Merge pull request #95 from wneessen/94-login-auth-next-handler-should-unconditionally-succeed-if-more-is-false

Fix SMTP AUTH LOGIN method for servers with uncommon success messages

Author: Winni Neessen

auth/auth_test.go

@@ -22,10 +22,10 @@ func TestAuth(t *testing.T) {
 	authTests := []authTest{
 		{
 			LoginAuth("user", "pass", "testserver"),
-			[]string{"Username:", "Password:", "2.7.0 Authentication successful", "Invalid:"},
+			[]string{"Username:", "Password:", "Invalid:"},
 			"LOGIN",
-			[]string{"", "user", "pass", "", ""},
-			[]bool{false, false, false, true},
+			[]string{"", "user", "pass", ""},
+			[]bool{false, false, true},
 		},
 	}
 

auth/login.go

@@ -9,7 +9,6 @@ import (
 	"errors"
 	"fmt"
 	"net/smtp"
-	"strings"
 )
 
 type loginAuth struct {
@@ -23,10 +22,6 @@ const (
 
 	// ServerRespPassword represents the "Password:" response by the SMTP server
 	ServerRespPassword = "Password:"
-
-	// ServerRespAuthSuccess represents the "Authentication successful:" response that is
-	// by sent by some SMTP servers
-	ServerRespAuthSuccess = "Authentication successful"
 )
 
 // LoginAuth returns an Auth that implements the LOGIN authentication
@@ -70,10 +65,9 @@ func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
 			return []byte(a.username), nil
 		case ServerRespPassword:
 			return []byte(a.password), nil
+		default:
+			return nil, fmt.Errorf("unexpected server response: %s", string(fromServer))
 		}
 	}
-	if strings.HasSuffix(string(fromServer), ServerRespAuthSuccess) {
-		return nil, nil
-	}
-	return nil, fmt.Errorf("unexpected server response: %s", string(fromServer))
+	return nil, nil
 }

client_test.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"net/smtp"
 	"os"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -1087,10 +1088,22 @@ func getTestConnection(auth bool) (*Client, error) {
 	if th == "" {
 		return nil, fmt.Errorf("no TEST_HOST set")
 	}
-	c, err := NewClient(th)
+	tp := 25
+	if tps := os.Getenv("TEST_PORT"); tps != "" {
+		tpi, err := strconv.Atoi(tps)
+		if err == nil {
+			tp = tpi
+		}
+	}
+	sv := false
+	if sve := os.Getenv("TEST_TLS_SKIP_VERIFY"); sve != "" {
+		sv = true
+	}
+	c, err := NewClient(th, WithPort(tp))
 	if err != nil {
 		return c, err
 	}
+	c.tlsconfig.InsecureSkipVerify = sv
 	if auth {
 		st := os.Getenv("TEST_SMTPAUTH_TYPE")
 		if st != "" {