From c97e6023c40b01aaf16d99de9996d7dbeb128fd9 Mon Sep 17 00:00:00 2001
From: habcawa <212562656+habcawa@users.noreply.github.com>
Date: Tue, 20 May 2025 16:19:09 +0200
Subject: [PATCH] fix(AuthKey): key_id is a signed long, not unsigned

---
 telethon/crypto/authkey.py       | 2 +-
 telethon/network/mtprotostate.py | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/telethon/crypto/authkey.py b/telethon/crypto/authkey.py
index 8475ec17..37f65017 100644
--- a/telethon/crypto/authkey.py
+++ b/telethon/crypto/authkey.py
@@ -39,7 +39,7 @@ class AuthKey:
         with BinaryReader(sha1(self._key).digest()) as reader:
             self.aux_hash = reader.read_long(signed=False)
             reader.read(4)
-            self.key_id = reader.read_long(signed=False)
+            self.key_id = reader.read_long(signed=True)
 
     # TODO This doesn't really fit here, it's only used in authentication
     def calc_new_nonce_hash(self, new_nonce, number):
diff --git a/telethon/network/mtprotostate.py b/telethon/network/mtprotostate.py
index 49fb7478..0ceaa513 100644
--- a/telethon/network/mtprotostate.py
+++ b/telethon/network/mtprotostate.py
@@ -144,7 +144,7 @@ class MTProtoState:
         msg_key = msg_key_large[8:24]
         aes_key, aes_iv = self._calc_key(self.auth_key.key, msg_key, True)
 
-        key_id = struct.pack('<Q', self.auth_key.key_id)
+        key_id = struct.pack('<q', self.auth_key.key_id)
         return (key_id + msg_key +
                 AES.encrypt_ige(data + padding, aes_key, aes_iv))
 
@@ -158,7 +158,7 @@ class MTProtoState:
             raise InvalidBufferError(body)
 
         # TODO Check salt, session_id and sequence_number
-        key_id = struct.unpack('<Q', body[:8])[0]
+        key_id = struct.unpack('<q', body[:8])[0]
         if key_id != self.auth_key.key_id:
             raise SecurityError('Server replied with an invalid auth key')