// CreateTimestamp creates a new timestamp. If a prev timestamp is provided, it
// is assumed this is the immediately previous one, and the new one will have a
// version number one higher than prev. The store is used to lookup the current
// snapshot, this function does not save the newly generated timestamp.
func CreateTimestamp(gun string, prev *data.SignedTimestamp, snapshot []byte, store storage.MetaStore, cryptoService signed.CryptoService) (*data.Signed, int, error) {
algorithm, public, err := store.GetKey(gun, data.CanonicalTimestampRole)
if err != nil {
// owner of gun must have generated a timestamp key otherwise
// we won't proceed with generating everything.
return nil, 0, err
}
key := data.NewPublicKey(algorithm, public)
sn := &data.Signed{}
err = json.Unmarshal(snapshot, sn)
if err != nil {
// couldn't parse snapshot
return nil, 0, err
}
ts, err := data.NewTimestamp(sn)
if err != nil {
return nil, 0, err
}
if prev != nil {
ts.Signed.Version = prev.Signed.Version + 1
}
sgndTs, err := json.MarshalCanonical(ts.Signed)
if err != nil {
return nil, 0, err
}
out := &data.Signed{
Signatures: ts.Signatures,
Signed: sgndTs,
}
err = signed.Sign(cryptoService, out, key)
if err != nil {
return nil, 0, err
}
return out, ts.Signed.Version, nil
}
// InitTimestamp initializes a timestamp based on the current snapshot
func (tr *Repo) InitTimestamp() error {
snap, err := tr.Snapshot.ToSigned()
if err != nil {
return err
}
timestamp, err := data.NewTimestamp(snap)
if err != nil {
return err
}
tr.Timestamp = timestamp
return nil
}