diff options
Diffstat (limited to 'Lib/smtplib.py')
| -rwxr-xr-x | Lib/smtplib.py | 240 |
1 files changed, 170 insertions, 70 deletions
diff --git a/Lib/smtplib.py b/Lib/smtplib.py index ac1f593789..dfbf5f9324 100755 --- a/Lib/smtplib.py +++ b/Lib/smtplib.py @@ -50,8 +50,9 @@ import email.generator import base64 import hmac import copy +import datetime +import sys from email.base64mime import body_encode as encode_base64 -from sys import stderr __all__ = ["SMTPException", "SMTPServerDisconnected", "SMTPResponseException", "SMTPSenderRefused", "SMTPRecipientsRefused", "SMTPDataError", @@ -70,6 +71,13 @@ OLDSTYLE_AUTH = re.compile(r"auth=(.*)", re.I) class SMTPException(OSError): """Base class for all exceptions raised by this module.""" +class SMTPNotSupportedError(SMTPException): + """The command or option is not supported by the SMTP server. + + This exception is raised when an attempt is made to run a command or a + command with an option which is not supported by the server. + """ + class SMTPServerDisconnected(SMTPException): """Not connected to any SMTP server. @@ -236,6 +244,7 @@ class SMTP: self._host = host self.timeout = timeout self.esmtp_features = {} + self.command_encoding = 'ascii' self.source_address = source_address if host: @@ -282,12 +291,17 @@ class SMTP: """ self.debuglevel = debuglevel + def _print_debug(self, *args): + if self.debuglevel > 1: + print(datetime.datetime.now().time(), *args, file=sys.stderr) + else: + print(*args, file=sys.stderr) + def _get_socket(self, host, port, timeout): # This makes it simpler for SMTP_SSL to use the SMTP connect code # and just alter the socket connection bit. if self.debuglevel > 0: - print('connect: to', (host, port), self.source_address, - file=stderr) + self._print_debug('connect: to', (host, port), self.source_address) return socket.create_connection((host, port), timeout, self.source_address) @@ -317,21 +331,24 @@ class SMTP: if not port: port = self.default_port if self.debuglevel > 0: - print('connect:', (host, port), file=stderr) + self._print_debug('connect:', (host, port)) self.sock = self._get_socket(host, port, self.timeout) self.file = None (code, msg) = self.getreply() if self.debuglevel > 0: - print("connect:", msg, file=stderr) + self._print_debug('connect:', repr(msg)) return (code, msg) def send(self, s): """Send `s' to the server.""" if self.debuglevel > 0: - print('send:', repr(s), file=stderr) + self._print_debug('send:', repr(s)) if hasattr(self, 'sock') and self.sock: if isinstance(s, str): - s = s.encode("ascii") + # send is used by the 'data' command, where command_encoding + # should not be used, but 'data' needs to convert the string to + # binary itself anyway, so that's not a problem. + s = s.encode(self.command_encoding) try: self.sock.sendall(s) except OSError: @@ -375,7 +392,7 @@ class SMTP: self.close() raise SMTPServerDisconnected("Connection unexpectedly closed") if self.debuglevel > 0: - print('reply:', repr(line), file=stderr) + self._print_debug('reply:', repr(line)) if len(line) > _MAXLINE: self.close() raise SMTPResponseException(500, "Line too long.") @@ -394,8 +411,7 @@ class SMTP: errmsg = b"\n".join(resp) if self.debuglevel > 0: - print('reply: retcode (%s); Msg: %s' % (errcode, errmsg), - file=stderr) + self._print_debug('reply: retcode (%s); Msg: %a' % (errcode, errmsg)) return errcode, errmsg def docmd(self, cmd, args=""): @@ -477,6 +493,7 @@ class SMTP: def rset(self): """SMTP 'rset' command -- resets session.""" + self.command_encoding = 'ascii' return self.docmd("rset") def _rset(self): @@ -496,9 +513,22 @@ class SMTP: return self.docmd("noop") def mail(self, sender, options=[]): - """SMTP 'mail' command -- begins mail xfer session.""" + """SMTP 'mail' command -- begins mail xfer session. + + This method may raise the following exceptions: + + SMTPNotSupportedError The options parameter