fix(digests): do not mandate sha256 as the only algorithm used for ha…

…shing blobs

Signed-off-by: Andrei Aaron <aaaron@luxoft.com>

pkg/api/controller_test.go

@@ -10533,6 +10533,167 @@ func RunAuthorizationTests(t *testing.T, client *resty.Client, baseURL, user str
 	})
 }
 
+func TestSupportedDigestAlgorithms(t *testing.T) {
+	port := test.GetFreePort()
+	baseURL := test.GetBaseURL(port)
+
+	conf := config.New()
+	conf.HTTP.Port = port
+
+	dir := t.TempDir()
+
+	ctlr := api.NewController(conf)
+	ctlr.Config.Storage.RootDirectory = dir
+	ctlr.Config.Storage.Dedupe = false
+	ctlr.Config.Storage.GC = false
+
+	cm := test.NewControllerManager(ctlr)
+
+	cm.StartAndWait(port)
+	defer cm.StopServer()
+
+	Convey("Test SHA512 single-arch image", t, func() {
+		image := CreateImageWithDigestAlgorithm(godigest.SHA512).
+			RandomLayers(1, 10).DefaultConfig().Build()
+
+		name := "algo-sha256"
+		tag := "singlearch"
+
+		err := UploadImage(image, baseURL, name, tag)
+		So(err, ShouldBeNil)
+
+		client := resty.New()
+
+		// The server picks canonical digests when tags are pushed
+		// See https://github.com/opencontainers/distribution-spec/issues/494
+		// It would be nice to be able to push tags with other digest algorithms and verify those are returned
+		// but there is no way to specify a client preference
+		// so all we can do is verify the correct algorithm is returned
+
+		expectedDigestStr := image.DigestForAlgorithm(godigest.Canonical).String()
+
+		verifyReturnedManifestDigest(t, client, baseURL, name, tag, expectedDigestStr)
+		verifyReturnedManifestDigest(t, client, baseURL, name, expectedDigestStr, expectedDigestStr)
+	})
+
+	Convey("Test SHA384 single-arch image", t, func() {
+		image := CreateImageWithDigestAlgorithm(godigest.SHA384).
+			RandomLayers(1, 10).DefaultConfig().Build()
+
+		name := "algo-sha384"
+		tag := "singlearch"
+
+		err := UploadImage(image, baseURL, name, tag)
+		So(err, ShouldBeNil)
+
+		client := resty.New()
+
+		// The server picks canonical digests when tags are pushed
+		// See https://github.com/opencontainers/distribution-spec/issues/494
+		// It would be nice to be able to push tags with other digest algorithms and verify those are returned
+		// but there is no way to specify a client preference
+		// so all we can do is verify the correct algorithm is returned
+
+		expectedDigestStr := image.DigestForAlgorithm(godigest.Canonical).String()
+
+		verifyReturnedManifestDigest(t, client, baseURL, name, tag, expectedDigestStr)
+		verifyReturnedManifestDigest(t, client, baseURL, name, expectedDigestStr, expectedDigestStr)
+	})
+
+	Convey("Test SHA512 multi-arch image", t, func() {
+		subImage1 := CreateImageWithDigestAlgorithm(godigest.SHA512).RandomLayers(1, 10).
+			DefaultConfig().Build()
+		subImage2 := CreateImageWithDigestAlgorithm(godigest.SHA512).RandomLayers(1, 10).
+			DefaultConfig().Build()
+		multiarch := CreateMultiarchWithDigestAlgorithm(godigest.SHA512).
+			Images([]Image{subImage1, subImage2}).Build()
+
+		name := "algo-sha256"
+		tag := "multiarch"
+
+		err := UploadMultiarchImage(multiarch, baseURL, name, tag)
+		So(err, ShouldBeNil)
+
+		client := resty.New()
+
+		// The server picks canonical digests when tags are pushed
+		// See https://github.com/opencontainers/distribution-spec/issues/494
+		// It would be nice to be able to push tags with other digest algorithms and verify those are returned
+		// but there is no way to specify a client preference
+		// so all we can do is verify the correct algorithm is returned
+		expectedDigestStr := multiarch.DigestForAlgorithm(godigest.Canonical).String()
+
+		verifyReturnedManifestDigest(t, client, baseURL, name, tag, expectedDigestStr)
