Add len checks for lobby and peer ids

We are getting some weird errors in our database that are exceeding the
type length. This should help us learn more about the issue.

internal/signaling/stores/postgres.go

@@ -141,6 +141,16 @@ func (s *PostgresStore) Publish(ctx context.Context, topic string, data []byte)
 }
 
 func (s *PostgresStore) CreateLobby(ctx context.Context, game, lobbyCode, peerID string) error {
+	if len(lobbyCode) > 20 {
+		logger := logging.GetLogger(ctx)
+		logger.Warn("lobby code too long", zap.String("lobbyCode", lobbyCode))
+		return ErrInvalidLobbyCode
+	}
+	if len(peerID) > 20 {
+		logger := logging.GetLogger(ctx)
+		logger.Warn("peer id too long", zap.String("peerID", peerID))
+		return ErrInvalidPeerID
+	}
 	res, err := s.DB.Exec(ctx, `
 		INSERT INTO lobbies (code, game, public)
 		VALUES ($1, $2, true)
@@ -156,6 +166,11 @@ func (s *PostgresStore) CreateLobby(ctx context.Context, game, lobbyCode, peerID
 }
 
 func (s *PostgresStore) JoinLobby(ctx context.Context, game, lobbyCode, peerID string) ([]string, error) {
+	if len(peerID) > 20 {
+		logger := logging.GetLogger(ctx)
+		logger.Warn("peer id too long", zap.String("peerID", peerID))
+		return nil, ErrInvalidPeerID
+	}
 	tx, err := s.DB.Begin(ctx)
 	if err != nil {
 		return nil, err
@@ -284,6 +299,13 @@ func (s *PostgresStore) ListLobbies(ctx context.Context, game, filter string) ([
 }
 
 func (s *PostgresStore) TimeoutPeer(ctx context.Context, peerID, secret, gameID string, lobbies []string) error {
+
+	if len(peerID) > 20 {
+		logger := logging.GetLogger(ctx)
+		logger.Warn("peer id too long", zap.String("peerID", peerID))
+		return ErrInvalidPeerID
+	}
+
 	now := util.Now(ctx)
 	_, err := s.DB.Exec(ctx, `
 		INSERT INTO timeouts (peer, secret, game, lobbies, created_at, updated_at)

internal/signaling/stores/shared.go

@@ -10,6 +10,8 @@ var ErrAlreadyInLobby = errors.New("peer already in lobby")
 var ErrLobbyExists = errors.New("lobby already exists")
 var ErrNotFound = errors.New("lobby not found")
 var ErrNoSuchTopic = errors.New("no such topic")
+var ErrInvalidLobbyCode = errors.New("invalid lobby code")
+var ErrInvalidPeerID = errors.New("invalid peer id")
 
 type SubscriptionCallback func(context.Context, []byte)