From 53dec19878519dd8897acf84209650ab9a67c67a Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Fri, 10 Apr 2026 22:58:16 +0300
Subject: [PATCH] login: increase buffer for QR renewal

---
 pkg/connector/login.go                    |  1 +
 pkg/connector/loginqr.go                  |  8 +++-----
 pkg/gotd/telegram/auth/qrlogin/qrlogin.go | 11 ++++++-----
 pkg/gotd/telegram/auth/qrlogin/token.go   |  7 ++++---
 4 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/pkg/connector/login.go b/pkg/connector/login.go
index 2b6bc267..5502f341 100644
--- a/pkg/connector/login.go
+++ b/pkg/connector/login.go
@@ -133,6 +133,7 @@ func (bl *baseLogin) makeClient(ctx context.Context, dispatcher *tg.UpdateDispat
 		Logger:               zaplog,
 		Device:               bl.main.deviceConfig(),
 		UpdateHandler:        updateManager,
+		NoUpdates:            true,
 	})
 
 	bl.ctx, bl.cancel = context.WithTimeoutCause(log.WithContext(bl.main.Bridge.BackgroundCtx), LoginTimeout, ErrLoginTimeout)
diff --git a/pkg/connector/loginqr.go b/pkg/connector/loginqr.go
index 7f8c151b..0fa65323 100644
--- a/pkg/connector/loginqr.go
+++ b/pkg/connector/loginqr.go
@@ -70,7 +70,8 @@ func (ql *QRLogin) Start(ctx context.Context) (*bridgev2.LoginStep, error) {
 	loggedIn := make(chan struct{})
 	dispatcher := tg.NewUpdateDispatcher()
 	dispatcher.OnLoginToken(func(ctx context.Context, e tg.Entities, update *tg.UpdateLoginToken) error {
-		loggedIn <- struct{}{}
+		log.Debug().Msg("Received updateLoginToken")
+		close(loggedIn)
 		return nil
 	})
 	err := ql.makeClient(ctx, &dispatcher)
@@ -78,13 +79,10 @@ func (ql *QRLogin) Start(ctx context.Context) (*bridgev2.LoginStep, error) {
 		return nil, err
 	}
 
-	qr := qrlogin.NewQR(ql.client.API(), ql.main.Config.APIID, ql.main.Config.APIHash, qrlogin.Options{
-		Migrate: ql.client.MigrateTo,
-	})
 	ql.qrToken = make(chan qrlogin.Token)
 	ql.auth = make(chan qrAuthResult)
 	go func() {
-		auth, err := qr.Auth(ql.ctx, loggedIn, func(ctx context.Context, token qrlogin.Token) error {
+		auth, err := ql.client.QR().Auth(ql.ctx, loggedIn, func(ctx context.Context, token qrlogin.Token) error {
 			ql.qrToken <- token
 			return nil
 		})
diff --git a/pkg/gotd/telegram/auth/qrlogin/qrlogin.go b/pkg/gotd/telegram/auth/qrlogin/qrlogin.go
index 64c44b04..510e3ead 100644
--- a/pkg/gotd/telegram/auth/qrlogin/qrlogin.go
+++ b/pkg/gotd/telegram/auth/qrlogin/qrlogin.go
@@ -140,6 +140,8 @@ func OnLoginToken(d interface {
 	return loggedIn
 }
 
+const QRRenewBuffer = 3 * time.Second
+
 // Auth generates new QR login token, shows it and awaits acceptation.
 //
 // NB: Show callback may be called more than once if QR expires.
@@ -150,7 +152,7 @@ func (q QR) Auth(
 	exceptIDs ...int64,
 ) (*tg.AuthAuthorization, error) {
 	until := func(token Token) time.Duration {
-		return token.Expires().Sub(q.clock.Now()).Truncate(time.Second)
+		return token.Expires().Sub(q.clock.Now()) - QRRenewBuffer
 	}
 
 	token, err := q.Export(ctx, exceptIDs...)
@@ -173,7 +175,7 @@ func (q QR) Auth(
 	defer clock.StopTimer(timer)
 
 	for {
-		if err := show(ctx, token); err != nil {
+		if err = show(ctx, token); err != nil {
 			return nil, errors.Wrap(err, "show")
 		}
 
@@ -181,18 +183,17 @@ func (q QR) Auth(
 		case <-ctx.Done():
 			return nil, ctx.Err()
 		case <-timer.C():
-			t, err := q.Export(ctx, exceptIDs...)
+			token, err = q.Export(ctx, exceptIDs...)
 			if err != nil {
 				return nil, err
 			}
 
-			if t.Empty() {
+			if token.Empty() {
 				// If empty token, it means AuthLoginTokenSuccess was returned.
 				// QR was scanned and accepted, break to import.
 				break
 			}
 
-			token = t
 			timer.Reset(until(token))
 
 			continue
diff --git a/pkg/gotd/telegram/auth/qrlogin/token.go b/pkg/gotd/telegram/auth/qrlogin/token.go
index f79b4af9..eec4075a 100644
--- a/pkg/gotd/telegram/auth/qrlogin/token.go
+++ b/pkg/gotd/telegram/auth/qrlogin/token.go
@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"image"
 	"net/url"
+	"strings"
 	"time"
 
 	"github.com/go-faster/errors"
@@ -33,7 +34,7 @@ func ParseTokenURL(u string) (Token, error) {
 	if q.Get("token") == "" {
 		return Token{}, errors.New("token is empty")
 	}
-	token, err := base64.URLEncoding.DecodeString(q.Get("token"))
+	token, err := base64.RawURLEncoding.DecodeString(strings.TrimRight(q.Get("token"), "="))
 	if err != nil {
 		return Token{}, err
 	}
@@ -56,7 +57,7 @@ func (t Token) Expires() time.Time {
 
 // String implements fmt.Stringer.
 func (t Token) String() string {
-	return base64.URLEncoding.EncodeToString(t.token)
+	return base64.RawURLEncoding.EncodeToString(t.token)
 }
 
 // Empty reports whether token is empty.
@@ -68,7 +69,7 @@ func (t Token) Empty() bool {
 //
 // See https://core.telegram.org/api/qr-login#exporting-a-login-token.
 func (t Token) URL() string {
-	return "tg://login?token=" + base64.URLEncoding.EncodeToString(t.token)
+	return "tg://login?token=" + base64.RawURLEncoding.EncodeToString(t.token)
 }
 
 // Image returns QR image.