Finish issue 5259 by adding tests and fixes for the 'login'

and 'cram-md5' auth methods.

Lib/smtplib.py

@@ -541,8 +541,9 @@ class SMTP:
 
         def encode_cram_md5(challenge, user, password):
             challenge = base64.decodestring(challenge)
-            response = user + " " + hmac.HMAC(password, challenge).hexdigest()
-            return encode_base64(response)
+            response = user + " " + hmac.HMAC(password.encode('ascii'),
+                                              challenge).hexdigest()
+            return encode_base64(response.encode('ascii'), eol='')
 
         def encode_plain(user, password):
             s = "\0%s\0%s" % (user, password)
@@ -584,10 +585,10 @@ class SMTP:
                 AUTH_PLAIN + " " + encode_plain(user, password))
         elif authmethod == AUTH_LOGIN:
             (code, resp) = self.docmd("AUTH",
-                "%s %s" % (AUTH_LOGIN, encode_base64(user)))
+                "%s %s" % (AUTH_LOGIN, encode_base64(user.encode('ascii'), eol='')))
             if code != 334:
                 raise SMTPAuthenticationError(code, resp)
-            (code, resp) = self.docmd(encode_base64(password))
+            (code, resp) = self.docmd(encode_base64(password.encode('ascii'), eol=''))
         elif authmethod is None:
             raise SMTPException("No suitable authentication method found.")
         if code not in (235, 503):

Lib/test/test_smtplib.py

@@ -285,7 +285,15 @@ sim_users = {'Mr.A@somewhere.com':'John A',
             }
 
 sim_auth = ('Mr.A@somewhere.com', 'somepassword')
-sim_auth_b64encoded = 'AE1yLkFAc29tZXdoZXJlLmNvbQBzb21lcGFzc3dvcmQ='
+sim_cram_md5_challenge = ('PENCeUxFREJoU0NnbmhNWitOMjNGNn'
+                          'dAZWx3b29kLmlubm9zb2Z0LmNvbT4=')
+sim_auth_credentials = {
+    'login': 'TXIuQUBzb21ld2hlcmUuY29t',
+    'plain': 'AE1yLkFAc29tZXdoZXJlLmNvbQBzb21lcGFzc3dvcmQ=',
+    'cram-md5': ('TXIUQUBZB21LD2HLCMUUY29TIDG4OWQ0MJ'
+                 'KWZGQ4ODNMNDA4NTGXMDRLZWMYZJDMODG1'),
+    }
+sim_auth_login_password = 'C29TZXBHC3N3B3JK'
 
 sim_lists = {'list-1':['Mr.A@somewhere.com','Mrs.C@somewhereesle.com'],
              'list-2':['Ms.B@somewhere.com',],
@@ -293,19 +301,28 @@ sim_lists = {'list-1':['Mr.A@somewhere.com','Mrs.C@somewhereesle.com'],
 
 # Simulated SMTP channel & server
 class SimSMTPChannel(smtpd.SMTPChannel):
+
+    def __init__(self, *args, **kw):
+        self.__extrafeatures = []
+        super(SimSMTPChannel, self).__init__(*args, **kw)
+
+    @property
+    def _extrafeatures(self):
+        return ''.join([ "250-{}\r\n".format(x) for x in self.__extrafeatures ])
+
+    def add_feature(self, feature):
+        self.__extrafeatures.append(feature)
+
     def smtp_EHLO(self, arg):
-        resp = '250-testhost\r\n' \
-               '250-EXPN\r\n' \
-               '250-SIZE 20000000\r\n' \
-               '250-STARTTLS\r\n' \
-               '250-DELIVERBY\r\n' \
-               '250-AUTH PLAIN\r\n' \
-               '250 HELP'
+        resp = ('250-testhost\r\n'
+                '250-EXPN\r\n'
+                '250-SIZE 20000000\r\n'
+                '250-STARTTLS\r\n'
+                '250-DELIVERBY\r\n')
+        resp = resp + self._extrafeatures + '250 HELP'
         self.push(resp)
 
     def smtp_VRFY(self, arg):
-#        print '\nsmtp_VRFY(%r)\n' % arg
-
         raw_addr = email.utils.parseaddr(arg)[1]
         quoted_addr = smtplib.quoteaddr(arg)
         if raw_addr in sim_users:
@@ -314,8 +331,6 @@ class SimSMTPChannel(smtpd.SMTPChannel):
             self.push('550 No such user: %s' % arg)
 
     def smtp_EXPN(self, arg):
-#        print '\nsmtp_EXPN(%r)\n' % arg
-
         list_name = email.utils.parseaddr(arg)[1].lower()
         if list_name in sim_lists:
             user_list = sim_lists[list_name]
@@ -329,24 +344,34 @@ class SimSMTPChannel(smtpd.SMTPChannel):
             self.push('550 No access for you!')
 
