Files
attest/pkg/oci/types.go
James Carnegie 8ba9656645 Add support for OCI Referrers and fallback (#50)
* Add support for OCI Referrers and fallback
2024-06-13 16:10:41 +01:00

68 lines
1.8 KiB
Go

package oci
import (
"fmt"
"log"
"github.com/google/go-containerregistry/pkg/authn"
"github.com/google/go-containerregistry/pkg/name"
v1 "github.com/google/go-containerregistry/pkg/v1"
"github.com/google/go-containerregistry/pkg/v1/layout"
"github.com/google/go-containerregistry/pkg/v1/remote"
)
const (
AttestationManifestType = "attestation-manifest"
InTotoPredicateType = "in-toto.io/predicate-type"
OciReferenceTarget = "org.opencontainers.image.ref.name"
)
type SubjectIndex struct {
Index v1.ImageIndex
Name string
}
func SubjectIndexFromPath(path string) (*SubjectIndex, error) {
wrapperIdx, err := layout.ImageIndexFromPath(path)
if err != nil {
return nil, fmt.Errorf("failed to load image index: %w", err)
}
idxm, err := wrapperIdx.IndexManifest()
if err != nil {
return nil, fmt.Errorf("failed to get digest: %w", err)
}
imageName := idxm.Manifests[0].Annotations[OciReferenceTarget]
idxDigest := idxm.Manifests[0].Digest
idx, err := wrapperIdx.ImageIndex(idxDigest)
if err != nil {
return nil, fmt.Errorf("failed to extract ImageIndex for digest %s: %w", idxDigest.String(), err)
}
return &SubjectIndex{
Index: idx,
Name: imageName,
}, nil
}
func SubjectIndexFromRemote(image string) (*SubjectIndex, error) {
ref, err := name.ParseReference(image)
if err != nil {
log.Fatalf("Failed to parse image name: %v", err)
}
// Get the authenticator from the default Docker keychain
auth, err := authn.DefaultKeychain.Resolve(ref.Context())
if err != nil {
log.Fatalf("Failed to get authenticator: %v", err)
}
// Pull the image from the registry
idx, err := remote.Index(ref, remote.WithAuth(auth))
if err != nil {
return nil, fmt.Errorf("failed to pull image %s: %w", image, err)
}
return &SubjectIndex{
Index: idx,
Name: image,
}, nil
}