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0bec96d6 | 1 | #! /usr/bin/env python3 |
ff4136c7 | 2 | # -*- coding: utf-8 -*- |
0bec96d6 AE |
3 | """********************************************************************* |
4 | * Edward is free software: you can redistribute it and/or modify * | |
5 | * it under the terms of the GNU Affero Public License as published by * | |
6 | * the Free Software Foundation, either version 3 of the License, or * | |
7 | * (at your option) any later version. * | |
8 | * * | |
9 | * Edward is distributed in the hope that it will be useful, * | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * | |
12 | * GNU Affero Public License for more details. * | |
13 | * * | |
14 | * You should have received a copy of the GNU Affero Public License * | |
15 | * along with Edward. If not, see <http://www.gnu.org/licenses/>. * | |
16 | * * | |
17 | * Copyright (C) 2014-2015 Andrew Engelbrecht (AGPLv3+) * | |
18 | * Copyright (C) 2014 Josh Drake (AGPLv3+) * | |
19 | * Copyright (C) 2014 Lisa Marie Maginnis (AGPLv3+) * | |
8bdfb6d4 AE |
20 | * Copyright (C) 2009-2015 Tails developers <tails@boum.org> ( GPLv3+) * |
21 | * Copyright (C) 2009 W. Trevor King <wking@drexel.edu> ( GPLv2+) * | |
0bec96d6 AE |
22 | * * |
23 | * Special thanks to Josh Drake for writing the original edward bot! :) * | |
24 | * * | |
25 | ************************************************************************ | |
26 | ||
a5385c04 | 27 | Code sourced from these projects: |
0bec96d6 | 28 | |
8bdfb6d4 AE |
29 | * http://agpl.fsf.org/emailselfdefense.fsf.org/edward/CURRENT/edward.tar.gz |
30 | * https://git-tails.immerda.ch/whisperback/tree/whisperBack/encryption.py?h=feature/python3 | |
31 | * http://www.physics.drexel.edu/~wking/code/python/send_pgp_mime | |
0bec96d6 AE |
32 | """ |
33 | ||
0bec96d6 AE |
34 | import re |
35 | import io | |
40c37ab3 | 36 | import os |
2f4ce2b2 | 37 | import sys |
0fd3389f | 38 | import enum |
2f4ce2b2 | 39 | import gpgme |
adcef2f7 | 40 | import importlib |
60ccbaf4 | 41 | import subprocess |
0bec96d6 | 42 | |
8bdfb6d4 AE |
43 | import email.parser |
44 | import email.message | |
45 | import email.encoders | |
46 | ||
e5dd6f23 | 47 | from email.mime.text import MIMEText |
8bdfb6d4 AE |
48 | from email.mime.multipart import MIMEMultipart |
49 | from email.mime.application import MIMEApplication | |
50 | from email.mime.nonmultipart import MIMENonMultipart | |
51 | ||
40c37ab3 | 52 | import edward_config |
c96f3837 | 53 | |
5b0e37d3 | 54 | langs = ["de", "el", "en", "fr", "ja", "pt-br", "ro", "ru", "tr"] |
adcef2f7 | 55 | |
def9196c AE |
56 | """This list contains the abbreviated names of reply languages available to |
57 | edward.""" | |
58 | ||
0fd3389f AE |
59 | class TxtType (enum.Enum): |
60 | text = 0 | |
61 | message = 1 | |
62 | pubkey = 2 | |
63 | detachedsig = 3 | |
64 | signature = 4 | |
def9196c | 65 | |
0fd3389f | 66 | |
2f4102b9 | 67 | match_pairs = [(TxtType.message, |
56578eaf | 68 | '-----BEGIN PGP MESSAGE-----.*?-----END PGP MESSAGE-----'), |
0fd3389f | 69 | (TxtType.pubkey, |
56578eaf | 70 | '-----BEGIN PGP PUBLIC KEY BLOCK-----.*?-----END PGP PUBLIC KEY BLOCK-----'), |
0fd3389f | 71 | (TxtType.detachedsig, |
38738401 | 72 | '-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----')] |
56578eaf | 73 | |
def9196c AE |
74 | """This list of tuples matches query names with re.search() queries used |
75 | to find GPG data for edward to process.""" | |
76 | ||
56578eaf AE |
77 | |
78 | class EddyMsg (object): | |
def9196c AE |
79 | """ |
80 | The EddyMsg class represents relevant parts of a mime message. | |
81 | ||
82 | The represented message can be single-part or multi-part. | |
83 | ||
84 | 'multipart' is set to True if there are multiple mime parts. | |
85 | ||
86 | 'subparts' points to a list of mime sub-parts if it is a multi-part | |
87 | message. Otherwise it points to an empty list. | |
88 | ||
6d8faaa7 AE |
89 | 'payload_bytes' is a binary representation of the mime part before header |
90 | removal and message decoding. | |
def9196c AE |
91 | |
92 | 'payload_pieces' is a list of objects containing strings that when strung | |
93 | together form the fully-decoded string representation of the mime part. | |
94 | ||
def9196c AE |
95 | The 'filename', 'content_type' and 'description_list' come from the mime |
96 | part parameters. | |
97 | """ | |
98 | ||
7d0b91d2 AE |
99 | multipart = False |
100 | subparts = [] | |
56578eaf | 101 | |
7d0b91d2 AE |
102 | payload_bytes = None |
103 | payload_pieces = [] | |
56578eaf | 104 | |
7d0b91d2 AE |
105 | filename = None |
106 | content_type = None | |
107 | description_list = None | |
56578eaf AE |
108 | |
109 | ||
110 | class PayloadPiece (object): | |
def9196c AE |
