From 41bf0bc92ce579b88dbd147df8fdd4025c96c1f1 Mon Sep 17 00:00:00 2001
From: 0xCA <0xCA@users.noreply.github.com>
Date: Fri, 29 Dec 2023 13:22:12 +0500
Subject: [PATCH] Telegram support (#488)

---
 README.md              |   3 +
 custom/js/helper.js    |  18 ++++-
 go.mod                 |   1 +
 go.sum                 |   2 +
 handler/routes.go      |  78 +++++++++++++++++++--
 main.go                |  67 +++++++++++++-----
 model/client.go        |   7 +-
 store/jsondb/jsondb.go |  27 +++++++
 telegram/bot.go        | 155 +++++++++++++++++++++++++++++++++++++++++
 templates/base.html    |  13 +++-
 templates/clients.html | 123 +++++++++++++++++++++++++++++++-
 templates/wg.conf      |   1 +
 util/cache.go          |   4 ++
 util/util.go           | 121 ++++++++++++++++++++++++++++++++
 14 files changed, 588 insertions(+), 32 deletions(-)
 create mode 100644 telegram/bot.go

diff --git a/README.md b/README.md
index b366d0c..003ff39 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,9 @@ docker-compose up
 | `SMTP_PASSWORD_FILE`        | Optional filepath for the SMTP user password. Leave `SMTP_PASSWORD` blank to take effect                                                                                    | N/A                                |
 | `SMTP_AUTH_TYPE`            | The SMTP authentication type. Possible values: `PLAIN`, `LOGIN`, `NONE`                                                                                                     | `NONE`                             |
 | `SMTP_ENCRYPTION`           | The encryption method. Possible values: `NONE`, `SSL`, `SSLTLS`, `TLS`, `STARTTLS`                                                                                          | `STARTTLS`                         |
+| `TELEGRAM_TOKEN`              | Telegram bot token for distributing configs to clients                                                                                                                    | N/A                                |
+| `TELEGRAM_ALLOW_CONF_REQUEST` | Allow users to get configs from the bot by sending a message                                                                                                              | `false`                            |
+| `TELEGRAM_FLOOD_WAIT`         | Time in minutes before the next conf request is processed                                                                                                                 | `60`                               |
 
 ### Defaults for server configuration
 
diff --git a/custom/js/helper.js b/custom/js/helper.js
index 4f21c1c..d98eacb 100644
--- a/custom/js/helper.js
+++ b/custom/js/helper.js
@@ -1,5 +1,20 @@
 function renderClientList(data) {
     $.each(data, function(index, obj) {
+        // render telegram button
+        let telegramButton = ''
+        if (obj.Client.telegram_userid) {
+            telegramButton =    `<div class="btn-group">      
+                                    <button type="button" class="btn btn-outline-primary btn-sm" data-toggle="modal"
+                                        data-target="#modal_telegram_client" data-clientid="${obj.Client.id}"
+                                        data-clientname="${obj.Client.name}">Telegram</button>
+                                </div>`
+        }
+
+        let telegramHtml = "";
+        if (obj.Client.telegram_userid && obj.Client.telegram_userid.length > 0) {
+            telegramHtml = `<span class="info-box-text" style="display: none"><i class="fas fa-tguserid"></i>${obj.Client.telegram_userid}</span>`
+        }
+
         // render client status css tag style
         let clientStatusHtml = '>'
         if (obj.Client.enabled) {
@@ -43,7 +58,7 @@ function renderClientList(data) {
                                         data-target="#modal_email_client" data-clientid="${obj.Client.id}"
                                         data-clientname="${obj.Client.name}">Email</button>
                                 </div>
-
+                                ${telegramButton}
                                 <div class="btn-group">
                                     <button type="button" class="btn btn-outline-danger btn-sm">More</button>
                                     <button type="button" class="btn btn-outline-danger btn-sm dropdown-toggle dropdown-icon" 
@@ -65,6 +80,7 @@ function renderClientList(data) {
                                 <span class="info-box-text"><i class="fas fa-user"></i> ${obj.Client.name}</span>
                                 <span class="info-box-text" style="display: none"><i class="fas fa-key"></i> ${obj.Client.public_key}</span>
                                 <span class="info-box-text" style="display: none"><i class="fas fa-subnetrange"></i>${subnetRangesString}</span>
+                                ${telegramHtml}
                                 <span class="info-box-text"><i class="fas fa-envelope"></i> ${obj.Client.email}</span>
                                 <span class="info-box-text"><i class="fas fa-clock"></i>
                                     ${prettyDateTime(obj.Client.created_at)}</span>
diff --git a/go.mod b/go.mod
index 5842acb..cb3d6b8 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/ngoduykhanh/wireguard-ui
 go 1.16
 
