// LoadStatement loads and verifies a statement from an input stream.
func LoadStatement(r io.Reader, authority *x509.CertPool) (*Statement, error) {
b, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
js, err := libtrust.ParsePrettySignature(b, "signatures")
if err != nil {
return nil, err
}
payload, err := js.Payload()
if err != nil {
return nil, err
}
var statement Statement
err = json.Unmarshal(payload, &statement.jsonStatement)
if err != nil {
return nil, err
}
if authority == nil {
_, err = js.Verify()
if err != nil {
return nil, err
}
} else {
_, err = js.VerifyChains(authority)
if err != nil {
return nil, err
}
}
statement.signature = js
return &statement, nil
}
// VerifyChains verifies the signature of the signed manifest against the
// certificate pool returning the list of verified chains. Signatures without
// an x509 chain are not checked.
func VerifyChains(sm *SignedManifest, ca *x509.CertPool) ([][]*x509.Certificate, error) {
js, err := libtrust.ParsePrettySignature(sm.Raw, "signatures")
if err != nil {
return nil, err
}
return js.VerifyChains(ca)
}
// Verify verifies the signature of the signed manifest returning the public
// keys used during signing.
func Verify(sm *SignedManifest) ([]libtrust.PublicKey, error) {
js, err := libtrust.ParsePrettySignature(sm.Raw, "signatures")
if err != nil {
logrus.WithField("err", err).Debugf("(*SignedManifest).Verify")
return nil, err
}
return js.Verify()
}
// Signatures returns the signatures as provided by
// (*libtrust.JSONSignature).Signatures. The byte slices are opaque jws
// signatures.
func (sm *SignedManifest) Signatures() ([][]byte, error) {
jsig, err := libtrust.ParsePrettySignature(sm.Raw, "signatures")
if err != nil {
return nil, err
}
// Resolve the payload in the manifest.
return jsig.Signatures()
}
func (s *TagStore) verifyManifest(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
}
// 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, dgst, ref string) (*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 manifestDigest digest.Digest
if dgst != "" {
manifestDigest, err = digest.ParseDigest(dgst)
if err != nil {
return nil, false, fmt.Errorf("invalid manifest digest from registry: %s", err)
}
dgstVerifier, err := digest.NewDigestVerifier(manifestDigest)
if err != nil {
return nil, false, fmt.Errorf("unable to verify manifest digest from registry: %s", err)
}
dgstVerifier.Write(payload)
if !dgstVerifier.Verified() {
computedDigest, _ := digest.FromBytes(payload)
return nil, false, fmt.Errorf("unable to verify manifest digest: registry has %q, computed %q", manifestDigest, computedDigest)
}
}
if utils.DigestReference(ref) && ref != manifestDigest.String() {
return nil, false, fmt.Errorf("mismatching image manifest digest: got %q, expected %q", manifestDigest, ref)
}
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
}