# Copyright (C) 1998-2008 by the Free Software Foundation, Inc. # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License # as published by the Free Software Foundation; either version 2 # of the License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, # USA. """Cook a message's Subject header.""" from __future__ import nested_scopes import re from types import UnicodeType from email.Charset import Charset from email.Header import Header, decode_header, make_header from email.Utils import parseaddr, formataddr, getaddresses from email.Errors import HeaderParseError from Mailman import mm_cfg from Mailman import Utils from Mailman.i18n import _ from Mailman.Logging.Syslog import syslog CONTINUATION = ',\n\t' COMMASPACE = ', ' MAXLINELEN = 78 # True/False try: True, False except NameError: True = 1 False = 0 def _isunicode(s): return isinstance(s, UnicodeType) nonascii = re.compile('[^\s!-~]') def uheader(mlist, s, header_name=None, continuation_ws='\t', maxlinelen=None): # Get the charset to encode the string in. Then search if there is any # non-ascii character is in the string. If there is and the charset is # us-ascii then we use iso-8859-1 instead. If the string is ascii only # we use 'us-ascii' if another charset is specified. charset = Utils.GetCharSet(mlist.preferred_language) if nonascii.search(s): # use list charset but ... if charset == 'us-ascii': charset = 'iso-8859-1' else: # there is no nonascii so ... charset = 'us-ascii' return Header(s, charset, maxlinelen, header_name, continuation_ws) def process(mlist, msg, msgdata): # Set the "X-Ack: no" header if noack flag is set. if msgdata.get('noack'): del msg['x-ack'] msg['X-Ack'] = 'no' # Because we're going to modify various important headers in the email # message, we want to save some of the information in the msgdata # dictionary for later. Specifically, the sender header will get waxed, # but we need it for the Acknowledge module later. msgdata['original_sender'] = msg.get_sender() # VirginRunner sets _fasttrack for internally crafted messages. fasttrack = msgdata.get('_fasttrack') if not msgdata.get('isdigest') and not fasttrack: try: prefix_subject(mlist, msg, msgdata) except (UnicodeError, ValueError): # TK: Sometimes subject header is not MIME encoded for 8bit # simply abort prefixing. pass # Mark message so we know we've been here, but leave any existing # X-BeenThere's intact. msg['X-BeenThere'] = mlist.GetListEmail() # Add Precedence: and other useful headers. None of these are standard # and finding information on some of them are fairly difficult. Some are # just common practice, and we'll add more here as they become necessary. # Good places to look are: # # http://www.dsv.su.se/~jpalme/ietf/jp-ietf-home.html # http://www.faqs.org/rfcs/rfc2076.html # # None of these headers are added if they already exist. BAW: some # consider the advertising of this a security breach. I.e. if there are # known exploits in a particular version of Mailman and we know a site is # using such an old version, they may be vulnerable. It's too easy to # edit the code to add a configuration variable to handle this. if not msg.has_key('x-mailman-version'): msg['X-Mailman-Version'] = mm_cfg.VERSION # We set "Precedence: list" because this is the recommendation from the # sendmail docs, the most authoritative source of this header's semantics. if not msg.has_key('precedence'): msg['Precedence'] = 'list' # Reply-To: munging. Do not do this if the message is "fast tracked", # meaning it is internally crafted and delivered to a specific user. BAW: # Yuck, I really hate this feature but I've caved under the sheer pressure # of the (very vocal) folks want it. OTOH, RFC 2822 allows Reply-To: to # be a list of addresses, so instead of replacing the original, simply # augment it. RFC 2822 allows max one Reply-To: header so collapse them # if we're adding a value, otherwise don't touch it. (Should we collapse # in all cases?) if not fasttrack: # A convenience function, requires nested scopes. pair is (name, addr) new = [] d = {} def add(pair): lcaddr = pair[1].lower() if d.has_key(lcaddr): return d[lcaddr] = pair new.append(pair) # List admin wants an explicit Reply-To: added if mlist.reply_goes_to_list == 2: add(parseaddr(mlist.reply_to_address)) # If