Add option to disable signatures

Add option for specifying trust key for signing schema1 manifests.
Since schema1 signature key identifiers are not verified anywhere and deprecated, storing signatures is no longer a requirement.
Furthermore in schema2 there is no signature, requiring the registry to already add signatures to generated schema1 manifests.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)

configuration/configuration.go

@@ -145,6 +145,21 @@ type Configuration struct {
 	Health Health `yaml:"health,omitempty"`
 
 	Proxy Proxy `yaml:"proxy,omitempty"`
+
+	// Compatibility is used for configurations of working with older or deprecated features.
+	Compatibility struct {
+		// Schema1 configures how schema1 manifests will be handled
+		Schema1 struct {
+			// TrustKey is the signing key to use for adding the signature to
+			// schema1 manifests.
+			TrustKey string `yaml:"signingkeyfile,omitempty"`
+
+			// DisableSignatureStore will cause all signatures attached to schema1 manifests
+			// to be ignored. Signatures will be generated on all schema1 manifest requests
+			// rather than only requests which converted schema2 to schema1.
+			DisableSignatureStore bool `yaml:"disablesignaturestore,omitempty"`
+		} `yaml:"schema1,omitempty"`
+	} `yaml:"compatibility,omitempty"`
 }
 
 // LogHook is composed of hook Level and Type.

manifest/schema1/manifest.go

@@ -102,7 +102,7 @@ type SignedManifest struct {
 	Canonical []byte `json:"-"`
 
 	// all contains the byte representation of the Manifest including signatures
-	// and is retuend by Payload()
+	// and is returned by Payload()
 	all []byte
 }
 

registry/handlers/app.go

@@ -155,11 +155,18 @@ func NewApp(ctx context.Context, config *configuration.Configuration) *App {
 	app.configureRedis(config)
 	app.configureLogHook(config)
 
-	// Generate an ephemeral key to be used for signing converted manifests
-	// for clients that don't support schema2.
-	app.trustKey, err = libtrust.GenerateECP256PrivateKey()
-	if err != nil {
-		panic(err)
+	if config.Compatibility.Schema1.TrustKey != "" {
+		app.trustKey, err = libtrust.LoadKeyFile(config.Compatibility.Schema1.TrustKey)
+		if err != nil {
+			panic(fmt.Sprintf(`could not load schema1 "signingkey" parameter: %v`, err))
+		}
+	} else {
+		// Generate an ephemeral key to be used for signing converted manifests
+		// for clients that don't support schema2.
+		app.trustKey, err = libtrust.GenerateECP256PrivateKey()
+		if err != nil {
+			panic(err)
+		}
 	}
 
 	if config.HTTP.Host != "" {
@@ -176,6 +183,11 @@ func NewApp(ctx context.Context, config *configuration.Configuration) *App {
 		options = append(options, storage.DisableDigestResumption)
 	}
 
+	if config.Compatibility.Schema1.DisableSignatureStore {
+		options = append(options, storage.DisableSchema1Signatures)
+		options = append(options, storage.Schema1SigningKey(app.trustKey))
+	}
+
 	// configure deletion
 	if d, ok := config.Storage["delete"]; ok {
 		e, ok := d["enabled"]

registry/storage/manifeststore_test.go

@@ -28,11 +28,10 @@ type manifestStoreTestEnv struct {
 	tag        string
 }
 
-func newManifestStoreTestEnv(t *testing.T, name reference.Named, tag string) *manifestStoreTestEnv {
+func newManifestStoreTestEnv(t *testing.T, name reference.Named, tag string, options ...RegistryOption) *manifestStoreTestEnv {
 	ctx := context.Background()
 	driver := inmemory.New()
-	registry, err := NewRegistry(ctx, driver, BlobDescriptorCacheProvider(
-		memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
+	registry, err := NewRegistry(ctx, driver, options...)
 	if err != nil {
 		t.Fatalf("error creating registry: %v", err)
 	}
@@ -53,13 +52,26 @@ func newManifestStoreTestEnv(t *testing.T, name reference.Named, tag string) *ma
 }
 
 func TestManifestStorage(t *testing.T) {
+	testManifestStorage(t, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
+}
+
+func TestManifestStorageDisabledSignatures(t *testing.T) {
+	k, err := libtrust.GenerateECP256PrivateKey()
+	if err != nil {
+		t.Fatal(err)
+	}
+	testManifestStorage(t, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect, DisableSchema1Signatures, Schema1SigningKey(k))
+}
+
+func testManifestStorage(t *testing.T, options ...RegistryOption) {
 	repoName, _ := reference.ParseNamed("foo/bar")
-	env := newManifestStoreTestEnv(t, repoName, "thetag")
+	env := newManifestStoreTestEnv(t, repoName, "thetag", options...)
 	ctx := context.Background()
 	ms, err := env.repository.Manifests(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}
+	equalSignatures := env.registry.(*registry).schema1SignaturesEnabled
 
 	m := schema1.Manifest{
 		Versioned: manifest.Versioned{
@@ -159,8 +171,14 @@ func TestManifestStorage(t *testing.T) {
 		t.Fatalf("unexpected manifest type from signedstore")
 	}
 
-	if !reflect.DeepEqual(fetchedManifest, sm) {
-		t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedManifest, sm)
+	if !bytes.Equal(fetchedManifest.Canonical, sm.Canonical) {
+		t.Fatalf("fetched payload does not match original payload: %q != %q", fetchedManifest.Canonical, sm.Canonical)
+	}
+
+	if equalSignatures {
+		if !reflect.DeepEqual(fetchedManifest, sm) {
+			t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedManifest.Manifest, sm.Manifest)
+		}
 	}
 
 	_, pl, err := fetchedManifest.Payload()
@@ -196,8 +214,19 @@ func TestManifestStorage(t *testing.T) {
 		t.Fatalf("unexpected error fetching manifest by digest: %v", err)
 	}
 
-	if !reflect.DeepEqual(fetchedByDigest, fetchedManifest) {
-		t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedByDigest, fetchedManifest)
+	byDigestManifest, ok := fetchedByDigest.(*schema1.SignedManifest)
+	if !ok {
+		t.Fatalf("unexpected manifest type from signedstore")
+	}
+
+	if !bytes.Equal(byDigestManifest.Canonical, fetchedManifest.Canonical) {
+		t.Fatalf("fetched manifest not equal: %q != %q", byDigestManifest.Canonical, fetchedManifest.Canonical)
+	}
+
+	if equalSignatures {
+		if !reflect.DeepEqual(fetchedByDigest, fetchedManifest) {
+			t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedByDigest, fetchedManifest)
+		}
 	}
 
 	sigs, err := fetchedJWS.Signatures()
@@ -286,14 +315,16 @@ func TestManifestStorage(t *testing.T) {
 		t.Fatalf("payloads are not equal")
 	}
 
-	receivedSigs, err := receivedJWS.Signatures()
-	if err != nil {
-		t.Fatalf("error getting signatures: %v", err)
-	}
+	if equalSignatures {
+		receivedSigs, err := receivedJWS.Signatures()
+		if err != nil {
+			t.Fatalf("error getting signatures: %v", err)
+		}
 
-	for i, sig := range receivedSigs {
-		if !bytes.Equal(sig, expectedSigs[i]) {
-			t.Fatalf("mismatched signatures from remote: %v != %v", string(sig), string(expectedSigs[i]))
+		for i, sig := range receivedSigs {
+			if !bytes.Equal(sig, expectedSigs[i]) {
+				t.Fatalf("mismatched signatures from remote: %v != %v", string(sig), string(expectedSigs[i]))
+			}
 		}
 	}
 

registry/storage/registry.go

@@ -6,6 +6,7 @@ import (
 	"github.com/docker/distribution/reference"
 	"github.com/docker/distribution/registry/storage/cache"
 	storagedriver "github.com/docker/distribution/registry/storage/driver"
+	"github.com/docker/libtrust"
 )
 
