From a7d6037fc52efbb8ad34bd6693a72c7069e75883 Mon Sep 17 00:00:00 2001
From: Dmitri Bogomolov <4glitch@gmail.com>
Date: Wed, 17 Mar 2021 22:47:26 +0200
Subject: [PATCH] Minimal useragent validation

---
 src/network/bmproto.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/network/bmproto.py b/src/network/bmproto.py
index bf2de760..008eadb0 100644
--- a/src/network/bmproto.py
+++ b/src/network/bmproto.py
@@ -5,6 +5,7 @@ Class BMProto defines bitmessage's network protocol workflow.
 import base64
 import hashlib
 import logging
+import re
 import socket
 import struct
 import time
@@ -535,6 +536,10 @@ class BMProto(AdvancedDispatcher, ObjectTracker):
             return True
         self.append_write_buf(protocol.CreatePacket('verack'))
         self.verackSent = True
+        ua_valid = re.match(
+            r'^/[a-zA-Z]+:[0-9]+\.?[\w\s\(\)\./:;-]*/$', self.userAgent)
+        if not ua_valid:
+            self.userAgent = '/INVALID:0/'
         if not self.isOutbound:
             self.append_write_buf(protocol.assembleVersionMessage(
                 self.destination.host, self.destination.port,