+		verifyReturnedManifestDigest(t, client, baseURL, name, expectedDigestStr, expectedDigestStr)
+
+		// While the expected multiarch manifest digest is always using the canonical algorithm
+		// the sub-imgage manifest digest can use any algorith
+		verifyReturnedManifestDigest(t, client, baseURL, name,
+			subImage1.ManifestDescriptor.Digest.String(), subImage1.ManifestDescriptor.Digest.String())
+		verifyReturnedManifestDigest(t, client, baseURL, name,
+			subImage2.ManifestDescriptor.Digest.String(), subImage2.ManifestDescriptor.Digest.String())
+	})
+
+	Convey("Test SHA384 multi-arch image", t, func() {
+		subImage1 := CreateImageWithDigestAlgorithm(godigest.SHA384).RandomLayers(1, 10).
+			DefaultConfig().Build()
+		subImage2 := CreateImageWithDigestAlgorithm(godigest.SHA384).RandomLayers(1, 10).
+			DefaultConfig().Build()
+		multiarch := CreateMultiarchWithDigestAlgorithm(godigest.SHA384).
+			Images([]Image{subImage1, subImage2}).Build()
+
+		name := "algo-sha384"
+		tag := "multiarch"
+
+		err := UploadMultiarchImage(multiarch, baseURL, name, tag)
+		So(err, ShouldBeNil)
+
+		client := resty.New()
+
+		// The server picks canonical digests when tags are pushed
+		// See https://github.com/opencontainers/distribution-spec/issues/494
+		// It would be nice to be able to push tags with other digest algorithms and verify those are returned
+		// but there is no way to specify a client preference
+		// so all we can do is verify the correct algorithm is returned
+		expectedDigestStr := multiarch.DigestForAlgorithm(godigest.Canonical).String()
+
+		verifyReturnedManifestDigest(t, client, baseURL, name, tag, expectedDigestStr)
+		verifyReturnedManifestDigest(t, client, baseURL, name, expectedDigestStr, expectedDigestStr)
+
+		// While the expected multiarch manifest digest is always using the canonical algorithm
+		// the sub-imgage manifest digest can use any algorith
+		verifyReturnedManifestDigest(t, client, baseURL, name,
+			subImage1.ManifestDescriptor.Digest.String(), subImage1.ManifestDescriptor.Digest.String())
+		verifyReturnedManifestDigest(t, client, baseURL, name,
+			subImage2.ManifestDescriptor.Digest.String(), subImage2.ManifestDescriptor.Digest.String())
+	})
+}
+
+func verifyReturnedManifestDigest(t *testing.T, client *resty.Client, baseURL, repoName,
+	reference, expectedDigestStr string,
+) {
+	t.Helper()
+
+	t.Logf("Verify Docker-Content-Digest returned for repo %s reference %s is %s",
+		repoName, reference, expectedDigestStr)
+
+	getResponse, err := client.R().Get(fmt.Sprintf("%s/v2/%s/manifests/%s", baseURL, repoName, reference))
+	So(err, ShouldBeNil)
+	So(getResponse, ShouldNotBeNil)
+	So(getResponse.StatusCode(), ShouldEqual, http.StatusOK)
+
+	contentDigestStr := getResponse.Header().Get("Docker-Content-Digest")
+	So(contentDigestStr, ShouldEqual, expectedDigestStr)
+
+	getResponse, err = client.R().Head(fmt.Sprintf("%s/v2/%s/manifests/%s", baseURL, repoName, reference))
+	So(err, ShouldBeNil)
+	So(getResponse, ShouldNotBeNil)
+	So(getResponse.StatusCode(), ShouldEqual, http.StatusOK)
+
+	contentDigestStr = getResponse.Header().Get("Docker-Content-Digest")
+	So(contentDigestStr, ShouldEqual, expectedDigestStr)
+}
+
 func getEmptyImageConfig() ([]byte, godigest.Digest) {
 	config := ispec.Image{}
 

pkg/storage/common/common.go

@@ -64,19 +64,19 @@ func GetManifestDescByReference(index ispec.Index, reference string) (ispec.Desc
 
 func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaType string, body []byte,
 	log zlog.Logger,
-) (godigest.Digest, error) {
+) error {
 	// validate the manifest
 	if !IsSupportedMediaType(mediaType) {
 		log.Debug().Interface("actual", mediaType).
 			Msg("bad manifest media type")
 
