| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Copyright 2019 Google LLC |
| */ |
| #ifndef __LINUX_BIO_CRYPT_CTX_H |
| #define __LINUX_BIO_CRYPT_CTX_H |
| |
| enum blk_crypto_mode_num { |
| BLK_ENCRYPTION_MODE_INVALID, |
| BLK_ENCRYPTION_MODE_AES_256_XTS, |
| BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV, |
| BLK_ENCRYPTION_MODE_ADIANTUM, |
| BLK_ENCRYPTION_MODE_MAX, |
| }; |
| |
| #ifdef CONFIG_BLOCK |
| #include <linux/blk_types.h> |
| |
| #ifdef CONFIG_BLK_INLINE_ENCRYPTION |
| |
| #define BLK_CRYPTO_MAX_KEY_SIZE 64 |
| #define BLK_CRYPTO_MAX_WRAPPED_KEY_SIZE 128 |
| |
| /** |
| * struct blk_crypto_key - an inline encryption key |
| * @crypto_mode: encryption algorithm this key is for |
| * @data_unit_size: the data unit size for all encryption/decryptions with this |
| * key. This is the size in bytes of each individual plaintext and |
| * ciphertext. This is always a power of 2. It might be e.g. the |
| * filesystem block size or the disk sector size. |
| * @data_unit_size_bits: log2 of data_unit_size |
| * @size: size of this key in bytes (determined by @crypto_mode) |
| * @hash: hash of this key, for keyslot manager use only |
| * @is_hw_wrapped: @raw points to a wrapped key to be used by an inline |
| * encryption hardware that accepts wrapped keys. |
| * @raw: the raw bytes of this key. Only the first @size bytes are used. |
| * |
| * A blk_crypto_key is immutable once created, and many bios can reference it at |
| * the same time. It must not be freed until all bios using it have completed. |
| */ |
| struct blk_crypto_key { |
| enum blk_crypto_mode_num crypto_mode; |
| unsigned int data_unit_size; |
| unsigned int data_unit_size_bits; |
| unsigned int size; |
| |
| /* |
| * Hack to avoid breaking KMI: pack both hash and dun_bytes into the |
| * hash field... |
| */ |
| #define BLK_CRYPTO_KEY_HASH_MASK 0xffffff |
| #define BLK_CRYPTO_KEY_DUN_BYTES_SHIFT 24 |
| unsigned int hash; |
| |
| bool is_hw_wrapped; |
| u8 raw[BLK_CRYPTO_MAX_WRAPPED_KEY_SIZE]; |
| }; |
| |
| #define BLK_CRYPTO_MAX_IV_SIZE 32 |
| #define BLK_CRYPTO_DUN_ARRAY_SIZE (BLK_CRYPTO_MAX_IV_SIZE/sizeof(u64)) |
| |
| static inline void |
| blk_crypto_key_set_hash_and_dun_bytes(struct blk_crypto_key *key, |
| u32 hash, unsigned int dun_bytes) |
| { |
| key->hash = (dun_bytes << BLK_CRYPTO_KEY_DUN_BYTES_SHIFT) | |
| (hash & BLK_CRYPTO_KEY_HASH_MASK); |
| } |
| |
| static inline u32 |
| blk_crypto_key_hash(const struct blk_crypto_key *key) |
| { |
| return key->hash & BLK_CRYPTO_KEY_HASH_MASK; |
| } |
| |
| static inline unsigned int |
| blk_crypto_key_dun_bytes(const struct blk_crypto_key *key) |
| { |
| return key->hash >> BLK_CRYPTO_KEY_DUN_BYTES_SHIFT; |
| } |
| |
| /** |
| * struct bio_crypt_ctx - an inline encryption context |
| * @bc_key: the key, algorithm, and data unit size to use |
| * @bc_keyslot: the keyslot that has been assigned for this key in @bc_ksm, |
| * or -1 if no keyslot has been assigned yet. |
| * @bc_dun: the data unit number (starting IV) to use |
| * @bc_ksm: the keyslot manager into which the key has been programmed with |
| * @bc_keyslot, or NULL if this key hasn't yet been programmed. |
| * |
| * A bio_crypt_ctx specifies that the contents of the bio will be encrypted (for |
| * write requests) or decrypted (for read requests) inline by the storage device |
| * or controller, or by the crypto API fallback. |
| */ |
| struct bio_crypt_ctx { |
| const struct blk_crypto_key *bc_key; |
| int bc_keyslot; |
| |
| /* Data unit number */ |
| u64 bc_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]; |
| |
| /* |
| * The keyslot manager where the key has been programmed |
| * with keyslot. |
| */ |
| struct keyslot_manager *bc_ksm; |
| }; |
| |
| int bio_crypt_ctx_init(void); |
| |