111 | """ |
112 | PayloadPiece represents a complte or sub-section of a mime part. | |
113 | ||
114 | Instances of this class are often strung together within one or more arrays | |
115 | pointed to by each instance of the EddyMsg class. | |
116 | ||
0fd3389f AE |
117 | 'piece_type' refers to an enum whose value describes the content of |
118 | 'string'. Examples include TxtType.pubkey, for public keys, and | |
119 | TxtType.message, for encrypted data (or armored signatures until they are | |
120 | known to be such.) Some of the names derive from the header and footer of | |
121 | each of these ascii-encoded gpg blocks. | |
def9196c AE |
122 | |
123 | 'string' contains some string of text, such as non-GPG text, an encrypted | |
124 | block of text, a signature, or a public key. | |
125 | ||
126 | 'gpg_data' points to any instances of GPGData that have been created based | |
127 | on the contents of 'string'. | |
128 | """ | |
129 | ||
7d0b91d2 AE |
130 | piece_type = None |
131 | string = None | |
132 | gpg_data = None | |
56578eaf AE |
133 | |
134 | ||
38738401 | 135 | class GPGData (object): |
def9196c AE |
136 | """ |
137 | GPGData holds info from decryption, sig. verification, and/or pub. keys. | |
138 | ||
139 | Instances of this class contain decrypted information, signature | |
140 | fingerprints and/or fingerprints of processed and imported public keys. | |
141 | ||
142 | 'decrypted' is set to True if 'plainobj' was created from encrypted data. | |
143 | ||
144 | 'plainobj' points to any decrypted, or signed part of, a GPG signature. It | |
145 | is intended to be an instance of the EddyMsg class. | |
146 | ||
147 | 'sigs' is a list of fingerprints of keys used to sign the data in plainobj. | |
148 | ||
149 | 'keys' is a list of fingerprints of keys obtained in public key blocks. | |
150 | """ | |
151 | ||
7d0b91d2 AE |
152 | decrypted = False |
153 | ||
154 | plainobj = None | |
155 | sigs = [] | |
156 | keys = [] | |
38738401 | 157 | |
38738401 | 158 | |
d873ff48 | 159 | class ReplyInfo (object): |
def9196c AE |
160 | """ |
161 | ReplyInfo contains details that edward uses in generating its reply. | |
162 | ||
163 | Instances of this class contain information about whether a message was | |
164 | successfully encrypted or signed, and whether a public key was attached, or | |
165 | retrievable, from the local GPG store. It stores the fingerprints of | |
166 | potential encryption key candidates and the message (if any at all) to | |
167 | quote in edward's reply. | |
168 | ||
169 | 'replies' points one of the dictionaries of translated replies. | |
170 | ||
171 | 'target_key' refers to the fingerprint of a key used to sign encrypted | |
172 | data. This is the preferred key, if it is set, and if is available. | |
173 | ||
174 | 'fallback_target_key' referst to the fingerprint of a key used to sign | |
175 | unencrypted data; alternatively it may be a public key attached to the | |
176 | message. | |
177 | ||
178 | 'msg_to_quote' refers to the part of a message which edward should quote in | |
179 | his reply. This should remain as None if there was no encrypted and singed | |
180 | part. This is to avoid making edward a service for decrypting other | |
181 | people's messages to edward. | |
182 | ||
183 | 'success_decrypt' is set to True if edward could decrypt part of the | |
184 | message. | |
185 | ||
186 | 'failed_decrypt' is set to True if edward failed to decrypt part of the | |
187 | message. | |
188 | ||
189 | 'publick_key_received' is set to True if edward successfully imported a | |
190 | public key. | |
191 | ||
192 | 'no_public_key' is set to True if edward doesn't have a key to encrypt to | |
193 | when replying to the user. | |
194 | ||
195 | 'sig_success' is set to True if edward could to some extent verify the | |
196 | signature of a signed part of the message to edward. | |
197 | ||
198 | 'sig_failure' is set to True if edward failed to some extent verify the | |
199 | signature of a signed part of the message to edward. | |
200 | """ | |
201 | ||
7d0b91d2 | 202 | replies = None |
6906d46d | 203 | |
7d0b91d2 AE |
204 | target_key = None |
205 | fallback_target_key = None | |
206 | msg_to_quote = "" | |
d873ff48 | 207 | |
7d0b91d2 AE |
208 | success_decrypt = False |
209 | failed_decrypt = False | |
210 | public_key_received = False | |
211 | no_public_key = False | |
212 | sig_success = False | |
213 | sig_failure = False | |
d873ff48 | 214 | |
38738401 | 215 | |
0bec96d6 AE |
216 | def main (): |
217 | ||
def9196c AE |
218 | """ |
219 | This is the main function for edward, a GPG reply bot. | |
220 | ||
221 | Edward responds to GPG-encrypted and signed mail, encrypting and signing | |
