1 /* SPDX-License-Identifier: MIT */ 2 /* 3 * Copyright (C) 2016 The Android Open Source Project 4 */ 5 6 #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) 7 #error "Never include this file directly, include libavb.h instead." 8 #endif 9 10 #ifndef AVB_HASHTREE_DESCRIPTOR_H_ 11 #define AVB_HASHTREE_DESCRIPTOR_H_ 12 13 #include "avb_descriptor.h" 14 15 #ifdef __cplusplus 16 extern "C" { 17 #endif 18 19 /* Flags for hashtree descriptors. 20 * 21 * AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB: Do not apply the default A/B 22 * partition logic to this partition. This is intentionally a negative boolean 23 * because A/B should be both the default and most used in practice. 24 */ 25 typedef enum { 26 AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB = (1 << 0), 27 } AvbHashtreeDescriptorFlags; 28 29 /* A descriptor containing information about a dm-verity hashtree. 30 * 31 * Hash-trees are used to verify large partitions typically containing 32 * file systems. See 33 * https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for more 34 * information about dm-verity. 35 * 36 * Following this struct are |partition_name_len| bytes of the 37 * partition name (UTF-8 encoded), |salt_len| bytes of salt, and then 38 * |root_digest_len| bytes of the root digest. 39 * 40 * The |reserved| field is for future expansion and must be set to NUL 41 * bytes. 42 * 43 * Changes in v1.1: 44 * - flags field is added which supports AVB_HASHTREE_DESCRIPTOR_FLAGS_USE_AB 45 * - digest_len may be zero, which indicates the use of a persistent digest 46 */ 47 typedef struct AvbHashtreeDescriptor { 48 AvbDescriptor parent_descriptor; 49 uint32_t dm_verity_version; 50 uint64_t image_size; 51 uint64_t tree_offset; 52 uint64_t tree_size; 53 uint32_t data_block_size; 54 uint32_t hash_block_size; 55 uint32_t fec_num_roots; 56 uint64_t fec_offset; 57 uint64_t fec_size; 58 uint8_t hash_algorithm[32]; 59 uint32_t partition_name_len; 60 uint32_t salt_len; 61 uint32_t root_digest_len; 62 uint32_t flags; 63 uint8_t reserved[60]; 64 } AVB_ATTR_PACKED AvbHashtreeDescriptor; 65 66 /* Copies |src| to |dest| and validates, byte-swapping fields in the 67 * process if needed. Returns true if valid, false if invalid. 68 * 69 * Data following the struct is not validated nor copied. 70 */ 71 bool avb_hashtree_descriptor_validate_and_byteswap( 72 const AvbHashtreeDescriptor* src, 73 AvbHashtreeDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; 74 75 #ifdef __cplusplus 76 } 77 #endif 78 79 #endif /* AVB_HASHTREE_DESCRIPTOR_H_ */ 80