1// SPDX-License-Identifier: MIT
2/*
3 * Copyright (C) 2016 The Android Open Source Project
4 */
5
6#include "avb_hash_descriptor.h"
7#include "avb_util.h"
8
9bool avb_hash_descriptor_validate_and_byteswap(const AvbHashDescriptor* src,
10                                               AvbHashDescriptor* dest) {
11  uint64_t expected_size;
12
13  avb_memcpy(dest, src, sizeof(AvbHashDescriptor));
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_HASH) {
20    avb_error("Invalid tag for hash descriptor.\n");
21    return false;
22  }
23
24  dest->image_size = avb_be64toh(dest->image_size);
25  dest->partition_name_len = avb_be32toh(dest->partition_name_len);
26  dest->salt_len = avb_be32toh(dest->salt_len);
27  dest->digest_len = avb_be32toh(dest->digest_len);
28  dest->flags = avb_be32toh(dest->flags);
29
30  /* Check that partition_name, salt, and digest are fully contained. */
31  expected_size = sizeof(AvbHashDescriptor) - sizeof(AvbDescriptor);
32  if (!avb_safe_add_to(&expected_size, dest->partition_name_len) ||
33      !avb_safe_add_to(&expected_size, dest->salt_len) ||
34      !avb_safe_add_to(&expected_size, dest->digest_len)) {
35    avb_error("Overflow while adding up sizes.\n");
36    return false;
37  }
38  if (expected_size > dest->parent_descriptor.num_bytes_following) {
39    avb_error("Descriptor payload size overflow.\n");
40    return false;
41  }
42  return true;
43}
44