Re: RE: [PATCH v2 3/3] virtio-crypto: implement RSA algorithm

[zhenwei pi]

> > +void virtio_crypto_akcipher_algs_unregister(struct virtio_crypto
> > +*vcrypto) {
> > +	int i = 0;
> > +
> > +	mutex_lock(&algs_lock);
> > +
> > +	for (i = 0; i < ARRAY_SIZE(virtio_crypto_akcipher_algs); i++) {
> > +		uint32_t service = virtio_crypto_akcipher_algs[i].service;
> > +		uint32_t algonum = virtio_crypto_akcipher_algs[i].algonum;
> > +
> > +		if (virtio_crypto_akcipher_algs[i].active_devs == 0 ||
> > +		    !virtcrypto_algo_is_supported(vcrypto, service, algonum))
> > +			continue;
> > +
> > +		if (virtio_crypto_akcipher_algs[i].active_devs == 1)
> > +
> > 	crypto_unregister_akcipher(&virtio_crypto_akcipher_algs[i].algo);
> > +
> > +		virtio_crypto_akcipher_algs[i].active_devs--;
> > +	}
> > +
> > +	mutex_unlock(&algs_lock);
> > +}
>
> Why don't you reuse the virtio_crypto_algs_register/unregister functions?
> The current code is too repetitive. Maybe we don't need create the new file virtio_crypto_akcipher_algo.c
> because we had virtio_crypto_algs.c which includes all algorithms.

Yes, this looks similar to virtio_crypto_algs_register/unregister.

Let's look at the difference:
struct virtio_crypto_akcipher_algo {
        uint32_t algonum;
        uint32_t service;
        unsigned int active_devs;
        struct akcipher_alg algo;
};

struct virtio_crypto_algo {
        uint32_t algonum;
        uint32_t service; 

        unsigned int active_devs;
        struct skcipher_alg algo; /* akcipher_alg VS skcipher_alg */
};

If reusing virtio_crypto_algs_register/unregister, we need to modify the 
data structure like this:
struct virtio_crypto_akcipher_algo {
        uint32_t algonum;
        uint32_t service;	/* use service to distinguish 
akcipher/skcipher */
        unsigned int active_devs;
	union {
		struct skcipher_alg skcipher;
	        struct akcipher_alg akcipher;
	} alg;
};

int virtio_crypto_akcipher_algs_register(struct virtio_crypto *vcrypto)
{
	...
        for (i = 0; i < ARRAY_SIZE(virtio_crypto_akcipher_algs); i++) {
                uint32_t service = virtio_crypto_akcipher_algs[i].service;
		...
		/* test service type then call 
crypto_register_akcipher/crypto_register_skcipher */
                if (service == VIRTIO_CRYPTO_SERVICE_AKCIPHER)
			crypto_register_akcipher(&virtio_crypto_akcipher_algs[i].algo.akcipher);
		else
			crypto_register_skcipher(&virtio_crypto_skcipher_algs[i].algo.skcipher);
		...
        }
	...
}

Also test service type and call 
crypto_unregister_skcipher/crypto_unregister_akcipher.

This gets unclear from current v2 version.

On the other hand, the kernel side prefers to separate skcipher and 
akcipher(separated header files and implementations).

--
zhenwei pi