[PATCH v3 3/3] block: sed-opal: keyring support for SED keys

[Ben Boeckel]

On Wed, Nov 30, 2022 at 09:19:25 -0600, Greg Joyce wrote:
> On Wed, 2022-11-30 at 08:00 +0100, Hannes Reinecke wrote:
> > On 11/30/22 00:25, gjoyce at linux.vnet.ibm.com wrote:
> > > +	case OPAL_KEYRING:
> > > +		/* the key is in the keyring */
> > > +		ret = read_sed_opal_key(OPAL_AUTH_KEY, key->key,
> > > OPAL_KEY_MAX);
> > > +		if (ret > 0) {
> > > +			if (ret > 255) {
> > 
> > Why is a key longer than 255 an error?
> > If this is a requirement, why not move the check into
> > read_sed_opal_key() such that one only has to check for
> > ret < 0 on errors?
> 
> The check is done here because the SED Opal spec stipulates 255 as the
> maximum key length. The key length (key->key_len) in the existing data
> structures is __u8, so a length greater than 255 can not be conveyed.
> For defensive purposes, I though it best to check here.

Perhaps naming it `OPAL_MAX_KEY_LEN` would help clarify this?

--Ben