"veyron/security": Make principal serializaiton backwards compatible
CL 6820 changed the serialization format for BlessingStores, as a result
of which principals serialized in the old format could no longer be
deserialized.
This turned out to be huge inconvenience as it required re-generating
credentials for all envyor binaries (pis, identity server, etc).
This CL restores support for the old serialization format. In
particular,
* Principals serialized according to the old format can be deserialized
* However, subsequent updates to the principal's state get saved in the
new format.
Once everyone has switched to the new serialization format, we will
remove support for the old one.
Change-Id: Icd1204c27e93fbb3cd710b072dbc7b621a47f2c8
diff --git a/security/blessingstore.go b/security/blessingstore.go
index 1a7540d..57ef450 100644
--- a/security/blessingstore.go
+++ b/security/blessingstore.go
@@ -175,18 +175,75 @@
}
}
+// TODO(ataly, ashankar): Get rid of this struct once we have switched all credentials
+// directories to the new serialization format.
+type oldState struct {
+ Store map[security.BlessingPattern]security.WireBlessings
+ Default security.WireBlessings
+}
+
+// TODO(ataly, ashankar): Get rid of this method once we have switched all
+// credentials directories to the new serialization format.
+func (bs *blessingStore) tryOldFormat() bool {
+ var empty security.WireBlessings
+ if len(bs.state.Store) == 0 {
+ return bs.state.Default == nil || reflect.DeepEqual(bs.state.Default.Value, empty)
+ }
+ for _, wb := range bs.state.Store {
+ if len(wb.Value.CertificateChains) == 0 {
+ return true
+ }
+ }
+ return false
+}
+
+// TODO(ataly, ashankar): Get rid of this method once we have switched all
+// credentials directories to the new serialization format.
+func (bs *blessingStore) deserializeOld() error {
+ data, signature, err := bs.serializer.Readers()
+ if err != nil {
+ return err
+ }
+ if data == nil && signature == nil {
+ return nil
+ }
+ var old oldState
+ if err := decodeFromStorage(&old, data, signature, bs.signer.PublicKey()); err != nil {
+ return err
+ }
+ for p, wire := range old.Store {
+ bs.state.Store[p] = &blessings{Value: wire}
+ }
+ bs.state.Default = &blessings{Value: old.Default}
+ return nil
+}
+
+func (bs *blessingStore) deserialize() error {
+ data, signature, err := bs.serializer.Readers()
+ if err != nil {
+ return err
+ }
+ if data == nil && signature == nil {
+ return nil
+ }
+ if err := decodeFromStorage(&bs.state, data, signature, bs.signer.PublicKey()); err == nil && !bs.tryOldFormat() {
+ return nil
+ }
+ if err := bs.deserializeOld(); err != nil {
+ return err
+ }
+ return nil
+}
+
// newPersistingBlessingStore returns a security.BlessingStore for a principal
// that is initialized with the persisted data. The returned security.BlessingStore
// also persists any updates to its state.
func newPersistingBlessingStore(serializer SerializerReaderWriter, signer serialization.Signer) (security.BlessingStore, error) {
verifyBlessings := func(wb *blessings, key security.PublicKey) error {
- if wb == nil {
- return nil
- }
if err := wb.Verify(); err != nil {
return err
}
- if b := wb.Blessings(); !reflect.DeepEqual(b.PublicKey(), key) {
+ if b := wb.Blessings(); b != nil && !reflect.DeepEqual(b.PublicKey(), key) {
return fmt.Errorf("read Blessings: %v that are not for provided PublicKey: %v", b, key)
}
return nil
@@ -200,21 +257,25 @@
serializer: serializer,
signer: signer,
}
- data, signature, err := bs.serializer.Readers()
- if err != nil {
+ if err := bs.deserialize(); err != nil {
return nil, err
}
- if data != nil && signature != nil {
- if err := decodeFromStorage(&bs.state, data, signature, bs.signer.PublicKey()); err != nil {
- return nil, err
- }
- }
for _, wb := range bs.state.Store {
if err := verifyBlessings(wb, bs.publicKey); err != nil {
return nil, err
}
}
- if err := verifyBlessings(bs.state.Default, bs.publicKey); err != nil {
+ if bs.state.Default != nil {
+ if err := verifyBlessings(bs.state.Default, bs.publicKey); err != nil {
+ return nil, err
+ }
+ }
+ // Save the blessingstore in the new serialization format. This will ensure
+ // that all credentials directories in the old format will switch to the new
+ // format.
+ // TODO(ataly, ashankar): Get rid of this once we have switched all
+ // credentials directories to the new serialization format.
+ if err := bs.save(); err != nil {
return nil, err
}
return bs, nil