we're not first stripping existing Reply-To: then we need to add # the original Reply-To:'s to the list we're building up. In both # cases we'll zap the existing field because RFC 2822 says max one is # allowed. if not mlist.first_strip_reply_to: orig = msg.get_all('reply-to', []) for pair in getaddresses(orig): add(pair) # Set Reply-To: header to point back to this list. Add this last # because some folks think that some MUAs make it easier to delete # addresses from the right than from the left. if mlist.reply_goes_to_list == 1: i18ndesc = uheader(mlist, mlist.description, 'Reply-To') add((str(i18ndesc), mlist.GetListEmail())) del msg['reply-to'] # Don't put Reply-To: back if there's nothing to add! if new: # Preserve order msg['Reply-To'] = COMMASPACE.join( [formataddr(pair) for pair in new]) # The To field normally contains the list posting address. However # when messages are fully personalized, that header will get # overwritten with the address of the recipient. We need to get the # posting address in one of the recipient headers or they won't be # able to reply back to the list. It's possible the posting address # was munged into the Reply-To header, but if not, we'll add it to a # Cc header. BAW: should we force it into a Reply-To header in the # above code? # Also skip Cc if this is an anonymous list as list posting address # is already in From and Reply-To in this case. if mlist.personalize == 2 and mlist.reply_goes_to_list <> 1 \ and not mlist.anonymous_list: # Watch out for existing Cc headers, merge, and remove dups. Note # that RFC 2822 says only zero or one Cc header is allowed. new = [] d = {} for pair in getaddresses(msg.get_all('cc', [])): add(pair) i18ndesc = uheader(mlist, mlist.description, 'Cc') add((str(i18ndesc), mlist.GetListEmail())) del msg['Cc'] msg['Cc'] = COMMASPACE.join([formataddr(pair) for pair in new]) # Add list-specific headers as defined in RFC 2369 and RFC 2919, but only # if the message is being crafted for a specific list (e.g. not for the # password reminders). # # BAW: Some people really hate the List-* headers. It seems that the free # version of Eudora (possibly on for some platforms) does not hide these # headers by default, pissing off their users. Too bad. Fix the MUAs. if msgdata.get('_nolist') or not mlist.include_rfc2369_headers: return # This will act like an email address for purposes of formataddr() listid = '%s.%s' % (mlist.internal_name(), mlist.host_name) cset = Utils.GetCharSet(mlist.preferred_language) if mlist.description: # Don't wrap the header since here we just want to get it properly RFC # 2047 encoded. i18ndesc = uheader(mlist, mlist.description, 'List-Id', maxlinelen=998) listid_h = formataddr((str(i18ndesc), listid)) else: # without desc we need to ensure the MUST brackets listid_h = '<%s>' % listid # We always add a List-ID: header. del msg['list-id'] msg['List-Id'] = listid_h # For internally crafted messages, we also add a (nonstandard), # "X-List-Administrivia: yes" header. For all others (i.e. those coming # from list posts), we add a bunch of other RFC 2369 headers. requestaddr = mlist.GetRequestEmail() subfieldfmt = '<%s>, <mailto:%s?subject=%ssubscribe>' listinfo = mlist.GetScriptURL('listinfo', absolute=1) useropts = mlist.GetScriptURL('options', absolute=1) headers = {} if msgdata.get('reduced_list_headers'): headers['X-List-Administrivia'] = 'yes' else: headers.update({ 'List-Help' : '<mailto:%s?subject=help>' % requestaddr, 'List-Unsubscribe': subfieldfmt % (useropts, requestaddr, 'un'), 'List-Subscribe' : subfieldfmt % (listinfo, requestaddr, ''), }) # List-Post: is controlled by a separate attribute if mlist.include_list_post_header: headers['List-Post'] = '<mailto:%s>' % mlist.GetListEmail() # Add this header if we're archiving if mlist.archive: archiveurl = mlist.GetBaseArchiveURL() if archiveurl.endswith('/'): archiveurl = archiveurl[:-1] headers['List-Archive'] = '<%s>' % archiveurl # First we delete any pre-existing headers because the RFC permits only # one copy of each, and we want to be sure it's ours. for h, v in headers.items(): del msg[h] # Wrap these lines if they are too long. 78 character width probably # shouldn't be hardcoded, but is at least text-MUA friendly. The # adding of 2 is for