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_HASH_DESCRIPTOR_H_
30#define AVB_HASH_DESCRIPTOR_H_
31
32#include "avb_descriptor.h"
33
34#ifdef __cplusplus
35extern "C" {
36#endif
37
38/* Flags for hash descriptors.
39 *
40 * AVB_HASH_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 */
44typedef enum {
45  AVB_HASH_DESCRIPTOR_FLAGS_DO_NOT_USE_AB = (1 << 0),
46} AvbHashDescriptorFlags;
47
48/* A descriptor containing information about hash for an image.
49 *
50 * This descriptor is typically used for boot partitions to verify the
51 * entire kernel+initramfs image before executing it.
52 *
53 * Following this struct are |partition_name_len| bytes of the
54 * partition name (UTF-8 encoded), |salt_len| bytes of salt, and then
55 * |digest_len| bytes of the digest.
56 *
57 * The |reserved| field is for future expansion and must be set to NUL
58 * bytes.
59 *
60 * Changes in v1.1:
61 *   - flags field is added which supports AVB_HASH_DESCRIPTOR_FLAGS_USE_AB
62 *   - digest_len may be zero, which indicates the use of a persistent digest
63 */
64typedef struct AvbHashDescriptor {
65  AvbDescriptor parent_descriptor;
66  uint64_t image_size;
67  uint8_t hash_algorithm[32];
68  uint32_t partition_name_len;
69  uint32_t salt_len;
70  uint32_t digest_len;
71  uint32_t flags;
72  uint8_t reserved[60];
73} AVB_ATTR_PACKED AvbHashDescriptor;
74
75/* Copies |src| to |dest| and validates, byte-swapping fields in the
76 * process if needed. Returns true if valid, false if invalid.
77 *
78 * Data following the struct is not validated nor copied.
79 */
80bool avb_hash_descriptor_validate_and_byteswap(const AvbHashDescriptor* src,
81                                               AvbHashDescriptor* dest)
82    AVB_ATTR_WARN_UNUSED_RESULT;
83
84#ifdef __cplusplus
85}
86#endif
87
88#endif /* AVB_HASH_DESCRIPTOR_H_ */
89