On Thu, 1 Apr 2021 at 19:00, Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote: > > Hello Richard, Sumit, > > On 01.04.21 15:17, Richard Weinberger wrote: > > Sumit, > > > > ----- Ursprüngliche Mail ----- > >> Von: "Sumit Garg" <sumit.garg@xxxxxxxxxx> > >> IIUC, this would require support for multiple trusted keys backends at > >> runtime but currently the trusted keys subsystem only supports a > >> single backend which is selected via kernel module parameter during > >> boot. > >> > >> So the trusted keys framework needs to evolve to support multiple > >> trust sources at runtime but I would like to understand the use-cases > >> first. IMO, selecting the best trust source available on a platform > >> for trusted keys should be a one time operation, so why do we need to > >> have other backends available at runtime as well? > > > > I thought about devices with a TPM-Chip and CAAM. In this case why would one prefer to use CAAM when you have standards compliant TPM-Chip which additionally offers sealing to specific PCR (integrity measurement) values. > > IMHO allowing only one backend at the same time is a little over simplified. > > It is, but I'd rather leave this until it's actually needed. > What can be done now is adopting a format for the exported keys that would > make this extension seamless in future. > +1 -Sumit > Cheers, > Ahmad > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |