Update test_smtplib.py from 3.13.11

RustPython · youknowone · Dec 19, 2025 · Dec 13, 2025 · Dec 13, 2025 · Dec 16, 2025
commit 936d9c683c0d1c1bd96bdc2b336ef35df0f9393b
diff --git a/Lib/test/test_smtplib.py b/Lib/test/test_smtplib.py
@@ -17,6 +17,7 @@
 import threading
 
 import unittest
+import unittest.mock as mock
 from test import support, mock_socket
 from test.support import hashlib_helper
 from test.support import socket_helper
@@ -350,7 +351,7 @@ def testVRFY(self):
                             timeout=support.LOOPBACK_TIMEOUT)
         self.addCleanup(smtp.close)
         expected = (252, b'Cannot VRFY user, but will accept message ' + \
-                    b'and attempt delivery')
+                         b'and attempt delivery')
         self.assertEqual(smtp.vrfy('[email protected]'), expected)
         self.assertEqual(smtp.verify('[email protected]'), expected)
         smtp.quit()
@@ -371,7 +372,7 @@ def testHELP(self):
                             timeout=support.LOOPBACK_TIMEOUT)
         self.addCleanup(smtp.close)
         self.assertEqual(smtp.help(), b'Supported commands: EHLO HELO MAIL ' + \
-                         b'RCPT DATA RSET NOOP QUIT VRFY')
+                                      b'RCPT DATA RSET NOOP QUIT VRFY')
         smtp.quit()
 
     def testSend(self):
@@ -527,7 +528,7 @@ def testSendMessageWithAddresses(self):
         smtp.quit()
         # make sure the Bcc header is still in the message.
         self.assertEqual(m['Bcc'], 'John Root <root@localhost>, "Dinsdale" '
-                                   '<[email protected]>')
+                                    '<[email protected]>')
 
         self.client_evt.set()
         self.serv_evt.wait()
@@ -766,7 +767,7 @@ def tearDown(self):
 
     def testFailingHELO(self):
         self.assertRaises(smtplib.SMTPConnectError, smtplib.SMTP,
-                          HOST, self.port, 'localhost', 3)
+                            HOST, self.port, 'localhost', 3)
 
 
 class TooLongLineTests(unittest.TestCase):
@@ -804,14 +805,14 @@ def testLineTooLong(self):
 sim_users = {'[email protected]':'John A',
              '[email protected]':'Sally B',
              '[email protected]':'Ruth C',
-             }
+            }
 
 sim_auth = ('[email protected]', 'somepassword')
 sim_cram_md5_challenge = ('PENCeUxFREJoU0NnbmhNWitOMjNGNn'
                           'dAZWx3b29kLmlubm9zb2Z0LmNvbT4=')
 sim_lists = {'list-1':['[email protected]','[email protected]'],
              'list-2':['[email protected]',],
-             }
+            }
 
 # Simulated SMTP channel & server
 class ResponseException(Exception): pass
@@ -830,6 +831,7 @@ class SimSMTPChannel(smtpd.SMTPChannel):
     def __init__(self, extra_features, *args, **kw):
         self._extrafeatures = ''.join(
             [ "250-{0}\r\n".format(x) for x in extra_features ])
+        self.all_received_lines = []
         super(SimSMTPChannel, self).__init__(*args, **kw)
 
     # AUTH related stuff.  It would be nice if support for this were in smtpd.
@@ -844,6 +846,7 @@ def found_terminator(self):
                 self.smtp_state = self.COMMAND
                 self.push('%s %s' % (e.smtp_code, e.smtp_error))
             return
+        self.all_received_lines.append(self.received_lines)
         super().found_terminator()
 
 
@@ -924,11 +927,14 @@ def _auth_cram_md5(self, arg=None):
             except ValueError as e:
                 self.push('535 Splitting response {!r} into user and password '
                           'failed: {}'.format(logpass, e))
-                return False
-            valid_hashed_pass = hmac.HMAC(
-                sim_auth[1].encode('ascii'),
-                self._decode_base64(sim_cram_md5_challenge).encode('ascii'),
-                'md5').hexdigest()
+                return
+            pwd = sim_auth[1].encode('ascii')
+            msg = self._decode_base64(sim_cram_md5_challenge).encode('ascii')
+            try:
+                valid_hashed_pass = hmac.HMAC(pwd, msg, 'md5').hexdigest()
+            except ValueError:
+                self.push('504 CRAM-MD5 is not supported')
+                return
             self._authenticated(user, hashed_pass == valid_hashed_pass)
     # end AUTH related stuff.
 