includes 'SMTPUTF8' + but the SMTPUTF8 extension is not supported by + the server. + """ optionlist = '' if options and self.does_esmtp: + if any(x.lower()=='smtputf8' for x in options): + if self.has_extn('smtputf8'): + self.command_encoding = 'utf-8' + else: + raise SMTPNotSupportedError( + 'SMTPUTF8 not supported by server') optionlist = ' ' + ' '.join(options) self.putcmd("mail", "FROM:%s%s" % (quoteaddr(sender), optionlist)) return self.getreply() @@ -524,7 +554,7 @@ class SMTP: self.putcmd("data") (code, repl) = self.getreply() if self.debuglevel > 0: - print("data:", (code, repl), file=stderr) + self._print_debug('data:', (code, repl)) if code != 354: raise SMTPDataError(code, repl) else: @@ -537,7 +567,7 @@ class SMTP: self.send(q) (code, msg) = self.getreply() if self.debuglevel > 0: - print("data:", (code, msg), file=stderr) + self._print_debug('data:', (code, msg)) return (code, msg) def verify(self, address): @@ -571,12 +601,77 @@ class SMTP: if not (200 <= code <= 299): raise SMTPHeloError(code, resp) - def login(self, user, password): + def auth(self, mechanism, authobject, *, initial_response_ok=True): + """Authentication command - requires response processing. + + 'mechanism' specifies which authentication mechanism is to + be used - the valid values are those listed in the 'auth' + element of 'esmtp_features'. + + 'authobject' must be a callable object taking a single argument: + + data = authobject(challenge) + + It will be called to process the server's challenge response; the + challenge argument it is passed will be a bytes. It should return + bytes data that will be base64 encoded and sent to the server. + + Keyword arguments: + - initial_response_ok: Allow sending the RFC 4954 initial-response + to the AUTH command, if the authentication methods supports it. + """ + # RFC 4954 allows auth methods to provide an initial response. Not all + # methods support it. By definition, if they return something other + # than None when challenge is None, then they do. See issue #15014. + mechanism = mechanism.upper() + initial_response = (authobject() if initial_response_ok else None) + if initial_response is not None: + response = encode_base64(initial_response.encode('ascii'), eol='') + (code, resp) = self.docmd("AUTH", mechanism + " " + response) + else: + (code, resp) = self.docmd("AUTH", mechanism) + # If server responds with a challenge, send the response. + if code == 334: + challenge = base64.decodebytes(resp) + response = encode_base64( + authobject(challenge).encode('ascii'), eol='') + (code, resp) = self.docmd(response) + if code in (235, 503): + return (code, resp) + raise SMTPAuthenticationError(code, resp) + + def auth_cram_md5(self, challenge=None): + """ Authobject to use with CRAM-MD5 authentication. Requires self.user + and self.password to be set.""" + # CRAM-MD5 does not support initial-response. + if challenge is None: + return None + return self.user + " " + hmac.HMAC( + self.password.encode('ascii'), challenge, 'md5').hexdigest() + + def auth_plain(self, challenge=None): + """ Authobject to use with PLAIN authentication. Requires self.user and + self.password to be set.""" + return "\0%s\0%s" % (self.user, self.password) + + def auth_login(self, challenge=None): + """ Authobject to use with LOGIN authentication. Requires self.user and + self.password to be set.""" + if challenge is None: + return self.user + else: + return self.password + + def login(self, user, password, *, initial_response_ok=True): """Log in on an SMTP server that requires authentication. The arguments are: - - user: The user name to authenticate with. - - password: The password for the authentication. + - user: The user name to authenticate with. + - password: The password for the authentication. + + Keyword arguments: + - initial_response_ok: Allow sending the RFC 4954 initial-response + to the AUTH command, if the authentication methods supports it. If there has been no previous EHLO or HELO command this session, this method tries ESMTP EHLO first. @@ -589,67 +684,49 @@ class SMTP: the helo greeting. SMTPAuthenticationError The server didn't accept the username/ password combination. + SMTPNotSupportedError The AUTH command is not supported by the + server. SMTPException No suitable authentication method was found. """ - def encode_cram_md5(challenge, user, password): - challenge = base64.decodebytes(challenge) - response = user + " " + hmac.HMAC(password.encode('ascii'), - challenge, 'md5').hexdigest() - return encode_base64(response.encode('ascii'), eol='') - - def encode_plain(user, password): - s = "\0%s\0%s" % (user, password) - return encode_base64(s.encode('ascii'), eol='') - - AUTH_PLAIN = "PLAIN" - AUTH_CRAM_MD5 = "CRAM-MD5" - AUTH_LOGIN = "LOGIN" - self.ehlo_or_helo_if_needed() - if not self.has_extn("auth"): - raise SMTPException("SMTP AUTH extension not supported by server.") + raise SMTPNotSupportedError( + "SMTP AUTH extension not supported by server.") # Authentication methods the server claims to support advertised_authlist = self.esmtp_features["auth"].split() - # List of authentication methods we support: from preferred to - # less preferred methods. Except for the purpose of testing the weaker - # ones, we prefer stronger methods like CRAM-MD5: - preferred_auths = [AUTH_CRAM_MD5, AUTH_PLAIN, AUTH_LOGIN] + # Authentication methods we can handle in our preferred order: + preferred_auths = ['CRAM-MD5', 'PLAIN', 'LOGIN'] - # We try the authentication methods the server advertises, but only the - # ones *we* support. And in our preferred order. - authlist = [auth for auth in preferred_auths if auth in advertised_authlist] + # We try the supported authentications in our preferred order, if + # the server supports them. + authlist = [auth for auth in preferred_auths + if auth in advertised_authlist] if not authlist: raise SMTPException("No suitable authentication method found.") # Some servers advertise authentication methods they don't really # support, so if authentication fails, we continue until we've tried # all methods. + self.user, self.password = user, password for authmethod in authlist: - if authmethod == AUTH_CRAM_MD5: - (code, resp) = self.docmd("AUTH", AUTH_CRAM_MD5) - if code == 334: - (code, resp) = self.docmd(encode_cram_md5(resp, user, password)) - elif authmethod == AUTH_PLAIN: - (code, resp) = self.docmd("AUTH", - AUTH_PLAIN + " " + encode_plain(user, password)) - elif authmethod == AUTH_LOGIN: - (code, resp) = self.docmd("AUTH", - "%s %s" % (AUTH_LOGIN, encode_base64(user.encode('ascii'), eol=''))) - if code == 334: - (code, resp) = self.docmd(encode_base64(password.encode('ascii'), eol='')) - - # 235 == 'Authentication successful' - # 503 == 'Error: already authenticated' - if code in (235, 503): - return (code, resp) - - # We could not login sucessfully. Return result of last attempt. - raise SMTPAuthenticationError(code, resp) + method_name = 'auth_' + authmethod.lower().replace('-', '_') + try: + (code, resp) = self.auth( + authmethod, getattr(self, method_name), + initial_response_ok=initial_response_ok) + # 235 == 'Authentication successful' + # 503 == 'Error: already authenticated' + if code in (235, 503): + return (code, resp) + except SMTPAuthenticationError as e: + last_exception = e + + # We could not login successfully. Return result of last attempt. + raise last_exception def starttls(self, keyfile=None, certfile=None, context=None): """Puts the connection to the SMTP server into TLS mode. @@ -670,7 +747,8 @@ class SMTP: """ self.ehlo_or_helo_if_needed() if not self.has_extn("starttls"): - raise SMTPException("STARTTLS extension not supported by server.") + raise SMTPNotSupportedError( + "STARTTLS extension not supported by