-		return "", zerr.ErrBadManifest
+		return zerr.ErrBadManifest
 	}
 
 	if len(body) == 0 {
 		log.Debug().Int("len", len(body)).Msg("invalid body length")
 
-		return "", zerr.ErrBadManifest
+		return zerr.ErrBadManifest
 	}
 
 	switch mediaType {
@@ -87,13 +87,13 @@ func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaTy
 		if err := ValidateManifestSchema(body); err != nil {
 			log.Error().Err(err).Msg("OCIv1 image manifest schema validation failed")
 
-			return "", zerr.NewError(zerr.ErrBadManifest).AddDetail("jsonSchemaValidation", err.Error())
+			return zerr.NewError(zerr.ErrBadManifest).AddDetail("jsonSchemaValidation", err.Error())
 		}
 
 		if err := json.Unmarshal(body, &manifest); err != nil {
 			log.Error().Err(err).Msg("unable to unmarshal JSON")
 
-			return "", zerr.ErrBadManifest
+			return zerr.ErrBadManifest
 		}
 
 		// validate blobs only for known media types
@@ -104,7 +104,7 @@ func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaTy
 			if !ok || err != nil {
 				log.Error().Err(err).Str("digest", manifest.Config.Digest.String()).Msg("missing config blob")
 
-				return "", zerr.ErrBadManifest
+				return zerr.ErrBadManifest
 			}
 
 			// validate layers - a lightweight check if the blob is present
@@ -120,7 +120,7 @@ func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaTy
 				if !ok || err != nil {
 					log.Error().Err(err).Str("digest", layer.Digest.String()).Msg("missing layer blob")
 
-					return "", zerr.ErrBadManifest
+					return zerr.ErrBadManifest
 				}
 			}
 		}
@@ -129,49 +129,58 @@ func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaTy
 		if err := json.Unmarshal(body, &m); err != nil {
 			log.Error().Err(err).Msg("unable to unmarshal JSON")
 
-			return "", zerr.ErrBadManifest
+			return zerr.ErrBadManifest
 		}
 	case ispec.MediaTypeImageIndex:
 		// validate manifest
 		if err := ValidateImageIndexSchema(body); err != nil {
 			log.Error().Err(err).Msg("OCIv1 image index manifest schema validation failed")
 
-			return "", zerr.NewError(zerr.ErrBadManifest).AddDetail("jsonSchemaValidation", err.Error())
+			return zerr.NewError(zerr.ErrBadManifest).AddDetail("jsonSchemaValidation", err.Error())
 		}
 
 		var indexManifest ispec.Index
 		if err := json.Unmarshal(body, &indexManifest); err != nil {
 			log.Error().Err(err).Msg("unable to unmarshal JSON")
 
-			return "", zerr.ErrBadManifest
+			return zerr.ErrBadManifest
 		}
 
 		for _, manifest := range indexManifest.Manifests {
 			if ok, _, _, err := imgStore.StatBlob(repo, manifest.Digest); !ok || err != nil {
 				log.Error().Err(err).Str("digest", manifest.Digest.String()).Msg("missing manifest blob")
 
-				return "", zerr.ErrBadManifest
+				return zerr.ErrBadManifest
 			}
 		}
 	}
 