222 | the response if the user's public key is, or was, included in the message. | |
223 | ||
224 | Args: | |
225 | None | |
226 | ||
227 | Returns: | |
a3d6aff8 | 228 | Nothing |
def9196c AE |
229 | |
230 | Pre: | |
231 | Mime or plaintext email passing in through standard input. Portions of | |
232 | the email may be encrypted. If the To: address contains the text | |
233 | "edward-ja", then the reply will contain a reply written in the | |
234 | Japanese language. There are other languages as well. The default | |
235 | language is English. | |
236 | ||
237 | Post: | |
238 | A reply email will be printed to standard output. The contents of the | |
239 | reply email depends on whether the original email was encrypted or not, | |
240 | has or doesn't have a signature, whether a public key used in the | |
241 | original message is provided or locally stored, and the language | |
242 | implied by the To: address in the original email. | |
243 | """ | |
244 | ||
60ccbaf4 | 245 | print_reply_only = handle_args() |
0bec96d6 | 246 | |
0a064403 AE |
247 | gpgme_ctx = get_gpg_context(edward_config.gnupghome, |
248 | edward_config.sign_with_key) | |
249 | ||
c96f3837 | 250 | email_text = sys.stdin.read() |
adcef2f7 AE |
251 | email_struct = parse_pgp_mime(email_text, gpgme_ctx) |
252 | ||
253 | email_to, email_from, email_subject = email_to_from_subject(email_text) | |
60ccbaf4 | 254 | lang, reply_from = import_lang_pick_address(email_to, edward_config.hostname) |
fafa21c3 | 255 | |
d873ff48 AE |
256 | replyinfo_obj = ReplyInfo() |
257 | replyinfo_obj.replies = lang.replies | |
258 | ||
259 | prepare_for_reply(email_struct, replyinfo_obj) | |
013f7cb8 | 260 | encrypt_to_key = get_key_from_fp(replyinfo_obj, gpgme_ctx) |
d873ff48 | 261 | reply_plaintext = write_reply(replyinfo_obj) |
adcef2f7 | 262 | |
2007103e AE |
263 | reply_mime = generate_encrypted_mime(reply_plaintext, email_from, \ |
264 | email_subject, encrypt_to_key, | |
265 | gpgme_ctx) | |
1fccb295 | 266 | |
60ccbaf4 AE |
267 | if print_reply_only == True: |
268 | print(reply_mime) | |
269 | else: | |
270 | send_reply(reply_mime, email_subject, email_from, reply_from) | |
c96f3837 | 271 | |
0bec96d6 | 272 | |
0a064403 | 273 | def get_gpg_context (gnupghome, sign_with_key_fp): |
a3d6aff8 AE |
274 | """ |
275 | This function returns the GPG context needed for encryption and signing. | |
276 | ||
277 | The context is needed by other functions which use GPG functionality. | |
278 | ||
279 | Args: | |
280 | gnupghome: The path to "~/.gnupg/" or its alternative. | |
281 | sign_with_key: The fingerprint of the key to sign with | |
282 | ||
283 | Returns: | |
284 | A gpgme context to be used for GPG functions. | |
285 | ||
286 | Post: | |
287 | the 'armor' flag is set to True and the list of signing keys contains | |
288 | the single specified key | |
289 | """ | |
0a064403 AE |
290 | |
291 | os.environ['GNUPGHOME'] = gnupghome | |
292 | ||
293 | gpgme_ctx = gpgme.Context() | |
294 | gpgme_ctx.armor = True | |
295 | ||
296 | try: | |
297 | sign_with_key = gpgme_ctx.get_key(sign_with_key_fp) | |
5f6f32b1 | 298 | except gpgme.GpgmeError: |
0a064403 AE |
299 | error("unable to load signing key. is the gnupghome " |
300 | + "and signing key properly set in the edward_config.py?") | |
301 | exit(1) | |
302 | ||
303 | gpgme_ctx.signers = [sign_with_key] | |
304 | ||
305 | return gpgme_ctx | |
306 | ||
307 | ||
38738401 | 308 | def parse_pgp_mime (email_text, gpgme_ctx): |
a3d6aff8 AE |
309 | """Parses the email for mime payloads and decrypts/verfies signatures. |
310 | ||
311 | This function creates a representation of a mime or plaintext email with | |
312 | the EddyMsg class. It then splits each mime payload into one or more pieces | |
313 | which may be plain text or GPG data. It then decrypts encrypted parts and | |
314 | does some very basic signature verification on those parts. | |
315 | ||
316 | Args: | |
317 | email_text: an email message in string format | |
318 | gpgme_ctx: a gpgme context | |
319 | ||
320 | Returns: | |
321 | A message as an instance of EddyMsg | |
322 | ||
323 | Post: | |
324 | the returned EddyMsg instance has split, decrypted, verified and pubkey | |
325 | imported payloads | |
326 | """ | |
394a1476 AE |
327 | |
328 | email_struct = email.parser.Parser().parsestr(email_text) | |
329 | ||
928e3819 AE |
330 | eddymsg_obj = parse_mime(email_struct) |
331 | split_payloads(eddymsg_obj) | |
332 | gpg_on_payloads(eddymsg_obj, gpgme_ctx) | |
8bb4b0d5 | 333 | |
928e3819 | 334 | return eddymsg_obj |
0bec96d6 | 335 | |
0bec96d6 | 336 | |
56578eaf | 337 | def parse_mime(msg_struct): |
a3d6aff8 AE |
338 | """Translates python's email.parser format into an EddyMsg format |
339 | ||
340 | If the message is multi-part, then a recursive object is created, where | |
