terraform-provider: add attestation data source (#2640)

Signed-off-by: Daniel Weiße <dw@edgeless.systems> Co-authored-by: Daniel Weiße <dw@edgeless.systems>
2024-12-24 23:19:39 -05:00 · 2023-11-28 17:30:11 +01:00 · 2023-11-28 17:30:11 +01:00 · a2de1d23ec
commit a2de1d23ec
parent 03c5692fdd
18 changed files with 871 additions and 177 deletions
--- a/bazel/ci/terraform.sh.in
+++ b/bazel/ci/terraform.sh.in
@ -71,7 +71,7 @@ check() {
  for exclude in "${excludeLockDirs[@]}"; do
    for i in "${!terraformLockModules[@]}"; do
      if [[ ${terraformLockModules[i]} == "${BUILD_WORKSPACE_DIRECTORY}/${exclude}"* ]]; then
-        echo "  ${terraformLockModules[i]}"
+        echo "${terraformLockModules[i]}"
        unset 'terraformLockModules[i]'
      fi
    done
@ -119,6 +119,14 @@ check() {
      ${terraform} -chdir="${module}" fmt -recursive > /dev/null
      ${terraform} -chdir="${module}" validate > /dev/null
      rm -rf "${module}/.terraform"
+      echo "Deleting lock files in the following directories:" # init generates lockfiles which should only be generated in the generate mode.
+      for dir in "${excludeLockDirs[@]}"; do
+        if [[ -d ${dir} ]]; then
+          find "${dir}" -name '*.lock.hcl' -type f -delete
+        else
+          echo "  Directory ${dir} does not exist, skipping"
+        fi
+      done
    done
    ;;

--- a/cli/internal/cmd/BUILD.bazel
+++ b/cli/internal/cmd/BUILD.bazel
@ -170,7 +170,6 @@ go_test(
        "//internal/license",
        "//internal/logger",
        "//internal/semver",
-        "//internal/sigstore",
        "//internal/state",
        "//internal/versions",
        "//operators/constellation-node-operator/api/v1alpha1",
--- a/cli/internal/cmd/configfetchmeasurements.go
+++ b/cli/internal/cmd/configfetchmeasurements.go
@ -17,12 +17,13 @@ import (
 	"github.com/edgelesssys/constellation/v2/internal/api/attestationconfigapi"
 	"github.com/edgelesssys/constellation/v2/internal/api/versionsapi"
 	"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
+	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
 	"github.com/edgelesssys/constellation/v2/internal/config"
 	"github.com/edgelesssys/constellation/v2/internal/constants"
 	"github.com/edgelesssys/constellation/v2/internal/featureset"
 	"github.com/edgelesssys/constellation/v2/internal/file"
 	"github.com/edgelesssys/constellation/v2/internal/sigstore"
-	"github.com/edgelesssys/constellation/v2/internal/sigstore/keyselect"
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@ -73,10 +74,18 @@ func (f *fetchMeasurementsFlags) parse(flags *pflag.FlagSet) error {
 	return nil
 }

+type verifyFetcher interface {
+	FetchAndVerifyMeasurements(ctx context.Context,
+		image string, csp cloudprovider.Provider, attestationVariant variant.Variant,
+		noVerify bool,
+	) (measurements.M, error)
+}
+
 type configFetchMeasurementsCmd struct {
 	flags                fetchMeasurementsFlags
 	canFetchMeasurements bool
 	log                  debugLog
+	verifyFetcher        verifyFetcher
 }

 func runConfigFetchMeasurements(cmd *cobra.Command, _ []string) error {
@ -90,19 +99,20 @@ func runConfigFetchMeasurements(cmd *cobra.Command, _ []string) error {
 	if err != nil {
 		return fmt.Errorf("constructing Rekor client: %w", err)
 	}
-	cfm := &configFetchMeasurementsCmd{log: log, canFetchMeasurements: featureset.CanFetchMeasurements}
+
+	verifyFetcher := measurements.NewVerifyFetcher(sigstore.NewCosignVerifier, rekor, http.DefaultClient)
+	cfm := &configFetchMeasurementsCmd{log: log, canFetchMeasurements: featureset.CanFetchMeasurements, verifyFetcher: verifyFetcher}
 	if err := cfm.flags.parse(cmd.Flags()); err != nil {
 		return fmt.Errorf("parsing flags: %w", err)
 	}
 	cfm.log.Debugf("Using flags %+v", cfm.flags)

 	fetcher := attestationconfigapi.NewFetcherWithClient(http.DefaultClient, constants.CDNRepositoryURL)
-	return cfm.configFetchMeasurements(cmd, sigstore.NewCosignVerifier, rekor, fileHandler, fetcher, http.DefaultClient)
+	return cfm.configFetchMeasurements(cmd, fileHandler, fetcher)
 }

 func (cfm *configFetchMeasurementsCmd) configFetchMeasurements(
-	cmd *cobra.Command, newCosignVerifier cosignVerifierConstructor, rekor rekorVerifier,
-	fileHandler file.Handler, fetcher attestationconfigapi.Fetcher, client *http.Client,
+	cmd *cobra.Command, fileHandler file.Handler, fetcher attestationconfigapi.Fetcher,
 ) error {
 	if !cfm.canFetchMeasurements {
 		cmd.PrintErrln("Fetching measurements is not supported in the OSS build of the Constellation CLI. Consult the documentation for instructions on where to download the enterprise version.")
@ -132,58 +142,16 @@ func (cfm *configFetchMeasurementsCmd) configFetchMeasurements(
 	if err := cfm.flags.updateURLs(conf); err != nil {
 		return err
 	}
-
-	cfm.log.Debugf("Fetching and verifying measurements")
-	imageVersion, err := versionsapi.NewVersionFromShortPath(conf.Image, versionsapi.VersionKindImage)
+	fetchedMeasurements, err := cfm.verifyFetcher.FetchAndVerifyMeasurements(ctx, conf.Image, conf.GetProvider(),
+		conf.GetAttestationConfig().GetVariant(), cfm.flags.insecure)
 	if err != nil {
-		return err
-	}
-
-	publicKey, err := keyselect.CosignPublicKeyForVersion(imageVersion)
-	if err != nil {
-		return fmt.Errorf("getting public key: %w", err)
-	}
-	cosign, err := newCosignVerifier(publicKey)
-	if err != nil {
-		return fmt.Errorf("creating cosign verifier: %w", err)
-	}
-
-	var fetchedMeasurements measurements.M
-	var hash string
-	if cfm.flags.insecure {
-		if err := fetchedMeasurements.FetchNoVerify(
-			ctx,
-			client,
-			cfm.flags.measurementsURL,
-			imageVersion,
-			conf.GetProvider(),
-			conf.GetAttestationConfig().GetVariant(),
-		); err != nil {
-			return fmt.Errorf("fetching measurements without verification: %w", err)
-		}
-
-		cfm.log.Debugf("Fetched measurements without verification")
-	} else {
-		hash, err = fetchedMeasurements.FetchAndVerify(
-			ctx,
-			client,
-			cosign,
-			cfm.flags.measurementsURL,
-			cfm.flags.signatureURL,
-			imageVersion,
-			conf.GetProvider(),
-			conf.GetAttestationConfig().GetVariant(),
-		)
-		if err != nil {
-			return fmt.Errorf("fetching and verifying measurements: %w", err)
-		}
-		cfm.log.Debugf("Fetched and verified measurements, hash is %s", hash)
-		if err := sigstore.VerifyWithRekor(cmd.Context(), publicKey, rekor, hash); err != nil {
+		var rekorErr *measurements.RekorError
+		if errors.As(err, &rekorErr) {
 			cmd.PrintErrf("Ignoring Rekor related error: %v\n", err)
 			cmd.PrintErrln("Make sure the downloaded measurements are trustworthy!")
+		} else {
+			return fmt.Errorf("fetching and verifying measurements: %w", err)
 		}
-
-		cfm.log.Debugf("Verified measurements with Rekor")
 	}
 	cfm.log.Debugf("Measurements:\n", fetchedMeasurements)

