client: add initial proxy support (#1062)

Author: really-not-lavacat

cmd/mautrix-telegram/legacymigrate.go

@@ -88,6 +88,12 @@ func migrateLegacyConfig(helper up.Helper) {
 	bridgeconfig.CopyToOtherLocation(helper, up.Int, []string{"bridge", "max_initial_member_sync"}, []string{"network", "member_list", "max_initial_sync"})
 	bridgeconfig.CopyToOtherLocation(helper, up.Bool, []string{"bridge", "sync_channel_members"}, []string{"network", "member_list", "sync_broadcast_channels"})
 	bridgeconfig.CopyToOtherLocation(helper, up.Bool, []string{"bridge", "skip_deleted_members"}, []string{"network", "member_list", "skip_deleted"})
+	bridgeconfig.CopyToOtherLocation(helper, up.Str, []string{"telegram", "proxy", "type"}, []string{"network", "proxy", "type"})
+	proxyAddress, _ := helper.Get(up.Str, "telegram", "proxy", "address")
+	proxyPort, _ := helper.Get(up.Int, "telegram", "proxy", "port")
+	helper.Set(up.Str, fmt.Sprintf("%s:%s", proxyAddress, proxyPort), "network", "proxy", "address")
+	bridgeconfig.CopyToOtherLocation(helper, up.Str, []string{"telegram", "proxy", "username"}, []string{"network", "proxy", "username"})
+	bridgeconfig.CopyToOtherLocation(helper, up.Str, []string{"telegram", "proxy", "password"}, []string{"network", "proxy", "password"})
 	bridgeconfig.CopyToOtherLocation(helper, up.Int, []string{"bridge", "max_member_count"}, []string{"network", "max_member_count"})
 	bridgeconfig.CopyToOtherLocation(helper, up.Int, []string{"bridge", "sync_update_limit"}, []string{"network", "sync", "update_limit"})
 	bridgeconfig.CopyToOtherLocation(helper, up.Int, []string{"bridge", "sync_create_limit"}, []string{"network", "sync", "create_limit"})

pkg/connector/client.go

@@ -210,11 +210,15 @@ func NewTelegramClient(ctx context.Context, tc *TelegramConnector, login *bridge
 		Storage:      client.ScopedStore,
 		AccessHasher: client.ScopedStore,
 	})
-
+	resolver, err := GetProxyResolver(tc.Config.ProxyConfig)
+	if err != nil {
+		return nil, err
+	}
 	client.client = telegram.NewClient(tc.Config.APIID, tc.Config.APIHash, telegram.Options{
 		CustomSessionStorage: &login.Metadata.(*UserLoginMetadata).Session,
 		Logger:               zaplog,
 		UpdateHandler:        client.updatesManager,
+		Resolver:             resolver,
 		OnDead:               client.onDead,
 		OnSession:            client.onSession,
 		OnConnected:          client.onConnected,

pkg/connector/config.go

@@ -55,6 +55,13 @@ type DeviceInfo struct {
 	LangCode       string `yaml:"lang_code"`
 }
 
+type ProxyConfig struct {
+	Type     string `yaml:"type"`
+	Address  string `yaml:"address"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+}
+
 type TelegramConfig struct {
 	APIID   int    `yaml:"api_id"`
 	APIHash string `yaml:"api_hash"`
@@ -68,6 +75,8 @@ type TelegramConfig struct {
 		TimeoutSeconds  int `yaml:"timeout_seconds"`
 	} `yaml:"ping"`
 
+	ProxyConfig ProxyConfig `yaml:"proxy"`
+
 	Sync struct {
 		UpdateLimit int  `yaml:"update_limit"`
 		CreateLimit int  `yaml:"create_limit"`
@@ -161,6 +170,10 @@ func upgradeConfig(helper up.Helper) {
 	helper.Copy(up.Bool, "member_list", "skip_deleted")
 	helper.Copy(up.Int, "ping", "interval_seconds")
 	helper.Copy(up.Int, "ping", "timeout_seconds")
+	helper.Copy(up.Str, "proxy", "type")
+	helper.Copy(up.Str|up.Null, "proxy", "address")
+	helper.Copy(up.Str|up.Null, "proxy", "username")
+	helper.Copy(up.Str|up.Null, "proxy", "password")
 	helper.Copy(up.Int, "sync", "update_limit")
 	helper.Copy(up.Int, "sync", "create_limit")
 	helper.Copy(up.Int, "sync", "login_sync_limit")
@@ -187,6 +200,7 @@ func (tc *TelegramConnector) GetConfig() (example string, data any, upgrader up.
 			{"animated_sticker"},
 			{"member_list"},
 			{"ping"},
+			{"proxy"},
 			{"sync"},
 			{"takeout"},
 			{"max_member_count"},

pkg/connector/example-config.yaml

@@ -54,6 +54,16 @@ ping:
     # The timeout (in seconds) for a single ping.
     timeout_seconds: 10
 
