prysm-pulse/beacon-chain/sync/decode_pubsub.go
Preston Van Loon 2916d183e8
Pubsub: ensure better TopicIDs validation (#7418)
* Ensure better topicIDs validation, add tests

* go mod tidy

* fix tests

Co-authored-by: Victor Farazdagi <simple.square@gmail.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
2020-10-03 01:51:58 +00:00

49 lines
1.2 KiB
Go

package sync
import (
"errors"
"strings"
"github.com/gogo/protobuf/proto"
pubsub "github.com/libp2p/go-libp2p-pubsub"
"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
)
var errTooManyTopics = errors.New("too many topic IDs")
var errNilPubsubMessage = errors.New("nil pubsub message")
var errInvalidTopic = errors.New("invalid topic format")
func (s *Service) decodePubsubMessage(msg *pubsub.Message) (proto.Message, error) {
if msg == nil || msg.TopicIDs == nil {
return nil, errNilPubsubMessage
}
if len(msg.TopicIDs) != 1 {
return nil, errTooManyTopics
}
topic := msg.TopicIDs[0]
topic = strings.TrimSuffix(topic, s.p2p.Encoding().ProtocolSuffix())
topic, err := s.replaceForkDigest(topic)
if err != nil {
return nil, err
}
base, ok := p2p.GossipTopicMappings[topic]
if !ok {
return nil, p2p.ErrMessageNotMapped
}
m := proto.Clone(base)
if err := s.p2p.Encoding().DecodeGossip(msg.Data, m); err != nil {
return nil, err
}
return m, nil
}
// Replaces our fork digest with the formatter.
func (s *Service) replaceForkDigest(topic string) (string, error) {
subStrings := strings.Split(topic, "/")
if len(subStrings) != 4 {
return "", errInvalidTopic
}
subStrings[2] = "%x"
return strings.Join(subStrings, "/"), nil
}