@ -234,5 +202,3 @@ type rekorVerifier interface {
 	SearchByHash(context.Context, string) ([]string, error)
 	VerifyEntry(context.Context, string, string) error
 }
-
-type cosignVerifierConstructor func([]byte) (sigstore.Verifier, error)
--- a/cli/internal/cmd/configfetchmeasurements_test.go
+++ b/cli/internal/cmd/configfetchmeasurements_test.go
@ -7,23 +7,20 @@ SPDX-License-Identifier: AGPL-3.0-only
 package cmd

 import (
-	"bytes"
 	"context"
-	"fmt"
-	"io"
 	"net/http"
 	"net/url"
 	"testing"

 	"github.com/edgelesssys/constellation/v2/internal/api/attestationconfigapi"
 	"github.com/edgelesssys/constellation/v2/internal/api/versionsapi"
+	"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
 	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
 	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
 	"github.com/edgelesssys/constellation/v2/internal/config"
 	"github.com/edgelesssys/constellation/v2/internal/constants"
 	"github.com/edgelesssys/constellation/v2/internal/file"
 	"github.com/edgelesssys/constellation/v2/internal/logger"
-	"github.com/edgelesssys/constellation/v2/internal/sigstore"
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@ -154,114 +151,17 @@ func newTestClient(fn roundTripFunc) *http.Client {
 }

 func TestConfigFetchMeasurements(t *testing.T) {
-	measurements := `{
-	"version": "v999.999.999",
-	"ref": "-",
-	"stream": "stable",
-	"list": [
-		{
-			"csp": "GCP",
-			"attestationVariant":"gcp-sev-es",
-			"measurements": {
-				"0": {
-					"expected": "0000000000000000000000000000000000000000000000000000000000000000",
-					"warnOnly":false
-				},
-				"1": {
-					"expected": "1111111111111111111111111111111111111111111111111111111111111111",
-					"warnOnly":false
-				},
-				"2": {
-					"expected": "2222222222222222222222222222222222222222222222222222222222222222",
-					"warnOnly":false
-				},
-				"3": {
-					"expected": "3333333333333333333333333333333333333333333333333333333333333333",
-					"warnOnly":false
-				},
-				"4": {
-					"expected": "4444444444444444444444444444444444444444444444444444444444444444",
-					"warnOnly":false
-				},
-				"5": {
-					"expected": "5555555555555555555555555555555555555555555555555555555555555555",
-					"warnOnly":false
-				},
-				"6": {
-					"expected": "6666666666666666666666666666666666666666666666666666666666666666",
-					"warnOnly":false
-				}
-			}
-		}
-	]
-}
-`
-	signature := "placeholder-signature"
-
-	client := newTestClient(func(req *http.Request) *http.Response {
-		if req.URL.Path == "/constellation/v2/ref/-/stream/stable/v999.999.999/image/measurements.json" {
-			return &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewBufferString(measurements)),
-				Header:     make(http.Header),
-			}
-		}
-		if req.URL.Path == "/constellation/v2/ref/-/stream/stable/v999.999.999/image/measurements.json.sig" {
-			return &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewBufferString(signature)),
-				Header:     make(http.Header),
-			}
-		}
-
-		fmt.Println("unexpected request", req.URL.String())
-		return &http.Response{
-			StatusCode: http.StatusNotFound,
-			Body:       io.NopCloser(bytes.NewBufferString("Not found.")),
-			Header:     make(http.Header),
-		}
-	})
-
 	testCases := map[string]struct {
-		cosign       cosignVerifierConstructor
-		rekor        rekorVerifier
 		insecureFlag bool
+		err          error
 		wantErr      bool
 	}{
-		"success": {
-			cosign: newStubCosignVerifier,
-			rekor:  singleUUIDVerifier(),
+		"no error succeeds": {},
+		"failing rekor verify should not result in error": {
+			err: &measurements.RekorError{},
 		},
-		"success without cosign": {
-			insecureFlag: true,
-			cosign: func(_ []byte) (sigstore.Verifier, error) {
-				return &stubCosignVerifier{
-					verifyError: assert.AnError,
-				}, nil
-			},
-			rekor: singleUUIDVerifier(),
-		},
-		"failing search should not result in error": {
-			cosign: newStubCosignVerifier,
-			rekor: &stubRekorVerifier{
-				SearchByHashUUIDs: []string{},
-				SearchByHashError: assert.AnError,
-			},
-		},
-		"failing verify should not result in error": {
-			cosign: newStubCosignVerifier,
-			rekor: &stubRekorVerifier{
-				SearchByHashUUIDs: []string{"11111111111111111111111111111111111111111111111111111111111111111111111111111111"},
-				VerifyEntryError:  assert.AnError,
-			},
-		},
-		"signature verification failure": {
-			cosign: func(_ []byte) (sigstore.Verifier, error) {
-				return &stubCosignVerifier{
-					verifyError: assert.AnError,
-				}, nil
-			},
-			rekor:   singleUUIDVerifier(),
+		"error other than Rekor fails": {
+			err:     assert.AnError,
 			wantErr: true,
 		},
 	}
@ -279,11 +179,12 @@ func TestConfigFetchMeasurements(t *testing.T) {

 			err := fileHandler.WriteYAML(constants.ConfigFilename, gcpConfig, file.OptMkdirAll)
 			require.NoError(err)
-			cfm := &configFetchMeasurementsCmd{canFetchMeasurements: true, log: logger.NewTest(t)}
+			fetcher := stubVerifyFetcher{err: tc.err}
+			cfm := &configFetchMeasurementsCmd{canFetchMeasurements: true, log: logger.NewTest(t), verifyFetcher: fetcher}
 			cfm.flags.insecure = tc.insecureFlag
 			cfm.flags.force = true

