package graph import ( "bytes" "encoding/json" "fmt" log "github.com/Sirupsen/logrus" "github.com/docker/docker/engine" "github.com/docker/docker/registry" "github.com/docker/libtrust" ) // loadManifest loads a manifest from a byte array and verifies its content. // The signature must be verified or an error is returned. If the manifest // contains no signatures by a trusted key for the name in the manifest, the // image is not considered verified. The parsed manifest object and a boolean // for whether the manifest is verified is returned. func (s *TagStore) loadManifest(eng *engine.Engine, manifestBytes []byte) (*registry.ManifestData, bool, error) { sig, err := libtrust.ParsePrettySignature(manifestBytes, "signatures") if err != nil { return nil, false, fmt.Errorf("error parsing payload: %s", err) } keys, err := sig.Verify() if err != nil { return nil, false, fmt.Errorf("error verifying payload: %s", err) } payload, err := sig.Payload() if err != nil { return nil, false, fmt.Errorf("error retrieving payload: %s", err) } var manifest registry.ManifestData if err := json.Unmarshal(payload, &manifest); err != nil { return nil, false, fmt.Errorf("error unmarshalling manifest: %s", err) } if manifest.SchemaVersion != 1 { return nil, false, fmt.Errorf("unsupported schema version: %d", manifest.SchemaVersion) } var verified bool for _, key := range keys { job := eng.Job("trust_key_check") b, err := key.MarshalJSON() if err != nil { return nil, false, fmt.Errorf("error marshalling public key: %s", err) } namespace := manifest.Name if namespace[0] != '/' { namespace = "/" + namespace } stdoutBuffer := bytes.NewBuffer(nil) job.Args = append(job.Args, namespace) job.Setenv("PublicKey", string(b)) // Check key has read/write permission (0x03) job.SetenvInt("Permission", 0x03) job.Stdout.Add(stdoutBuffer) if err = job.Run(); err != nil { return nil, false, fmt.Errorf("error running key check: %s", err) } result := engine.Tail(stdoutBuffer, 1) log.Debugf("Key check result: %q", result) if result == "verified" { verified = true } } return &manifest, verified, nil } func checkValidManifest(manifest *registry.ManifestData) error { if len(manifest.FSLayers) != len(manifest.History) { return fmt.Errorf("length of history not equal to number of layers") } if len(manifest.FSLayers) == 0 { return fmt.Errorf("no FSLayers in manifest") } return nil }