341 | each sub-part is also a EddyMsg instance. | |
342 | ||
343 | Args: | |
344 | msg_struct: an email parsed with email.parser.Parser(), which can be | |
345 | multi-part | |
346 | ||
347 | Returns: | |
348 | an instance of EddyMsg, potentially a recursive one. | |
349 | """ | |
0bec96d6 | 350 | |
928e3819 | 351 | eddymsg_obj = EddyMsg() |
8bb4b0d5 | 352 | |
56578eaf AE |
353 | if msg_struct.is_multipart() == True: |
354 | payloads = msg_struct.get_payload() | |
0bec96d6 | 355 | |
928e3819 AE |
356 | eddymsg_obj.multipart = True |
357 | eddymsg_obj.subparts = list(map(parse_mime, payloads)) | |
dd11a483 | 358 | |
56578eaf | 359 | else: |
928e3819 | 360 | eddymsg_obj = get_subpart_data(msg_struct) |
394a1476 | 361 | |
928e3819 | 362 | return eddymsg_obj |
c267c233 | 363 | |
80119cab | 364 | |
2f4102b9 | 365 | def scan_and_split (payload_piece, match_name, pattern): |
a3d6aff8 AE |
366 | """This splits the payloads of an EddyMsg object into GPG and text parts. |
367 | ||
368 | An EddyMsg object's payload_pieces starts off as a list containing a single | |
369 | PayloadPiece object. This function returns a list of these objects which | |
370 | have been split into GPG data and regular text, if such splits need to be/ | |
371 | can be made. | |
372 | ||
373 | Args: | |
374 | payload_piece: a single payload or a split part of a payload | |
2f4102b9 | 375 | match_name: the type of data to try to spit out from the payload piece |
a3d6aff8 AE |
376 | pattern: the search pattern to be used for finding that type of data |
377 | ||
378 | Returns: | |
379 | a list of objects of the PayloadPiece class, in the order that the | |
380 | string part of payload_piece originally was, broken up according to | |
381 | matches specified by 'pattern'. | |
382 | """ | |
cf75de65 | 383 | |
a5d37d44 | 384 | # don't try to re-split pieces containing gpg data |
0fd3389f | 385 | if payload_piece.piece_type != TxtType.text: |
a5d37d44 AE |
386 | return [payload_piece] |
387 | ||
56578eaf AE |
388 | flags = re.DOTALL | re.MULTILINE |
389 | matches = re.search("(?P<beginning>.*?)(?P<match>" + pattern + | |
390 | ")(?P<rest>.*)", payload_piece.string, flags=flags) | |
86663388 | 391 | |
56578eaf AE |
392 | if matches == None: |
393 | pieces = [payload_piece] | |
c96f3837 | 394 | |
56578eaf | 395 | else: |
d437f8b2 | 396 | |
56578eaf AE |
397 | beginning = PayloadPiece() |
398 | beginning.string = matches.group('beginning') | |
399 | beginning.piece_type = payload_piece.piece_type | |
d437f8b2 | 400 | |
56578eaf AE |
401 | match = PayloadPiece() |
402 | match.string = matches.group('match') | |
2f4102b9 | 403 | match.piece_type = match_name |
d437f8b2 | 404 | |
56578eaf AE |
405 | rest = PayloadPiece() |
406 | rest.string = matches.group('rest') | |
407 | rest.piece_type = payload_piece.piece_type | |
d437f8b2 | 408 | |
2f4102b9 | 409 | more_pieces = scan_and_split(rest, match_name, pattern) |
4615b156 | 410 | pieces = [beginning, match ] + more_pieces |
d437f8b2 | 411 | |
56578eaf | 412 | return pieces |
d437f8b2 | 413 | |
d437f8b2 | 414 | |
56578eaf | 415 | def get_subpart_data (part): |
a3d6aff8 AE |
416 | """This function grabs information from a single part mime object. |
417 | ||
418 | It copies needed data from a single part email.parser.Parser() object over | |
419 | to an EddyMsg object. | |
420 | ||
421 | Args: | |
422 | part: a non-multi-part mime.parser.Parser() object | |
423 | ||
424 | Returns: | |
425 | a single-part EddyMsg() object | |
426 | """ | |
0bec96d6 | 427 | |
6d8faaa7 AE |
428 | charset = part.get_content_charset() |
429 | mime_decoded_bytes = part.get_payload(decode=True) | |
0bec96d6 | 430 | |
6d8faaa7 AE |
431 | obj = EddyMsg() |
432 | obj.payload_bytes = part.as_bytes() | |
56578eaf AE |
433 | |
434 | obj.filename = part.get_filename() | |
435 | obj.content_type = part.get_content_type() | |
436 | obj.description_list = part['content-description'] | |
437 | ||
438 | # your guess is as good as a-myy-ee-ine... | |
6d8faaa7 AE |
439 | if charset == None: |
440 | charset = 'utf-8' | |
56578eaf | 441 | |
6d8faaa7 | 442 | if mime_decoded_bytes != None: |
0eb75d9c AE |
443 | try: |
444 | payload = PayloadPiece() | |
6d8faaa7 | 445 | payload.string = mime_decoded_bytes.decode(charset) |
0fd3389f | 446 | payload.piece_type = TxtType.text |
0eb75d9c AE |
447 | |
448 | obj.payload_pieces = [payload] | |
449 | except UnicodeDecodeError: | |
450 | pass | |
56578eaf AE |
451 | |
452 | return obj | |
453 | ||
454 | ||
928e3819 | 455 | def do_to_eddys_pieces (function_to_do, eddymsg_obj, data): |
a3d6aff8 AE |
456 | """A function which maps another function onto a message's subparts. |
457 | ||
458 | This is a higer-order function which recursively performs a specified | |
