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
9bool 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