diff -r c43362d35d8d Doc/library/smtpd.rst --- a/Doc/library/smtpd.rst Fri Jul 04 17:00:25 2014 -0700 +++ b/Doc/library/smtpd.rst Wed Jul 30 01:09:56 2014 +0200 @@ -20,7 +20,8 @@ Additionally the SMTPChannel may be extended to implement very specific interaction behaviour with SMTP clients. -The code supports :RFC:`5321`, plus the :rfc:`1870` SIZE extension. +The code supports :RFC:`5321`, plus the :rfc:`1870` SIZE and :rfc:`6531` +SMTPUTF8 extensions. SMTPServer Objects @@ -28,7 +29,7 @@ .. class:: SMTPServer(localaddr, remoteaddr, data_size_limit=33554432,\ - map=None, decode_data=True) + map=None, enable_SMTPUTF8=False, decode_data=True) Create a new :class:`SMTPServer` object, which binds to local address *localaddr*. It will treat *remoteaddr* as an upstream SMTP relayer. It @@ -39,6 +40,12 @@ accepted in a ``DATA`` command. A value of ``None`` or ``0`` means no limit. + *enable_SMTPUTF8* determins whether the ``SMTPUTF8`` extension (as defined + in :RFC:`6531`) should be enabled. The default is ``False``. If + *enable_SMTPUTF* is set to ``True``, the :meth:`process_smtputf8_message` + method must be defined. A :exc:`ValueError` is raised if both + *enable_SMTPUTF8* and *decode_data* are set to ``True`` at the same time. + A dictionary can be specified in *map* to avoid using a global socket map. *decode_data* specifies whether the data portion of the SMTP transaction @@ -48,18 +55,34 @@ .. method:: process_message(peer, mailfrom, rcpttos, data) - Raise :exc:`NotImplementedError` exception. Override this in subclasses to + Raise a :exc:`NotImplementedError` exception. Override this in subclasses to do something useful with this message. Whatever was passed in the constructor as *remoteaddr* will be available as the :attr:`_remoteaddr` attribute. *peer* is the remote host's address, *mailfrom* is the envelope originator, *rcpttos* are the envelope recipients and *data* is a string - containing the contents of the e-mail (which should be in :rfc:`2822` + containing the contents of the e-mail (which should be in :rfc:`5321` format). If the *decode_data* constructor keyword is set to ``True``, the *data* argument will be a unicode string. If it is set to ``False``, it will be a bytes object. + Return ``None`` to request a normal ``250 Ok`` response; otherwise + return the desired response string in :RFC:`5321` format. + + .. method:: process_smtputf8_message(peer, mailfrom, rcpttos, data) + + Raise a :exc:`NotImplementedError` exception. Override this in + subclasses to do something useful with messages when *enable_SMTPUTF8* + has been set to ``True`` and the SMTP client requested ``SMTPUTF8``, + since this method is called rather than :meth:`process_message` + when the client actively requests ``SMTPUTF8``. The *data* + argument will always be a bytes object. + Return ``None`` to request a normal ``250 Ok`` response; otherwise + return the desired response string in :RFC:`6531` format. + + Otherwise the API is the same as for :meth:`process_message`. + .. attribute:: channel_class Override this in subclasses to use a custom :class:`SMTPChannel` for @@ -68,8 +91,12 @@ .. versionchanged:: 3.4 The *map* argument was added. - .. versionchanged:: 3.5 the *decode_data* argument was added, and *localaddr* - and *remoteaddr* may now contain IPv6 addresses. + .. versionchanged:: 3.5 + *localaddr* and *remoteaddr* may now contain IPv6 addresses. + + .. versionadded:: 3.5 + the *decode_data* and *enable_SMTPUTF8* constructor arguments, and the + :meth:`process_smtputf8_message` method. DebuggingServer Objects @@ -109,7 +136,7 @@ ------------------- .. class:: SMTPChannel(server, conn, addr, data_size_limit=33554432,\ - map=None, decode_data=True) + map=None, enable_SMTPUTF8=False, decode_data=True) Create a new :class:`SMTPChannel` object which manages the communication between the server and a single SMTP client. @@ -120,6 +147,11 @@ accepted in a ``DATA`` command. A value of ``None`` or ``0`` means no limit. + *enable_SMTPUTF8* determins whether the ``SMTPUTF8`` extension (as defined + in :RFC:`6531`) should be enabled. The default is ``False``. A + :exc:`ValueError` is raised if both *enable_SMTPUTF8* and *decode_data* are + set to ``True`` at the same time. + A dictionary can be