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 9 bool 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
