Re: Can an ahash driver be used through shash API?

From: Richard Weinberger
Date: Wed May 29 2019 - 16:25:24 EST


Stephan,

----- UrsprÃngliche Mail -----
>> 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.

is there a reason why we don't emulate the synchronous functionality
in the crypto API layer if a driver implements only the async interface?

Or is it just a matter of -ENOPATCH? :)

Thanks,
//richard