@@ -1170,8 +1176,7 @@ def auth_buggy(challenge=None):
         finally:
             smtp.close()
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
+    @unittest.expectedFailure # TODO: RUSTPYTHON
     @hashlib_helper.requires_hashdigest('md5', openssl=True)
     def testAUTH_CRAM_MD5(self):
         self.serv.add_feature("AUTH CRAM-MD5")
@@ -1181,8 +1186,40 @@ def testAUTH_CRAM_MD5(self):
         self.assertEqual(resp, (235, b'Authentication Succeeded'))
         smtp.close()
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
+    @mock.patch("hmac.HMAC")
+    @mock.patch("smtplib._have_cram_md5_support", False)
+    def testAUTH_CRAM_MD5_blocked(self, hmac_constructor):
+        # CRAM-MD5 is the only "known" method by the server,
+        # but it is not supported by the client. In particular,
+        # no challenge will ever be sent.
+        self.serv.add_feature("AUTH CRAM-MD5")
+        smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost',
+                            timeout=support.LOOPBACK_TIMEOUT)
+        self.addCleanup(smtp.close)
+        msg = re.escape("No suitable authentication method found.")
+        with self.assertRaisesRegex(smtplib.SMTPException, msg):
+            smtp.login(sim_auth[0], sim_auth[1])
+        hmac_constructor.assert_not_called()  # call has been bypassed
+
+    @mock.patch("smtplib._have_cram_md5_support", False)
+    def testAUTH_CRAM_MD5_blocked_and_fallback(self):
+        # Test that PLAIN is tried after CRAM-MD5 failed
+        self.serv.add_feature("AUTH CRAM-MD5 PLAIN")
+        smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost',
+                            timeout=support.LOOPBACK_TIMEOUT)
+        self.addCleanup(smtp.close)
+        with (
+            mock.patch.object(smtp, "auth_cram_md5") as smtp_auth_cram_md5,
+            mock.patch.object(
+                smtp, "auth_plain", wraps=smtp.auth_plain
+            ) as smtp_auth_plain
+        ):
+            resp = smtp.login(sim_auth[0], sim_auth[1])
+        smtp_auth_plain.assert_called_once()
+        smtp_auth_cram_md5.assert_not_called()  # no call to HMAC constructor
+        self.assertEqual(resp, (235, b'Authentication Succeeded'))
+
+    @unittest.expectedFailure # TODO: RUSTPYTHON
     @hashlib_helper.requires_hashdigest('md5', openssl=True)
     def testAUTH_multiple(self):
         # Test that multiple authentication methods are tried.
@@ -1193,8 +1230,7 @@ def testAUTH_multiple(self):
         self.assertEqual(resp, (235, b'Authentication Succeeded'))
         smtp.close()
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
+    @unittest.expectedFailure # TODO: RUSTPYTHON
     def test_auth_function(self):
         supported = {'PLAIN', 'LOGIN'}
         try:
@@ -1354,6 +1390,18 @@ def test_name_field_not_included_in_envelop_addresses(self):
         self.assertEqual(self.serv._addresses['from'], '[email protected]')
         self.assertEqual(self.serv._addresses['tos'], ['[email protected]'])
 
+    def test_lowercase_mail_from_rcpt_to(self):
+        m = 'A test message'
+        smtp = smtplib.SMTP(
+            HOST, self.port, local_hostname='localhost',
+            timeout=support.LOOPBACK_TIMEOUT)
+        self.addCleanup(smtp.close)
+
+        smtp.sendmail('John', 'Sally', m)
+
+        self.assertIn(['mail from:<John> size=14'], self.serv._SMTPchannel.all_received_lines)
+        self.assertIn(['rcpt to:<Sally>'], self.serv._SMTPchannel.all_received_lines)
+
 
 class SimSMTPUTF8Server(SimSMTPServer):
 
@@ -1372,7 +1420,7 @@ def handle_accepted(self, conn, addr):
         )
 
     def process_message(self, peer, mailfrom, rcpttos, data, mail_options=None,
-                        rcpt_options=None):
+                                                             rcpt_options=None):
         self.last_peer = peer
         self.last_mailfrom = mailfrom
         self.last_rcpttos = rcpttos