From 3635d312ce4dae726d9ae555d754f0613b2b3786 Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Wed, 11 Aug 2021 01:27:58 +0300
Subject: [PATCH] GramJs: Use "-1" DCs for file transfers (generate keys with
 standard DCs) (#1368)

---
 src/lib/gramjs/Utils.js                 | 19 +++++++++++++------
 src/lib/gramjs/client/TelegramClient.js |  3 ++-
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/lib/gramjs/Utils.js b/src/lib/gramjs/Utils.js
index 3cb93892a..4f80f66e7 100644
--- a/src/lib/gramjs/Utils.js
+++ b/src/lib/gramjs/Utils.js
@@ -605,37 +605,44 @@ function isListLike(item) {
     )
 }
 */
-function getDC(dcId) {
+/**
+ * Returns the appropriate DC based on the id
+ * @param dcId the id of the DC.
+ * @param downloadDC whether to use -1 DCs or not
+ * (These only support downloading/uploading and not creating a new AUTH key)
+ * @return {{port: number, ipAddress: string, id: number}}
+ */
+function getDC(dcId, downloadDC = false) {
     // TODO Move to external config
     switch (dcId) {
         case 1:
             return {
                 id: 1,
-                ipAddress: 'zws1.web.telegram.org',
+                ipAddress: `zws1${downloadDC ? '-1' : ''}.web.telegram.org`,
                 port: 443,
             };
         case 2:
             return {
                 id: 2,
-                ipAddress: 'zws2.web.telegram.org',
+                ipAddress: `zws2${downloadDC ? '-1' : ''}.web.telegram.org`,
                 port: 443,
             };
         case 3:
             return {
                 id: 3,
-                ipAddress: 'zws3.web.telegram.org',
+                ipAddress: `zws3${downloadDC ? '-1' : ''}.web.telegram.org`,
                 port: 443,
             };
         case 4:
             return {
                 id: 4,
-                ipAddress: 'zws4.web.telegram.org',
+                ipAddress: `zws4${downloadDC ? '-1' : ''}.web.telegram.org`,
                 port: 443,
             };
         case 5:
             return {
                 id: 5,
-                ipAddress: 'zws5.web.telegram.org',
+                ipAddress: `zws5${downloadDC ? '-1' : ''}.web.telegram.org`,
                 port: 443,
             };
         default:
diff --git a/src/lib/gramjs/client/TelegramClient.js b/src/lib/gramjs/client/TelegramClient.js
index 422603116..1e83b75eb 100644
--- a/src/lib/gramjs/client/TelegramClient.js
+++ b/src/lib/gramjs/client/TelegramClient.js
@@ -327,7 +327,8 @@ class TelegramClient {
     }
 
     async _connectSender(sender, dcId) {
-        const dc = utils.getDC(dcId);
+        // if we don't already have an auth key we want to use normal DCs not -1
+        const dc = utils.getDC(dcId, !!sender.authKey.getKey());
 
         while (true) {
             try {