2 * Copyright (C) 2015 Google, Inc.
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
15 #ifndef DM_ANDROID_VERITY_H
16 #define DM_ANDROID_VERITY_H
18 #include <crypto/sha.h>
20 #define RSANUMBYTES 256
21 #define VERITY_METADATA_MAGIC_NUMBER 0xb001b001
22 #define VERITY_METADATA_MAGIC_DISABLE 0x46464f56
23 #define VERITY_METADATA_VERSION 0
24 #define VERITY_STATE_DISABLE 1
25 #define DATA_BLOCK_SIZE (4 * 1024)
26 #define VERITY_METADATA_SIZE (8 * DATA_BLOCK_SIZE)
27 #define VERITY_TABLE_ARGS 10
28 #define VERITY_COMMANDLINE_PARAM_LENGTH 20
29 #define BUILD_VARIANT 20
32 * <subject>:<sha1-id> is the format for the identifier.
33 * subject can either be the Common Name(CN) + Organization Name(O) or
34 * just the CN if the it is prefixed with O
35 * From https://tools.ietf.org/html/rfc5280#appendix-A
36 * ub-organization-name-length INTEGER ::= 64
37 * ub-common-name-length INTEGER ::= 64
39 * http://lxr.free-electrons.com/source/crypto/asymmetric_keys/x509_cert_parser.c?v=3.9#L278
40 * ctx->o_size + 2 + ctx->cn_size + 1
41 * + 41 characters for ":" and sha1 id
42 * 64 + 2 + 64 + 1 + 1 + 40 (172)
43 * setting VERITY_DEFAULT_KEY_ID_LENGTH to 200 characters.
45 #define VERITY_DEFAULT_KEY_ID_LENGTH 200
47 #define FEC_MAGIC 0xFECFECFE
48 #define FEC_BLOCK_SIZE (4 * 1024)
51 #define FEC_ARG_LENGTH 300
53 #define VERITY_TABLE_OPT_RESTART "restart_on_corruption"
54 #define VERITY_TABLE_OPT_LOGGING "ignore_corruption"
55 #define VERITY_TABLE_OPT_IGNZERO "ignore_zero_blocks"
57 #define VERITY_TABLE_OPT_FEC_FORMAT \
58 "use_fec_from_device %s fec_start %llu fec_blocks %llu fec_roots %u ignore_zero_blocks"
59 #define VERITY_TABLE_OPT_FEC_ARGS 9
61 #define VERITY_DEBUG 0
63 #define DM_MSG_PREFIX "android-verity"
65 #define DM_LINEAR_ARGS 2
66 #define DM_LINEAR_TARGET_OFFSET "0"
69 * There can be two formats.
71 * <data_blocks> <verity_tree> <verity_metdata_32K><fec_data><fec_data_4K>
72 * if fec is not present
73 * <data_blocks> <verity_tree> <verity_metdata_32K>
82 u8 hash[SHA256_DIGEST_SIZE];
83 } __attribute__((packed));
85 struct android_metadata_header {
87 __le32 protocol_version;
88 char signature[RSANUMBYTES];
92 struct android_metadata {
93 struct android_metadata_header *header;
97 struct fec_ecc_metadata {
106 struct page **page_io;
110 extern struct target_type linear_target;
112 extern void dm_linear_dtr(struct dm_target *ti);
113 extern int dm_linear_map(struct dm_target *ti, struct bio *bio);
114 extern void dm_linear_status(struct dm_target *ti, status_type_t type,
115 unsigned status_flags, char *result, unsigned maxlen);
116 extern int dm_linear_prepare_ioctl(struct dm_target *ti,
117 struct block_device **bdev, fmode_t *mode);
118 extern int dm_linear_iterate_devices(struct dm_target *ti,
119 iterate_devices_callout_fn fn, void *data);
120 extern int dm_linear_ctr(struct dm_target *ti, unsigned int argc, char **argv);
121 #endif /* DM_ANDROID_VERITY_H */