Re: [PATCH] Security: Keys: Big keys stored encrypted

[David Howells]

Kirill Marinushkin <k.marinushkin@xxxxxxxxx> wrote:

> +enum {
> +	ENC,
> +	DEC,
> +};

"enum big_key_mode" and use it as a parameter type to big_key_crypt().

Also BIG_KEY_ENC, BIG_KEY_DEC.  Please use prefixes consistently.

> +static const char *rng_name = "stdrng";
> +
> +/*
> + * Algorithm name for big_key data encryption
> + */
> +static const char *alg_name = "ecb(aes)";

Use const char arrays not const char pointers as that saves on a pointer
storage.

> +/*
> + * Aligned data length of big_key encryption
> + */
> +#define ALIGNED_LEN(l)	(l + ENC_BLOCK_SIZE - l % ENC_BLOCK_SIZE)

Surely there's a crypto thing for this?  The block size and key size ought to
be functions of the algorithm you select rather than being hardcoded.

> +static int gen_enckey(u8 *key)

big_key_gen_enckey().

> +{
> +	int ret = -EINVAL;
> +	struct crypto_rng *rng = NULL;
> +
> +	rng = crypto_alloc_rng(rng_name, 0, 0);
> +	if (IS_ERR(rng))
> +		return -EFAULT;
> +
> +	ret = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
> +
> +	if (!ret)
> +		ret = crypto_rng_get_bytes(rng, key, ENC_KEY_SIZE);
> +
> +	if (rng)

rng can be NULL here?!

> +static int big_crypt(u8 op, u8 *data, size_t datalen, u8 *key)

big_key_crypt().