Re: [PATCH RFC v5 3/4] crypto: rsa: add a new rsa generic implementation

[Stephan Mueller <smueller@chronox.de>]

Am Montag, 15. Juni 2015, 13:18:47 schrieb Tadeusz Struk:

Hi Tadeusz,

> Add a new rsa generic SW implementation.
> This implements only cryptographic primitives.

Thank you, that seems to address the issues around the FIPS side including the 
self test code.

Though, I have one question:

> +
> +int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
> +	      const void *value, size_t vlen)
> +{
> +	struct crypto_akcipher *tfm = context;
> +	struct rsa_key *key = tfm->key;
> +
> +	key->n = mpi_read_raw_data(value, vlen);
> +
> +	if (!key->n)
> +		return -ENOMEM;
> +
> +	/* In FIPS mode only allow key size minimum 2K */
> +	if (fips_enabled && (mpi_get_size(key->n) < 256)) {

Considering my previous email, shouldn't that check rather be

if (fips_enabled &&
    ((mpi_get_size(key->n) != 256) || (mpi_get_size(key->n) != 384))

?

> +		pr_err("RSA: key size not allowed in FIPS mode\n");
> +		mpi_free(key->n);
> +		key->n = NULL;
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
> +	      const void *value, size_t vlen)
> +{
> +	struct crypto_akcipher *tfm = context;
> +	struct rsa_key *key = tfm->key;
> +
> +	key->e = mpi_read_raw_data(value, vlen);
> +
> +	if (!key->e)
> +		return -ENOMEM;
> +
> +	return 0;
> +}
> +
> +int rsa_get_d(void *context, size_t hdrlen, unsigned char tag,
> +	      const void *value, size_t vlen)
> +{
> +	struct crypto_akcipher *tfm = context;
> +	struct rsa_key *key = tfm->key;
> +
> +	key->d = mpi_read_raw_data(value, vlen);
> +
> +	if (!key->d)
> +		return -ENOMEM;
> +
> +	/* In FIPS mode only allow key size minimum 2K */
> +	if (fips_enabled && (mpi_get_size(key->d) < 256)) {

dto.

> +		pr_err("RSA: key size not allowed in FIPS mode\n");
> +		mpi_free(key->d);
> +		key->d = NULL;
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +

Thanks
-- 
Ciao
Stephan