-			err = cfm.configFetchMeasurements(cmd, tc.cosign, tc.rekor, fileHandler, stubAttestationFetcher{}, client)
+			err = cfm.configFetchMeasurements(cmd, fileHandler, stubAttestationFetcher{})
 			if tc.wantErr {
 				assert.Error(err)
 				return
@ -293,6 +194,14 @@ func TestConfigFetchMeasurements(t *testing.T) {
 	}
 }

+type stubVerifyFetcher struct {
+	err error
+}
+
+func (f stubVerifyFetcher) FetchAndVerifyMeasurements(_ context.Context, _ string, _ cloudprovider.Provider, _ variant.Variant, _ bool) (measurements.M, error) {
+	return nil, f.err
+}
+
 type stubAttestationFetcher struct{}

 func (f stubAttestationFetcher) FetchSEVSNPVersionList(_ context.Context, _ attestationconfigapi.SEVSNPVersionList) (attestationconfigapi.SEVSNPVersionList, error) {
--- a/cli/internal/cmd/verifier_test.go
+++ b/cli/internal/cmd/verifier_test.go
@ -8,8 +8,6 @@ package cmd

 import (
 	"context"
-
-	"github.com/edgelesssys/constellation/v2/internal/sigstore"
 )

 // singleUUIDVerifier constructs a RekorVerifier that returns a single UUID and no errors,
@ -43,10 +41,6 @@ type stubCosignVerifier struct {
 	verifyError error
 }

-func newStubCosignVerifier(_ []byte) (sigstore.Verifier, error) {
-	return &stubCosignVerifier{}, nil
-}
-
 func (v *stubCosignVerifier) VerifySignature(_, _ []byte) error {
 	return v.verifyError
 }
--- a/internal/api/attestationconfigapi/fetcher.go
+++ b/internal/api/attestationconfigapi/fetcher.go
@ -26,7 +26,7 @@ var ErrNoVersionsFound = errors.New("no versions found")
 type Fetcher interface {
 	FetchSEVSNPVersion(ctx context.Context, version SEVSNPVersionAPI) (SEVSNPVersionAPI, error)
 	FetchSEVSNPVersionList(ctx context.Context, list SEVSNPVersionList) (SEVSNPVersionList, error)
-	FetchSEVSNPVersionLatest(ctx context.Context, attesation variant.Variant) (SEVSNPVersionAPI, error)
+	FetchSEVSNPVersionLatest(ctx context.Context, attestation variant.Variant) (SEVSNPVersionAPI, error)
 }

 // fetcher fetches AttestationCfg API resources without authentication.
--- a/internal/attestation/measurements/BUILD.bazel
+++ b/internal/attestation/measurements/BUILD.bazel
@ -4,6 +4,7 @@ load("//bazel/go:go_test.bzl", "go_test")
 go_library(
    name = "measurements",
    srcs = [
+        "fetchmeasurements.go",
        "measurements.go",
        # keep
        "measurements_enterprise.go",
@ -16,6 +17,8 @@ go_library(
        "//internal/api/versionsapi",
        "//internal/attestation/variant",
        "//internal/cloud/cloudprovider",
+        "//internal/sigstore",
+        "//internal/sigstore/keyselect",
        "@com_github_google_go_tpm//tpmutil",
        "@com_github_siderolabs_talos_pkg_machinery//config/encoder",
        "@in_gopkg_yaml_v3//:yaml_v3",
@ -24,7 +27,10 @@ go_library(

