ||
41 !avb_safe_add_to(&expected_size, dest->salt_len) ||
42 !avb_safe_add_to(&expected_size, dest->root_digest_len)) {
43 avb_error("Overflow while adding up sizes.\n");
44 return false;
45 }
46 if (expected_size > dest->parent_descriptor.num_bytes_following) {
47 avb_error("Descriptor payload size overflow.\n");
48 return false;
49 }
50 return true;
51 }
52