 require (
+	github.com/NicoNex/echotron/v3 v3.27.0
 	github.com/glendc/go-external-ip v0.0.0-20170425150139-139229dcdddd
 	github.com/go-playground/universal-translator v0.17.0 // indirect
 	github.com/gorilla/sessions v1.2.0
diff --git a/go.sum b/go.sum
index ee957cb..90023eb 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,6 @@
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
+github.com/NicoNex/echotron/v3 v3.27.0 h1:iq4BLPO+Dz1JHjh2HPk0D0NldAZSYcAjaOicgYEhUzw=
+github.com/NicoNex/echotron/v3 v3.27.0/go.mod h1:LpP5IyHw0y+DZUZMBgXEDAF9O8feXrQu7w7nlJzzoZI=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/appleboy/gofight/v2 v2.1.2/go.mod h1:frW+U1QZEdDgixycTj4CygQ48yLTUhplt43+Wczp3rw=
diff --git a/handler/routes.go b/handler/routes.go
index 0358750..75a6eea 100644
--- a/handler/routes.go
+++ b/handler/routes.go
@@ -10,6 +10,7 @@ import (
 	"os"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 
@@ -18,12 +19,14 @@ import (
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/gommon/log"
 	"github.com/rs/xid"
+	"github.com/skip2/go-qrcode"
 	"golang.zx2c4.com/wireguard/wgctrl"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
 	"github.com/ngoduykhanh/wireguard-ui/emailer"
 	"github.com/ngoduykhanh/wireguard-ui/model"
 	"github.com/ngoduykhanh/wireguard-ui/store"
+	"github.com/ngoduykhanh/wireguard-ui/telegram"
 	"github.com/ngoduykhanh/wireguard-ui/util"
 )
 
@@ -385,9 +388,9 @@ func GetClient(db store.IStore) echo.HandlerFunc {
 		}
 
 		qrCodeSettings := model.QRCodeSettings{
-			Enabled:       true,
-			IncludeDNS:    true,
-			IncludeMTU:    true,
+			Enabled:    true,
+			IncludeDNS: true,
+			IncludeMTU: true,
 		}
 
 		clientData, err := db.GetClientByID(clientID, qrCodeSettings)
@@ -406,6 +409,14 @@ func NewClient(db store.IStore) echo.HandlerFunc {
 		var client model.Client
 		c.Bind(&client)
 
+		// Validate Telegram userid if provided
+		if client.TgUserid != "" {
+			idNum, err := strconv.ParseInt(client.TgUserid, 10, 64)
+			if err != nil || idNum == 0 {
+				return c.JSON(http.StatusBadRequest, jsonHTTPResponse{false, "Telegram userid must be a non-zero number"})
+			}
+		}
+
 		// read server information
 		server, err := db.GetServer()
 		if err != nil {
@@ -517,9 +528,9 @@ func EmailClient(db store.IStore, mailer emailer.Emailer, emailSubject, emailCon
 		}
 
 		qrCodeSettings := model.QRCodeSettings{
-			Enabled:       true,
-			IncludeDNS:    true,
-			IncludeMTU:    true,
+			Enabled:    true,
+			IncludeDNS: true,
+			IncludeMTU: true,
 		}
 		clientData, err := db.GetClientByID(payload.ID, qrCodeSettings)
 		if err != nil {
@@ -560,6 +571,51 @@ func EmailClient(db store.IStore, mailer emailer.Emailer, emailSubject, emailCon
 	}
 }
 
+// SendTelegramClient handler to send the configuration via Telegram
+func SendTelegramClient(db store.IStore) echo.HandlerFunc {
+	type clientIdUseridPayload struct {
+		ID     string `json:"id"`
+		Userid string `json:"userid"`
+	}
+	return func(c echo.Context) error {
+		var payload clientIdUseridPayload
+		c.Bind(&payload)
+
+		clientData, err := db.GetClientByID(payload.ID, model.QRCodeSettings{Enabled: false})
+		if err != nil {
+			log.Errorf("Cannot generate client id %s config file for downloading: %v", payload.ID, err)
+			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
+		}
+
+		// build config
+		server, _ := db.GetServer()
+		globalSettings, _ := db.GetGlobalSettings()
+		config := util.BuildClientConfig(*clientData.Client, server, globalSettings)
+		configData := []byte(config)
+		var qrData []byte
+
+		if clientData.Client.PrivateKey != "" {
+			qrData, err = qrcode.Encode(config, qrcode.Medium, 512)
+			if err != nil {
+				return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, "qr gen: " + err.Error()})
+			}
+		}
+
+		userid, err := strconv.ParseInt(clientData.Client.TgUserid, 10, 64)
+		if err != nil {
+			return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, "userid: " + err.Error()})
+		}
+
+		err = telegram.SendConfig(userid, clientData.Client.Name, configData, qrData, false)
+
+		if err != nil {
+			return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, err.Error()})
+		}
+
+		return c.JSON(http.StatusOK, jsonHTTPResponse{true, "Telegram message sent successfully"})
+	}
+}
+
 // UpdateClient handler to update client information
 func UpdateClient(db store.IStore) echo.HandlerFunc {
 	return func(c echo.Context) error {
@@ -577,6 +633,14 @@ func UpdateClient(db store.IStore) echo.HandlerFunc {
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
 		}
 
+		// Validate Telegram userid if provided
+		if _client.TgUserid != "" {
+			idNum, err := strconv.ParseInt(_client.TgUserid, 10, 64)
+			if err != nil || idNum == 0 {
+				return c.JSON(http.StatusBadRequest, jsonHTTPResponse{false, "Telegram userid must be a non-zero number"})
+			}
+		}
+
 		server, err := db.GetServer()
 		if err != nil {
 			return c.JSON(http.StatusBadRequest, jsonHTTPResponse{
@@ -644,6 +708,7 @@ func UpdateClient(db store.IStore) echo.HandlerFunc {
 		// map new data
 		client.Name = _client.Name
 		client.Email = _client.Email
+		client.TgUserid = _client.TgUserid
 		client.Enabled = _client.Enabled
 		client.UseServerDNS = _client.UseServerDNS
 		client.AllocatedIPs = _client.AllocatedIPs
@@ -1115,7 +1180,6 @@ func ApplyServerConfig(db store.IStore, tmplDir fs.FS) echo.HandlerFunc {
 	}
 }
 
-
 // GetHashesChanges handler returns if database hashes have changed
 func GetHashesChanges(db store.IStore) echo.HandlerFunc {
 	return func(c echo.Context) error {
diff --git a/main.go b/main.go
index 5f6e341..c3f03f1 100644
--- a/main.go
+++ b/main.go
@@ -15,6 +15,7 @@ import (
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/gommon/log"
 	"github.com/ngoduykhanh/wireguard-ui/store"
+	"github.com/ngoduykhanh/wireguard-ui/telegram"
 
 	"github.com/ngoduykhanh/wireguard-ui/emailer"
 	"github.com/ngoduykhanh/wireguard-ui/handler"
@@ -30,22 +31,25 @@ var (
 	gitRef     = "N/A"
 	buildTime  = fmt.Sprintf(time.Now().UTC().Format("01-02-2006 15:04:05"))
 	// configuration variables
-	flagDisableLogin   bool   = false
-	flagBindAddress    string = "0.0.0.0:5000"
-	flagSmtpHostname   string = "127.0.0.1"
-	flagSmtpPort       int    = 25
-	flagSmtpUsername   string
-	flagSmtpPassword   string
-	flagSmtpAuthType   string = "NONE"
-	flagSmtpNoTLSCheck bool   = false
-	flagSmtpEncryption string = "STARTTLS"
-	flagSendgridApiKey string
-	flagEmailFrom      string
-	flagEmailFromName  string = "WireGuard UI"
-	flagSessionSecret  string = util.RandomString(32)
-	flagWgConfTemplate string
-	flagBasePath       string
-	flagSubnetRanges   string
+	flagDisableLogin             bool   = false
+	flagBindAddress              string = "0.0.0.0:5000"
+	flagSmtpHostname             string = "127.0.0.1"
+	flagSmtpPort                 int    = 25
+	flagSmtpUsername             string
+	flagSmtpPassword             string
+	flagSmtpAuthType             string = "NONE"
+	flagSmtpNoTLSCheck           bool   = false
+	flagSmtpEncryption           string = "STARTTLS"
+	flagSendgridApiKey           string
+	flagEmailFrom                string
+	flagEmailFromName            string = "WireGuard UI"
+	flagTelegramToken            string
+	flagTelegramAllowConfRequest bool   = false
+	flagTelegramFloodWait        int    = 60
+	flagSessionSecret            string = util.RandomString(32)
+	flagWgConfTemplate           string
+	flagBasePath                 string
+	flagSubnetRanges             string
 )
 
 const (
@@ -80,6 +84,9 @@ func init() {
 	flag.StringVar(&flagSmtpAuthType, "smtp-auth-type", util.LookupEnvOrString("SMTP_AUTH_TYPE", flagSmtpAuthType), "SMTP Auth Type : PLAIN, LOGIN or NONE.")
 	flag.StringVar(&flagEmailFrom, "email-from", util.LookupEnvOrString("EMAIL_FROM_ADDRESS", flagEmailFrom), "'From' email address.")
 	flag.StringVar(&flagEmailFromName, "email-from-name", util.LookupEnvOrString("EMAIL_FROM_NAME", flagEmailFromName), "'From' email name.")
+	flag.StringVar(&flagTelegramToken, "telegram-token", util.LookupEnvOrString("TELEGRAM_TOKEN", flagTelegramToken), "Telegram bot token for distributing configs to clients.")
+	flag.BoolVar(&flagTelegramAllowConfRequest, "telegram-allow-conf-request", util.LookupEnvOrBool("TELEGRAM_ALLOW_CONF_REQUEST", flagTelegramAllowConfRequest), "Allow users to get configs from the bot by sending a message.")
+	flag.IntVar(&flagTelegramFloodWait, "telegram-flood-wait", util.LookupEnvOrInt("TELEGRAM_FLOOD_WAIT", flagTelegramFloodWait), "Time in minutes before the next conf request is processed.")
 	flag.StringVar(&flagWgConfTemplate, "wg-conf-template", util.LookupEnvOrString("WG_CONF_TEMPLATE", flagWgConfTemplate), "Path to custom wg.conf template.")
 	flag.StringVar(&flagBasePath, "base-path", util.LookupEnvOrString("BASE_PATH", flagBasePath), "The base path of the URL")
 	flag.StringVar(&flagSubnetRanges, "subnet-ranges", util.LookupEnvOrString("SUBNET_RANGES", flagSubnetRanges), "IP ranges to choose from when assigning an IP for a client.")
@@ -131,8 +138,15 @@ func init() {
 	util.BasePath = util.ParseBasePath(flagBasePath)
 	util.SubnetRanges = util.ParseSubnetRanges(flagSubnetRanges)
 