 go_test(
    name = "measurements_test",
-    srcs = ["measurements_test.go"],
+    srcs = [
+        "fetchmeasurements_test.go",
+        "measurements_test.go",
+    ],
    embed = [":measurements"],
    deps = [
        "//internal/api/versionsapi",
--- a/internal/attestation/measurements/fetchmeasurements.go
+++ b/internal/attestation/measurements/fetchmeasurements.go
@ -0,0 +1,113 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package measurements
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/edgelesssys/constellation/v2/internal/api/versionsapi"
+	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
+	"github.com/edgelesssys/constellation/v2/internal/sigstore"
+	"github.com/edgelesssys/constellation/v2/internal/sigstore/keyselect"
+)
+
+// RekorError is returned when verifying measurements with Rekor fails.
+type RekorError struct {
+	err error
+}
+
+// Error returns the error message.
+func (e *RekorError) Error() string {
+	return fmt.Sprintf("verifying measurements with Rekor failed: %s", e.err)
+}
+
+// Unwrap returns the wrapped error.
+func (e *RekorError) Unwrap() error {
+	return e.err
+}
+
+// VerifyFetcher is a high-level fetcher that fetches measurements and verifies them.
+type VerifyFetcher struct {
+	client            *http.Client
+	newCosignVerifier cosignVerifierConstructor
+	rekor             rekorVerifier
+}
+
+// NewVerifyFetcher creates a new MeasurementFetcher.
+func NewVerifyFetcher(newCosignVerifier func([]byte) (sigstore.Verifier, error), rekor rekorVerifier, client *http.Client) *VerifyFetcher {
+	return &VerifyFetcher{
+		newCosignVerifier: newCosignVerifier,
+		rekor:             rekor,
+		client:            client,
+	}
+}
+
+// FetchAndVerifyMeasurements fetches and verifies measurements for the given version and attestation variant.
+func (m *VerifyFetcher) FetchAndVerifyMeasurements(ctx context.Context,
+	image string, csp cloudprovider.Provider, attestationVariant variant.Variant,
+	noVerify bool,
+) (M, error) {
+	version, err := versionsapi.NewVersionFromShortPath(image, versionsapi.VersionKindImage)
+	if err != nil {
+		return nil, fmt.Errorf("parsing image version: %w", err)
+	}
+	publicKey, err := keyselect.CosignPublicKeyForVersion(version)
+	if err != nil {
+		return nil, fmt.Errorf("getting public key: %w", err)
+	}
+
+	cosign, err := m.newCosignVerifier(publicKey)
+	if err != nil {
+		return nil, fmt.Errorf("creating cosign verifier: %w", err)
+	}
+
+	measurementsURL, signatureURL, err := versionsapi.MeasurementURL(version)
+	if err != nil {
+		return nil, err
+	}
+	var fetchedMeasurements M
+	if noVerify {
+		if err := fetchedMeasurements.FetchNoVerify(
+			ctx,
+			m.client,
+			measurementsURL,
+			version,
+			csp,
+			attestationVariant,
+		); err != nil {
+			return nil, fmt.Errorf("fetching measurements: %w", err)
+		}
+	} else {
+		hash, err := fetchedMeasurements.FetchAndVerify(
+			ctx,
+			m.client,
+			cosign,
+			measurementsURL,
+			signatureURL,
+			version,
+			csp,
+			attestationVariant,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("fetching and verifying measurements: %w", err)
+		}
+		if err := sigstore.VerifyWithRekor(ctx, publicKey, m.rekor, hash); err != nil {
+			return nil, &RekorError{err: err}
+		}
+	}
+	return fetchedMeasurements, nil
+}
+
+type cosignVerifierConstructor func([]byte) (sigstore.Verifier, error)
+
+type rekorVerifier interface {
+	SearchByHash(context.Context, string) ([]string, error)
+	VerifyEntry(context.Context, string, string) error
+}
--- a/internal/attestation/measurements/fetchmeasurements_test.go
+++ b/internal/attestation/measurements/fetchmeasurements_test.go
@ -0,0 +1,198 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package measurements
+
+import (
+	"bytes"
+	"context"
+	"encoding/hex"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
+	"github.com/edgelesssys/constellation/v2/internal/sigstore"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFetchMeasurements(t *testing.T) {
+	measurements := `{
+	"version": "v999.999.999",
+	"ref": "-",
+	"stream": "stable",
+	"list": [
+		{
+			"csp": "GCP",
+			"attestationVariant":"gcp-sev-es",
+			"measurements": {
+				"0": {
+					"expected": "0000000000000000000000000000000000000000000000000000000000000000",
+					"warnOnly":false
+				},
+				"1": {
+					"expected": "1111111111111111111111111111111111111111111111111111111111111111",
+					"warnOnly":false
+				},
+				"2": {
+					"expected": "2222222222222222222222222222222222222222222222222222222222222222",
+					"warnOnly":false
+				},
+				"3": {
+					"expected": "3333333333333333333333333333333333333333333333333333333333333333",
+					"warnOnly":false
+				},
+				"4": {
+					"expected": "4444444444444444444444444444444444444444444444444444444444444444",
+					"warnOnly":false
+				},
+				"5": {
+					"expected": "5555555555555555555555555555555555555555555555555555555555555555",
+					"warnOnly":false
+				},
+				"6": {
+					"expected": "6666666666666666666666666666666666666666666666666666666666666666",
+					"warnOnly":true
+				}
+			}
+		}
+	]
+}
+`
+	signature := "placeholder-signature"
+
+	client := newTestClient(func(req *http.Request) *http.Response {
+		if req.URL.Path == "/constellation/v2/ref/-/stream/stable/v999.999.999/image/measurements.json" {
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBufferString(measurements)),
+				Header:     make(http.Header),
+			}
+		}
+		if req.URL.Path == "/constellation/v2/ref/-/stream/stable/v999.999.999/image/measurements.json.sig" {
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBufferString(signature)),
+				Header:     make(http.Header),
+			}
+		}
+
+		return &http.Response{
+			StatusCode: http.StatusNotFound,
+			Body:       io.NopCloser(bytes.NewBufferString("Not found.")),
+			Header:     make(http.Header),
+		}
+	})
+
+	testCases := map[string]struct {
+		cosign     cosignVerifierConstructor
+		rekor      rekorVerifier
+		noVerify   bool
+		wantErr    bool
+		asRekorErr bool
+	}{
+		"success": {
+			cosign: newStubCosignVerifier,
+			rekor:  singleUUIDVerifier(),
+		},
+		"success without cosign verify": {
+			noVerify: true,
+			cosign: func(_ []byte) (sigstore.Verifier, error) {
+				return &stubCosignVerifier{
+					verifyError: assert.AnError,
+				}, nil
+			},
+			rekor: singleUUIDVerifier(),
+		},
+		"failing search results is ErrRekor": {
+			cosign: newStubCosignVerifier,
+			rekor: &stubRekorVerifier{
+				SearchByHashUUIDs: []string{},
+				SearchByHashError: assert.AnError,
+			},
+			wantErr:    true,
+			asRekorErr: true,
+		},
+		"failing verify is ErrRekor": {