459 | function on each subpart of a multi-part message. Each single-part sub-part | |
460 | has the function applied to it. This function also works if the part passed | |
461 | in is single-part. | |
462 | ||
463 | Args: | |
464 | function_to_do: function to perform on sub-parts | |
465 | eddymsg_obj: a single part or multi-part EddyMsg object | |
466 | data: a second argument to pass to 'function_to_do' | |
467 | ||
468 | Returns: | |
469 | Nothing | |
470 | ||
471 | Post: | |
472 | The passed-in EddyMsg object is transformed recursively on its | |
473 | sub-parts according to 'function_to_do'. | |
474 | """ | |
56578eaf | 475 | |
928e3819 AE |
476 | if eddymsg_obj.multipart == True: |
477 | for sub in eddymsg_obj.subparts: | |
d873ff48 | 478 | do_to_eddys_pieces(function_to_do, sub, data) |
394a1476 | 479 | else: |
928e3819 | 480 | function_to_do(eddymsg_obj, data) |
dd11a483 AE |
481 | |
482 | ||
928e3819 | 483 | def split_payloads (eddymsg_obj): |
a3d6aff8 AE |
484 | """Splits all (sub-)payloads of a message into GPG data and regular text. |
485 | ||
486 | Recursively performs payload splitting on all sub-parts of an EddyMsg | |
487 | object into the various GPG data types, such as GPG messages, public key | |
488 | blocks and signed text. | |
489 | ||
490 | Args: | |
491 | eddymsg_obj: an instance of EddyMsg | |
492 | ||
493 | Returns: | |
494 | Nothing | |
495 | ||
496 | Pre: | |
497 | The EddyMsg object has payloads that are unsplit (by may be split).. | |
498 | ||
499 | Post: | |
500 | The EddyMsg object's payloads are all split into GPG and non-GPG parts. | |
501 | """ | |
a5d37d44 | 502 | |
2f4102b9 AE |
503 | for match_pair in match_pairs: |
504 | do_to_eddys_pieces(split_payload_pieces, eddymsg_obj, match_pair) | |
a5d37d44 | 505 | |
a5d37d44 | 506 | |
2f4102b9 | 507 | def split_payload_pieces (eddymsg_obj, match_pair): |
a3d6aff8 AE |
508 | """A helper function for split_payloads(); works on PayloadPiece objects. |
509 | ||
510 | This function splits up PayloadPiece objects into multipe PayloadPiece | |
511 | objects and replaces the EddyMsg object's previous list of payload pieces | |
512 | with the new split up one. | |
513 | ||
514 | Args: | |
515 | eddymsg_obj: a single-part EddyMsg object. | |
2f4102b9 | 516 | match_pair: a tuple from the match_pairs list, which specifies a match |
a3d6aff8 AE |
517 | name and a match pattern. |
518 | ||
519 | Returns: | |
520 | Nothing | |
521 | ||
522 | Pre: | |
523 | The payload piece(s) of an EddyMsg object may be already split or | |
524 | unsplit. | |
525 | ||
526 | Post: | |
527 | The EddyMsg object's payload piece(s) are split into a list of pieces | |
2f4102b9 | 528 | if matches of the match_pair are found. |
a3d6aff8 | 529 | """ |
a5d37d44 | 530 | |
2f4102b9 | 531 | (match_name, pattern) = match_pair |
a5d37d44 AE |
532 | |
533 | new_pieces_list = [] | |
928e3819 | 534 | for piece in eddymsg_obj.payload_pieces: |
a5d37d44 AE |
535 | new_pieces_list += scan_and_split(piece, match_name, pattern) |
536 | ||
928e3819 | 537 | eddymsg_obj.payload_pieces = new_pieces_list |
a5d37d44 AE |
538 | |
539 | ||
928e3819 | 540 | def gpg_on_payloads (eddymsg_obj, gpgme_ctx, prev_parts=[]): |
a3d6aff8 AE |
541 | """Performs GPG operations on the GPG parts of the message |
542 | ||
543 | This function decrypts text, verifies signatures, and imports public keys | |
544 | included in an email. | |
545 | ||
546 | Args: | |
547 | eddymsg_obj: an EddyMsg object with its payload_pieces split into GPG | |
548 | and non-GPG sections by split_payloads() | |
549 | gpgme_ctx: a gpgme context | |
550 | ||
551 | prev_parts: a list of mime parts that occur before the eddymsg_obj | |
552 | part, under the same multi-part mime part. This is used for | |
553 | verifying detached signatures. For the root mime part, this should | |
554 | be an empty list, which is the default value if this paramater is | |
555 | omitted. | |
556 | ||
557 | Return: | |
558 | Nothing | |
559 | ||
560 | Pre: | |
561 | eddymsg_obj should have its payloads split into gpg and non-gpg pieces. | |
562 | ||
563 | Post: | |
564 | Decryption, verification and key imports occur. the gpg_data member of | |
565 | PayloadPiece objects get filled in with GPGData objects. | |
566 | """ | |
38738401 | 567 | |
928e3819 | 568 | if eddymsg_obj.multipart == True: |
101d54a8 | 569 | prev_parts=[] |
928e3819 | 570 | for sub in eddymsg_obj.subparts: |
101d54a8 AE |
571 | gpg_on_payloads (sub, gpgme_ctx, prev_parts) |
572 | prev_parts += [sub] | |
38738401 | 573 | |
d873ff48 | 574 | return |
38738401 | 575 | |
928e3819 | 576 | for piece in eddymsg_obj.payload_pieces: |
38738401 | 577 | |
0fd3389f | 578 | if piece.piece_type == TxtType.text: |