 // registry is the top-level implementation of Registry for use in the storage
@@ -17,6 +18,8 @@ type registry struct {
 	blobDescriptorCacheProvider cache.BlobDescriptorCacheProvider
 	deleteEnabled               bool
 	resumableDigestEnabled      bool
+	schema1SignaturesEnabled    bool
+	schema1SigningKey           libtrust.PrivateKey
 }
 
 // RegistryOption is the type used for functional options for NewRegistry.
@@ -43,6 +46,24 @@ func DisableDigestResumption(registry *registry) error {
 	return nil
 }
 
+// DisableSchema1Signatures is a functional option for NewRegistry. It disables
+// signature storage and ensures all schema1 manifests will only be returned
+// with a signature from a provided signing key.
+func DisableSchema1Signatures(registry *registry) error {
+	registry.schema1SignaturesEnabled = false
+	return nil
+}
+
+// Schema1SigningKey returns a functional option for NewRegistry. It sets the
+// signing key for adding a signature to all schema1 manifests. This should be
+// used in conjunction with disabling signature store.
+func Schema1SigningKey(key libtrust.PrivateKey) RegistryOption {
+	return func(registry *registry) error {
+		registry.schema1SigningKey = key
+		return nil
+	}
+}
+
 // BlobDescriptorCacheProvider returns a functional option for
 // NewRegistry. It creates a cached blob statter for use by the
 // registry.
@@ -85,8 +106,9 @@ func NewRegistry(ctx context.Context, driver storagedriver.StorageDriver, option
 			statter: statter,
 			pathFn:  bs.path,
 		},
-		statter:                statter,
-		resumableDigestEnabled: true,
+		statter:                  statter,
+		resumableDigestEnabled:   true,
+		schema1SignaturesEnabled: true,
 	}
 
 	for _, option := range options {

registry/storage/signedmanifesthandler.go

@@ -25,10 +25,17 @@ var _ ManifestHandler = &signedManifestHandler{}
 
 func (ms *signedManifestHandler) Unmarshal(ctx context.Context, dgst digest.Digest, content []byte) (distribution.Manifest, error) {
 	context.GetLogger(ms.ctx).Debug("(*signedManifestHandler).Unmarshal")
-	// Fetch the signatures for the manifest
-	signatures, err := ms.signatures.Get(dgst)
-	if err != nil {
-		return nil, err
+
+	var (
+		signatures [][]byte
+		err        error
+	)
+	if ms.repository.schema1SignaturesEnabled {
+		// Fetch the signatures for the manifest
+		signatures, err = ms.signatures.Get(dgst)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	jsig, err := libtrust.NewJSONSignature(content, signatures...)
@@ -36,6 +43,14 @@ func (ms *signedManifestHandler) Unmarshal(ctx context.Context, dgst digest.Dige
 		return nil, err
 	}
 
+	if ms.repository.schema1SigningKey != nil {
+		if err := jsig.Sign(ms.repository.schema1SigningKey); err != nil {
+			return nil, err
+		}
+	} else if !ms.repository.schema1SignaturesEnabled {
+		return nil, fmt.Errorf("missing signing key with signature store disabled")
+	}
+
 	// Extract the pretty JWS
 	raw, err := jsig.PrettySignature("signatures")
 	if err != nil {
@@ -75,14 +90,16 @@ func (ms *signedManifestHandler) Put(ctx context.Context, manifest distribution.
 		return "", err
 	}
 
-	// Grab each json signature and store them.
-	signatures, err := sm.Signatures()
-	if err != nil {
-		return "", err
-	}
+	if ms.repository.schema1SignaturesEnabled {
+		// Grab each json signature and store them.
+		signatures, err := sm.Signatures()
+		if err != nil {
+			return "", err
+		}
 
-	if err := ms.signatures.Put(revision.Digest, signatures...); err != nil {
-		return "", err
+		if err := ms.signatures.Put(revision.Digest, signatures...); err != nil {
+			return "", err
+		}
 	}
 
 	return revision.Digest, nil