+			cosign: newStubCosignVerifier,
+			rekor: &stubRekorVerifier{
+				SearchByHashUUIDs: []string{"11111111111111111111111111111111111111111111111111111111111111111111111111111111"},
+				VerifyEntryError:  assert.AnError,
+			},
+			wantErr:    true,
+			asRekorErr: true,
+		},
+		"signature verification failure": {
+			cosign: func(_ []byte) (sigstore.Verifier, error) {
+				return &stubCosignVerifier{
+					verifyError: assert.AnError,
+				}, nil
+			},
+			rekor:   singleUUIDVerifier(),
+			wantErr: true,
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+			sut := NewVerifyFetcher(tc.cosign, tc.rekor, client)
+			m, err := sut.FetchAndVerifyMeasurements(context.Background(), "v999.999.999", cloudprovider.GCP, variant.GCPSEVES{}, tc.noVerify)
+			if tc.wantErr {
+				assert.Error(err)
+				if tc.asRekorErr {
+					var rekErr *RekorError
+					assert.ErrorAs(err, &rekErr)
+				}
+				return
+			}
+			assert.NoError(err)
+			// verify example measurements
+			assert.Equal("6666666666666666666666666666666666666666666666666666666666666666", hex.EncodeToString(m[6].Expected))
+			assert.Equal(WarnOnly, m[6].ValidationOpt)
+		})
+	}
+}
+
+// SubRekorVerifier is a stub for RekorVerifier.
+type stubRekorVerifier struct {
+	SearchByHashUUIDs []string
+	SearchByHashError error
+	VerifyEntryError  error
+}
+
+// SearchByHash returns the exported fields SearchByHashUUIDs, SearchByHashError.
+func (v *stubRekorVerifier) SearchByHash(context.Context, string) ([]string, error) {
+	return v.SearchByHashUUIDs, v.SearchByHashError
+}
+
+// VerifyEntry returns the exported field VerifyEntryError.
+func (v *stubRekorVerifier) VerifyEntry(context.Context, string, string) error {
+	return v.VerifyEntryError
+}
+
+type stubCosignVerifier struct {
+	verifyError error
+}
+
+func newStubCosignVerifier(_ []byte) (sigstore.Verifier, error) {
+	return &stubCosignVerifier{}, nil
+}
+
+func (v *stubCosignVerifier) VerifySignature(_, _ []byte) error {
+	return v.verifyError
+}
+
+// singleUUIDVerifier constructs a RekorVerifier that returns a single UUID and no errors,
+// and should work for most tests on the happy path.
+func singleUUIDVerifier() *stubRekorVerifier {
+	return &stubRekorVerifier{
+		SearchByHashUUIDs: []string{"11111111111111111111111111111111111111111111111111111111111111111111111111111111"},
+		SearchByHashError: nil,
+		VerifyEntryError:  nil,
+	}
+}
--- a/terraform-provider-constellation/docs/data-sources/attestation.md
+++ b/terraform-provider-constellation/docs/data-sources/attestation.md
@ -0,0 +1,76 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "constellation_attestation Data Source - constellation"
+subcategory: ""
+description: |-
+  The data source to fetch measurements from a configured cloud provider and image.
+---
+
+# constellation_attestation (Data Source)
+
+The data source to fetch measurements from a configured cloud provider and image.
+
+## Example Usage
+
+```terraform
+data "constellation_attestation" "test" {
+  csp                 = "aws"
+  attestation_variant = "aws-sev-snp"
+  image_version       = "v2.13.0"
+}
+```
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `attestation_variant` (String) Attestation variant the image should work with. Can be one of:
+  * `aws-sev-snp`
+  * `aws-nitro-tpm`
+  * `azure-sev-snp`
+  * `gcp-sev-es`
+- `csp` (String) CSP (Cloud Service Provider) to use. (e.g. `azure`)
+See the [full list of CSPs](https://docs.edgeless.systems/constellation/overview/clouds) that Constellation supports.
+- `image_version` (String) The image version to use
+
+### Optional
+
+- `maa_url` (String) For Azure only, the URL of the Microsoft Azure Attestation service
+
+### Read-Only
+
+- `attestation` (Attributes) Only relevant for SEV-SNP. (see [below for nested schema](#nestedatt--attestation))
+- `id` (String) The ID of the data source
+- `measurements` (Attributes Map) (see [below for nested schema](#nestedatt--measurements))
+
+<a id="nestedatt--attestation"></a>
+### Nested Schema for `attestation`
+
+Read-Only:
+
+- `amd_root_key` (String)
+- `azure_firmware_signer_config` (Attributes) (see [below for nested schema](#nestedatt--attestation--azure_firmware_signer_config))
+- `bootloader_version` (Number)
+- `microcode_version` (Number)
+- `snp_version` (Number)
+- `tee_version` (Number)
+
+<a id="nestedatt--attestation--azure_firmware_signer_config"></a>
+### Nested Schema for `attestation.azure_firmware_signer_config`
+
+Read-Only:
+
+- `accepted_key_digests` (List of String)
+- `enforcement_policy` (String)
+- `maa_url` (String)
+
+
+
+<a id="nestedatt--measurements"></a>
+### Nested Schema for `measurements`
+
+Read-Only:
+
+- `expected` (String)
+- `warn_only` (Boolean)
--- a/terraform-provider-constellation/examples/data-sources/constellation_attestation/data-source.tf
+++ b/terraform-provider-constellation/examples/data-sources/constellation_attestation/data-source.tf
@ -0,0 +1,5 @@
+data "constellation_attestation" "test" {
+  csp                 = "aws"
+  attestation_variant = "aws-sev-snp"
+  image_version       = "v2.13.0"
+}
--- a/terraform-provider-constellation/go.mod
+++ b/terraform-provider-constellation/go.mod
@ -21,6 +21,7 @@ require (
 	github.com/agext/levenshtein v1.2.2 // indirect
 	github.com/apparentlymart/go-textseg/v15 v15.0.0 // indirect
 	github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 // indirect
+	github.com/aws/aws-sdk-go v1.44.297 // indirect
 	github.com/aws/aws-sdk-go-v2 v1.18.1 // indirect
 	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.4.10 // indirect
 	github.com/aws/aws-sdk-go-v2/config v1.18.27 // indirect
@ -65,6 +66,7 @@ require (
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/google/go-containerregistry v0.15.2 // indirect
+	github.com/google/go-tpm v0.9.0 // indirect
 	github.com/google/uuid v1.4.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.0 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
@ -112,6 +114,7 @@ require (
 	github.com/sassoftware/relic v7.2.1+incompatible // indirect
 	github.com/schollz/progressbar/v3 v3.13.1 // indirect
 	github.com/secure-systems-lab/go-securesystemslib v0.6.0 // indirect
+	github.com/siderolabs/talos/pkg/machinery v1.4.6 // indirect
 	github.com/sigstore/rekor v1.2.2 // indirect
 	github.com/sigstore/sigstore v1.7.1 // indirect
 	github.com/spf13/afero v1.10.0 // indirect
--- a/terraform-provider-constellation/go.sum
+++ b/terraform-provider-constellation/go.sum
@ -60,6 +60,8 @@ github.com/apparentlymart/go-textseg/v15 v15.0.0/go.mod h1:K8XmNZdhEBkdlyDdvbmms
 github.com/asaskevich/govalidator v0.0.0-20200907205600-7a23bdc65eef/go.mod h1:WaHUgvxTVq04UNunO+XhnAqY/wQc+bxr74GqbsZ/Jqw=
