From 16af73dc704fe897a0a7ab7c00f977b0444aea00 Mon Sep 17 00:00:00 2001
From: Aleksey Shaposhnikov <1584156+alexey-sh@users.noreply.github.com>
Date: Wed, 4 Sep 2024 12:59:08 +0300
Subject: [PATCH] chore: stricter ProxyInterface (#718)

---
 gramjs/client/telegramBaseClient.ts     |  6 +++---
 gramjs/extensions/PromisedNetSockets.ts | 17 +++++++----------
 gramjs/network/connection/TCPMTProxy.ts | 16 +++++++++++-----
 3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/gramjs/client/telegramBaseClient.ts b/gramjs/client/telegramBaseClient.ts
index bd611119..fb5c893c 100644
--- a/gramjs/client/telegramBaseClient.ts
+++ b/gramjs/client/telegramBaseClient.ts
@@ -284,11 +284,11 @@ export abstract class TelegramBaseClient {
         }
         this._connection = clientParams.connection;
         let initProxy;
-        if (this._proxy?.MTProxy) {
+        if (this._proxy && 'MTProxy' in this._proxy) {
             this._connection = ConnectionTCPMTProxyAbridged;
             initProxy = new Api.InputClientProxy({
-                address: this._proxy!.ip,
-                port: this._proxy!.port,
+                address: this._proxy.ip,
+                port: this._proxy.port,
             });
         }
         this._initRequest = new Api.InitConnection({
diff --git a/gramjs/extensions/PromisedNetSockets.ts b/gramjs/extensions/PromisedNetSockets.ts
index e1f0c405..35d92783 100644
--- a/gramjs/extensions/PromisedNetSockets.ts
+++ b/gramjs/extensions/PromisedNetSockets.ts
@@ -2,7 +2,7 @@ import * as net from "./net";
 import { SocksClient } from "./socks";
 
 import { Mutex } from "async-mutex";
-import { ProxyInterface } from "../network/connection/TCPMTProxy";
+import { ProxyInterface, SocksProxyType } from "../network/connection/TCPMTProxy";
 
 const mutex = new Mutex();
 
@@ -14,22 +14,22 @@ export class PromisedNetSockets {
     private stream: Buffer;
     private canRead?: boolean | Promise<boolean>;
     private resolveRead: ((value?: any) => void) | undefined;
-    private proxy?: ProxyInterface;
+    private proxy?: SocksProxyType;
 
     constructor(proxy?: ProxyInterface) {
         this.client = undefined;
         this.closed = true;
         this.stream = Buffer.alloc(0);
-        if (!proxy?.MTProxy) {
+        if (proxy) {
             // we only want to use this when it's not an MTProto proxy.
-            if (proxy) {
+            if (!('MTProxy' in proxy)) {
                 if (!proxy.ip || !proxy.port || !proxy.socksType) {
                     throw new Error(
-                        `Invalid sockets params. ${proxy.ip}, ${proxy.port}, ${proxy.socksType}`
+                        `Invalid sockets params: ip=${proxy.ip}, port=${proxy.port}, socksType=${proxy.socksType}`
                     );
                 }
+                this.proxy = proxy;
             }
-            this.proxy = proxy;
         }
     }
 
@@ -90,10 +90,7 @@ export class PromisedNetSockets {
                 proxy: {
                     host: this.proxy.ip,
                     port: this.proxy.port,
-                    type:
-                        this.proxy.socksType != undefined
-                            ? this.proxy.socksType
-                            : 5, // Proxy version (4 or 5)
+                    type: this.proxy.socksType,
                     userId: this.proxy.username,
                     password: this.proxy.password,
                 },
diff --git a/gramjs/network/connection/TCPMTProxy.ts b/gramjs/network/connection/TCPMTProxy.ts
index 71d6d184..f5584784 100644
--- a/gramjs/network/connection/TCPMTProxy.ts
+++ b/gramjs/network/connection/TCPMTProxy.ts
@@ -8,16 +8,22 @@ import {
 } from "../../extensions";
 import { CTR } from "../../crypto/CTR";
 
-export interface ProxyInterface {
-    socksType?: 4 | 5;
+interface BasicProxyInterface {
     ip: string;
     port: number;
-    secret?: string;
-    MTProxy?: boolean;
     timeout?: number;
     username?: string;
     password?: string;
 }
+export type MTProxyType = BasicProxyInterface & {
+    secret: string;
+    MTProxy: true;
+}
+export type SocksProxyType = BasicProxyInterface & {
+    socksType: 4 | 5;
+}
+
+export type ProxyInterface = MTProxyType | SocksProxyType;
 
 class MTProxyIO {
     header?: Buffer = undefined;
@@ -154,7 +160,7 @@ export class TCPMTProxy extends ObfuscatedConnection {
             proxy: proxy,
             testServers: testServers,
         });
-        if (!proxy.MTProxy) {
+        if (!('MTProxy' in proxy)) {
             throw new Error("This connection only supports MPTProxies");
         }
         if (!proxy.secret) {