+	lvl, _ := util.ParseLogLevel(util.LookupEnvOrString(util.LogLevel, "INFO"))
+
+	telegram.Token = flagTelegramToken
+	telegram.AllowConfRequest = flagTelegramAllowConfRequest
+	telegram.FloodWait = flagTelegramFloodWait
+	telegram.LogLevel = lvl
+
 	// print only if log level is INFO or lower
-	if lvl, _ := util.ParseLogLevel(util.LookupEnvOrString(util.LogLevel, "INFO")); lvl <= log.INFO {
+	if lvl <= log.INFO {
 		// print app information
 		fmt.Println("Wireguard UI")
 		fmt.Println("App Version\t:", appVersion)
@@ -221,6 +235,7 @@ func main() {
 	app.POST(util.BasePath+"/new-client", handler.NewClient(db), handler.ValidSession, handler.ContentTypeJson)
 	app.POST(util.BasePath+"/update-client", handler.UpdateClient(db), handler.ValidSession, handler.ContentTypeJson)
 	app.POST(util.BasePath+"/email-client", handler.EmailClient(db, sendmail, defaultEmailSubject, defaultEmailContent), handler.ValidSession, handler.ContentTypeJson)
+	app.POST(util.BasePath+"/send-telegram-client", handler.SendTelegramClient(db), handler.ValidSession, handler.ContentTypeJson)
 	app.POST(util.BasePath+"/client/set-status", handler.SetClientStatus(db), handler.ValidSession, handler.ContentTypeJson)
 	app.POST(util.BasePath+"/remove-client", handler.RemoveClient(db), handler.ValidSession, handler.ContentTypeJson)
 	app.GET(util.BasePath+"/download", handler.DownloadClient(db), handler.ValidSession)
@@ -248,6 +263,13 @@ func main() {
 	// serves other static files
 	app.GET(util.BasePath+"/static/*", echo.WrapHandler(http.StripPrefix(util.BasePath+"/static/", assetHandler)))
 
+	initDeps := telegram.TgBotInitDependencies{
+		DB:                             db,
+		SendRequestedConfigsToTelegram: util.SendRequestedConfigsToTelegram,
+	}
+
+	initTelegram(initDeps)
+
 	if strings.HasPrefix(util.BindAddress, "unix://") {
 		// Listen on unix domain socket.
 		// https://github.com/labstack/echo/issues/830
@@ -296,3 +318,14 @@ func initServerConfig(db store.IStore, tmplDir fs.FS) {
 		log.Fatalf("Cannot create server config: ", err)
 	}
 }
+
+func initTelegram(initDeps telegram.TgBotInitDependencies) {
+	go func() {
+		for {
+			err := telegram.Start(initDeps)
+			if err == nil {
+				break
+			}
+		}
+	}()
+}
diff --git a/model/client.go b/model/client.go
index 187ec72..cb00016 100644
--- a/model/client.go
+++ b/model/client.go
@@ -11,6 +11,7 @@ type Client struct {
 	PublicKey       string    `json:"public_key"`
 	PresharedKey    string    `json:"preshared_key"`
 	Name            string    `json:"name"`
+	TgUserid        string    `json:"telegram_userid"`
 	Email           string    `json:"email"`
 	SubnetRanges    []string  `json:"subnet_ranges,omitempty"`
 	AllocatedIPs    []string  `json:"allocated_ips"`
@@ -30,7 +31,7 @@ type ClientData struct {
 }
 
 type QRCodeSettings struct {
-	Enabled       bool
-	IncludeDNS    bool
-	IncludeMTU    bool
+	Enabled    bool
+	IncludeDNS bool
+	IncludeMTU bool
 }
diff --git a/store/jsondb/jsondb.go b/store/jsondb/jsondb.go
index 757ccdc..03b5b62 100644
--- a/store/jsondb/jsondb.go
+++ b/store/jsondb/jsondb.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"strconv"
 	"time"
 
 	"github.com/sdomino/scribble"
@@ -161,6 +162,20 @@ func (o *JsonDB) Init() error {
 		}
 	}
 
+	// init cache
+	clients, err := o.GetClients(false)
+	if err != nil {
+		return nil
+	}
+	for _, cl := range clients {
+		client := cl.Client
+		if client.Enabled && len(client.TgUserid) > 0 {
+			if userid, err := strconv.ParseInt(client.TgUserid, 10, 64); err == nil {
+				util.UpdateTgToClientID(userid, client.ID)
+			}
+		}
+	}
+
 	return nil
 }
 