 github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 h1:DklsrG3dyBCFEj5IhUbnKptjxatkF07cF2ak3yi77so=
 github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2/go.mod h1:WaHUgvxTVq04UNunO+XhnAqY/wQc+bxr74GqbsZ/Jqw=
+github.com/aws/aws-sdk-go v1.44.297 h1:uL4EV0gQxotQVYegIoBqK079328MOJqgG95daFYSkAM=
+github.com/aws/aws-sdk-go v1.44.297/go.mod h1:aVsgQcEevwlmQ7qHE9I3h+dtQgpqhFB+i8Phjh7fkwI=
 github.com/aws/aws-sdk-go-v2 v1.18.1 h1:+tefE750oAb7ZQGzla6bLkOwfcQCEtC5y2RqoqCeqKo=
 github.com/aws/aws-sdk-go-v2 v1.18.1/go.mod h1:uzbQtefpm44goOPmdKyAlXSNcwlRgF3ePWVW6EtJvvw=
 github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.4.10 h1:dK82zF6kkPeCo8J1e+tGx4JdvDIQzj7ygIoLg8WMuGs=
@ -291,6 +293,8 @@ github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/go-containerregistry v0.15.2 h1:MMkSh+tjSdnmJZO7ljvEqV1DjfekB6VUEAZgy3a+TQE=
 github.com/google/go-containerregistry v0.15.2/go.mod h1:wWK+LnOv4jXMM23IT/F1wdYftGWGr47Is8CG+pmHK1Q=
+github.com/google/go-tpm v0.9.0 h1:sQF6YqWMi+SCXpsmS3fd21oPy/vSddwZry4JnmltHVk=
+github.com/google/go-tpm v0.9.0/go.mod h1:FkNVkc6C+IsvDI9Jw1OveJmxGZUUaKxtrpOS47QWKfU=
 github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
 github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
@ -689,6 +693,7 @@ golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/net v0.0.0-20210421230115-4e50805a0758/go.mod h1:72T/g9IO56b78aLF+1Kcs5dz7/ng1VjMUvfKvpfy+jM=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/net v0.1.0/go.mod h1:Cx3nUiGt4eDBEyega/BKRp+/AlGL8hYe7U9odMt2Cco=
 golang.org/x/net v0.2.0/go.mod h1:KqCZLdyyvdV855qA2rE3GC2aiw5xGR5TEjj8smXukLY=
 golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
 golang.org/x/net v0.8.0/go.mod h1:QVkue5JL9kW//ek3r6jTKnTFis1tRmNAW2P1shuFdJc=
@ -765,6 +770,7 @@ golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@ -773,6 +779,7 @@ golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE=
 golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.1.0/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.2.0/go.mod h1:TVmDHMZPmdnySmBfhjOoOdhjzdE1h4u1VwSiw2l1Nuc=
 golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
 golang.org/x/term v0.6.0/go.mod h1:m6U89DPEgQRMq3DNkDClhWw02AUbt2daBVO4cn4Hv9U=
--- a/terraform-provider-constellation/internal/provider/BUILD.bazel
+++ b/terraform-provider-constellation/internal/provider/BUILD.bazel
@ -4,6 +4,7 @@ load("//bazel/go:go_test.bzl", "go_test")
 go_library(
    name = "provider",
    srcs = [
+        "attestation_data_source.go",
        "example_resource.go",
        "image_data_source.go",
        "provider.go",
@ -11,9 +12,13 @@ go_library(
    importpath = "github.com/edgelesssys/constellation/v2/terraform-provider-constellation/internal/provider",
    visibility = ["//terraform-provider-constellation:__subpackages__"],
    deps = [
+        "//internal/api/attestationconfigapi",
+        "//internal/attestation/measurements",
        "//internal/attestation/variant",
        "//internal/cloud/cloudprovider",
+        "//internal/config",
        "//internal/imagefetcher",
+        "//internal/sigstore",
        "//terraform-provider-constellation/internal/data",
        "@com_github_hashicorp_terraform_plugin_framework//datasource",
        "@com_github_hashicorp_terraform_plugin_framework//datasource/schema",
@ -35,6 +40,7 @@ go_library(
 go_test(
    name = "provider_test",
    srcs = [
+        "attestation_data_source_test.go",
        "image_data_source_test.go",
        "provider_test.go",
    ],
--- a/terraform-provider-constellation/internal/provider/attestation_data_source.go
+++ b/terraform-provider-constellation/internal/provider/attestation_data_source.go
@ -0,0 +1,306 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package provider
+
+import (
+	"context"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net/http"
+	"strconv"
+
+	"github.com/edgelesssys/constellation/v2/internal/api/attestationconfigapi"
+	"github.com/edgelesssys/constellation/v2/internal/attestation/measurements"
+	"github.com/edgelesssys/constellation/v2/internal/attestation/variant"
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
+	"github.com/edgelesssys/constellation/v2/internal/config"
+	"github.com/edgelesssys/constellation/v2/internal/sigstore"
+	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
+	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
+	"github.com/hashicorp/terraform-plugin-framework/path"
+	"github.com/hashicorp/terraform-plugin-framework/schema/validator"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/hashicorp/terraform-plugin-log/tflog"
+)
+
+// Ensure provider defined types fully satisfy framework interfaces.
+var _ datasource.DataSource = &AttestationDataSource{}
+
+// NewAttestationDataSource creates a new attestation data source.
+func NewAttestationDataSource() datasource.DataSource {
+	return &AttestationDataSource{}
+}
+
+// AttestationDataSource defines the data source implementation.
+type AttestationDataSource struct {
+	client  *http.Client
+	fetcher attestationconfigapi.Fetcher
+	rekor   *sigstore.Rekor
+}
+
+// AttestationDataSourceModel describes the data source data model.
+type AttestationDataSourceModel struct {
+	CSP                types.String `tfsdk:"csp"`
+	AttestationVariant types.String `tfsdk:"attestation_variant"`
+	ImageVersion       types.String `tfsdk:"image_version"`
+	MaaURL             types.String `tfsdk:"maa_url"`
+	ID                 types.String `tfsdk:"id"`
+	Measurements       types.Map    `tfsdk:"measurements"`
+	Attestation        types.Object `tfsdk:"attestation"`
+}
+
+// Configure configures the data source.
+func (d *AttestationDataSource) Configure(_ context.Context, _ datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
+	d.client = http.DefaultClient
+	d.fetcher = attestationconfigapi.NewFetcher()
+	rekor, err := sigstore.NewRekor()
+	if err != nil {
+		resp.Diagnostics.AddError("constructing rekor client", err.Error())
+		return
+	}
+	d.rekor = rekor
+}
+
+// Metadata returns the metadata for the data source.
+func (d *AttestationDataSource) Metadata(_ context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
+	resp.TypeName = req.ProviderTypeName + "_attestation"
+}
+
+// Schema returns the schema for the data source.
+func (d *AttestationDataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
+	resp.Schema = schema.Schema{
+		// This description is used by the documentation generator and the language server.
+		MarkdownDescription: "The data source to fetch measurements from a configured cloud provider and image.",
+
