Am Mittwoch, 29. Mai 2019, 16:04:47 CEST schrieb David Gstir: Hi David, > Hi! > > I've done some testing with hardware acceleration of hash functions > and noticed that, when using the synchronous message digest API (shash), > some drivers are not usable. In my case the CAAM driver for SHA256. > Using the asynchronous interface (ahash), everything works as expected. > Looking at the driver source, the CAAM driver only implements the ahash > interface. > > I'm wondering if there a way to use an ahash driver through the shash > interface? Short: no. > > I've seen that it does actually work the other way around, since > crypto_init_shash_ops_async() in crypto/shash.c takes care of translating > calls from ahash to shash and that's how the *-generic drivers are usable > through the ahash API. The crypto_alloc_shash will only identify cipher implementations that were registered with the CRYPTO_ALG_TYPE_SHASH flag. That flag is set when a cipher is registered using crypto_register_shash. Thus, ciphers registered with crypto_register_ahash will not bear this flag and thus will not be found by the allocation function. Ciao Stephan
