Messages in this thread | | | From | Dionna Amalie Glaze <> | Date | Fri, 4 Aug 2023 10:07:39 -0700 | Subject | Re: [PATCH 1/4] keys: Introduce tsm keys |
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> > Just on this one, it's already specified in the latest SVSM doc: > > https://lore.kernel.org/linux-coco/a2f31400-9e1c-c12a-ad7f-ea0265a12068@amd.com/ > > The Service Attestation Data on page 36-37. It says TPMT_PUBLIC of the > EK. However, what it doesn't say is *which* EK. I already sent in a > comment saying it should be the TCG template for the P-256 curve EK. > > So asking the SVSM to give you the attestation report for the VTPM > service binds the EK of the vTPM. >
Yes, thanks. It sounds like you have to ask the SVSM to certify the EK separately from asking the TPM for a quote. We can't rely entirely on the TPM API and avoid a sev-guest device for talking to the SVSM. Or are you saying the SVSM attestation report will get encoded in the x.509 EK certificate that the TPM API returns, such as the report is in a cert extension? I'm less clear on how TPM software would interpret the Issuer of that cert.
> James >
-- -Dionna Glaze, PhD (she/her)
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