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 #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) 26 #error "Never include this file directly, include libavb.h instead." 27 #endif 28 29 #ifndef AVB_HASHTREE_DESCRIPTOR_H_ 30 #define AVB_HASHTREE_DESCRIPTOR_H_ 31 32 #include "avb_descriptor.h" 33 34 #ifdef __cplusplus 35 extern "C" { 36 #endif 37 38 /* Flags for hashtree descriptors. 39 * 40 * AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB: Do not apply the default A/B 41 * partition logic to this partition. This is intentionally a negative boolean 42 * because A/B should be both the default and most used in practice. 43 */ 44 typedef enum { 45 AVB_HASHTREE_DESCRIPTOR_FLAGS_DO_NOT_USE_AB = (1 << 0), 46 } AvbHashtreeDescriptorFlags; 47 48 /* A descriptor containing information about a dm-verity hashtree. 49 * 50 * Hash-trees are used to verify large partitions typically containing 51 * file systems. See 52 * https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for more 53 * information about dm-verity. 54 * 55 * Following this struct are |partition_name_len| bytes of the 56 * partition name (UTF-8 encoded), |salt_len| bytes of salt, and then 57 * |root_digest_len| bytes of the root digest. 58 * 59 * The |reserved| field is for future expansion and must be set to NUL 60 * bytes. 61 * 62 * Changes in v1.1: 63 * - flags field is added which supports AVB_HASHTREE_DESCRIPTOR_FLAGS_USE_AB 64 * - digest_len may be zero, which indicates the use of a persistent digest 65 */ 66 typedef struct AvbHashtreeDescriptor { 67 AvbDescriptor parent_descriptor; 68 uint32_t dm_verity_version; 69 uint64_t image_size; 70 uint64_t tree_offset; 71 uint64_t tree_size; 72 uint32_t data_block_size; 73 uint32_t hash_block_size; 74 uint32_t fec_num_roots; 75 uint64_t fec_offset; 76 uint64_t fec_size; 77 uint8_t hash_algorithm[32]; 78 uint32_t partition_name_len; 79 uint32_t salt_len; 80 uint32_t root_digest_len; 81 uint32_t flags; 82 uint8_t reserved[60]; 83 } AVB_ATTR_PACKED AvbHashtreeDescriptor; 84 85 /* Copies |src| to |dest| and validates, byte-swapping fields in the 86 * process if needed. Returns true if valid, false if invalid. 87 * 88 * Data following the struct is not validated nor copied. 89 */ 90 bool avb_hashtree_descriptor_validate_and_byteswap( 91 const AvbHashtreeDescriptor* src, 92 AvbHashtreeDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; 93 94 #ifdef __cplusplus 95 } 96 #endif 97 98 #endif /* AVB_HASHTREE_DESCRIPTOR_H_ */ 99
