imagetools: add sigstore bundle v3 to supported referrer formats

This was added after the initial version was written.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

Author: tonistiigi

commands/imagetools/create.go

@@ -171,6 +171,7 @@ func runCreate(ctx context.Context, dockerCli command.Cli, in createOptions, arg
 	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.oci.empty.v1+json", "empty")
 	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.cosign.artifact.sig.v1+json", "cosign")
 	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.cosign.simplesigning.v1+json", "simplesigning")
+	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.sigstore.bundle.v0.3+json", "sigstore-bundle")
 
 	dt, desc, manifests, err := r.Combine(ctx, srcs, annotations, in.preferIndex, platforms)
 	if err != nil {

util/imagetools/create.go

@@ -27,11 +27,13 @@ import (
 const (
 	artifactTypeAttestationManifest = "application/vnd.docker.attestation.manifest.v1+json"
 	artifactTypeCosignSignature     = "application/vnd.dev.cosign.artifact.sig.v1+json"
+	artifactTypeSigstoreBundle      = "application/vnd.dev.sigstore.bundle.v0.3+json"
 )
 
 var supportedArtifactTypes = map[string]struct{}{
 	artifactTypeAttestationManifest: {},
 	artifactTypeCosignSignature:     {},
+	artifactTypeSigstoreBundle:      {},
 }
 
 type Source struct {