diff options
Diffstat (limited to 'include/crypto/skcipher.h')
| -rw-r--r-- | include/crypto/skcipher.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h index 0f987f50bb52..a381f57ea695 100644 --- a/include/crypto/skcipher.h +++ b/include/crypto/skcipher.h @@ -65,6 +65,75 @@ struct crypto_skcipher { struct crypto_tfm base; }; +/** + * struct skcipher_alg - symmetric key cipher definition + * @min_keysize: Minimum key size supported by the transformation. This is the + * smallest key length supported by this transformation algorithm. + * This must be set to one of the pre-defined values as this is + * not hardware specific. Possible values for this field can be + * found via git grep "_MIN_KEY_SIZE" include/crypto/ + * @max_keysize: Maximum key size supported by the transformation. This is the + * largest key length supported by this transformation algorithm. + * This must be set to one of the pre-defined values as this is + * not hardware specific. Possible values for this field can be + * found via git grep "_MAX_KEY_SIZE" include/crypto/ + * @setkey: Set key for the transformation. This function is used to either + * program a supplied key into the hardware or store the key in the + * transformation context for programming it later. Note that this + * function does modify the transformation context. This function can + * be called multiple times during the existence of the transformation + * object, so one must make sure the key is properly reprogrammed into + * the hardware. This function is also responsible for checking the key + * length for validity. In case a software fallback was put in place in + * the @cra_init call, this function might need to use the fallback if + * the algorithm doesn't support all of the key sizes. + * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt + * the supplied scatterlist containing the blocks of data. The crypto + * API consumer is responsible for aligning the entries of the + * scatterlist properly and making sure the chunks are correctly + * sized. In case a software fallback was put in place in the + * @cra_init call, this function might need to use the fallback if + * the algorithm doesn't support all of the key sizes. In case the + * key was stored in transformation context, the key might need to be + * re-programmed into the hardware in this function. This function + * shall not modify the transformation context, as this function may + * be called in parallel with the same transformation object. + * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt + * and the conditions are exactly the same. + * @init: Initialize the cryptographic transformation object. This function + * is used to initialize the cryptographic transformation object. + * This function is called only once at the instantiation time, right + * after the transformation context was allocated. In case the + * cryptographic hardware has some special requirements which need to + * be handled by software, this function shall check for the precise + * requirement of the transformation and put any software fallbacks + * in place. + * @exit: Deinitialize the cryptographic transformation object. This is a + * counterpart to @init, used to remove various changes set in + * @init. + * @ivsize: IV size applicable for transformation. The consumer must provide an + * IV of exactly that size to perform the encrypt or decrypt operation. + * @chunksize: Equal to the block size except for stream ciphers such as + * CTR where it is set to the underlying block size. + * + * All fields except @ivsize are mandatory and must be filled. + */ +struct skcipher_alg { + int (*setkey)(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen); + int (*encrypt)(struct skcipher_request *req); + int (*decrypt)(struct skcipher_request *req); + int (*init)(struct crypto_skcipher *tfm); + void (*exit)(struct crypto_skcipher *tfm); + + unsigned int min_keysize; + unsigned int max_keysize; + unsigned int ivsize; + unsigned int chunksize; + + struct crypto_alg base; +}; + #define SKCIPHER_REQUEST_ON_STACK(name, tfm) \ char __##name##_desc[sizeof(struct skcipher_request) + \ crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \ @@ -231,12 +300,43 @@ static inline int crypto_has_skcipher(const char *alg_name, u32 type, crypto_skcipher_mask(mask)); } +/** + * crypto_has_skcipher2() - Search for the availability of an skcipher. + * @alg_name: is the cra_name / name or cra_driver_name / driver name of the + * skcipher + * @type: specifies the type of the skcipher + * @mask: specifies the mask for the skcipher + * + * Return: true when the skcipher is known to the kernel crypto API; false + * otherwise + */ +int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask); + static inline const char *crypto_skcipher_driver_name( struct crypto_skcipher *tfm) { return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm)); } +static inline struct skcipher_alg *crypto_skcipher_alg( + struct crypto_skcipher *tfm) +{ + return container_of(crypto_skcipher_tfm(tfm)->__crt_alg, + struct skcipher_alg, base); +} + +static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg) +{ + if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) == + CRYPTO_ALG_TYPE_BLKCIPHER) + return alg->base.cra_blkcipher.ivsize; + + if (alg->base.cra_ablkcipher.encrypt) + return alg->base.cra_ablkcipher.ivsize; + + return alg->ivsize; +} + /** * crypto_skcipher_ivsize() - obtain IV size * @tfm: cipher handle @@ -251,6 +351,36 @@ static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm) return tfm->ivsize; } +static inline unsigned int crypto_skcipher_alg_chunksize( + struct skcipher_alg *alg) +{ + if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) == + CRYPTO_ALG_TYPE_BLKCIPHER) + return alg->base.cra_blocksize; + + if (alg->base.cra_ablkcipher.encrypt) + return alg->base.cra_blocksize; + + return alg->chunksize; +} + +/** + * crypto_skcipher_chunksize() - obtain chunk size + * @tfm: cipher handle + * + * The block size is set to one for ciphers such as CTR. However, + * you still need to provide incremental updates in multiples of + * the underlying block size as the IV does not have sub-block + * granularity. This is known in this API as the chunk size. + * + * Return: chunk size in bytes + */ +static inline unsigned int crypto_skcipher_chunksize( + struct crypto_skcipher *tfm) +{ + return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm)); +} + /** * crypto_skcipher_blocksize() - obtain block size of cipher * @tfm: cipher handle |