1 # Copyright (C) 2012 W. Trevor King <wking@drexel.edu>
3 # This file is part of pygrader.
5 # pygrader is free software: you can redistribute it and/or modify it under the
6 # terms of the GNU General Public License as published by the Free Software
7 # Foundation, either version 3 of the License, or (at your option) any later
10 # pygrader is distributed in the hope that it will be useful, but WITHOUT ANY
11 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12 # A PARTICULAR PURPOSE. See the GNU General Public License for more details.
14 # You should have received a copy of the GNU General Public License along with
15 # pygrader. If not, see <http://www.gnu.org/licenses/>.
17 from __future__ import absolute_import
19 from email import message_from_file as _message_from_file
20 from email.header import decode_header as _decode_header
21 import hashlib as _hashlib
22 import locale as _locale
23 import mailbox as _mailbox
25 import os.path as _os_path
29 from pgp_mime import verify as _verify
30 from lxml import etree as _etree
32 from . import LOG as _LOG
33 from .color import standard_colors as _standard_colors
34 from .color import color_string as _color_string
35 from .extract_mime import extract_mime as _extract_mime
36 from .extract_mime import message_time as _message_time
37 from .storage import assignment_path as _assignment_path
38 from .storage import set_late as _set_late
41 def mailpipe(basedir, course, stream=None, mailbox=None, input_=None,
42 output=None, max_late=0, use_color=None, dry_run=False, **kwargs):
43 """Run from procmail to sort incomming submissions
45 For example, you can setup your ``.procmailrc`` like this::
51 LOGFILE=$MAILDIR/procmail.log
53 PYGRADE_MAILPIPE="pg.py -d $HOME/grades/phys160"
55 # Grab all incoming homeworks emails. This rule eats matching emails
56 # (i.e. no further procmail processing).
58 * ^Subject:.*\[phys160-sub]
59 | "$PYGRADE_MAILPIPE" mailpipe
61 If you don't want procmail to eat the message, you can use the
62 ``c`` flag (carbon copy) by starting your rule off with ``:0 c``.
66 for msg,person,assignment,time in _load_messages(
67 course=course, stream=stream, mailbox=mailbox, input_=input_,
68 output=output, use_color=use_color, dry_run=dry_run):
69 assignment_path = _assignment_path(basedir, assignment, person)
70 _save_local_message_copy(
71 msg=msg, person=person, assignment_path=assignment_path,
72 use_color=use_color, dry_run=dry_run)
73 _extract_mime(message=msg, output=assignment_path, dry_run=dry_run)
75 basedir=basedir, assignment=assignment, person=person, time=time,
76 max_late=max_late, use_color=use_color, dry_run=dry_run)
78 def _load_messages(course, stream, mailbox=None, input_=None, output=None,
79 use_color=None, dry_run=False):
82 messages = [(None,_message_from_file(stream))]
83 elif mailbox == 'mbox':
84 mbox = _mailbox.mbox(input_, factory=None, create=False)
85 messages = mbox.items()
86 if output is not None:
87 ombox = _mailbox.mbox(output, factory=None, create=True)
88 elif mailbox == 'maildir':
89 mbox = _mailbox.Maildir(input_, factory=None, create=False)
90 messages = mbox.items()
91 if output is not None:
92 ombox = _mailbox.Maildir(output, factory=None, create=True)
94 raise ValueError(mailbox)
95 for key,msg in messages:
97 course=course, msg=msg, use_color=use_color)
99 if mbox is not None and output is not None and dry_run is False:
100 # move message from input mailbox to output mailbox
105 def _parse_message(course, msg, use_color=None):
106 highlight,lowlight,good,bad = _standard_colors(use_color=use_color)
107 mid = msg['Message-ID']
108 sender = msg['Return-Path'] # RFC 822
110 _LOG.debug(_color_string(
111 string='no Return-Path in {}'.format(mid), color=lowlight))
113 sender = sender[1:-1] # strip wrapping '<' and '>'
115 people = list(course.find_people(email=sender))
117 _LOG.warn(_color_string(
118 string='no person found to match {}'.format(sender),
122 _LOG.warn(_color_string(
123 string='multiple people match {} ({})'.format(
124 sender, ', '.join(str(p) for p in people)),
130 msg = _get_verified_message(msg, person.pgp_key, use_color=use_color)
134 if msg['Subject'] is None:
135 _LOG.warn(_color_string(
136 string='no subject in {}'.format(mid), color=bad))
138 parts = _decode_header(msg['Subject'])
140 _LOG.warn(_color_string(
