cmd/oci-image-tool: validate descriptors MediaType

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

image/descriptor.go

@@ -73,7 +73,17 @@ func findDescriptor(w walker, name string) (*descriptor, error) {
 	}
 }
 
-func (d *descriptor) validate(w walker) error {
+func (d *descriptor) validate(w walker, mts []string) error {
+	var found bool
+	for _, mt := range mts {
+		if d.MediaType == mt {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return fmt.Errorf("invalid descriptor MediaType %q", d.MediaType)
+	}
 	switch err := w.walk(func(path string, info os.FileInfo, r io.Reader) error {
 		if info.IsDir() {
 			return nil

image/image.go

@@ -19,6 +19,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 )
 
@@ -42,13 +43,18 @@ func Validate(tarFile, ref string) error {
 	return validate(newTarWalker(f), ref)
 }
 
+var validRefMediaTypes = []string{
+	v1.MediaTypeImageManifest,
+	v1.MediaTypeImageManifestList,
+}
+
 func validate(w walker, refName string) error {
 	ref, err := findDescriptor(w, refName)
 	if err != nil {
 		return err
 	}
 
-	if err = ref.validate(w); err != nil {
+	if err = ref.validate(w, validRefMediaTypes); err != nil {
 		return err
 	}
 
@@ -88,7 +94,7 @@ func unpack(w walker, dest, refName string) error {
 		return err
 	}
 
-	if err = ref.validate(w); err != nil {
+	if err = ref.validate(w, validRefMediaTypes); err != nil {
 		return err
 	}
 
@@ -130,7 +136,7 @@ func createRuntimeBundle(w walker, dest, refName, rootfs string) error {
 		return err
 	}
 
-	if err = ref.validate(w); err != nil {
+	if err = ref.validate(w, validRefMediaTypes); err != nil {
 		return err
 	}
 

image/manifest.go

@@ -28,6 +28,7 @@ import (
 	"time"
 
 	"github.com/opencontainers/image-spec/schema"
+	"github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 )
 
@@ -74,12 +75,12 @@ func findManifest(w walker, d *descriptor) (*manifest, error) {
 }
 
 func (m *manifest) validate(w walker) error {
-	if err := m.Config.validate(w); err != nil {
+	if err := m.Config.validate(w, []string{v1.MediaTypeImageConfig}); err != nil {
 		return errors.Wrap(err, "config validation failed")
 	}
 
 	for _, d := range m.Layers {
-		if err := d.validate(w); err != nil {
+		if err := d.validate(w, []string{v1.MediaTypeImageLayer}); err != nil {
 			return errors.Wrap(err, "layer validation failed")
 		}
 	}