diff --git a/socks5.go b/socks5.go
index 9b8d314..8a32b59 100644
--- a/socks5.go
+++ b/socks5.go
@@ -176,6 +176,11 @@ func (req *UserPassRequest) Write(w io.Writer) error {
 	return err
 }
 
+func (req *UserPassRequest) String() string {
+	return fmt.Sprintf("%d %s:%s",
+		req.Version, req.Username, req.Password)
+}
+
 /*
  Username/Password authentication response
  +----+--------+
@@ -219,6 +224,11 @@ func (res *UserPassResponse) Write(w io.Writer) error {
 	return err
 }
 
+func (res *UserPassResponse) String() string {
+	return fmt.Sprintf("%d %d",
+		res.Version, res.Status)
+}
+
 type Addr struct {
 	Type uint8
 	Host string