141 string='multi-part header {}'.format(parts), color=bad))
143 subject,encoding = parts[0]
146 _LOG.debug('decoded header {} -> {}'.format(parts[0], subject))
147 subject = subject.lower().replace('#', '')
148 for assignment in course.assignments:
149 if _match_assignment(assignment, subject):
151 if not _match_assignment(assignment, subject):
152 _LOG.warn(_color_string(
153 string='no assignment found in {}'.format(repr(subject)),
157 time = _message_time(message=msg, use_color=use_color)
158 return (msg, person, assignment, time)
160 def _match_assignment(assignment, subject):
161 return assignment.name.lower() in subject
163 def _save_local_message_copy(msg, person, assignment_path, use_color=None,
165 highlight,lowlight,good,bad = _standard_colors(use_color=use_color)
167 _os.makedirs(assignment_path)
170 mpath = _os_path.join(assignment_path, 'mail')
172 mbox = _mailbox.Maildir(mpath, factory=None, create=not dry_run)
173 except _mailbox.NoSuchMailboxError as e:
174 _LOG.debug(_color_string(
175 string='could not open mailbox at {}'.format(mpath),
181 for other_msg in mbox:
182 if other_msg['Message-ID'] == msg['Message-ID']:
186 _LOG.debug(_color_string(
187 string='saving email from {} to {}'.format(
188 person, assignment_path), color=good))
189 if mbox is not None and not dry_run:
190 mdmsg = _mailbox.MaildirMessage(msg)
195 _LOG.debug(_color_string(
196 string='already found {} in {}'.format(
197 msg['Message-ID'], mpath), color=good))
199 def _check_late(basedir, assignment, person, time, max_late=0, use_color=None,
201 highlight,lowlight,good,bad = _standard_colors(use_color=use_color)
202 if time > assignment.due + max_late:
203 dt = time - assignment.due
204 _LOG.warn(_color_string(
205 string='{} {} late by {} seconds ({} hours)'.format(
206 person.name, assignment.name, dt, dt/3600.),
209 _set_late(basedir=basedir, assignment=assignment, person=person)
211 def _get_verified_message(message, pgp_key, use_color=None):
214 >>> from copy import deepcopy
215 >>> from pgp_mime import sign, encodedMIMEText
217 The student composes a message...
219 >>> message = encodedMIMEText('1.23 joules')
221 ... and signs it (with the pgp-mime test key).
223 >>> signed = sign(message, signers=['pgp-mime-test'])
225 As it is being delivered, the message picks up extra headers.
227 >>> signed['Message-ID'] = '<01234567@home.net>'
228 >>> signed['Received'] = 'from smtp.mail.uu.edu ...'
229 >>> signed['Received'] = 'from smtp.home.net ...'
231 We check that the message is signed, and that it is signed by the
234 >>> our_message = _get_verified_message(
235 ... deepcopy(signed), pgp_key='4332B6E3')
236 >>> print(our_message.as_string()) # doctest: +REPORT_UDIFF
237 Content-Type: text/plain; charset="us-ascii"
239 Content-Transfer-Encoding: 7bit
240 Content-Disposition: inline
241 Message-ID: <01234567@home.net>
242 Received: from smtp.mail.uu.edu ...
243 Received: from smtp.home.net ...
247 If it is signed, but not by the right key, we get ``None``.
249 >>> print(_get_verified_message(
250 ... deepcopy(signed), pgp_key='01234567'))
253 If it is not signed at all, we get ``None``.
255 >>> print(_get_verified_message(
256 ... deepcopy(message), pgp_key='4332B6E3'))
259 highlight,lowlight,good,bad = _standard_colors(use_color=use_color)
260 mid = message['message-id']
262 decrypted,verified,result = _verify(message=message)
263 except (ValueError, AssertionError):
264 _LOG.warn(_color_string(
265 string='could not verify {} (not signed?)'.format(mid),
268 _LOG.info(_color_string(str(result, 'utf-8'), color=lowlight))
269 tree = _etree.fromstring(result.replace(b'\x00', b''))
271 for signature in tree.findall('.//signature'):
272 for fingerprint in signature.iterchildren('fpr'):
273 if fingerprint.text.endswith(pgp_key):
277 _LOG.warn(_color_string(
278 string='{} is not signed by the expected key'.format(mid),
282 sumhex = list(signature.iterchildren('summary'))[0].get('value')
283 summary = int(sumhex, 16)
285 _LOG.warn(_color_string(
286 string='{} has an unverified signature'.format(mid),
289 # otherwise, we may have an untrusted key. We'll count that
290 # as verified here, because the caller is explicity looking
291 # for signatures by this fingerprint.
292 for k,v in message.items(): # copy over useful headers
293 if k.lower() not in ['content-type',
295 'content-disposition',