+		Attributes: map[string]schema.Attribute{
+			"csp": schema.StringAttribute{
+				Description: "CSP (Cloud Service Provider) to use. (e.g. `azure`)",
+				MarkdownDescription: "CSP (Cloud Service Provider) to use. (e.g. `azure`)\n" +
+					"See the [full list of CSPs](https://docs.edgeless.systems/constellation/overview/clouds) that Constellation supports.",
+				Required: true,
+				Validators: []validator.String{
+					stringvalidator.OneOf("aws", "azure", "gcp"),
+				},
+			},
+			"attestation_variant": schema.StringAttribute{
+				Description: "Attestation variant the image should work with. (e.g. `azure-sev-snp`)",
+				MarkdownDescription: "Attestation variant the image should work with. Can be one of:\n" +
+					"  * `aws-sev-snp`\n" +
+					"  * `aws-nitro-tpm`\n" +
+					"  * `azure-sev-snp`\n" +
+					"  * `gcp-sev-es`\n",
+				Required: true,
+				Validators: []validator.String{
+					stringvalidator.OneOf("aws-sev-snp", "aws-nitro-tpm", "azure-sev-snp", "gcp-sev-es"),
+				},
+			},
+			"image_version": schema.StringAttribute{
+				MarkdownDescription: "The image version to use",
+				Required:            true,
+			},
+			"maa_url": schema.StringAttribute{
+				MarkdownDescription: "For Azure only, the URL of the Microsoft Azure Attestation service",
+				Optional:            true,
+			},
+			"id": schema.StringAttribute{
+				Computed:            true,
+				MarkdownDescription: "The ID of the data source",
+			},
+			"measurements": schema.MapNestedAttribute{
+				Computed: true,
+				NestedObject: schema.NestedAttributeObject{
+					Attributes: map[string]schema.Attribute{
+						"expected": schema.StringAttribute{
+							Computed: true,
+						},
+						"warn_only": schema.BoolAttribute{
+							Computed: true,
+						},
+					},
+				},
+			},
+			"attestation": schema.SingleNestedAttribute{
+				Computed:            true,
+				MarkdownDescription: "Only relevant for SEV-SNP.",
+				Description:         "The values provide sensible defaults. See the docs for advanced usage.", // TODO(elchead): AB#3568
+				Attributes: map[string]schema.Attribute{
+					"bootloader_version": schema.Int64Attribute{
+						Computed: true,
+					},
+					"tee_version": schema.Int64Attribute{
+						Computed: true,
+					},
+					"snp_version": schema.Int64Attribute{
+						Computed: true,
+					},
+					"microcode_version": schema.Int64Attribute{
+						Computed: true,
+					},
+					"azure_firmware_signer_config": schema.SingleNestedAttribute{
+						Computed: true,
+						Attributes: map[string]schema.Attribute{
+							"accepted_key_digests": schema.ListAttribute{
+								Computed:    true,
+								ElementType: types.StringType,
+							},
+							"enforcement_policy": schema.StringAttribute{
+								Computed: true,
+							},
+							"maa_url": schema.StringAttribute{
+								Computed: true,
+							},
+						},
+					},
+					"amd_root_key": schema.StringAttribute{
+						Computed: true,
+					},
+				},
+			},
+		},
+	}
+}
+
+// Read reads from the data source.
+func (d *AttestationDataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) {
+	var data AttestationDataSourceModel
+
+	// Read Terraform configuration data into the model
+	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
+
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	csp := cloudprovider.FromString(data.CSP.ValueString())
+	if csp == cloudprovider.Unknown {
+		resp.Diagnostics.AddAttributeError(
+			path.Root("csp"),
+			"Invalid CSP",
+			fmt.Sprintf("Invalid CSP: %s", data.CSP.ValueString()),
+		)
+		return
+	}
+	attestationVariant, err := variant.FromString(data.AttestationVariant.ValueString())
+	if err != nil {
+		resp.Diagnostics.AddAttributeError(
+			path.Root("attestation_variant"),
+			"Invalid Attestation Variant",
+			fmt.Sprintf("Invalid attestation variant: %s", data.CSP.ValueString()),
+		)
+		return
+	}
+	if attestationVariant.Equal(variant.AzureSEVSNP{}) || attestationVariant.Equal(variant.AWSSEVSNP{}) {
+		snpVersions, err := d.fetcher.FetchSEVSNPVersionLatest(ctx, attestationVariant)
+		if err != nil {
+			resp.Diagnostics.AddError("Fetching SNP Version numbers", err.Error())
+			return
+		}
+		tfSnpAttestation, err := convertSNPAttestationTfStateCompatible(attestationVariant, snpVersions)
+		if err != nil {
+			resp.Diagnostics.AddError("Converting SNP attestation", err.Error())
+		}
+		diags := resp.State.SetAttribute(ctx, path.Root("attestation"), tfSnpAttestation)
+		resp.Diagnostics.Append(diags...)
+		if resp.Diagnostics.HasError() {
+			return
+		}
+	}
+
+	verifyFetcher := measurements.NewVerifyFetcher(sigstore.NewCosignVerifier, d.rekor, d.client)
+	fetchedMeasurements, err := verifyFetcher.FetchAndVerifyMeasurements(ctx, data.ImageVersion.ValueString(),
+		csp, attestationVariant, false)
+	if err != nil {
+		var rekErr *measurements.RekorError
+		if errors.As(err, &rekErr) {
+			resp.Diagnostics.AddWarning("Ignoring Rekor related error", err.Error())
+		} else {
+			resp.Diagnostics.AddError("fetching and verifying measurements", err.Error())
+			return
+		}
+	}
+	tfMeasurements := convertMeasurementsTfStateCompatible(fetchedMeasurements)
+	diags := resp.State.SetAttribute(ctx, path.Root("measurements"), tfMeasurements)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	tflog.Trace(ctx, "read constellation attestation data source")
+}
+
+func convertSNPAttestationTfStateCompatible(attestationVariant variant.Variant,
+	snpVersions attestationconfigapi.SEVSNPVersionAPI,
+) (tfSnpAttestation sevSnpAttestation, err error) {
+	var cert config.Certificate
+	switch attestationVariant.(type) {
+	case variant.AWSSEVSNP:
+		cert = config.DefaultForAWSSEVSNP().AMDRootKey
+	case variant.AzureSEVSNP:
+		cert = config.DefaultForAzureSEVSNP().AMDRootKey
+	}
+	certBytes, err := cert.MarshalJSON()
+	if err != nil {
+		return tfSnpAttestation, err
+	}
+	tfSnpAttestation = sevSnpAttestation{
+		BootloaderVersion: snpVersions.Bootloader,
+		TEEVersion:        snpVersions.TEE,
+		SNPVersion:        snpVersions.SNP,
+		MicrocodeVersion:  snpVersions.Microcode,
+		AMDRootKey:        string(certBytes),
+	}
+	if attestationVariant.Equal(variant.AzureSEVSNP{}) {
+		firmwareCfg := config.DefaultForAzureSEVSNP().FirmwareSignerConfig
+		keyDigestAny, err := firmwareCfg.AcceptedKeyDigests.MarshalYAML()
+		if err != nil {
+			return tfSnpAttestation, err
+		}
+		keyDigest, ok := keyDigestAny.([]string)
+		if !ok {
+			return tfSnpAttestation, errors.New("reading Accepted Key Digests: could not convert to []string")
+		}
+		tfSnpAttestation.AzureSNPFirmwareSignerConfig = azureSnpFirmwareSignerConfig{
+			AcceptedKeyDigests: keyDigest,
