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_chain_partition_descriptor.h"
26 #include "avb_util.h"
27 
avb_chain_partition_descriptor_validate_and_byteswap(const AvbChainPartitionDescriptor * src,AvbChainPartitionDescriptor * dest)28 bool avb_chain_partition_descriptor_validate_and_byteswap(
29     const AvbChainPartitionDescriptor* src, AvbChainPartitionDescriptor* dest) {
30   uint64_t expected_size;
31 
32   avb_memcpy(dest, src, sizeof(AvbChainPartitionDescriptor));
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_CHAIN_PARTITION) {
39     avb_error("Invalid tag for chain partition descriptor.\n");
40     return false;
41   }
42 
43   dest->rollback_index_location = avb_be32toh(dest->rollback_index_location);
44   dest->partition_name_len = avb_be32toh(dest->partition_name_len);
45   dest->public_key_len = avb_be32toh(dest->public_key_len);
46 
47   if (dest->rollback_index_location < 1) {
48     avb_error("Invalid rollback index location value.\n");
49     return false;
50   }
51 
52   /* Check that partition_name and public_key are fully contained. */
53   expected_size = sizeof(AvbChainPartitionDescriptor) - sizeof(AvbDescriptor);
54   if (!avb_safe_add_to(&expected_size, dest->partition_name_len) ||
55       !avb_safe_add_to(&expected_size, dest->public_key_len)) {
56     avb_error("Overflow while adding up sizes.\n");
57     return false;
58   }
59   if (expected_size > dest->parent_descriptor.num_bytes_following) {
60     avb_error("Descriptor payload size overflow.\n");
61     return false;
62   }
63   return true;
64 }
65