func verify(ps peer.Peerstore, r *dhtpb.Record) error {
v := make(record.Validator)
v["pk"] = record.PublicKeyValidator
p := peer.ID(r.GetAuthor())
pk := ps.PubKey(p)
if pk == nil {
return fmt.Errorf("do not have public key for %s", p)
}
if err := record.CheckRecordSig(r, pk); err != nil {
return err
}
if err := v.VerifyRecord(r); err != nil {
return err
}
return nil
}
// verifyRecordLocally attempts to verify a record. if we do not have the public
// key, we fail. we do not search the dht.
func (dht *IpfsDHT) verifyRecordLocally(r *pb.Record) error {
if len(r.Signature) > 0 {
// First, validate the signature
p := peer.ID(r.GetAuthor())
pk := dht.peerstore.PubKey(p)
if pk == nil {
return fmt.Errorf("do not have public key for %s", p)
}
if err := record.CheckRecordSig(r, pk); err != nil {
return err
}
}
return dht.Validator.VerifyRecord(r)
}
// verifyRecordOnline verifies a record, searching the DHT for the public key
// if necessary. The reason there is a distinction in the functions is that
// retrieving arbitrary public keys from the DHT as a result of passively
// receiving records (e.g. through a PUT_VALUE or ADD_PROVIDER) can cause a
// massive amplification attack on the dht. Use with care.
func (dht *IpfsDHT) verifyRecordOnline(ctx context.Context, r *pb.Record) error {
if len(r.Signature) > 0 {
// get the public key, search for it if necessary.
p := peer.ID(r.GetAuthor())
pk, err := dht.GetPublicKey(ctx, p)
if err != nil {
return err
}
err = record.CheckRecordSig(r, pk)
if err != nil {
return err
}
}
return dht.Validator.VerifyRecord(r)
}
