tor: use random credentials for circuit isolation

fetch.py

@@ -1,4 +1,4 @@
-import re, random, time
+import re, random, time, string
 import threading
 import rocksock
 import network_stats
@@ -7,6 +7,14 @@ from soup_parser import soupify
 from misc import _log
 
 config = None
+
+
+def tor_proxy_url(torhost):
+    """Generate Tor SOCKS5 proxy URL with random credentials for circuit isolation."""
+    chars = string.ascii_lowercase + string.digits
+    user = ''.join(random.choice(chars) for _ in range(8))
+    passwd = ''.join(random.choice(chars) for _ in range(8))
+    return 'socks5://%s:%s@%s' % (user, passwd, torhost)
 _last_fail_log = 0
 _fail_log_interval = 60
 
@@ -58,7 +66,7 @@ def _fetch_contents(url, head = False, proxy=None):
     http = None
     try:
         while True:
-            proxies = [rocksock.RocksockProxyFromURL('socks4://%s' % random.choice( config.torhosts ))]
+            proxies = [rocksock.RocksockProxyFromURL(tor_proxy_url(random.choice(config.torhosts)))]
             if proxy: proxies.append( rocksock.RocksockProxyFromURL(proxy))
 
             http = RsHttp(host,ssl=ssl,port=port, keep_alive=True, timeout=config.ppf.timeout, max_tries=config.ppf.http_retries, follow_redirects=True, auto_set_cookies=True, proxies=proxies, user_agent='Mozilla/5.0 (Windows NT 6.1; rv:60.0) Gecko/20100101 Firefox/60.0', log_errors=False)