server.") (resp, reply) = self.docmd("STARTTLS") if resp == 220: if not _have_ssl: @@ -740,6 +818,9 @@ class SMTP: SMTPDataError The server replied with an unexpected error code (other than a refusal of a recipient). + SMTPNotSupportedError The mail_options parameter includes 'SMTPUTF8' + but the SMTPUTF8 extension is not supported by + the server. Note: the connection will be open even after an exception is raised. @@ -768,8 +849,6 @@ class SMTP: if isinstance(msg, str): msg = _fix_eols(msg).encode('ascii') if self.does_esmtp: - # Hmmm? what's this? -ddm - # self.esmtp_features['7bit']="" if self.has_extn('size'): esmtp_opts.append("size=%d" % len(msg)) for option in mail_options: @@ -817,7 +896,13 @@ class SMTP: to_addr, any Bcc field (or Resent-Bcc field, when the Message is a resent) of the Message object won't be transmitted. The Message object is then serialized using email.generator.BytesGenerator and - sendmail is called to transmit the message. + sendmail is called to transmit the message. If the sender or any of + the recipient addresses contain non-ASCII and the server advertises the + SMTPUTF8 capability, the policy is cloned with utf8 set to True for the + serialization, and SMTPUTF8 and BODY=8BITMIME are asserted on the send. + If the server does not support SMTPUTF8, an SMPTNotSupported error is + raised. Otherwise the generator is called without modifying the + policy. """ # 'Resent-Date' is a mandatory field if the Message is resent (RFC 2822 @@ -830,6 +915,7 @@ class SMTP: # option allowing the user to enable the heuristics. (It should be # possible to guess correctly almost all of the time.) + self.ehlo_or_helo_if_needed() resent = msg.get_all('Resent-Date') if resent is None: header_prefix = '' @@ -845,14 +931,30 @@ class SMTP: if to_addrs is None: addr_fields = [f for f in (msg[header_prefix + 'To'], msg[header_prefix + 'Bcc'], - msg[header_prefix + 'Cc']) if f is not None] + msg[header_prefix + 'Cc']) + if f is not None] to_addrs = [a[1] for a in email.utils.getaddresses(addr_fields)] # Make a local copy so we can delete the bcc headers. msg_copy = copy.copy(msg) del msg_copy['Bcc'] del msg_copy['Resent-Bcc'] + international = False + try: + ''.join([from_addr, *to_addrs]).encode('ascii') + except UnicodeEncodeError: + if not self.has_extn('smtputf8'): + raise SMTPNotSupportedError( + "One or more source or delivery addresses require" + " internationalized email support, but the server" + " does not advertise the required SMTPUTF8 capability") + international = True with io.BytesIO() as bytesmsg: - g = email.generator.BytesGenerator(bytesmsg) + if international: + g = email.generator.BytesGenerator( + bytesmsg, policy=msg.policy.clone(utf8=True)) + mail_options += ['SMTPUTF8', 'BODY=8BITMIME'] + else: + g = email.generator.BytesGenerator(bytesmsg) g.flatten(msg_copy, linesep='\r\n') flatmsg = bytesmsg.getvalue() return self.sendmail(from_addr, to_addrs, flatmsg, mail_options, @@ -920,7 +1022,7 @@ if _have_ssl: def _get_socket(self, host, port, timeout): if self.debuglevel > 0: - print('connect:', (host, port), file=stderr) + self._print_debug('connect:', (host, port)) new_socket = socket.create_connection((host, port), timeout, self.source_address) new_socket = self.context.wrap_socket(new_socket, @@ -968,22 +1070,20 @@ class LMTP(SMTP): self.sock.connect(host) except OSError: if self.debuglevel > 0: - print('connect fail:', host, file=stderr) + self._print_debug('connect fail:', host) if self.sock: self.sock.close() self.sock = None raise (code, msg) = self.getreply() if self.debuglevel > 0: - print('connect:', msg, file=stderr) + self._print_debug('connect:', msg) return (code, msg) # Test the sendmail method, which tests most of the others. # Note: This always sends to localhost. if __name__ == '__main__': - import sys - def prompt(prompt): sys.stdout.write(prompt + ": ") sys.stdout.flush() |