specified in *map* to avoid using a global socket map. *decode_data* specifies whether the data portion of the SMTP transaction @@ -131,7 +163,7 @@ :attr:`SMTPServer.channel_class` of your :class:`SMTPServer`. .. versionchanged:: 3.5 - the *decode_data* argument was added. + the *decode_data* and *enable_SMTPUTF8* arguments were added. The :class:`SMTPChannel` has the following instance variables: diff -r c43362d35d8d Lib/smtpd.py --- a/Lib/smtpd.py Fri Jul 04 17:00:25 2014 -0700 +++ b/Lib/smtpd.py Wed Jul 30 01:09:56 2014 +0200 @@ -1,5 +1,5 @@ #! /usr/bin/env python3 -"""An RFC 5321 smtp proxy. +"""An RFC 5321 smtp proxy with optional RFC 1870 and RFC 6531 extensions. Usage: %(program)s [options] [localhost:localport [remotehost:remoteport]] @@ -25,6 +25,10 @@ Restrict the total size of the incoming message to "limit" number of bytes via the RFC 1870 SIZE extension. Defaults to 33554432 bytes. + --smtputf8 + -u + Enable the SMTPUTF8 extension and behave as an RFC 6531 smtp proxy. + --debug -d Turn on debugging prints. @@ -115,18 +119,27 @@ command_size_limit = 512 command_size_limits = collections.defaultdict(lambda x=command_size_limit: x) - command_size_limits.update({ - 'MAIL': command_size_limit + 26, - }) - max_command_size_limit = max(command_size_limits.values()) + + @property + def max_command_size_limit(self): + try: + return max(self.command_size_limits.values()) + except ValueError: + return self.command_size_limit def __init__(self, server, conn, addr, data_size_limit=DATA_SIZE_DEFAULT, - map=None, decode_data=None): + map=None, enable_SMTPUTF8=False, decode_data=None): asynchat.async_chat.__init__(self, conn, map=map) self.smtp_server = server self.conn = conn self.addr = addr self.data_size_limit = data_size_limit + self.enable_SMTPUTF8 = enable_SMTPUTF8 + if enable_SMTPUTF8: + if decode_data: + ValueError("decode_data and enable_SMTPUTF8 cannot be set to" + " True at the same time") + decode_data = False if decode_data is None: warn("The decode_data default of True will change to False in 3.6;" " specify an explicit value for this keyword", @@ -143,14 +156,11 @@ self._linesep = b'\r\n' self._dotsep = b'.' self._newline = b'\n' - self.received_lines = [] - self.smtp_state = self.COMMAND + self._set_rset_state() self.seen_greeting = '' - self.mailfrom = None - self.rcpttos = [] - self.received_data = '' + self.extended_smtp = False + self.command_size_limits.clear() self.fqdn = socket.getfqdn() - self.num_bytes = 0 try: self.peer = conn.getpeername() except OSError as err: @@ -162,8 +172,22 @@ return print('Peer:', repr(self.peer), file=DEBUGSTREAM) self.push('220 %s %s' % (self.fqdn, __version__)) + + def _set_post_data_state(self): + """Reset state variables to their post-DATA state.""" + self.smtp_state = self.COMMAND + self.mailfrom = None + self.rcpttos = [] + self.require_SMTPUTF8 = False + self.num_bytes = 0 self.set_terminator(b'\r\n') - self.extended_smtp = False + + def _set_rset_state(self): + """Reset all state variables except the greeting.""" + self._set_post_data_state() + self.received_data = '' + self.received_lines = [] + # properties for backwards-compatibility @property @@ -287,9 +311,10 @@ "set 'addr' instead", DeprecationWarning, 2) self.addr = value - # Overrides base class for convenience + # Overrides base class for convenience. def push(self, msg): - asynchat.async_chat.push(self, bytes(msg + '\r\n', 'ascii')) + asynchat.async_chat.push(self, bytes( + msg + '\r\n', 'utf-8' if self.require_SMTPUTF8 else 'ascii')) # Implementation of base class abstract method def collect_incoming_data(self, data): @@ -317,7 +342,6 @@ if not line: self.push('500 Error: bad syntax') return - method = None if not self._decode_data: line = str(line, 'utf-8') i = line.find(' ') @@ -356,15 +380,12 @@ else: data.append(text) self.received_data = self._newline.join(data) - status = self.smtp_server.process_message(self.peer, - self.mailfrom, - self.rcpttos, - self.received_data) - self.rcpttos = [] - self.mailfrom = None - self.smtp_state = self.COMMAND - self.num_bytes = 0 - self.set_terminator(b'\r\n') + args = (self.peer, self.mailfrom, self.rcpttos, self.received_data) + if self.require_SMTPUTF8: + status = self.smtp_server.process_smtputf8_message(*args) + else: + status = self.smtp_server.process_message(*args) + self._set_post_data_state() if not status: self.push('250 OK') else: @@ -375,26 +396,34 @@ if not arg: self.push('501 Syntax: HELO hostname') return + # See issue #21783 for a discussion of this behavior. if self.seen_greeting: self.push('503 Duplicate HELO/EHLO') - else: - self.seen_greeting = arg - self.extended_smtp = False - self.push('250 %s' % self.fqdn) + return + self._set_rset_state() + self.seen_greeting = arg + self.push('250 %s' % self.fqdn) def smtp_EHLO(self, arg): if not arg: self.push('501 Syntax: EHLO hostname') return + # See issue #21783 for a discussion of this behavior. if self.seen_greeting: self.push('503 Duplicate HELO/EHLO') - else: - self.seen_greeting = arg - self.extended_smtp = True - self.push('250-%s' % self.fqdn) - if self.data_size_limit: - self.push('250-SIZE %s' % self.data_size_limit) - self.push('250 HELP') + return + self._set_rset_state() + self.seen_greeting = arg + self.extended_smtp = True + self.push('250-%s' % self.fqdn) + if self.data_size_limit: + self.push('250-SIZE %s' % self.data_size_limit) + self.command_size_limits['MAIL'] += 26 + if self.enable_SMTPUTF8: + self.push('250-8BITMIME') + self.push('250-SMTPUTF8') + self.command_size_limits['MAIL'] += 10 + self.push('250 HELP') def smtp_NOOP(self, arg): if arg: @@ -427,8 +456,8 @@ def _getparams(self, params): # Return any parameters that appear to be syntactically valid according # to RFC 1869, ignore all others. (Postel rule: accept what we can.) - params = [param.split('=', 1) for param in params.split() - if '=' in param] + params = [param.split('=', 1) if '=' in param else (param, True) + for param in params.split()] return {k: v for k, v in params if k.isalnum()} def smtp_HELP(self, arg): @@ -506,6 +535,14 @@ if params is None: self.push(syntaxerr) return + body = params.pop('BODY', '7BIT') + if self.enable_SMTPUTF8 and params.pop('SMTPUTF8', False): + if body != '8BITMIME': + self.push('501 Syntax: MAIL FROM:
' + ' [BODY=8BITMIME SMTPUTF8]') + return + else: + self.require_SMTPUTF8 = True size = params.pop('SIZE', None) if size: if not size.isdigit(): @@ -566,11 +603,7 @@ if arg: self.push('501 Syntax: RSET') return - # Resets the sender, recipients, and data, but not the greeting - self.mailfrom = None - self.rcpttos = [] - self.received_data = '' - self.smtp_state = self.COMMAND + self._set_rset_state() self.push('250 OK') def smtp_DATA(self, arg): @@ -598,10 +631,17 @@ def __init__(self, localaddr, remoteaddr, data_size_limit=DATA_SIZE_DEFAULT, map=None, - decode_data=None): + enable_SMTPUTF8=False, decode_data=None): self._localaddr = localaddr self._remoteaddr = remoteaddr self.data_size_limit = data_size_limit + self.enable_SMTPUTF8 = enable_SMTPUTF8 + if enable_SMTPUTF8: + if decode_data: + raise ValueError("The decode_data and enable_SMTPUTF8" + " parameters cannot be set to True at the" + " same time.") + decode_data = False if decode_data is None: warn("The decode_data default of True will change to False in 3.6;" " specify an explicit value for this keyword", @@ -627,8 +667,13 @@ def handle_accepted(self, conn, addr): print('Incoming connection from %s' % repr(addr), file=DEBUGSTREAM) - channel = self.channel_class(self, conn, addr, self.data_size_limit, - self._map, self._decode_data) + channel = self.channel_class(self, + conn, + addr, + self.data_size_limit, + self._map, + self.enable_SMTPUTF8, + self._decode_data) # API for "doing something useful with the message" def process_message(self, peer, mailfrom, rcpttos, data): @@ -649,29 +694,58 @@ containing a `.' followed by other text has had the leading dot removed. - This function should return None, for a normal `250 Ok' response; - otherwise it returns the desired response string in RFC 821 format. + This function should return None for a normal `250 Ok' response; + otherwise, it should return the desired response string in RFC 821 + format. """ raise NotImplementedError + # API for processing messeges needing Unicode support (RFC 6531, RFC 6532). + def process_smtputf8_message(self, peer, mailfrom, rcpttos, data): + """Same as ``process_message`` but for messages for which the client + has sent the SMTPUTF8 parameter with the MAIL command (see the + enable_SMTPUTF8 parameter of the constructor). + + This function should return None for a normal `250 Ok' response; + otherwise, it should return the desired response string in RFC 6531 + format. + + """ + raise NotImplementedError + class DebuggingServer(SMTPServer): - # Do something with the gathered message - def process_message(self, peer, mailfrom, rcpttos, data): + def _print_message_content(self, peer, data): inheaders = 1 + if type(data) == bytes: + # Preserve newlines and cut off "b''": + data = str(data).replace('\\n', '\n')[2:-1] lines = data.split('\n') - print('---------- MESSAGE FOLLOWS ----------') for line in lines: # headers first if inheaders and not line: print('X-Peer:', peer[0]) inheaders = 0 print(line) + + def process_message(self, peer, mailfrom, rcpttos, data): + print('---------- MESSAGE FOLLOWS ----------') + self._print_message_content(peer, data) print('------------ END MESSAGE ------------') + def process_smtputf8_message(self, peer, mailfrom, rcpttos, data): + print('----- SMTPUTF8 MESSAGE FOLLOWS ------') + self._print_message_content(peer, data) + print('------------ END MESSAGE ------------') + class PureProxy(SMTPServer): + def __init__(self, *args, **kwargs): + if 'enable_SMTPUTF8' in kwargs and kwargs['enable_SMTPUTF8']: + raise ValueError("PureProxy does not support SMTPUTF8.") + super(PureProxy, self).__init__(*args, **kwargs) + def process_message(self, peer, mailfrom, rcpttos, data): lines = data.split('\n') # Look for the last header @@ -712,6 +786,11 @@ class MailmanProxy(PureProxy): + def __init__(self, *args, **kwargs): + if 'enable_SMTPUTF8' in kwargs and kwargs['enable_SMTPUTF8']: + raise ValueError("MailmanProxy does not support SMTPUTF8.") + super(PureProxy, self).__init__(*args, **kwargs) + def process_message(self, peer, mailfrom, rcpttos, data): from io import StringIO from Mailman import Utils @@ -790,17 +869,19 @@ class Options: - setuid = 1 + setuid = True classname = 'PureProxy' size_limit = None + enable_SMTPUTF8 = False def parseargs(): global DEBUGSTREAM try: opts, args = getopt.getopt( - sys.argv[1:], 'nVhc:s:d', - ['class=', 'nosetuid', 'version', 'help', 'size=', 'debug']) + sys.argv[1:], 'nVhc:s:du', + ['class=', 'nosetuid', 'version', 'help', 'size=', 'debug', + 'smtputf8']) except getopt.error as e: usage(1, e) @@ -812,11 +893,13 @@ print(__version__) sys.exit(0) elif opt in ('-n', '--nosetuid'): - options.setuid = 0 + options.setuid = False elif opt in ('-c', '--class'): options.classname = arg elif opt in ('-d', '--debug'): DEBUGSTREAM = sys.stderr + elif opt in ('-u', '--smtputf8'): + options.enable_SMTPUTF8 = True elif opt in ('-s', '--size'): try: int_size = int(arg) @@ -871,7 +954,7 @@ class_ = getattr(mod, classname) proxy = class_((options.localhost, options.localport), (options.remotehost, options.remoteport), - options.size_limit) + options.size_limit, enable_SMTPUTF8=options.enable_SMTPUTF8) if options.setuid: try: import pwd diff -r c43362d35d8d Lib/test/test_smtpd.py --- a/Lib/test/test_smtpd.py Fri Jul 04 17:00:25 2014 -0700 +++ b/Lib/test/test_smtpd.py Wed Jul 30 01:09:56 2014 +0200 @@ -7,11 +7,10 @@ class DummyServer(smtpd.SMTPServer): - def __init__(self, localaddr, remoteaddr, decode_data=True): - smtpd.SMTPServer.__init__(self, localaddr, remoteaddr, - decode_data=decode_data) + def __init__(self, *args, **kwargs): + smtpd.SMTPServer.__init__(self, *args, **kwargs) self.messages = [] - if decode_data: + if self._decode_data: self.return_status = 'return status' else: self.return_status = b'return status' @@ -21,6 +20,9 @@ if data == self.return_status: return '250 Okish' + def process_smtputf8_message(self, *args, **kwargs): + return '250 SMTPUTF8 message okish' + class DummyDispatcherBroken(Exception): pass @@ -51,15 +53,113 @@ write_line(b'DATA') self.assertRaises(NotImplementedError, write_line, b'spam\r\n.\r\n') + def test_process_smtputf8_message_unimplemented(self): + server = smtpd.SMTPServer((support.HOST, 0), ('b', 0), + enable_SMTPUTF8=True) + conn, addr = server.accept() + channel = smtpd.SMTPChannel(server, conn, addr, enable_SMTPUTF8=True) + + def write_line(line): + channel.socket.queue_recv(line) + channel.handle_read() + + write_line(b'EHLO example') + write_line(b'MAIL From: