Merge pull request cli#9421 from cli/eugene/attestation/fetch-oci-bundle

Fetch bundle from OCI registry for verify

pkg/cmd/attestation/artifact/artifact.go

@@ -7,6 +7,8 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/google/go-containerregistry/pkg/name"
+
 	"github.com/cli/cli/v2/pkg/cmd/attestation/artifact/oci"
 )
 
@@ -22,6 +24,7 @@ type DigestedArtifact struct {
 	URL       string
 	digest    string
 	digestAlg string
+	nameRef   name.Reference
 }
 
 func normalizeReference(reference string, pathSeparator rune) (normalized string, artifactType artifactType, err error) {
@@ -77,3 +80,7 @@ func (a *DigestedArtifact) Algorithm() string {
 func (a *DigestedArtifact) DigestWithAlg() string {
 	return fmt.Sprintf("%s:%s", a.digestAlg, a.digest)
 }
+
+func (a *DigestedArtifact) NameRef() name.Reference {
+	return a.nameRef
+}

pkg/cmd/attestation/artifact/image.go

@@ -15,7 +15,8 @@ func digestContainerImageArtifact(url string, client oci.Client) (*DigestedArtif
 		return nil, fmt.Errorf("artifact %s is not a valid registry reference: %v", url, err)
 	}
 
-	digest, err := client.GetImageDigest(named.String())
+	digest, nameRef, err := client.GetImageDigest(named.String())
+
 	if err != nil {
 		return nil, err
 	}
@@ -24,5 +25,6 @@ func digestContainerImageArtifact(url string, client oci.Client) (*DigestedArtif
 		URL:       fmt.Sprintf("oci://%s", named.String()),
 		digest:    digest.Hex,
 		digestAlg: digest.Algorithm,
+		nameRef:   nameRef,
 	}, nil
 }

pkg/cmd/attestation/artifact/oci/client.go

@@ -3,10 +3,16 @@ package oci
 import (
 	"errors"
 	"fmt"
+	"io"
+	"net/http"
+	"strings"
 
 	"github.com/google/go-containerregistry/pkg/authn"
 	"github.com/google/go-containerregistry/pkg/name"
-	"github.com/google/go-containerregistry/pkg/v1"
+	"github.com/sigstore/sigstore-go/pkg/bundle"
+
+	"github.com/cli/cli/v2/pkg/cmd/attestation/api"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/remote"
 	"github.com/google/go-containerregistry/pkg/v1/remote/transport"
 )
@@ -15,7 +21,8 @@ var ErrDenied = errors.New("the provided token was denied access to the requeste
 var ErrRegistryAuthz = errors.New("remote registry authorization failed, please authenticate with the registry and try again")
 
 type Client interface {
-	GetImageDigest(imgName string) (*v1.Hash, error)
+	GetImageDigest(imgName string) (*v1.Hash, name.Reference, error)
+	GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error)
 }
 
 func checkForUnauthorizedOrDeniedErr(err transport.Error) error {
@@ -35,13 +42,16 @@ type LiveClient struct {
 	get            func(name.Reference, ...remote.Option) (*remote.Descriptor, error)
 }
 
