diff options
Diffstat (limited to 'include/crypto')
| -rw-r--r-- | include/crypto/hash.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/include/crypto/hash.h b/include/crypto/hash.h index 74b13ec1ebd4..bf458fc272aa 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -17,6 +17,28 @@ struct crypto_ahash; +/** + * DOC: Message Digest Algorithm Definitions + * + * These data structures define modular message digest algorithm + * implementations, managed via crypto_register_ahash(), + * crypto_register_shash(), crypto_unregister_ahash() and + * crypto_unregister_shash(). + */ + +/** + * struct hash_alg_common - define properties of message digest + * @digestsize: Size of the result of the transformation. A buffer of this size + * must be available to the @final and @finup calls, so they can + * store the resulting hash into it. For various predefined sizes, + * search include/crypto/ using + * git grep _DIGEST_SIZE include/crypto. + * @statesize: Size of the block for partial state of the transformation. A + * buffer of this size must be passed to the @export function as it + * will save the partial state of the transformation into it. On the + * other side, the @import function will load the state from a + * buffer of this size as well. + */ struct hash_alg_common { unsigned int digestsize; unsigned int statesize; @@ -37,6 +59,62 @@ struct ahash_request { void *__ctx[] CRYPTO_MINALIGN_ATTR; }; +/** + * struct ahash_alg - asynchronous message digest definition + * @init: Initialize the transformation context. Intended only to initialize the + * state of the HASH transformation at the begining. This shall fill in + * the internal structures used during the entire duration of the whole + * transformation. No data processing happens at this point. + * @update: Push a chunk of data into the driver for transformation. This + * function actually pushes blocks of data from upper layers into the + * driver, which then passes those to the hardware as seen fit. This + * function must not finalize the HASH transformation by calculating the + * final message digest as this only adds more data into the + * transformation. This function shall not modify the transformation + * context, as this function may be called in parallel with the same + * transformation object. Data processing can happen synchronously + * [SHASH] or asynchronously [AHASH] at this point. + * @final: Retrieve result from the driver. This function finalizes the + * transformation and retrieves the resulting hash from the driver and + * pushes it back to upper layers. No data processing happens at this + * point. + * @finup: Combination of @update and @final. This function is effectively a + * combination of @update and @final calls issued in sequence. As some + * hardware cannot do @update and @final separately, this callback was + * added to allow such hardware to be used at least by IPsec. Data + * processing can happen synchronously [SHASH] or asynchronously [AHASH] + * at this point. + * @digest: Combination of @init and @update and @final. This function + * effectively behaves as the entire chain of operations, @init, + * @update and @final issued in sequence. Just like @finup, this was + * added for hardware which cannot do even the @finup, but can only do + * the whole transformation in one run. Data processing can happen + * synchronously [SHASH] or asynchronously [AHASH] at this point. + * @setkey: Set optional key used by the hashing algorithm. Intended to push + * optional key used by the hashing algorithm from upper layers into + * the driver. This function can store the key in the transformation + * context or can outright program it into the hardware. In the former + * case, one must be careful to program the key into the hardware at + * appropriate time and one must be careful that .setkey() can be + * called multiple times during the existence of the transformation + * object. Not all hashing algorithms do implement this function as it + * is only needed for keyed message digests. SHAx/MDx/CRCx do NOT + * implement this function. HMAC(MDx)/HMAC(SHAx)/CMAC(AES) do implement + * this function. This function must be called before any other of the + * @init, @update, @final, @finup, @digest is called. No data + * processing happens at this point. + * @export: Export partial state of the transformation. This function dumps the + * entire state of the ongoing transformation into a provided block of + * data so it can be @import 'ed back later on. This is useful in case + * you want to save partial result of the transformation after + * processing certain amount of data and reload this partial result + * multiple times later on for multiple re-use. No data processing + * happens at this point. + * @import: Import partial state of the transformation. This function loads the + * entire state of the ongoing transformation from a provided block of + * data so the transformation can continue from this point onward. No + * data processing happens at this point. + */ struct ahash_alg { int (*init)(struct ahash_request *req); int (*update)(struct ahash_request *req); @@ -63,6 +141,23 @@ struct shash_desc { crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \ struct shash_desc *shash = (struct shash_desc *)__##shash##_desc +/** + * struct shash_alg - synchronous message digest definition + * @init: see struct ahash_alg + * @update: see struct ahash_alg + * @final: see struct ahash_alg + * @finup: see struct ahash_alg + * @digest: see struct ahash_alg + * @export: see struct ahash_alg + * @import: see struct ahash_alg + * @setkey: see struct ahash_alg + * @digestsize: see struct ahash_alg + * @statesize: see struct ahash_alg + * @dedcsize: Size of the operational state for the message digest. This state + * size is the memory size that needs to be allocated for + * shash_desc.__ctx + * @base: internally used + */ struct shash_alg { int (*init)(struct shash_desc *desc); int (*update)(struct shash_desc *desc, const u8 *data, |