diff options
Diffstat (limited to 'include/linux/blk-crypto.h')
-rw-r--r-- | include/linux/blk-crypto.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h new file mode 100644 index 000000000000..e82342907f2b --- /dev/null +++ b/include/linux/blk-crypto.h @@ -0,0 +1,123 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright 2019 Google LLC + */ + +#ifndef __LINUX_BLK_CRYPTO_H +#define __LINUX_BLK_CRYPTO_H + +#include <linux/types.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, +}; + +#define BLK_CRYPTO_MAX_KEY_SIZE 64 +/** + * struct blk_crypto_config - an inline encryption key's crypto configuration + * @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. + * @dun_bytes: the maximum number of bytes of DUN used when using this key + */ +struct blk_crypto_config { + enum blk_crypto_mode_num crypto_mode; + unsigned int data_unit_size; + unsigned int dun_bytes; +}; + +/** + * struct blk_crypto_key - an inline encryption key + * @crypto_cfg: the crypto configuration (like crypto_mode, key size) for this + * key + * @data_unit_size_bits: log2 of data_unit_size + * @size: size of this key in bytes (determined by @crypto_cfg.crypto_mode) + * @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 + * and it has been evicted from all devices on which it may have been used. + */ +struct blk_crypto_key { + struct blk_crypto_config crypto_cfg; + unsigned int data_unit_size_bits; + unsigned int size; + u8 raw[BLK_CRYPTO_MAX_KEY_SIZE]; +}; + +#define BLK_CRYPTO_MAX_IV_SIZE 32 +#define BLK_CRYPTO_DUN_ARRAY_SIZE (BLK_CRYPTO_MAX_IV_SIZE / sizeof(u64)) + +/** + * struct bio_crypt_ctx - an inline encryption context + * @bc_key: the key, algorithm, and data unit size to use + * @bc_dun: the data unit number (starting IV) to use + * + * 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; + u64 bc_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]; +}; + +#include <linux/blk_types.h> +#include <linux/blkdev.h> + +struct request; +struct request_queue; + +#ifdef CONFIG_BLK_INLINE_ENCRYPTION + +static inline bool bio_has_crypt_ctx(struct bio *bio) +{ + return bio->bi_crypt_context; +} + +void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key, + const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], + gfp_t gfp_mask); + +bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc, + unsigned int bytes, + const u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]); + +int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key, + enum blk_crypto_mode_num crypto_mode, + unsigned int dun_bytes, + unsigned int data_unit_size); + +int blk_crypto_start_using_key(const struct blk_crypto_key *key, + struct request_queue *q); + +int blk_crypto_evict_key(struct request_queue *q, + const struct blk_crypto_key *key); + +bool blk_crypto_config_supported(struct request_queue *q, + const struct blk_crypto_config *cfg); + +#else /* CONFIG_BLK_INLINE_ENCRYPTION */ + +static inline bool bio_has_crypt_ctx(struct bio *bio) +{ + return false; +} + +#endif /* CONFIG_BLK_INLINE_ENCRYPTION */ + +void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); +static inline void bio_crypt_clone(struct bio *dst, struct bio *src, + gfp_t gfp_mask) +{ + if (bio_has_crypt_ctx(src)) + __bio_crypt_clone(dst, src, gfp_mask); +} + +#endif /* __LINUX_BLK_CRYPTO_H */ |