the colon-space separator. if len(h) + 2 + len(v) > 78: v = CONTINUATION.join(v.split(', ')) msg[h] = v def prefix_subject(mlist, msg, msgdata): # Add the subject prefix unless the message is a digest or is being fast # tracked (e.g. internally crafted, delivered to a single user such as the # list admin). prefix = mlist.subject_prefix.strip() if not prefix: return subject = msg.get('subject', '') # Try to figure out what the continuation_ws is for the header if isinstance(subject, Header): lines = str(subject).splitlines() else: lines = subject.splitlines() ws = '\t' if len(lines) > 1 and lines[1] and lines[1][0] in ' \t': ws = lines[1][0] msgdata['origsubj'] = subject # The subject may be multilingual but we take the first charset as major # one and try to decode. If it is decodable, returned subject is in one # line and cset is properly set. If fail, subject is mime-encoded and # cset is set as us-ascii. See detail for ch_oneline() (CookHeaders one # line function). subject, cset = ch_oneline(subject) # TK: Python interpreter has evolved to be strict on ascii charset code # range. It is safe to use unicode string when manupilating header # contents with re module. It would be best to return unicode in # ch_oneline() but here is temporary solution. subject = unicode(subject, cset) # If the subject_prefix contains '%d', it is replaced with the # mailing list sequential number. Sequential number format allows # '%d' or '%05d' like pattern. prefix_pattern = re.escape(prefix) # unescape '%' :-< prefix_pattern = '%'.join(prefix_pattern.split(r'\%')) p = re.compile('%\d*d') if p.search(prefix, 1): # prefix have number, so we should search prefix w/number in subject. # Also, force new style. prefix_pattern = p.sub(r'\s*\d+\s*', prefix_pattern) old_style = False else: old_style = mm_cfg.OLD_STYLE_PREFIXING subject = re.sub(prefix_pattern, '', subject) rematch = re.match('((RE|AW|SV|VS)(\[\d+\])?:\s*)+', subject, re.I) if rematch: subject = subject[rematch.end():] recolon = 'Re:' else: recolon = '' # At this point, subject may become null if someone post mail with # subject: [subject prefix] if subject.strip() == '': subject = _('(no subject)') cset = Utils.GetCharSet(mlist.preferred_language) subject = unicode(subject, cset) # and substitute %d in prefix with post_id try: prefix = prefix % mlist.post_id except TypeError: pass # If charset is 'us-ascii', try to concatnate as string because there # is some weirdness in Header module (TK) if cset == 'us-ascii': try: if old_style: h = u' '.join([recolon, prefix, subject]) else: if recolon: h = u' '.join([prefix, recolon, subject]) else: h = u' '.join([prefix, subject]) h = h.encode('us-ascii') h = uheader(mlist, h, 'Subject', continuation_ws=ws) del msg['subject'] msg['Subject'] = h ss = u' '.join([recolon, subject]) ss = ss.encode('us-ascii') ss = uheader(mlist, ss, 'Subject', continuation_ws=ws) msgdata['stripped_subject'] = ss return except UnicodeError: pass # Get the header as a Header instance, with proper unicode conversion if old_style: h = uheader(mlist, recolon, 'Subject', continuation_ws=ws) h.append(prefix) else: h = uheader(mlist, prefix, 'Subject', continuation_ws=ws) h.append(recolon) # TK: Subject is concatenated and unicode string. subject = subject.encode(cset, 'replace') h.append(subject, cset) del msg['subject'] msg['Subject'] = h ss = uheader(mlist, recolon, 'Subject', continuation_ws=ws) ss.append(subject, cset) msgdata['stripped_subject'] = ss def ch_oneline(headerstr): # Decode header string in one line and convert into single charset # copied and modified from ToDigest.py and Utils.py # return (string, cset) tuple as check for failure try: d = decode_header(headerstr) # at this point, we should rstrip() every string because some # MUA deliberately add trailing spaces when composing return # message. d = [(s.rstrip(), c) for (s,c) in d] cset = 'us-ascii' for x in d: # search for no-None charset if x[1]: cset = x[1] break h = make_header(d) ustr = h.__unicode__() oneline = u''.join(ustr.splitlines()) return oneline.encode(cset, 'replace'), cset except (LookupError, UnicodeError, ValueError, HeaderParseError): # possibly charset problem. return with undecoded string in one line. return ''.join(headerstr.splitlines()), 'us-ascii'