     def smtp_AUTH(self, arg):
+        if arg.strip().lower()=='cram-md5':
+            self.push('334 {}'.format(sim_cram_md5_challenge))
+            return
         mech, auth = arg.split()
-        if mech.lower() == 'plain':
-            if auth == sim_auth_b64encoded:
-                self.push('235 ok, go ahead')
+        mech = mech.lower()
+        if mech not in sim_auth_credentials:
+            self.push('504 auth type unimplemented')
+            return
+        if mech == 'plain' and auth==sim_auth_credentials['plain']:
+            self.push('235 plain auth ok')
+        elif mech=='login' and auth==sim_auth_credentials['login']:
+            self.push('334 Password:')
         else:
             self.push('550 No access for you!')
-        else:
-            self.push('504 auth type unimplemented')
 
 
 class SimSMTPServer(smtpd.SMTPServer):
+
     def handle_accept(self):
         conn, addr = self.accept()
-        channel = SimSMTPChannel(self, conn, addr)
+        self._SMTPchannel = SimSMTPChannel(self, conn, addr)
 
     def process_message(self, peer, mailfrom, rcpttos, data):
         pass
 
+    def add_feature(self, feature):
+        self._SMTPchannel.add_feature(feature)
+
 
 # Test various SMTP & ESMTP commands/behaviors that require a simulated server
 # (i.e., something with more features than DebuggingServer)
@@ -386,7 +411,6 @@ class SMTPSimTests(TestCase):
                              'size': '20000000',
                              'starttls': '',
                              'deliverby': '',
-                             'auth': ' PLAIN',
                              'help': '',
                              }
 
@@ -427,12 +451,41 @@ class SMTPSimTests(TestCase):
         self.assertEqual(smtp.expn(u), expected_unknown)
         smtp.quit()
 
-    def testAUTH(self):
+    def testAUTH_PLAIN(self):
         smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
+        self.serv.add_feature("AUTH PLAIN")
 
-        expected_auth_ok = (235, b'ok, go ahead')
+        expected_auth_ok = (235, b'plain auth ok')
         self.assertEqual(smtp.login(sim_auth[0], sim_auth[1]), expected_auth_ok)
 
+    # SimSMTPChannel doesn't fully support LOGIN or CRAM-MD5 auth because they
+    # require a synchronous read to obtain the credentials...so instead smtpd
+    # sees the credential sent by smtplib's login method as an unknown command,
+    # which results in smtplib raising an auth error.  Fortunately the error
+    # message contains the encoded credential, so we can partially check that it
+    # was generated correctly (partially, because the 'word' is uppercased in
+    # the error message).
+
+    def testAUTH_LOGIN(self):
+        smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
+        self.serv.add_feature("AUTH LOGIN")
+        try: smtp.login(sim_auth[0], sim_auth[1])
+        except smtplib.SMTPAuthenticationError as err:
+            if sim_auth_login_password not in str(err):
+                raise "expected encoded password not found in error message"
+
+    def testAUTH_CRAM_MD5(self):
+        smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
+        self.serv.add_feature("AUTH CRAM-MD5")
+
+        try: smtp.login(sim_auth[0], sim_auth[1])
+        except smtplib.SMTPAuthenticationError as err:
+            if sim_auth_credentials['cram-md5'] not in str(err):
+                raise "expected encoded credentials not found in error message"
+
+    #TODO: add tests for correct AUTH method fallback now that the
+    #test infrastructure can support it.
+
 
 def test_main(verbose=None):
     support.run_unittest(GeneralTests, DebuggingServerTests,

Misc/NEWS

@@ -34,6 +34,8 @@ Core and Builtins
 Library
 -------
 
+- smtplib 'login' and 'cram-md5' login are also fixed (see Issue #5259).
+
 - Issue #6121: pydoc now ignores leading and trailing spaces in the
   argument to the 'help' function.