@@ -314,6 +329,17 @@ func (o *JsonDB) GetClientByID(clientID string, qrCodeSettings model.QRCodeSetti
 func (o *JsonDB) SaveClient(client model.Client) error {
 	clientPath := path.Join(path.Join(o.dbPath, "clients"), client.ID+".json")
 	output := o.conn.Write("clients", client.ID, client)
+	if output == nil {
+		if client.Enabled && len(client.TgUserid) > 0 {
+			if userid, err := strconv.ParseInt(client.TgUserid, 10, 64); err == nil {
+				util.UpdateTgToClientID(userid, client.ID)
+			}
+		} else {
+			util.RemoveTgToClientID(client.ID)
+		}
+	} else {
+		util.RemoveTgToClientID(client.ID)
+	}
 	err := util.ManagePerms(clientPath)
 	if err != nil {
 		return err
@@ -322,6 +348,7 @@ func (o *JsonDB) SaveClient(client model.Client) error {
 }
 
 func (o *JsonDB) DeleteClient(clientID string) error {
+	util.RemoveTgToClientID(clientID)
 	return o.conn.Delete("clients", clientID)
 }
 
diff --git a/telegram/bot.go b/telegram/bot.go
new file mode 100644
index 0000000..7e33de7
--- /dev/null
+++ b/telegram/bot.go
@@ -0,0 +1,155 @@
+package telegram
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/NicoNex/echotron/v3"
+	"github.com/labstack/gommon/log"
+	"github.com/ngoduykhanh/wireguard-ui/store"
+)
+
+type SendRequestedConfigsToTelegram func(db store.IStore, userid int64) []string
+
+type TgBotInitDependencies struct {
+	DB                             store.IStore
+	SendRequestedConfigsToTelegram SendRequestedConfigsToTelegram
+}
+
+var (
+	Token            string
+	AllowConfRequest bool
+	FloodWait        int
+	LogLevel         log.Lvl
+
+	Bot      *echotron.API
+	BotMutex sync.RWMutex
+
+	floodWait        = make(map[int64]int64, 0)
+	floodMessageSent = make(map[int64]struct{}, 0)
+)
+
+func Start(initDeps TgBotInitDependencies) (err error) {
+	ticker := time.NewTicker(time.Minute)
+	defer func() {
+		if err != nil {
+			BotMutex.Lock()
+			Bot = nil
+			BotMutex.Unlock()
+			ticker.Stop()
+		}
+		if r := recover(); r != nil {
+			err = fmt.Errorf("[PANIC] recovered from panic: %v", r)
+		}
+	}()
+
+	token := Token
+	if token == "" || len(token) < 30 {
+		return
+	}
+
+	bot := echotron.NewAPI(token)
+
+	res, err := bot.GetMe()
+	if !res.Ok || err != nil {
+		log.Warnf("[Telegram] Unable to connect to bot.\n%v\n%v", res.Description, err)
+		return
+	}
+
+	BotMutex.Lock()
+	Bot = &bot
+	BotMutex.Unlock()
+
+	if LogLevel <= log.INFO {
+		fmt.Printf("[Telegram] Authorized as %s\n", res.Result.Username)
+	}
+
+	go func() {
+		for range ticker.C {
+			updateFloodWait()
+		}
+	}()
+
+	if !AllowConfRequest {
+		return
+	}
+
+	updatesChan := echotron.PollingUpdatesOptions(token, false, echotron.UpdateOptions{AllowedUpdates: []echotron.UpdateType{echotron.MessageUpdate}})
+	for update := range updatesChan {
+		if update.Message != nil {
+			userid := update.Message.Chat.ID
+			if _, wait := floodWait[userid]; wait {
+				if _, notified := floodMessageSent[userid]; notified {
+					continue
+				}
+				floodMessageSent[userid] = struct{}{}
+				bot.SendMessage(
+					fmt.Sprintf("You can only request your configs once per %d minutes", FloodWait),
+					userid,
+					&echotron.MessageOptions{
+						ReplyToMessageID: update.Message.ID,
+					})
+				continue
+			}
+			floodWait[userid] = time.Now().Unix()
+
+			failed := initDeps.SendRequestedConfigsToTelegram(initDeps.DB, userid)
+			if len(failed) > 0 {
+				messageText := "Failed to send configs:\n"
+				for _, f := range failed {
+					messageText += f + "\n"
+				}
+				bot.SendMessage(
+					messageText,
+					userid,
+					&echotron.MessageOptions{
+						ReplyToMessageID: update.Message.ID,
+					})
+			}
+		}
+	}
+	return err
+}
+
+func SendConfig(userid int64, clientName string, confData, qrData []byte, ignoreFloodWait bool) error {
+	BotMutex.RLock()
+	defer BotMutex.RUnlock()
+
+	if Bot == nil {
+		return fmt.Errorf("telegram bot is not configured or not available")
+	}
+
+	if _, wait := floodWait[userid]; wait && !ignoreFloodWait {
+		return fmt.Errorf("this client already got their config less than %d minutes ago", FloodWait)
+	}
+
+	if !ignoreFloodWait {
+		floodWait[userid] = time.Now().Unix()
+	}
+
+	qrAttachment := echotron.NewInputFileBytes("qr.png", qrData)
+	_, err := Bot.SendPhoto(qrAttachment, userid, &echotron.PhotoOptions{Caption: clientName})
+	if err != nil {
+		log.Error(err)
+		return fmt.Errorf("unable to send qr picture")
+	}
+
+	confAttachment := echotron.NewInputFileBytes(clientName+".conf", confData)
+	_, err = Bot.SendDocument(confAttachment, userid, nil)
+	if err != nil {
+		log.Error(err)
+		return fmt.Errorf("unable to send conf file")
+	}
+	return nil
+}
+
+func updateFloodWait() {
+	thresholdTS := time.Now().Unix() - 60*int64(FloodWait)
+	for userid, ts := range floodWait {
+		if ts < thresholdTS {
+			delete(floodWait, userid)
+			delete(floodMessageSent, userid)
+		}
+	}
+}
diff --git a/templates/base.html b/templates/base.html
index 7110fd5..ab086e1 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -281,6 +281,14 @@
                                     <input type="text" class="form-control" id="client_preshared_key" name="client_preshared_key" placeholder="Autogenerated - enter &quot;-&quot; to skip generation">
                                 </div>
                             </details>
+                            <details style="margin-top: 0.5rem;">
+                                <summary><strong>Additional configuration</strong>
+                                </summary>
+                                <div class="form-group" style="margin-top: 0.5rem;">
+                                    <label for="client_telegram_userid" class="control-label">Telegram userid</label>
+                                    <input type="text" class="form-control" id="client_telegram_userid" name="client_telegram_userid">
+                                </div>
+                            </details>
                         </div>
                         <div class="modal-footer justify-content-between">
                             <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
@@ -452,6 +460,7 @@
         function submitNewClient() {
             const name = $("#client_name").val();
             const email = $("#client_email").val();
+            const telegram_userid = $("#client_telegram_userid").val();
             const allocated_ips = $("#client_allocated_ips").val().split(",");
             const allowed_ips = $("#client_allowed_ips").val().split(",");
             const endpoint = $("#client_endpoint").val();
@@ -475,7 +484,7 @@
             const public_key = $("#client_public_key").val();
             const preshared_key = $("#client_preshared_key").val();
 
-            const data = {"name": name, "email": email, "allocated_ips": allocated_ips, "allowed_ips": allowed_ips,
+            const data = {"name": name, "email": email, "telegram_userid": telegram_userid, "allocated_ips": allocated_ips, "allowed_ips": allowed_ips,
                 "extra_allowed_ips": extra_allowed_ips, "endpoint": endpoint, "use_server_dns": use_server_dns, "enabled": enabled,
                 "public_key": public_key, "preshared_key": preshared_key};
 
@@ -616,6 +625,8 @@
                 $("#client_preshared_key").val("");
                 $("#client_allocated_ips").importTags('');
                 $("#client_extra_allowed_ips").importTags('');
+                $("#client_endpoint").val('');
+                $("#client_telegram_userid").val('');
                 updateSubnetRangesList("#subnet_ranges");
                 updateIPAllocationSuggestion(true);
             });
diff --git a/templates/clients.html b/templates/clients.html
index fcc6de0..cf11e0a 100644
--- a/templates/clients.html
+++ b/templates/clients.html
@@ -80,6 +80,35 @@ Wireguard Clients
 </div>
 <!-- /.modal -->
 
+<div class="modal fade" id="modal_telegram_client">
+    <div class="modal-dialog">
+        <div class="modal-content">
+            <div class="modal-header">
+                <h4 class="modal-title">Telegram Configuration</h4>
+                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+                    <span aria-hidden="true">&times;</span>
+                </button>
+            </div>
+            <form name="frm_telegram_client" id="frm_telegram_client">
+                <div class="modal-body">
+                    <input type="hidden" id="tg_client_id" name="tg_client_id">
+                    <div class="form-group">
+                        <label for="tg_client_userid" class="control-label">Telegram userid</label>
+                        <input type="text" class="form-control" id="tg_client_userid" name="tg_client_userid">
+                    </div>
+                </div>
+                <div class="modal-footer justify-content-between">
+                    <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
+                    <button type="submit" class="btn btn-success">Send</button>
+                </div>
+            </form>
+        </div>
+        <!-- /.modal-content -->
+    </div>
+    <!-- /.modal-dialog -->
+</div>
+<!-- /.modal -->
+
 <div class="modal fade" id="modal_edit_client">
     <div class="modal-dialog">
         <div class="modal-content">
@@ -159,6 +188,14 @@ Wireguard Clients
                             <input type="text" class="form-control" id="_client_preshared_key" name="_client_preshared_key">
                         </div>
                     </details>
+                    <details style="margin-top: 0.5rem;">
+                        <summary><strong>Additional configuration</strong>
+                        </summary>
+                        <div class="form-group" style="margin-top: 0.5rem;">
+                            <label for="_client_telegram_userid" class="control-label">Telegram userid</label>
+                            <input type="text" class="form-control" id="_client_telegram_userid" name="_client_telegram_userid">
+                        </div>
+                    </details>
                 </div>
                 <div class="modal-footer justify-content-between">
                     <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
@@ -383,6 +420,11 @@ Wireguard Clients
                 }
                 })
             $(".badge-secondary").filter(':contains("' + query + '")').parent().parent().parent().show();
+            $(".fa-tguserid").each(function () {
+                if ($(this).parent().text().trim().indexOf(query.trim()) != -1) {
+                    $(this).closest('.col-lg-4').show();
+                }
+            })
         })
 
         $("#status-selector").on('change', function () {
@@ -573,6 +615,7 @@ Wireguard Clients
 
                         modal.find(".modal-title").text("Edit Client " + client.name);
                         modal.find("#_client_id").val(client.id);
+                        modal.find("#_client_telegram_userid").val(client.telegram_userid);
                         modal.find("#_client_name").val(client.name);
                         modal.find("#_client_email").val(client.email);
 
