diff options
Diffstat (limited to 'src/mailman/handlers/dmarc.py')
| -rw-r--r-- | src/mailman/handlers/dmarc.py | 97 |
1 files changed, 51 insertions, 46 deletions
diff --git a/src/mailman/handlers/dmarc.py b/src/mailman/handlers/dmarc.py index 99d8e08df..13707d397 100644 --- a/src/mailman/handlers/dmarc.py +++ b/src/mailman/handlers/dmarc.py @@ -43,6 +43,7 @@ from zope.interface import implementer log = logging.getLogger('mailman.error') COMMASPACE = ', ' +EMPTYSTRING = '' MAXLINELEN = 78 NONASCII = re.compile('[^\s!-~]') # Headers from the original that we want to keep in the wrapper. These are @@ -84,48 +85,49 @@ def munged_headers(mlist, msg, msgdata): # goals is priority order. # # Be as robust as possible here. - faddrs = getaddresses(msg.get_all('from', [])) + all_froms = getaddresses(msg.get_all('from', [])) # Strip the nulls and bad emails. - faddrs = [x for x in faddrs if x[1].find('@') > 0] - if len(faddrs) == 1: - realname, email = o_from = faddrs[0] + froms = [email for email in all_froms if '@' in email[1]] + if len(froms) == 1: + realname, email = original_from = froms[0] else: # No From: or multiple addresses. Just punt and take # the get_sender result. realname = '' email = msgdata['original_sender'] - o_from = (realname, email) + original_from = (realname, email) + # If there was no display name in the email header, see if we have a + # matching member with a display name. if len(realname) == 0: member = mlist.members.get_member(email) if member: realname = member.display_name or email else: realname = email - # Remove domain from realname if it looks like an email address. + # Remove the domain from realname if it looks like an email address. realname = re.sub(r'@([^ .]+\.)+[^ .]+$', '---', realname) # Make a display name and RFC 2047 encode it if necessary. This is - # difficult and kludgy. If the realname came from From: it should be - # ascii or RFC 2047 encoded. If it came from the list, it should be - # a string. If it's from the email address, it should be an ascii string. - # In any case, ensure it's an unencoded string. - srn = '' - for frag, cs in decode_header(realname): - if not cs: - # Character set should be ascii, but use iso-8859-1 anyway. - cs = 'iso-8859-1' - if not isinstance(frag, str): - srn += str(frag, cs, errors='replace') + # difficult and kludgy. If the realname came from From: it should be + # ASCII or RFC 2047 encoded. If it came from the member record, it should + # be a string. If it's from the email address, it should be an ASCII + # string. In any case, ensure it's an unencoded string. + realname_bits = [] + for fragment, charset in decode_header(realname): + if not charset: + # Character set should be ASCII, but use iso-8859-1 anyway. + charset = 'iso-8859-1' + if not isinstance(fragment, str): + realname_bits.append(str(fragment, charset, errors='replace')) else: - srn += frag - # The list's real_name is a string. - lrn = mlist.display_name # noqa F841 - realname = srn + realname_bits.append(fragment) + # The member's display name is a string. + realname = EMPTYSTRING.join(realname_bits) # Ensure the i18n context is the list's preferred_language. with _.using(mlist.preferred_language.code): - via = _('$realname via $lrn') + via = _('$realname via $mlist.display_name') # Get an RFC 2047 encoded header string. - dn = str(Header(via, mlist.preferred_language.charset)) - retn = [('From', formataddr((dn, mlist.posting_address)))] + display_name = str(Header(via, mlist.preferred_language.charset)) + value = [('From', formataddr((display_name, mlist.posting_address)))] # We've made the munged From:. Now put the original in Reply-To: or Cc: if mlist.reply_goes_to_list is ReplyToMunging.no_munging: # Add original from to Reply-To: @@ -133,52 +135,54 @@ def munged_headers(mlist, msg, msgdata): else: # Add original from to Cc: add_to = 'Cc' - orig = getaddresses(msg.get_all(add_to, [])) - if o_from[1] not in [x[1] for x in orig]: - orig.append(o_from) - retn.append((add_to, COMMASPACE.join(formataddr(x) for x in orig))) - return retn + original = getaddresses(msg.get_all(add_to, [])) + if original_from[1] not in [x[1] for x in original]: + original.append(original_from) + value.append((add_to, COMMASPACE.join(formataddr(x) for x in original))) + return value def munge_from(mlist, msg, msgdata): - for k, v in munged_headers(mlist, msg, msgdata): - del msg[k] - msg[k] = v + for key, value in munged_headers(mlist, msg, msgdata): + del msg[key] + msg[key] = value return def wrap_message(mlist, msg, msgdata): # Create a wrapper message around the original. + # # There are various headers in msg that we don't want, so we basically - # make a copy of the msg, then delete almost everything and set/copy + # make a copy of the message, then delete almost everything and set/copy # what we want. - omsg = copy.deepcopy(msg) + original_msg = copy.deepcopy(msg) for key in msg: keep = False for keeper in KEEPERS: - if re.match(keeper, key, re.I): + if re.match(keeper, key, re.IGNORECASE): keep = True break if not keep: del msg[key] msg['MIME-Version'] = '1.0' msg['Message-ID'] = make_msgid() - for k, v in munged_headers(mlist, omsg, msgdata): - msg[k] = v + for key, value in munged_headers(mlist, original_msg, msgdata): + msg[key] = value # Are we including dmarc_wrapped_message_text? if len(mlist.dmarc_wrapped_message_text) > 0: - part1 = MIMEText(wrap(mlist.dmarc_wrapped_message_text), - 'plain', - mlist.preferred_language.charset) + part1 = MIMEText( + wrap(mlist.dmarc_wrapped_message_text), + 'plain', + mlist.preferred_language.charset) part1['Content-Disposition'] = 'inline' - part2 = MIMEMessage(omsg) + part2 = MIMEMessage(original_msg) part2['Content-Disposition'] = 'inline' msg['Content-Type'] = 'multipart/mixed' msg.set_payload([part1, part2]) else: msg['Content-Type'] = 'message/rfc822' msg['Content-Disposition'] = 'inline' - msg.set_payload([omsg]) + msg.set_payload([original_msg]) return @@ -186,7 +190,7 @@ def process(mlist, msg, msgdata): # If we're mitigating on policy and we have no hit, return. if not msgdata.get('dmarc') and not mlist.dmarc_mitigate_unconditionally: return - # if we're not mitigating, return. + # If we're not mitigating, return. if mlist.dmarc_mitigate_action is DMARCMitigateAction.no_mitigation: return if mlist.anonymous_list: @@ -198,10 +202,11 @@ def process(mlist, msg, msgdata): elif mlist.dmarc_mitigate_action is DMARCMitigateAction.wrap_message: wrap_message(mlist, msg, msgdata) else: - # We can get here if DMARCMitigateAction is reject or discard - # but the From: domain has no reject or quarantine policy and - # mlist.dmarc_mitigate_unconditionally is True. We just ignore + # We can get here if DMARCMitigateAction is reject or discard but + # the From: domain has no reject or quarantine policy and + # mlist.dmarc_mitigate_unconditionally is True. Log and ignore # this. + log.error('Invalid DMARC combination for list: %s', mlist) return else: raise AssertionError( |