Re: EXTERNAL - [PATCH v5 1/6] tools: mkeficapsule: Add support for pkcs11

[Wojciech Dubowik <Wojciech.Dubowik@mt.com>]

On Fri, Feb 13, 2026 at 02:56:48PM +0200, Ilias Apalodimas wrote:

Hi Ilias,

> Hi Wojciech,
> 
> On Wed Jan 28, 2026 at 10:05 AM EET, Wojciech Dubowik wrote:
> > With pkcs11 support it's now possible to specify keys
> > with URI format. To use this feature the filename must
> > begin "pkcs11:.." and have valid URI pointing to certificate
> > and private key in HSM.
> >
> > The environment variable PKCS11_MODULE_PATH must point to the
> > right pkcs11 provider i.e. with softhsm:
> > export PKCS11_MODULE_PATH=<path>/libsofthsm2.so
> >
> >
> 
> [...]
> 
> > -	ret = read_bin_file(ctx->cert_file, &cert.data, &file_size);
> > -	if (ret < 0)
> > -		return -1;
> > -	if (file_size > UINT_MAX)
> > -		return -1;
> > -	cert.size = file_size;
> > +	if (!strncmp(ctx->cert_file, "pkcs11:", 7))
> 
> Can we do strlen() instead of 7 ?

Will do in the next iteration.
> 
> > +		pkcs11_cert = true;
> >
> > -	ret = read_bin_file(ctx->key_file, &key.data, &file_size);
> > -	if (ret < 0)
> > -		return -1;
> > -	if (file_size > UINT_MAX)
> > -		return -1;
> > -	key.size = file_size;
> > +	if (!strncmp(ctx->key_file, "pkcs11:", 7))
> 
> Same
> 
> > +		pkcs11_key = true;
> > +
> > +	if (pkcs11_cert || pkcs11_key) {
> 
> Don't you need both the cert & key to sign the capsule?
> I'd simplify the logic here. Instead of having both a pkcs_key and a pkcs_cert,
> replace the variables with is_pcks and have that set to true if both the key
> and cert have been found.
This is what I have done in the first iteration. Later I have learned that there
is a need for mixed pkcs11/local file usage. The HSM devices are very expensive
(at least some of them) and have limited memory. It's quite common to use private
key from HSM over pkcs11 protocol and all the public stuff locally.

The test is implemented so at the moment.

Regards,
Wojtek
> 
> Then the if/else cases later will become a bit easier to read since you'll have
> to load the private key & crt on a single if/else cases depending on is_pkcs.
> 
> > +		lib = getenv("PKCS11_MODULE_PATH");
> > +		if (!lib) {
> 
> [...]
> 
> Thanks
> /Ilias