| struct bio_crypt_ctx *bio_crypt_alloc_ctx(gfp_t gfp_mask); |
| |
| void bio_crypt_free_ctx(struct bio *bio); |
| |
| static inline bool bio_has_crypt_ctx(struct bio *bio) |
| { |
| return bio->bi_crypt_context; |
| } |
| |
| void bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); |
| |
| static inline void bio_crypt_set_ctx(struct bio *bio, |
| const struct blk_crypto_key *key, |
| u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], |
| gfp_t gfp_mask) |
| { |
| struct bio_crypt_ctx *bc = bio_crypt_alloc_ctx(gfp_mask); |
| |
| bc->bc_key = key; |
| memcpy(bc->bc_dun, dun, sizeof(bc->bc_dun)); |
| bc->bc_ksm = NULL; |
| bc->bc_keyslot = -1; |
| |
| bio->bi_crypt_context = bc; |
| } |
| |
| void bio_crypt_ctx_release_keyslot(struct bio_crypt_ctx *bc); |
| |
| int bio_crypt_ctx_acquire_keyslot(struct bio_crypt_ctx *bc, |
| struct keyslot_manager *ksm); |
| |
| struct request; |
| bool bio_crypt_should_process(struct request *rq); |
| |
| static inline bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc, |
| unsigned int bytes, |
| u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]) |
| { |
| int i = 0; |
| unsigned int inc = bytes >> bc->bc_key->data_unit_size_bits; |
| |
| while (i < BLK_CRYPTO_DUN_ARRAY_SIZE) { |
| if (bc->bc_dun[i] + inc != next_dun[i]) |
| return false; |
| inc = ((bc->bc_dun[i] + inc) < inc); |
| i++; |
| } |
| |
| return true; |
| } |
| |
| |
| static inline void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], |
| unsigned int inc) |
| { |
| int i = 0; |
| |
| while (inc && i < BLK_CRYPTO_DUN_ARRAY_SIZE) { |
| dun[i] += inc; |
| inc = (dun[i] < inc); |
| i++; |
| } |
| } |
| |
| static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes) |
| { |
| struct bio_crypt_ctx *bc = bio->bi_crypt_context; |
| |
| if (!bc) |
| return; |
| |
| bio_crypt_dun_increment(bc->bc_dun, |
| bytes >> bc->bc_key->data_unit_size_bits); |
| } |
| |
| bool bio_crypt_ctx_compatible(struct bio *b_1, struct bio *b_2); |
| |
| bool bio_crypt_ctx_mergeable(struct bio *b_1, unsigned int b1_bytes, |
| struct bio *b_2); |
| |
| #else /* CONFIG_BLK_INLINE_ENCRYPTION */ |
| static inline int bio_crypt_ctx_init(void) |
| { |
| return 0; |
| } |
| |
| static inline bool bio_has_crypt_ctx(struct bio *bio) |
| { |
| return false; |
| } |
| |
| static inline void bio_crypt_clone(struct bio *dst, struct bio *src, |
| gfp_t gfp_mask) { } |
| |
| static inline void bio_crypt_free_ctx(struct bio *bio) { } |
| |
| static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes) { } |
| |
| static inline bool bio_crypt_ctx_compatible(struct bio *b_1, struct bio *b_2) |
| { |
| return true; |
| } |
| |
| static inline bool bio_crypt_ctx_mergeable(struct bio *b_1, |
| unsigned int b1_bytes, |
| struct bio *b_2) |
| { |
| return true; |
| } |
| |
| #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ |
| |
| #if IS_ENABLED(CONFIG_DM_DEFAULT_KEY) |
| static inline void bio_set_skip_dm_default_key(struct bio *bio) |
| { |
| bio->bi_skip_dm_default_key = true; |
| } |
| |
| static inline bool bio_should_skip_dm_default_key(const struct bio *bio) |
| { |
| return bio->bi_skip_dm_default_key; |
| } |
| |
| static inline void bio_clone_skip_dm_default_key(struct bio *dst, |
| const struct bio *src) |
| { |
| dst->bi_skip_dm_default_key = src->bi_skip_dm_default_key; |
| } |
| #else /* CONFIG_DM_DEFAULT_KEY */ |
| static inline void bio_set_skip_dm_default_key(struct bio *bio) |
| { |
| } |
| |
| static inline bool bio_should_skip_dm_default_key(const struct bio *bio) |
| { |
| return false; |
| } |
| |
| static inline void bio_clone_skip_dm_default_key(struct bio *dst, |
| const struct bio *src) |
| { |
| } |
| #endif /* !CONFIG_DM_DEFAULT_KEY */ |
| |
| #endif /* CONFIG_BLOCK */ |
| |
| #endif /* __LINUX_BIO_CRYPT_CTX_H */ |