+# Proxy settings
+proxy:
+    # Allowed types: disabled, socks5, mtproxy
+    type: disabled
+    # Proxy IP address/domain name and port.
+    address: "127.0.0.1:1080"
+    # Proxy authentication (optional). Put MTProxy secret in password field.
+    username:
+    password:
+
 sync:
     # Number of most recently active dialogs to check when syncing chats.
     # Set to -1 to remove limit.

pkg/connector/login.go

@@ -125,7 +125,12 @@ func (bl *baseLogin) makeClient(ctx context.Context, dispatcher *tg.UpdateDispat
 	if dispatcher == nil {
 		dispatcher = ptr.Ptr(tg.NewUpdateDispatcher())
 	}
+	resolver, err := GetProxyResolver(bl.main.Config.ProxyConfig)
+	if err != nil {
+		return err
+	}
 	bl.client = telegram.NewClient(bl.main.Config.APIID, bl.main.Config.APIHash, telegram.Options{
+		Resolver:             resolver,
 		CustomSessionStorage: &bl.session,
 		Logger:               zaplog,
 		Device:               bl.main.deviceConfig(),

pkg/connector/loginbot.go

@@ -63,7 +63,16 @@ func (bl *BotLogin) SubmitUserInput(ctx context.Context, input map[string]string
 	ctx = log.WithContext(ctx)
 
 	botToken := input[LoginStepIDBotToken]
-	err := logoutBotAPI(ctx, botToken)
+	dialFunc, err := GetProxyDialFunc(bl.main.Config.ProxyConfig)
+	if err != nil {
+		return nil, err
+	}
+	httpClient := &http.Client{
+		Transport: &http.Transport{
+			DialContext: dialFunc,
+		},
+	}
+	err = logoutBotAPI(ctx, botToken, httpClient)
 	if err != nil {
 		return nil, fmt.Errorf("failed to logout from bot API: %w", err)
 	}
@@ -86,12 +95,12 @@ type botAPIResponse struct {
 	Description string `json:"description"`
 }
 
-func logoutBotAPI(ctx context.Context, token string) error {
+func logoutBotAPI(ctx context.Context, token string, client *http.Client) error {
 	req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://api.telegram.org/bot"+token+"/logOut", nil)
 	if err != nil {
 		return fmt.Errorf("failed to prepare request: %w", err)
 	}
-	resp, err := http.DefaultClient.Do(req)
+	resp, err := client.Do(req)
 	if err != nil {
 		return fmt.Errorf("failed to send request: %w", err)
 	}

pkg/connector/proxy.go

@@ -0,0 +1,61 @@
+// mautrix-telegram - A Matrix-Telegram puppeting bridge.
+// Copyright (C) 2026 Vladislav Agarkov
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package connector
+
+import (
+	"fmt"
+
+	"golang.org/x/net/proxy"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/dcs"
+)
+
+func GetProxyDialFunc(cfg ProxyConfig) (dcs.DialFunc, error) {
+	switch cfg.Type {
+	// we can't proxy HTTP through mtproxy
+	case "disabled", "mtproxy":
+		return nil, nil
+	case "socks5":
+		var auth *proxy.Auth
+		if cfg.Username != "" && cfg.Password != "" {
+			auth = &proxy.Auth{User: cfg.Username, Password: cfg.Password}
+		}
+		sock5, err := proxy.SOCKS5("tcp", cfg.Address, auth, proxy.Direct)
+		if err != nil {
+			return nil, err
+		}
+		return sock5.(proxy.ContextDialer).DialContext, nil
+	default:
+		return nil, fmt.Errorf("unsupported proxy type %s", cfg.Type)
+	}
+}
+
+func GetProxyResolver(cfg ProxyConfig) (dcs.Resolver, error) {
+	switch cfg.Type {
+	case "disabled", "socks5":
+		dialer, err := GetProxyDialFunc(cfg)
+		if err != nil {
+			return nil, err
+		}
+		resolver := dcs.Plain(dcs.PlainOptions{Dial: dialer})
+		return resolver, nil
+	case "mtproxy":
+		return dcs.MTProxy(cfg.Address, []byte(cfg.Password), dcs.MTProxyOptions{})
+	default:
+		return nil, fmt.Errorf("unsupported proxy type %s", cfg.Type)
+	}
+}