38738401 AE |
579 | # don't transform the plaintext. |
580 | pass | |
581 | ||
0fd3389f | 582 | elif piece.piece_type == TxtType.message: |
7e18f14d | 583 | (plaintext, sigs) = decrypt_block(piece.string, gpgme_ctx) |
38738401 AE |
584 | |
585 | if plaintext: | |
586 | piece.gpg_data = GPGData() | |
b23e171d | 587 | piece.gpg_data.decrypted = True |
38738401 AE |
588 | piece.gpg_data.sigs = sigs |
589 | # recurse! | |
590 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
3a753fd0 AE |
591 | continue |
592 | ||
593 | # if not encrypted, check to see if this is an armored signature. | |
594 | (plaintext, sigs) = verify_sig_message(piece.string, gpgme_ctx) | |
595 | ||
596 | if plaintext: | |
0fd3389f | 597 | piece.piece_type = TxtType.signature |
3a753fd0 AE |
598 | piece.gpg_data = GPGData() |
599 | piece.gpg_data.sigs = sigs | |
600 | # recurse! | |
601 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
129543c3 | 602 | |
d7d8bf7c AE |
603 | # FIXME: consider handling pubkeys first, so that signatures can be |
604 | # validated on freshly imported keys | |
0fd3389f | 605 | elif piece.piece_type == TxtType.pubkey: |
f8ee6bd3 | 606 | key_fps = add_gpg_key(piece.string, gpgme_ctx) |
8f61c66a | 607 | |
f8ee6bd3 | 608 | if key_fps != []: |
8f61c66a | 609 | piece.gpg_data = GPGData() |
f8ee6bd3 | 610 | piece.gpg_data.keys = key_fps |
129543c3 | 611 | |
0fd3389f | 612 | elif piece.piece_type == TxtType.detachedsig: |
101d54a8 | 613 | for prev in prev_parts: |
6d8faaa7 | 614 | sig_fps = verify_detached_signature(piece.string, prev.payload_bytes, gpgme_ctx) |
101d54a8 | 615 | |
6d240f68 AE |
616 | if sig_fps != []: |
617 | piece.gpg_data = GPGData() | |
618 | piece.gpg_data.sigs = sig_fps | |
619 | piece.gpg_data.plainobj = prev | |
620 | break | |
7e18f14d | 621 | |
38738401 AE |
622 | else: |
623 | pass | |
624 | ||
625 | ||
928e3819 | 626 | def prepare_for_reply (eddymsg_obj, replyinfo_obj): |
67691346 AE |
627 | """Updates replyinfo_obj with info on the message's GPG success/failures |
628 | ||
629 | This function marks replyinfo_obj with information about whether encrypted | |
630 | text in eddymsg_obj was successfully decrypted, signatures were verified | |
631 | and whether a public key was found or not. | |
632 | ||
633 | Args: | |
634 | eddymsg_obj: a message in the EddyMsg format | |
635 | replyinfo_obj: an instance of ReplyInfo | |
636 | ||
637 | Returns: | |
638 | Nothing | |
639 | ||
640 | Pre: | |
641 | eddymsg_obj has had its gpg_data created by gpg_on_payloads | |
642 | ||
643 | Post: | |
644 | replyinfo_obj has been updated with info about decryption/sig | |
645 | verififcation status, etc. However the desired key isn't imported until | |
646 | later, so the success or failure of that updates the values set here. | |
647 | """ | |
dd11a483 | 648 | |
928e3819 | 649 | do_to_eddys_pieces(prepare_for_reply_pieces, eddymsg_obj, replyinfo_obj) |
56578eaf | 650 | |
928e3819 | 651 | def prepare_for_reply_pieces (eddymsg_obj, replyinfo_obj): |
67691346 AE |
652 | """A helper function for prepare_for_reply |
653 | ||
654 | It updates replyinfo_obj with GPG success/failure information, when | |
655 | supplied a single-part EddyMsg object. | |
656 | ||
657 | Args: | |
658 | eddymsg_obj: a single-part message in the EddyMsg format | |
659 | replyinfo_obj: an object which holds information about the message's | |
660 | GPG status | |
661 | ||
662 | Returns: | |
663 | Nothing | |
664 | ||
665 | Pre: | |
666 | eddymsg_obj is a single-part message. (it may be a part of a multi-part | |
667 | message.) It has had its gpg_data created by gpg_on_payloads if it has | |
668 | gpg data. | |
669 | ||
670 | Post: | |
671 | replyinfo_obj has been updated with gpg success/failure information | |
672 | """ | |
56578eaf | 673 | |
928e3819 | 674 | for piece in eddymsg_obj.payload_pieces: |
0fd3389f | 675 | if piece.piece_type == TxtType.text: |
d873ff48 AE |
676 | # don't quote the plaintext part. |
677 | pass | |
678 | ||
0fd3389f | 679 | elif piece.piece_type == TxtType.message: |
05683768 | 680 | prepare_for_reply_message(piece, replyinfo_obj) |
d873ff48 | 681 | |
0fd3389f | 682 | elif piece.piece_type == TxtType.pubkey: |
05683768 | 683 | prepare_for_reply_pubkey(piece, replyinfo_obj) |
6906d46d | 684 | |
0fd3389f AE |
685 | elif (piece.piece_type == TxtType.detachedsig) \ |
686 | or (piece.piece_type == TxtType.signature): | |
05683768 | 687 | prepare_for_reply_sig(piece, replyinfo_obj) |
d873ff48 | 688 | |
d873ff48 | 689 | |
05683768 | 690 | def prepare_for_reply_message (piece, replyinfo_obj): |
67691346 AE |
691 | """Helper function for prepare_for_reply() |
692 | ||
693 | This function is called when the piece_type of a payload piece is | |