-	return "", nil
+	return nil
 }
 
-func GetAndValidateRequestDigest(body []byte, digestStr string, log zlog.Logger) (godigest.Digest, error) {
-	bodyDigest := godigest.FromBytes(body)
+// Returns the canonical digest or the digest provided by the reference if any
+// Per spec, the canonical digest would always be returned to the client in
+// request headers, but that does not make sense if the client requested a different digest algorithm
+// See https://github.com/opencontainers/distribution-spec/issues/494
+func GetAndValidateRequestDigest(body []byte, reference string, log zlog.Logger) (
+	godigest.Digest, error,
+) {
+	expectedDigest, err := godigest.Parse(reference)
+	if err != nil {
+		// This is a non-digest reference
+		return godigest.Canonical.FromBytes(body), err
+	}
+
+	actualDigest := expectedDigest.Algorithm().FromBytes(body)
 
-	d, err := godigest.Parse(digestStr)
-	if err == nil {
-		if d.String() != bodyDigest.String() {
-			log.Error().Str("actual", bodyDigest.String()).Str("expected", d.String()).
-				Msg("manifest digest is not valid")
+	if expectedDigest.String() != actualDigest.String() {
+		log.Error().Str("actual", actualDigest.String()).Str("expected", expectedDigest.String()).
+			Msg("manifest digest is not valid")
 
-			return "", zerr.ErrBadManifest
-		}
+		return actualDigest, zerr.ErrBadManifest
 	}
 
-	return bodyDigest, err
+	return actualDigest, nil
 }
 
 /*

pkg/storage/common/common_test.go

@@ -51,6 +51,23 @@ func TestValidateManifest(t *testing.T) {
 		So(err, ShouldBeNil)
 		So(clen, ShouldEqual, len(cblob))
 
+		Convey("bad manifest mediatype", func() {
+			manifest := ispec.Manifest{}
+
+			body, err := json.Marshal(manifest)
+			So(err, ShouldBeNil)
+
+			_, _, err = imgStore.PutImageManifest("test", "1.0", ispec.MediaTypeImageConfig, body)
+			So(err, ShouldNotBeNil)
+			So(err, ShouldEqual, zerr.ErrBadManifest)
+		})
+
+		Convey("empty manifest", func() {
+			_, _, err = imgStore.PutImageManifest("test", "1.0", ispec.MediaTypeImageConfig, []byte(""))
+			So(err, ShouldNotBeNil)
+			So(err, ShouldEqual, zerr.ErrBadManifest)
+		})
+
 		Convey("bad manifest schema version", func() {
 			manifest := ispec.Manifest{
 				Config: ispec.Descriptor{

pkg/storage/gc/gc.go

@@ -579,20 +579,19 @@ func (gc GarbageCollect) removeUnreferencedBlobs(repo string, delay time.Duratio
 
 	gcBlobs := make([]godigest.Digest, 0)
 
-	for _, blob := range allBlobs {
-		digest := godigest.NewDigestFromEncoded(godigest.SHA256, blob)
+	for _, digest := range allBlobs {
 		if err = digest.Validate(); err != nil {
-			log.Error().Err(err).Str("module", "gc").Str("repository", repo).Str("digest", blob).
-				Msg("unable to parse digest")
+			log.Error().Err(err).Str("module", "gc").Str("repository", repo).
+				Str("digest", digest.String()).Msg("unable to parse digest")
 
 			return err
 		}
 
 		if _, ok := refBlobs[digest.String()]; !ok {
 			canGC, err := isBlobOlderThan(gc.imgStore, repo, digest, delay, log)
 			if err != nil {
-				log.Error().Err(err).Str("module", "gc").Str("repository", repo).Str("digest", blob).
-					Msg("unable to determine GC delay")
+				log.Error().Err(err).Str("module", "gc").Str("repository", repo).
+					Str("digest", digest.String()).Msg("unable to determine GC delay")
 
 				return err
 			}

pkg/storage/gc/gc_internal_test.go

@@ -440,8 +440,8 @@ func TestGarbageCollectWithMockedImageStore(t *testing.T) {
 				GetIndexContentFn: func(repo string) ([]byte, error) {
 					return returnedIndexJSONBuf, nil
 				},
-				GetAllBlobsFn: func(repo string) ([]string, error) {
-					return []string{}, errGC
+				GetAllBlobsFn: func(repo string) ([]godigest.Digest, error) {
+					return []godigest.Digest{}, errGC
 				},
 			}