+			EnforcementPolicy:  firmwareCfg.EnforcementPolicy.String(),
+			MAAURL:             firmwareCfg.MAAURL,
+		}
+	}
+	return tfSnpAttestation, nil
+}
+
+func convertMeasurementsTfStateCompatible(m measurements.M) map[string]measurement {
+	tfMeasurements := map[string]measurement{}
+	for key, value := range m {
+		keyStr := strconv.FormatUint(uint64(key), 10)
+		tfMeasurements[keyStr] = measurement{
+			Expected: hex.EncodeToString(value.Expected[:]),
+			WarnOnly: bool(value.ValidationOpt),
+		}
+	}
+	return tfMeasurements
+}
+
+type measurement struct {
+	Expected string `tfsdk:"expected"`
+	WarnOnly bool   `tfsdk:"warn_only"`
+}
+
+type sevSnpAttestation struct {
+	BootloaderVersion            uint8                        `tfsdk:"bootloader_version"`
+	TEEVersion                   uint8                        `tfsdk:"tee_version"`
+	SNPVersion                   uint8                        `tfsdk:"snp_version"`
+	MicrocodeVersion             uint8                        `tfsdk:"microcode_version"`
+	AMDRootKey                   string                       `tfsdk:"amd_root_key"`
+	AzureSNPFirmwareSignerConfig azureSnpFirmwareSignerConfig `tfsdk:"azure_firmware_signer_config"`
+}
+
+type azureSnpFirmwareSignerConfig struct {
+	AcceptedKeyDigests []string `tfsdk:"accepted_key_digests"`
+	EnforcementPolicy  string   `tfsdk:"enforcement_policy"`
+	MAAURL             string   `tfsdk:"maa_url"`
+}
--- a/terraform-provider-constellation/internal/provider/attestation_data_source_test.go
+++ b/terraform-provider-constellation/internal/provider/attestation_data_source_test.go
@ -0,0 +1,100 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package provider
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+)
+
+func TestAccAttestationSource(t *testing.T) {
+	// Set the path to the Terraform binary for acceptance testing when running under Bazel.
+	bazelPreCheck := func() { bazelSetTerraformBinaryPath(t) }
+
+	testCases := map[string]resource.TestCase{
+		"aws sev-snp succcess": {
+			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+			PreCheck:                 bazelPreCheck,
+			Steps: []resource.TestStep{
+				{
+					Config: testingConfig + `
+					data "constellation_attestation" "test" {
+						csp = "aws"
+						attestation_variant = "aws-sev-snp"
+						image_version = "v2.13.0"
+					}
+					`,
+					Check: resource.ComposeAggregateTestCheckFunc(
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.bootloader_version", "3"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.microcode_version", "209"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.snp_version", "20"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.tee_version", "0"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.amd_root_key", "\"-----BEGIN CERTIFICATE-----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\\nAFZEAwoKCQ==\\n-----END CERTIFICATE-----\\n\""),
+
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "measurements.0.expected", "7b068c0c3ac29afe264134536b9be26f1d4ccd575b88d3c3ceabf36ac99c0278"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "measurements.0.warn_only", "true"),
+					),
+				},
+			},
+		},
+		"azure sev-snp success": {
+			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+			PreCheck:                 bazelPreCheck,
+			Steps: []resource.TestStep{
+				{
+					Config: testingConfig + `
+					data "constellation_attestation" "test" {
+						csp = "azure"
+						attestation_variant = "azure-sev-snp"
+						image_version = "v2.13.0"
+					}
+					`,
+					Check: resource.ComposeAggregateTestCheckFunc(
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.bootloader_version", "3"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.microcode_version", "115"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.snp_version", "8"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.tee_version", "0"),
+
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.azure_firmware_signer_config.accepted_key_digests.0", "0356215882a825279a85b300b0b742931d113bf7e32dde2e50ffde7ec743ca491ecdd7f336dc28a6e0b2bb57af7a44a3"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.azure_firmware_signer_config.enforcement_policy", "MAAFallback"),
+
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "attestation.amd_root_key", "\"-----BEGIN CERTIFICATE-----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\\nAFZEAwoKCQ==\\n-----END CERTIFICATE-----\\n\""),
+
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "measurements.1.expected", "3d458cfe55cc03ea1f443f1562beec8df51c75e14a9fcf9a7234a13f198e7969"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "measurements.1.warn_only", "true"),
+					),
+				},
+			},
+		},
+		"gcp sev-snp succcess": {
+			ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+			PreCheck:                 bazelPreCheck,
+			Steps: []resource.TestStep{
+				{
+					Config: testingConfig + `
+					data "constellation_attestation" "test" {
+						csp = "gcp"
+						attestation_variant = "gcp-sev-es"
+						image_version = "v2.13.0"
+					}
+					`,
+					Check: resource.ComposeAggregateTestCheckFunc(
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "measurements.1.expected", "745f2fb4235e4647aa0ad5ace781cd929eb68c28870e7dd5d1a1535854325e56"),
+						resource.TestCheckResourceAttr("data.constellation_attestation.test", "measurements.1.warn_only", "true"),
+					),
+				},
+			},
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			resource.Test(t, tc)
+		})
+	}
+}
--- a/terraform-provider-constellation/internal/provider/image_data_source.go
+++ b/terraform-provider-constellation/internal/provider/image_data_source.go
@ -160,8 +160,6 @@ func (d *ImageDataSource) Read(ctx context.Context, req datasource.ReadRequest,

 	// Save data into Terraform state
 	data.Reference = types.StringValue(imageRef)
-	// Use a placeholder ID for testing, as per https://developer.hashicorp.com/terraform/plugin/framework/acctests#no-id-found-in-attributes
-	data.ID = types.StringValue("placeholder")

 	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
 }
--- a/terraform-provider-constellation/internal/provider/provider.go
+++ b/terraform-provider-constellation/internal/provider/provider.go
@ -85,6 +85,6 @@ func (p *ConstellationProvider) Resources(_ context.Context) []func() resource.R
 // DataSources lists the data sources implemented by the provider.
 func (p *ConstellationProvider) DataSources(_ context.Context) []func() datasource.DataSource {
 	return []func() datasource.DataSource{
-		NewImageDataSource,
+		NewImageDataSource, NewAttestationDataSource,
 	}
 }