0fd3389f | 694 | TxtType.message, or GPG Message block. This should be encrypted text. If the |
67691346 AE |
695 | encryted block is signed, a sig will be attached to .target_key unless |
696 | there is already one there. | |
697 | ||
698 | Args: | |
699 | piece: a PayloadPiece object. | |
700 | replyinfo_obj: object which gets updated with decryption status, etc. | |
701 | ||
702 | ||
703 | Returns: | |
704 | Nothing | |
705 | ||
706 | Pre: | |
0fd3389f | 707 | the piece.payload_piece value should be TxtType.message. |
67691346 AE |
708 | |
709 | Post: | |
710 | replyinfo_obj gets updated with decryption status, signing status and a | |
711 | potential signing key. | |
712 | """ | |
44fe39b7 | 713 | |
05683768 AE |
714 | if piece.gpg_data == None: |
715 | replyinfo_obj.failed_decrypt = True | |
716 | return | |
717 | ||
5c40e676 | 718 | replyinfo_obj.success_decrypt = True |
05683768 AE |
719 | |
720 | # we already have a key (and a message) | |
721 | if replyinfo_obj.target_key != None: | |
722 | return | |
723 | ||
724 | if piece.gpg_data.sigs != []: | |
725 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
726 | get_signed_part = False | |
727 | else: | |
728 | # only include a signed message in the reply. | |
729 | get_signed_part = True | |
730 | ||
8c3e5397 | 731 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, get_signed_part) |
05683768 AE |
732 | |
733 | # to catch public keys in encrypted blocks | |
734 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
735 | ||
736 | ||
737 | def prepare_for_reply_pubkey (piece, replyinfo_obj): | |
67691346 AE |
738 | """Helper function for prepare_for_reply(). Marks pubkey import status. |
739 | ||
740 | Marks replyinfo_obj with pub key import status. | |
741 | ||
742 | Args: | |
743 | piece: a PayloadPiece object | |
744 | replyinfo_obj: a ReplyInfo object | |
745 | ||
746 | Pre: | |
0fd3389f | 747 | piece.piece_type should be set to TxtType.pubkey . |
67691346 AE |
748 | |
749 | Post: | |
750 | replyinfo_obj has its fields updated. | |
751 | """ | |
05683768 AE |
752 | |
753 | if piece.gpg_data == None or piece.gpg_data.keys == []: | |
754 | replyinfo_obj.no_public_key = True | |
755 | else: | |
756 | replyinfo_obj.public_key_received = True | |
757 | ||
3ceb92e5 AE |
758 | # prefer public key as a fallback for the encrypted reply |
759 | replyinfo_obj.fallback_target_key = piece.gpg_data.keys[0] | |
05683768 AE |
760 | |
761 | ||
762 | def prepare_for_reply_sig (piece, replyinfo_obj): | |
67691346 AE |
763 | """Helper function for prepare_for_reply(). Marks sig verification status. |
764 | ||
765 | Marks replyinfo_obj with signature verification status. | |
766 | ||
767 | Args: | |
768 | piece: a PayloadPiece object | |
769 | replyinfo_obj: a ReplyInfo object | |
770 | ||
771 | Pre: | |
0fd3389f AE |
772 | piece.piece_type should be set to TxtType.signature, or |
773 | TxtType.detachedsig . | |
67691346 AE |
774 | |
775 | Post: | |
776 | replyinfo_obj has its fields updated. | |
777 | """ | |
05683768 AE |
778 | |
779 | if piece.gpg_data == None or piece.gpg_data.sigs == []: | |
780 | replyinfo_obj.sig_failure = True | |
781 | else: | |
782 | replyinfo_obj.sig_success = True | |
783 | ||
784 | if replyinfo_obj.fallback_target_key == None: | |
785 | replyinfo_obj.fallback_target_key = piece.gpg_data.sigs[0] | |
6906d46d AE |
786 | |
787 | ||
8c3e5397 AE |
788 | def flatten_decrypted_payloads (eddymsg_obj, replyinfo_obj, get_signed_part): |
789 | """For creating a string representation of a signed, encrypted part. | |
39e2c525 | 790 | |
8c3e5397 AE |
791 | When given a decrypted payload, it will add either the plaintext or signed |
792 | plaintext to the reply message, depeding on 'get_signed_part'. This is | |
793 | useful for ensuring that the reply message only comes from a signed and | |
794 | ecrypted GPG message. It also sets the target_key for encrypting the reply | |
795 | if it's told to get signed text only. | |
39e2c525 AE |
796 | |
797 | Args: | |
798 | eddymsg_obj: the message in EddyMsg format created by decrypting GPG | |
799 | text | |
8c3e5397 AE |
800 | replyinfo_obj: a ReplyInfo object for holding the message to quote and |
801 | the target_key to encrypt to. | |
39e2c525 AE |
802 | get_signed_part: True if we should only include text that contains a |
803 | further signature. If False, then include plain text. | |
804 | ||
805 | Returns: | |
8c3e5397 | 806 | Nothing |
39e2c525 AE |
807 | |
808 | Pre: | |
809 | The EddyMsg instance passed in should be a piece.gpg_data.plainobj | |
810 | which represents decrypted text. It may or may not be signed on that | |
811 | level. | |
d873ff48 | 812 | |
8c3e5397 AE |
813 | Post: |
814 | the ReplyInfo instance may have a new 'target_key' set and its | |
