create a logger interface and use it everywhere

internal/handshake/cookie_handler.go

@@ -11,15 +11,16 @@ import (
 // The cookie is sent in the TLS Retry.
 // By including the cookie in its ClientHello, a client can proof ownership of its source address.
 type CookieHandler struct {
-	callback func(net.Addr, *Cookie) bool
-
+	callback        func(net.Addr, *Cookie) bool
 	cookieGenerator *CookieGenerator
+
+	logger utils.Logger
 }
 
 var _ mint.CookieHandler = &CookieHandler{}
 
 // NewCookieHandler creates a new CookieHandler.
-func NewCookieHandler(callback func(net.Addr, *Cookie) bool) (*CookieHandler, error) {
+func NewCookieHandler(callback func(net.Addr, *Cookie) bool, logger utils.Logger) (*CookieHandler, error) {
 	cookieGenerator, err := NewCookieGenerator()
 	if err != nil {
 		return nil, err
@@ -27,6 +28,7 @@ func NewCookieHandler(callback func(net.Addr, *Cookie) bool) (*CookieHandler, er
 	return &CookieHandler{
 		callback:        callback,
 		cookieGenerator: cookieGenerator,
+		logger:          logger,
 	}, nil
 }
 
@@ -42,7 +44,7 @@ func (h *CookieHandler) Generate(conn *mint.Conn) ([]byte, error) {
 func (h *CookieHandler) Validate(conn *mint.Conn, token []byte) bool {
 	data, err := h.cookieGenerator.DecodeToken(token)
 	if err != nil {
-		utils.Debugf("Couldn't decode cookie from %s: %s", conn.RemoteAddr(), err.Error())
+		h.logger.Debugf("Couldn't decode cookie from %s: %s", conn.RemoteAddr(), err.Error())
 		return false
 	}
 	return h.callback(conn.RemoteAddr(), data)