CVE-2021-4189 More fixes to get tests passing

Various things that need to be fixed to make things work in Python2 land

Author: rickprice

Lib/ftplib.py

@@ -109,32 +109,54 @@ class FTP:
     welcome = None
     passiveserver = 1
     encoding = "latin-1"
-    # Disables https://bugs.python.org/issue43285 security if set to True.
-    trust_server_pasv_ipv4_address = False
+    # # Disables https://bugs.python.org/issue43285 security if set to True.
+    # trust_server_pasv_ipv4_address = False
 
     # Initialization method (called by class instantiation).
     # Initialize host to localhost, port to standard ftp port
     # Optional arguments are host (for connect()),
     # and user, passwd, acct (for login())
     def __init__(self, host='', user='', passwd='', acct='',
-                 timeout=_GLOBAL_DEFAULT_TIMEOUT):
+                 timeout=_GLOBAL_DEFAULT_TIMEOUT, source_address=None):
+        self.source_address = source_address
+        # Disables https://bugs.python.org/issue43285 security if set to True.
+        self.trust_server_pasv_ipv4_address = False
         self.timeout = timeout
         if host:
             self.connect(host)
             if user:
                 self.login(user, passwd, acct)
 
-    def connect(self, host='', port=0, timeout=-999):
+    def __enter__(self):
+        return self
+
+    # Context management protocol: try to quit() if active
+    def __exit__(self, *args):
+        if self.sock is not None:
+            try:
+                self.quit()
+            except (OSError, EOFError):
+                pass
+            finally:
+                if self.sock is not None:
+                    self.close()
+
+    def connect(self, host='', port=0, timeout=-999, source_address=None):
         '''Connect to host.  Arguments are:
          - host: hostname to connect to (string, default previous host)
          - port: port to connect to (integer, default previous port)
+         - timeout: the timeout to set against the ftp socket(s)
+         - source_address: a 2-tuple (host, port) for the socket to bind
+           to as its source address before connecting.
         '''
         if host != '':
             self.host = host
         if port > 0:
             self.port = port
         if timeout != -999:
             self.timeout = timeout
+        if source_address is not None:
+            self.source_address = source_address
         self.sock = socket.create_connection((self.host, self.port), self.timeout)
         self.af = self.sock.family
         self.file = self.sock.makefile('rb')

Lib/test/test_ftplib.py

@@ -15,6 +15,7 @@
 except ImportError:
     ssl = None
 
+from contextlib import closing
 from unittest import TestCase, SkipTest, skipUnless
 from test import test_support
 from test.test_support import HOST, HOSTv6
@@ -648,7 +649,7 @@ def is_client_connected():
 
     def test_source_address(self):
         self.client.quit()
-        port = support.find_unused_port()
+        port = test_support.find_unused_port()
         try:
             self.client.connect(self.server.host, self.server.port,
                                 source_address=(HOST, port))
@@ -660,10 +661,10 @@ def test_source_address(self):
             raise
 
     def test_source_address_passive_connection(self):
-        port = support.find_unused_port()
+        port = test_support.find_unused_port()
         self.client.source_address = (HOST, port)
         try:
-            with self.client.transfercmd('list') as sock:
+            with closing(self.client.transfercmd('list')) as sock:
                 self.assertEqual(sock.getsockname()[1], port)
         except OSError as e:
             if e.errno == errno.EADDRINUSE: