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1b262839 ST |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* | |
3 | * Copyright 2019 Google LLC | |
4 | */ | |
5 | ||
6 | #ifndef __LINUX_BLK_CRYPTO_H | |
7 | #define __LINUX_BLK_CRYPTO_H | |
8 | ||
a892c8d5 ST |
9 | #include <linux/types.h> |
10 | ||
1b262839 ST |
11 | enum blk_crypto_mode_num { |
12 | BLK_ENCRYPTION_MODE_INVALID, | |
13 | BLK_ENCRYPTION_MODE_AES_256_XTS, | |
14 | BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV, | |
15 | BLK_ENCRYPTION_MODE_ADIANTUM, | |
16 | BLK_ENCRYPTION_MODE_MAX, | |
17 | }; | |
18 | ||
19 | #define BLK_CRYPTO_MAX_KEY_SIZE 64 | |
20 | /** | |
21 | * struct blk_crypto_config - an inline encryption key's crypto configuration | |
22 | * @crypto_mode: encryption algorithm this key is for | |
23 | * @data_unit_size: the data unit size for all encryption/decryptions with this | |
24 | * key. This is the size in bytes of each individual plaintext and | |
25 | * ciphertext. This is always a power of 2. It might be e.g. the | |
26 | * filesystem block size or the disk sector size. | |
27 | * @dun_bytes: the maximum number of bytes of DUN used when using this key | |
28 | */ | |
29 | struct blk_crypto_config { | |
30 | enum blk_crypto_mode_num crypto_mode; | |
31 | unsigned int data_unit_size; | |
32 | unsigned int dun_bytes; | |
33 | }; | |
34 | ||
35 | /** | |
36 | * struct blk_crypto_key - an inline encryption key | |
37 | * @crypto_cfg: the crypto configuration (like crypto_mode, key size) for this | |
38 | * key | |
39 | * @data_unit_size_bits: log2 of data_unit_size | |
40 | * @size: size of this key in bytes (determined by @crypto_cfg.crypto_mode) | |
41 | * @raw: the raw bytes of this key. Only the first @size bytes are used. | |
42 | * | |
43 | * A blk_crypto_key is immutable once created, and many bios can reference it at | |
44 | * the same time. It must not be freed until all bios using it have completed | |
45 | * and it has been evicted from all devices on which it may have been used. | |
46 | */ | |
47 | struct blk_crypto_key { | |
48 | struct blk_crypto_config crypto_cfg; | |
49 | unsigned int data_unit_size_bits; | |
50 | unsigned int size; | |
51 | u8 raw[BLK_CRYPTO_MAX_KEY_SIZE]; | |
52 | }; | |
53 | ||
a892c8d5 ST |
54 | #define BLK_CRYPTO_MAX_IV_SIZE 32 |
55 | #define BLK_CRYPTO_DUN_ARRAY_SIZE (BLK_CRYPTO_MAX_IV_SIZE / sizeof(u64)) | |
56 | ||
57 | /** | |
58 | * struct bio_crypt_ctx - an inline encryption context | |
59 | * @bc_key: the key, algorithm, and data unit size to use | |
60 | * @bc_dun: the data unit number (starting IV) to use | |
61 | * | |
62 | * A bio_crypt_ctx specifies that the contents of the bio will be encrypted (for | |
63 | * write requests) or decrypted (for read requests) inline by the storage device | |
488f6682 | 64 | * or controller, or by the crypto API fallback. |
a892c8d5 ST |
65 | */ |
66 | struct bio_crypt_ctx { | |
67 | const struct blk_crypto_key *bc_key; | |
68 | u64 bc_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]; | |
69 | }; | |
70 | ||
71 | #include <linux/blk_types.h> | |
72 | #include <linux/blkdev.h> | |
73 | ||
74 | struct request; | |
75 | struct request_queue; | |
76 | ||
77 | #ifdef CONFIG_BLK_INLINE_ENCRYPTION | |
78 | ||
79 | static inline bool bio_has_crypt_ctx(struct bio *bio) | |
80 | { | |
81 | return bio->bi_crypt_context; | |
82 | } | |
83 | ||
84 | void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key, | |
85 | const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], | |
86 | gfp_t gfp_mask); | |
87 | ||
88 | bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc, | |
89 | unsigned int bytes, | |
90 | const u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]); | |
91 | ||
92 | int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key, | |
93 | enum blk_crypto_mode_num crypto_mode, | |
94 | unsigned int dun_bytes, | |
95 | unsigned int data_unit_size); | |
96 | ||
97 | int blk_crypto_start_using_key(const struct blk_crypto_key *key, | |
98 | struct request_queue *q); | |
99 | ||
100 | int blk_crypto_evict_key(struct request_queue *q, | |
101 | const struct blk_crypto_key *key); | |
102 | ||
103 | bool blk_crypto_config_supported(struct request_queue *q, | |
104 | const struct blk_crypto_config *cfg); | |
105 | ||
106 | #else /* CONFIG_BLK_INLINE_ENCRYPTION */ | |
107 | ||
108 | static inline bool bio_has_crypt_ctx(struct bio *bio) | |
109 | { | |
110 | return false; | |
111 | } | |
112 | ||
113 | #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ | |
114 | ||
07560151 EB |
115 | int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); |
116 | /** | |
117 | * bio_crypt_clone - clone bio encryption context | |
118 | * @dst: destination bio | |
119 | * @src: source bio | |
120 | * @gfp_mask: memory allocation flags | |
121 | * | |
122 | * If @src has an encryption context, clone it to @dst. | |
123 | * | |
124 | * Return: 0 on success, -ENOMEM if out of memory. -ENOMEM is only possible if | |
125 | * @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM. | |
126 | */ | |
127 | static inline int bio_crypt_clone(struct bio *dst, struct bio *src, | |
128 | gfp_t gfp_mask) | |
a892c8d5 ST |
129 | { |
130 | if (bio_has_crypt_ctx(src)) | |
07560151 EB |
131 | return __bio_crypt_clone(dst, src, gfp_mask); |
132 | return 0; | |
a892c8d5 ST |
133 | } |
134 | ||
1b262839 | 135 | #endif /* __LINUX_BLK_CRYPTO_H */ |