AB#2644 Fetch measurements from CDN (#653)

* Fetch measurements from CDN

* Perform metadata validation on fetched measurements

* Remove deprecated public bucket

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

hack/pcr-reader/main.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
 	"github.com/edgelesssys/constellation/v2/internal/attestation/vtpm"
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
 	"github.com/edgelesssys/constellation/v2/internal/constants"
 	"github.com/edgelesssys/constellation/v2/internal/crypto"
 	"github.com/edgelesssys/constellation/v2/verify/verifyproto"
@@ -73,7 +74,7 @@ func main() {
 
 	if *metadata {
 		outputWithMetadata := measurements.WithMetadata{
-			CSP:          strings.ToLower(*csp),
+			CSP:          cloudprovider.FromString(*csp),
 			Image:        strings.ToLower(*image),
 			Measurements: pcrs,
 		}

hack/pcr-reader/main_test.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
 	"github.com/edgelesssys/constellation/v2/internal/attestation/vtpm"
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
 	"github.com/google/go-tpm-tools/proto/attest"
 	"github.com/google/go-tpm-tools/proto/tpm"
 	"github.com/stretchr/testify/assert"
@@ -152,22 +153,22 @@ func TestPrintPCRs(t *testing.T) {
 func TestPrintPCRsWithMetadata(t *testing.T) {
 	testCases := map[string]struct {
 		format string
-		csp    string
+		csp    cloudprovider.Provider
 		image  string
 	}{
 		"json": {
 			format: "json",
-			csp:    "azure",
+			csp:    cloudprovider.Azure,
 			image:  "v2.0.0",
 		},
 		"yaml": {
-			csp:    "gcp",
+			csp:    cloudprovider.GCP,
 			image:  "v2.0.0-testimage",
 			format: "yaml",
 		},
 		"empty format": {
 			format: "",
-			csp:    "qemu",
+			csp:    cloudprovider.QEMU,
 			image:  "v2.0.0-testimage",
 		},
 		"empty": {},