+func (c LiveClient) ParseReference(ref string) (name.Reference, error) {
+	return c.parseReference(ref)
+}
+
 // where name is formed like ghcr.io/github/my-image-repo
-func (c LiveClient) GetImageDigest(imgName string) (*v1.Hash, error) {
+func (c LiveClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
 	name, err := c.parseReference(imgName)
 	if err != nil {
-		return nil, fmt.Errorf("failed to create image tag: %v", err)
+		return nil, nil, fmt.Errorf("failed to create image tag: %v", err)
 	}
-
 	// The user must already be authenticated with the container registry
 	// The authn.DefaultKeychain argument indicates that Get should checks the
 	// user's configuration for the registry credentials
@@ -50,13 +60,92 @@ func (c LiveClient) GetImageDigest(imgName string) (*v1.Hash, error) {
 		var transportErr *transport.Error
 		if errors.As(err, &transportErr) {
 			if accessErr := checkForUnauthorizedOrDeniedErr(*transportErr); accessErr != nil {
-				return nil, accessErr
+				return nil, nil, accessErr
 			}
 		}
-		return nil, fmt.Errorf("failed to fetch remote image: %v", err)
+		return nil, nil, fmt.Errorf("failed to fetch remote image: %v", err)
+	}
+
+	return &desc.Digest, name, nil
+}
+
+type noncompliantRegistryTransport struct{}
+
+// RoundTrip will check if a request and associated response fulfill the following:
+// 1. The response returns a 406 status code
+// 2. The request path contains /referrers/
+// If both conditions are met, the response's status code will be overwritten to 404
+// This is a temporary solution to handle non compliant registries that return
+// an unexpected status code 406 when the go-containerregistry library used
+// by this code attempts to make a request to the referrers API.
+// The go-containerregistry library can handle 404 response but not a 406 response.
+// See the related go-containerregistry issue: https://github.com/google/go-containerregistry/issues/1962
+func (a *noncompliantRegistryTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, err := http.DefaultTransport.RoundTrip(req)
+	if err != nil {
+		return resp, err
+	}
+	if resp.StatusCode == http.StatusNotAcceptable && strings.Contains(req.URL.Path, "/referrers/") {
+		resp.StatusCode = http.StatusNotFound
+	}
+
+	return resp, err
+}
+
+func (c LiveClient) GetAttestations(ref name.Reference, digest string) ([]*api.Attestation, error) {
+	attestations := make([]*api.Attestation, 0)
+
+	transportOpts := []remote.Option{remote.WithTransport(&noncompliantRegistryTransport{}), remote.WithAuthFromKeychain(authn.DefaultKeychain)}
+	referrers, err := remote.Referrers(ref.Context().Digest(digest), transportOpts...)
+	if err != nil {
+		return attestations, fmt.Errorf("error getting referrers: %w", err)
 	}
+	refManifest, err := referrers.IndexManifest()
+	if err != nil {
+		return attestations, fmt.Errorf("error getting referrers manifest: %w", err)
+	}
+
+	for _, refDesc := range refManifest.Manifests {
+		if !strings.HasPrefix(refDesc.ArtifactType, "application/vnd.dev.sigstore.bundle") {
+			continue
+		}
+
+		refImg, err := remote.Image(ref.Context().Digest(refDesc.Digest.String()), remote.WithAuthFromKeychain(authn.DefaultKeychain))
+		if err != nil {
+			return attestations, fmt.Errorf("error getting referrer image: %w", err)
+		}
+		layers, err := refImg.Layers()
+		if err != nil {
+			return attestations, fmt.Errorf("error getting referrer image: %w", err)
+		}
+
+		if len(layers) > 0 {
+			layer0, err := layers[0].Uncompressed()
+			if err != nil {
+				return attestations, fmt.Errorf("error getting referrer image: %w", err)
+			}
+			defer layer0.Close()
 
-	return &desc.Digest, nil
+			bundleBytes, err := io.ReadAll(layer0)
+
+			if err != nil {
+				return attestations, fmt.Errorf("error getting referrer image: %w", err)
+			}
+
+			b := &bundle.ProtobufBundle{}
+			err = b.UnmarshalJSON(bundleBytes)
+
+			if err != nil {
+				return attestations, fmt.Errorf("error unmarshalling bundle: %w", err)
+			}
+
+			a := api.Attestation{Bundle: b}
+			attestations = append(attestations, &a)
+		} else {
+			return attestations, fmt.Errorf("error getting referrer image: no layers found")
+		}
+	}
+	return attestations, nil
 }
 
 // Unlike other parts of this command set, we cannot pass a custom HTTP client

pkg/cmd/attestation/artifact/oci/client_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 
 	"github.com/google/go-containerregistry/pkg/name"
-	"github.com/google/go-containerregistry/pkg/v1"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/remote"
 	"github.com/google/go-containerregistry/pkg/v1/remote/transport"
 
@@ -30,9 +30,10 @@ func TestGetImageDigest_Success(t *testing.T) {
 		},
 	}
 
-	digest, err := c.GetImageDigest("test")
+	digest, nameRef, err := c.GetImageDigest("test")
 	require.NoError(t, err)
 	require.Equal(t, &expectedDigest, digest)
+	require.Equal(t, name.Tag{}, nameRef)
 }
 
 func TestGetImageDigest_ReferenceFail(t *testing.T) {
@@ -45,9 +46,10 @@ func TestGetImageDigest_ReferenceFail(t *testing.T) {
 		},
 	}
 
-	digest, err := c.GetImageDigest("test")
+	digest, nameRef, err := c.GetImageDigest("test")
 	require.Error(t, err)
 	require.Nil(t, digest)
+	require.Nil(t, nameRef)
 }
 
 func TestGetImageDigest_AuthFail(t *testing.T) {
@@ -60,10 +62,11 @@ func TestGetImageDigest_AuthFail(t *testing.T) {
 		},
 	}
 
-	digest, err := c.GetImageDigest("test")
+	digest, nameRef, err := c.GetImageDigest("test")
 	require.Error(t, err)
 	require.ErrorIs(t, err, ErrRegistryAuthz)
 	require.Nil(t, digest)
+	require.Nil(t, nameRef)
 }
 
 func TestGetImageDigest_Denied(t *testing.T) {
@@ -76,8 +79,9 @@ func TestGetImageDigest_Denied(t *testing.T) {
 		},
 	}
 
-	digest, err := c.GetImageDigest("test")
+	digest, nameRef, err := c.GetImageDigest("test")
 	require.Error(t, err)
 	require.ErrorIs(t, err, ErrDenied)
 	require.Nil(t, digest)
+	require.Nil(t, nameRef)
 }

pkg/cmd/attestation/artifact/oci/mock_client.go

@@ -3,32 +3,83 @@ package oci
 import (
 	"fmt"
 
-	"github.com/google/go-containerregistry/pkg/v1"
+	"github.com/cli/cli/v2/pkg/cmd/attestation/api"
+	"github.com/cli/cli/v2/pkg/cmd/attestation/test/data"
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 )
 
