constellation/internal/attestation/qemu/validator.go
Daniel Weiße 5a0234b3f2
attestation: add option for MAA fallback to verify azure's snp-sev id key digest (#1257)
* Convert enforceIDKeyDigest setting to enum

* Use MAA fallback in Azure SNP attestation

* Only create MAA provider if MAA fallback is enabled

---------

Signed-off-by: Daniel Weiße <dw@edgeless.systems>
Co-authored-by: Thomas Tendyck <tt@edgeless.systems>
2023-03-21 12:46:49 +01:00

46 lines
1.1 KiB
Go

/*
Copyright (c) Edgeless Systems GmbH
SPDX-License-Identifier: AGPL-3.0-only
*/
package qemu
import (
"context"
"crypto"
"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
"github.com/edgelesssys/constellation/v2/internal/attestation/vtpm"
"github.com/edgelesssys/constellation/v2/internal/oid"
"github.com/google/go-tpm-tools/proto/attest"
"github.com/google/go-tpm/tpm2"
)
// Validator for QEMU VM attestation.
type Validator struct {
oid.QEMUVTPM
*vtpm.Validator
}
// NewValidator initializes a new QEMU validator with the provided PCR values.
func NewValidator(pcrs measurements.M, log vtpm.AttestationLogger) *Validator {
return &Validator{
Validator: vtpm.NewValidator(
pcrs,
unconditionalTrust,
func(vtpm.AttestationDocument, *attest.MachineState) error { return nil },
log,
),
}
}
// unconditionalTrust returns the given public key as the trusted attestation key.
func unconditionalTrust(_ context.Context, attDoc vtpm.AttestationDocument, _ []byte) (crypto.PublicKey, error) {
pubArea, err := tpm2.DecodePublic(attDoc.Attestation.AkPub)
if err != nil {
return nil, err
}
return pubArea.Key()
}