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
avb_hash_descriptor_validate_and_byteswap(const AvbHashDescriptor * src,AvbHashDescriptor * dest)9 bool 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