Asynchronous Message Digest API

crypto_alloc_ahash — allocate ahash cipher handle
crypto_free_ahash — zeroize and free the ahash handle
crypto_ahash_init — (re)initialize message digest handle
crypto_ahash_digestsize — obtain message digest size
crypto_ahash_reqtfm — obtain cipher handle from request
crypto_ahash_reqsize — obtain size of the request data structure
crypto_ahash_setkey — set key for cipher handle
crypto_ahash_finup — update and finalize message digest
crypto_ahash_final — calculate message digest
crypto_ahash_digest — calculate message digest for a buffer
crypto_ahash_export — extract current message digest state
crypto_ahash_import — import message digest state

The asynchronous message digest API is used with the ciphers of type CRYPTO_ALG_TYPE_AHASH (listed as type ahash in /proc/crypto)

The asynchronous cipher operation discussion provided for the CRYPTO_ALG_TYPE_ABLKCIPHER API applies here as well.