Post by josephreynolds1 on Jun 22, 2022 21:21:01 GMT
What is the right way to represent a BMC-attached Trusted Module (TPM) and the measurements it records? This TPM would record measurements for the BMC as differentiated from the host TPM.
Specifically, per a recent OpenBMC Security Working Group meeting, the intention is for a Redfish client to read measurements from a BMC-attached TPM.
Could the TrustedModules property in the ComputerSystem schema be adapted for use in the Manager schema? [Edit:append]: This schema seems like a good place to start, but it lacks a representation of the "measurements" stored in the TPM. Can we enhance this interface to represent the measurements, and allow Redfish clients to GET them?
Post by josephreynolds1 on Jun 28, 2022 1:25:56 GMT
With thanks to Ratan, I understand we can add a ComponentIntegrity resource to the BMC Manager object, where ComponentIntegrityType = TPM. This will allow Redfish clients to read BMC TPM measurements. That answers my question.
That's right; these resources are in their own location off of service root. The reason for this is to avoid RDE devices from populating this information in a malicious manner; by not putting it subordinate to the resource, an RDE device would not be able to slip it past the consuming manager.