+func makeTestAttestation() api.Attestation {
+	return api.Attestation{Bundle: data.SigstoreBundle(nil)}
+}
+
 type MockClient struct{}
 
-func (c MockClient) GetImageDigest(imgName string) (*v1.Hash, error) {
+func (c MockClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
 	return &v1.Hash{
 		Hex:       "1234567890abcdef",
 		Algorithm: "sha256",
-	}, nil
+	}, nil, nil
+}
+
+func (c MockClient) GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error) {
+	att1 := makeTestAttestation()
+	att2 := makeTestAttestation()
+	return []*api.Attestation{&att1, &att2}, nil
 }
 
 type ReferenceFailClient struct{}
 
-func (c ReferenceFailClient) GetImageDigest(imgName string) (*v1.Hash, error) {
-	return nil, fmt.Errorf("failed to parse reference")
+func (c ReferenceFailClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
+	return nil, nil, fmt.Errorf("failed to parse reference")
+}
+
+func (c ReferenceFailClient) GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error) {
+	return nil, nil
 }
 
 type AuthFailClient struct{}
 
-func (c AuthFailClient) GetImageDigest(imgName string) (*v1.Hash, error) {
-	return nil, ErrRegistryAuthz
+func (c AuthFailClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
+	return nil, nil, ErrRegistryAuthz
+}
+
+func (c AuthFailClient) GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error) {
+	return nil, nil
 }
 
 type DeniedClient struct{}
 
-func (c DeniedClient) GetImageDigest(imgName string) (*v1.Hash, error) {
-	return nil, ErrDenied
+func (c DeniedClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
+	return nil, nil, ErrDenied
+}
+
+func (c DeniedClient) GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error) {
+	return nil, nil
+}
+
+type NoAttestationsClient struct{}
+
+func (c NoAttestationsClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
+	return &v1.Hash{
+		Hex:       "1234567890abcdef",
+		Algorithm: "sha256",
+	}, nil, nil
+}
+
+func (c NoAttestationsClient) GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error) {
+	return nil, nil
+}
+
+type FailedToFetchAttestationsClient struct{}
+
+func (c FailedToFetchAttestationsClient) GetImageDigest(imgName string) (*v1.Hash, name.Reference, error) {
+	return &v1.Hash{
+		Hex:       "1234567890abcdef",
+		Algorithm: "sha256",
+	}, nil, nil
+}
+
+func (c FailedToFetchAttestationsClient) GetAttestations(name name.Reference, digest string) ([]*api.Attestation, error) {
+	return nil, fmt.Errorf("failed to fetch attestations")
 }

pkg/cmd/attestation/verification/attestation.go

@@ -9,19 +9,24 @@ import (
 	"path/filepath"
 
 	"github.com/cli/cli/v2/pkg/cmd/attestation/api"
+	"github.com/cli/cli/v2/pkg/cmd/attestation/artifact/oci"
+	"github.com/google/go-containerregistry/pkg/name"
 	protobundle "github.com/sigstore/protobuf-specs/gen/pb-go/bundle/v1"
 	"github.com/sigstore/sigstore-go/pkg/bundle"
 )
 
 var ErrUnrecognisedBundleExtension = errors.New("bundle file extension not supported, must be json or jsonl")
 
 type FetchAttestationsConfig struct {
-	APIClient  api.Client
-	BundlePath string
-	Digest     string
-	Limit      int
-	Owner      string
-	Repo       string
+	APIClient             api.Client
+	BundlePath            string
+	Digest                string
+	Limit                 int
+	Owner                 string
+	Repo                  string
+	OCIClient             oci.Client
+	UseBundleFromRegistry bool
+	NameRef               name.Reference
 }
 
 func (c *FetchAttestationsConfig) IsBundleProvided() bool {
@@ -32,6 +37,11 @@ func GetAttestations(c FetchAttestationsConfig) ([]*api.Attestation, error) {
 	if c.IsBundleProvided() {
 		return GetLocalAttestations(c.BundlePath)
 	}
+
+	if c.UseBundleFromRegistry {
+		return GetOCIAttestations(c)
+	}
+
 	return GetRemoteAttestations(c)
 }
 
@@ -115,6 +125,17 @@ func GetRemoteAttestations(c FetchAttestationsConfig) ([]*api.Attestation, error
 	return nil, fmt.Errorf("owner or repo must be provided")
 }
 
+func GetOCIAttestations(c FetchAttestationsConfig) ([]*api.Attestation, error) {
+	attestations, err := c.OCIClient.GetAttestations(c.NameRef, c.Digest)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch OCI attestations: %w", err)
+	}
+	if len(attestations) == 0 {
+		return nil, fmt.Errorf("no attestations found in the OCI registry. Retry the command without the --bundle-from-oci flag to check GitHub for the attestation")
+	}
+	return attestations, nil
+}
+
 type IntotoStatement struct {
 	PredicateType string `json:"predicateType"`
 }