Example #1
0
// getLocal attempts to retrieve the value from the datastore
func (dht *IpfsDHT) getLocal(key u.Key) ([]byte, error) {
	dht.dslock.Lock()
	defer dht.dslock.Unlock()
	log.Debug("getLocal %s", key)
	v, err := dht.datastore.Get(key.DsKey())
	if err != nil {
		return nil, err
	}
	log.Debug("found in db")

	byt, ok := v.([]byte)
	if !ok {
		return nil, errors.New("value stored in datastore not []byte")
	}
	rec := new(pb.Record)
	err = proto.Unmarshal(byt, rec)
	if err != nil {
		return nil, err
	}

	// TODO: 'if paranoid'
	if u.Debug {
		err = dht.verifyRecord(rec)
		if err != nil {
			log.Errorf("local record verify failed: %s", err)
			return nil, err
		}
	}

	return rec.GetValue(), nil
}
Example #2
0
// creates and signs a dht record for the given key/value pair
func (dht *IpfsDHT) makePutRecord(key u.Key, value []byte) (*pb.Record, error) {
	record := new(pb.Record)

	record.Key = proto.String(string(key))
	record.Value = value
	record.Author = proto.String(string(dht.self.ID()))
	blob := bytes.Join([][]byte{[]byte(key), value, []byte(dht.self.ID())}, []byte{})
	sig, err := dht.self.PrivKey().Sign(blob)
	if err != nil {
		return nil, err
	}
	record.Signature = sig
	return record, nil
}
Example #3
0
func (dht *IpfsDHT) verifyRecord(r *pb.Record) error {
	// First, validate the signature
	p, err := dht.peerstore.Get(peer.ID(r.GetAuthor()))
	if err != nil {
		return err
	}
	k := u.Key(r.GetKey())

	blob := bytes.Join([][]byte{[]byte(k),
		r.GetValue(),
		[]byte(r.GetAuthor())}, []byte{})

	ok, err := p.PubKey().Verify(blob, r.GetSignature())
	if err != nil {
		log.Error("Signature verify failed.")
		return err
	}

	if !ok {
		return ErrBadRecord
	}

	// Now, check validity func
	parts := strings.Split(r.GetKey(), "/")
	if len(parts) < 3 {
		log.Errorf("Record had bad key: %s", u.Key(r.GetKey()))
		return ErrBadRecord
	}

	fnc, ok := dht.Validators[parts[1]]
	if !ok {
		log.Errorf("Unrecognized key prefix: %s", parts[1])
		return ErrInvalidRecordType
	}

	return fnc(u.Key(r.GetKey()), r.GetValue())
}