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_hashtree_descriptor.h"
26#include "avb_util.h"
27
28bool avb_hashtree_descriptor_validate_and_byteswap(
29    const AvbHashtreeDescriptor* src, AvbHashtreeDescriptor* dest) {
30  uint64_t expected_size;
31
32  avb_memcpy(dest, src, sizeof(AvbHashtreeDescriptor));
33
34  if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src,
35                                            (AvbDescriptor*)dest))
36    return false;
37
38  if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_HASHTREE) {
39    avb_error("Invalid tag for hashtree descriptor.\n");
40    return false;
41  }
42
43  dest->dm_verity_version = avb_be32toh(dest->dm_verity_version);
44  dest->image_size = avb_be64toh(dest->image_size);
45  dest->tree_offset = avb_be64toh(dest->tree_offset);
46  dest->tree_size = avb_be64toh(dest->tree_size);
47  dest->data_block_size = avb_be32toh(dest->data_block_size);
48  dest->hash_block_size = avb_be32toh(dest->hash_block_size);
49  dest->fec_num_roots = avb_be32toh(dest->fec_num_roots);
50  dest->fec_offset = avb_be64toh(dest->fec_offset);
51  dest->fec_size = avb_be64toh(dest->fec_size);
52  dest->partition_name_len = avb_be32toh(dest->partition_name_len);
53  dest->salt_len = avb_be32toh(dest->salt_len);
54  dest->root_digest_len = avb_be32toh(dest->root_digest_len);
55
56  /* Check that partition_name, salt, and root_digest are fully contained. */
57  expected_size = sizeof(AvbHashtreeDescriptor) - sizeof(AvbDescriptor);
58  if (!avb_safe_add_to(&expected_size, dest->partition_name_len) ||
59      !avb_safe_add_to(&expected_size, dest->salt_len) ||
60      !avb_safe_add_to(&expected_size, dest->root_digest_len)) {
61    avb_error("Overflow while adding up sizes.\n");
62    return false;
63  }
64  if (expected_size > dest->parent_descriptor.num_bytes_following) {
65    avb_error("Descriptor payload size overflow.\n");
66    return false;
67  }
68  return true;
69}
70