@@ -664,8 +707,29 @@ Wireguard Clients
                 success: function(resp) {
                     $("#modal_email_client").modal('hide');
                     toastr.success('Sent email to client successfully');
-                     // Refresh the home page (clients page) after sending email successfully
-                    location.reload();
+                },
+                error: function(jqXHR, exception) {
+                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                    toastr.error(responseJson['message']);
+                }
+            });
+        }
+
+        // submitTelegramClient function for sending a telegram message with the configuration to the client
+        function submitTelegramClient() {
+            const client_id = $("#tg_client_id").val();
+            const userid = $("#tg_client_userid").val();
+            const data = {"id": client_id, "userid": userid};
+            $.ajax({
+                cache: false,
+                method: 'POST',
+                url: '{{.basePath}}/send-telegram-client',
+                dataType: 'json',
+                contentType: "application/json",
+                data: JSON.stringify(data),
+                success: function(resp) {
+                    $("#modal_telegram_client").modal('hide');
+                    toastr.success('Sent config via telegram to client successfully');
                 },
                 error: function(jqXHR, exception) {
                     const responseJson = jQuery.parseJSON(jqXHR.responseText);
@@ -681,6 +745,7 @@ Wireguard Clients
             const client_id = $("#_client_id").val();
             const name = $("#_client_name").val();
             const email = $("#_client_email").val();
+            const telegram_userid = $("#_client_telegram_userid").val();
             const allocated_ips = $("#_client_allocated_ips").val().split(",");
             const allowed_ips = $("#_client_allowed_ips").val().split(",");
             let use_server_dns = false;
@@ -704,7 +769,7 @@ Wireguard Clients
                 enabled = true;
             }
 
-            const data = {"id": client_id, "name": name, "email": email, "allocated_ips": allocated_ips,
+            const data = {"id": client_id, "name": name, "email": email, "telegram_userid": telegram_userid, "allocated_ips": allocated_ips,
                 "allowed_ips": allowed_ips, "extra_allowed_ips": extra_allowed_ips, "endpoint": endpoint,
                 "use_server_dns": use_server_dns, "enabled": enabled, "public_key": public_key, "preshared_key": preshared_key};
 
@@ -735,6 +800,8 @@ Wireguard Clients
                 submitEditClient();
             } else if (formId === "frm_email_client") {
                 submitEmailClient();
+            } else if (formId === "frm_telegram_client") {
+                submitTelegramClient();
             }
         }
 
@@ -771,6 +838,30 @@ Wireguard Clients
             regenerateQRCode();
         });
 
+        $("#modal_telegram_client").on('show.bs.modal', function (event) {
+            let modal = $(this);
+            const button = $(event.relatedTarget);
+            const client_id = button.data('clientid');
+            $.ajax({
+                cache: false,
+                method: 'GET',
+                url: '{{.basePath}}/api/client/' + client_id,
+                dataType: 'json',
+                contentType: "application/json",
+                success: function (resp) {
+                    const client = resp.Client;
+
+                    modal.find(".modal-title").text("Send config to client " + client.name);
+                    modal.find("#tg_client_id").val(client.id);
+                    modal.find("#tg_client_userid").val(client.telegram_userid);
+                },
+                error: function (jqXHR, exception) {
+                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                    toastr.error(responseJson['message']);
+                }
+            });
+        });
+
         $(document).ready(function () {
             $.validator.setDefaults({
                 submitHandler: function (form) {
@@ -826,6 +917,32 @@ Wireguard Clients
                     $(element).removeClass('is-invalid');
                 }
             });
+            // Telegram client form validation
+            $("#frm_telegram_client").validate({
+                rules: {
+                    tg_client_userid: {
+                        required: true,
+                        number: true,
+                    },
+                },
+                messages: {
+                    tg_client_userid: {
+                        required: "Please enter a telegram userid",
+                        number: "Please enter a valid telegram userid"
+                    },
+                },
+                errorElement: 'span',
+                errorPlacement: function (error, element) {
+                    error.addClass('invalid-feedback');
+                    element.closest('.form-group').append(error);
+                },
+                highlight: function (element, errorClass, validClass) {
+                    $(element).addClass('is-invalid');
+                },
+                unhighlight: function (element, errorClass, validClass) {
+                    $(element).removeClass('is-invalid');
+                }
+            });
             // 
         });
     </script>
diff --git a/templates/wg.conf b/templates/wg.conf
index 2112a0c..793876e 100644
--- a/templates/wg.conf
+++ b/templates/wg.conf
@@ -17,6 +17,7 @@ Table = {{ .globalSettings.Table }}
 # ID:           {{ .Client.ID }}
 # Name:         {{ .Client.Name }}
 # Email:        {{ .Client.Email }}
+# Telegram:     {{ .Client.TgUserid }}
 # Created at:   {{ .Client.CreatedAt }}
 # Update at:    {{ .Client.UpdatedAt }}
 [Peer]
diff --git a/util/cache.go b/util/cache.go
index 340f73d..8037c30 100644
--- a/util/cache.go
+++ b/util/cache.go
@@ -1,3 +1,7 @@
 package util
 
+import "sync"
+
 var IPToSubnetRange = map[string]uint16{}
+var TgUseridToClientID = map[int64]([]string){}
+var TgUseridToClientIDMutex sync.RWMutex
diff --git a/util/util.go b/util/util.go
index fa168fd..337745a 100644
--- a/util/util.go
+++ b/util/util.go
@@ -19,6 +19,8 @@ import (
 	"time"
 
 	"github.com/ngoduykhanh/wireguard-ui/store"
+	"github.com/ngoduykhanh/wireguard-ui/telegram"
+	"github.com/skip2/go-qrcode"
 	"golang.org/x/mod/sumdb/dirhash"
 
 	externalip "github.com/glendc/go-external-ip"
@@ -27,6 +29,12 @@ import (
 	"github.com/sdomino/scribble"
 )
 
+var qrCodeSettings = model.QRCodeSettings{
+	Enabled:    true,
+	IncludeDNS: true,
+	IncludeMTU: true,
+}
+
 // BuildClientConfig to create wireguard client config string
 func BuildClientConfig(client model.Client, server model.Server, setting model.GlobalSetting) string {
 	// Interface section
@@ -578,6 +586,57 @@ func WriteWireGuardServerConfig(tmplDir fs.FS, serverConfig model.Server, client
 	return nil
 }
 
+// SendRequestedConfigsToTelegram to send client all their configs. Returns failed configs list.
+func SendRequestedConfigsToTelegram(db store.IStore, userid int64) []string {
+	failedList := make([]string, 0)
+	TgUseridToClientIDMutex.RLock()
+	if clids, found := TgUseridToClientID[userid]; found && len(clids) > 0 {
+		TgUseridToClientIDMutex.RUnlock()
+
+		for _, clid := range clids {
+			clientData, err := db.GetClientByID(clid, qrCodeSettings)
+			if err != nil {
+				// return fmt.Errorf("unable to get client")
+				failedList = append(failedList, clid)
+				continue
+			}
+
+			// build config
+			server, _ := db.GetServer()
+			globalSettings, _ := db.GetGlobalSettings()
+			config := BuildClientConfig(*clientData.Client, server, globalSettings)
+			configData := []byte(config)
+			var qrData []byte
+
+			if clientData.Client.PrivateKey != "" {
+				qrData, err = qrcode.Encode(config, qrcode.Medium, 512)
+				if err != nil {
+					// return fmt.Errorf("unable to encode qr")
+					failedList = append(failedList, clientData.Client.Name)
+					continue
+				}
+			}
+
+			userid, err := strconv.ParseInt(clientData.Client.TgUserid, 10, 64)
+			if err != nil {
+				// return fmt.Errorf("tg usrid is unreadable")
+				failedList = append(failedList, clientData.Client.Name)
+				continue
+			}
+
+			err = telegram.SendConfig(userid, clientData.Client.Name, configData, qrData, true)
+			if err != nil {
+				failedList = append(failedList, clientData.Client.Name)
+				continue
+			}
+			time.Sleep(2 * time.Second)
+		}
+	} else {
+		TgUseridToClientIDMutex.RUnlock()
+	}
+	return failedList
+}
+
 func LookupEnvOrString(key string, defaultVal string) string {
 	if val, ok := os.LookupEnv(key); ok {
 		return val
@@ -707,3 +766,65 @@ func ManagePerms(path string) error {
 	err := os.Chmod(path, 0600)
 	return err
 }
+
+func AddTgToClientID(userid int64, clientID string) {
+	TgUseridToClientIDMutex.Lock()
+	defer TgUseridToClientIDMutex.Unlock()
+
+	if _, ok := TgUseridToClientID[userid]; ok && TgUseridToClientID[userid] != nil {
+		TgUseridToClientID[userid] = append(TgUseridToClientID[userid], clientID)
+	} else {
+		TgUseridToClientID[userid] = []string{clientID}
+	}
+}
+
+func UpdateTgToClientID(userid int64, clientID string) {
+	TgUseridToClientIDMutex.Lock()
+	defer TgUseridToClientIDMutex.Unlock()
+
+	// Detach clientID from any existing userid
+	for uid, cls := range TgUseridToClientID {
+		if cls != nil {
+			filtered := filterStringSlice(cls, clientID)
+			if len(filtered) > 0 {
+				TgUseridToClientID[uid] = filtered
+			} else {
+				delete(TgUseridToClientID, uid)
+			}
+		}
+	}
+
+	// Attach it to the new one
+	if _, ok := TgUseridToClientID[userid]; ok && TgUseridToClientID[userid] != nil {
+		TgUseridToClientID[userid] = append(TgUseridToClientID[userid], clientID)
+	} else {
+		TgUseridToClientID[userid] = []string{clientID}
+	}
+}
+
+func RemoveTgToClientID(clientID string) {
+	TgUseridToClientIDMutex.Lock()
+	defer TgUseridToClientIDMutex.Unlock()
+
+	// Detach clientID from any existing userid
+	for uid, cls := range TgUseridToClientID {
+		if cls != nil {
+			filtered := filterStringSlice(cls, clientID)
+			if len(filtered) > 0 {
+				TgUseridToClientID[uid] = filtered
+			} else {
+				delete(TgUseridToClientID, uid)
+			}
+		}
+	}
+}
+
+func filterStringSlice(s []string, excludedStr string) []string {
+	filtered := s[:0]
+	for _, v := range s {
+		if v != excludedStr {
+			filtered = append(filtered, v)
+		}
+	}
+	return filtered
+}