815 | 'msg_to_quote' will be updated with (possibly signed) plaintext, if any | |
816 | could be found. | |
817 | """ | |
d873ff48 | 818 | |
0aa88c27 | 819 | if eddymsg_obj == None: |
8c3e5397 | 820 | return |
0aa88c27 | 821 | |
0402995a | 822 | # recurse on multi-part mime |
928e3819 AE |
823 | if eddymsg_obj.multipart == True: |
824 | for sub in eddymsg_obj.subparts: | |
8c3e5397 | 825 | flatten_decrypted_payloads(sub, replyinfo_obj, get_signed_part) |
d873ff48 | 826 | |
928e3819 | 827 | for piece in eddymsg_obj.payload_pieces: |
0402995a | 828 | if (get_signed_part): |
0fd3389f AE |
829 | if ((piece.piece_type == TxtType.detachedsig) \ |
830 | or (piece.piece_type == TxtType.signature)) \ | |
0402995a | 831 | and (piece.gpg_data != None): |
8c3e5397 AE |
832 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, False) |
833 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
c3d417bf AE |
834 | break |
835 | else: | |
0fd3389f | 836 | if piece.piece_type == TxtType.text: |
8c3e5397 | 837 | replyinfo_obj.msg_to_quote += piece.string |
d873ff48 AE |
838 | |
839 | ||
013f7cb8 | 840 | def get_key_from_fp (replyinfo_obj, gpgme_ctx): |
39e2c525 AE |
841 | """Obtains a public key object from a key fingerprint |
842 | ||
843 | If the .target_key is not set, then we use .fallback_target_key. | |
844 | ||
845 | Args: | |
846 | replyinfo_obj: ReplyInfo instance | |
847 | gpgme_ctx: the gpgme context | |
848 | ||
849 | Return: | |
850 | The key object of the key of either the target_key or the fallback one | |
851 | if .target_key is not set. If the key cannot be loaded, then return | |
852 | None. | |
853 | ||
854 | Pre: | |
855 | Loading a key requires that we have the public key imported. This | |
856 | requires that they email contains the pub key block, or that it was | |
857 | previously sent to edward. | |
858 | ||
859 | Post: | |
860 | If the key cannot be loaded, then the replyinfo_obj is marked for | |
861 | having no public key available. | |
862 | """ | |
013f7cb8 | 863 | |
dc24daf1 AE |
864 | if replyinfo_obj.target_key == None: |
865 | replyinfo_obj.target_key = replyinfo_obj.fallback_target_key | |
866 | ||
013f7cb8 AE |
867 | if replyinfo_obj.target_key != None: |
868 | try: | |
869 | encrypt_to_key = gpgme_ctx.get_key(replyinfo_obj.target_key) | |
870 | return encrypt_to_key | |
871 | ||
5f6f32b1 | 872 | except gpgme.GpgmeError: |
013f7cb8 AE |
873 | pass |
874 | ||
875 | # no available key to use | |
876 | replyinfo_obj.target_key = None | |
877 | replyinfo_obj.fallback_target_key = None | |
878 | ||
879 | replyinfo_obj.no_public_key = True | |
880 | replyinfo_obj.public_key_received = False | |
881 | ||
882 | return None | |
883 | ||
884 | ||
d873ff48 | 885 | def write_reply (replyinfo_obj): |
39e2c525 AE |
886 | """Write the reply email body about the GPG successes/failures. |
887 | ||
888 | The reply is about whether decryption, sig verification and key | |
889 | import/loading was successful or failed. If text was successfully decrypted | |
890 | and verified, then the first instance of such text will be included in | |
891 | quoted form. | |
892 | ||
893 | Args: | |
894 | replyinfo_obj: contains details of GPG processing status | |
895 | ||
896 | Returns: | |
897 | the plaintext message to be sent to the user | |
898 | ||
899 | Pre: | |
900 | replyinfo_obj should be populated with info about GPG processing status. | |
901 | """ | |
d873ff48 AE |
902 | |
903 | reply_plain = "" | |
904 | ||
905 | if replyinfo_obj.success_decrypt == True: | |
d873ff48 | 906 | reply_plain += replyinfo_obj.replies['success_decrypt'] |
2694709a AE |
907 | |
908 | if replyinfo_obj.no_public_key == False: | |
909 | quoted_text = email_quote_text(replyinfo_obj.msg_to_quote) | |
910 | reply_plain += quoted_text | |
d873ff48 AE |
911 | |
912 | elif replyinfo_obj.failed_decrypt == True: | |
913 | reply_plain += replyinfo_obj.replies['failed_decrypt'] | |
914 | ||
915 | ||
916 | if replyinfo_obj.sig_success == True: | |
917 | reply_plain += "\n\n" | |
918 | reply_plain += replyinfo_obj.replies['sig_success'] | |
919 | ||
920 | elif replyinfo_obj.sig_failure == True: | |
921 | reply_plain += "\n\n" | |
922 | reply_plain += replyinfo_obj.replies['sig_failure'] | |
923 | ||
924 | ||
925 | if replyinfo_obj.public_key_received == True: | |
926 | reply_plain += "\n\n" | |
927 | reply_plain += replyinfo_obj.replies['public_key_received'] | |
928 | ||
929 | elif replyinfo_obj.no_public_key == True: | |
930 | reply_plain += "\n\n" | |
931 | reply_plain += replyinfo_obj.replies['no_public_key'] | |
932 | ||
933 | ||
934 | reply_plain += "\n\n" | |
935 | reply_plain += replyinfo_obj.replies['signature'] | |
7eefdf97 | 936 | reply_plain += "\n" |
56578eaf | 937 | |
d873ff48 | 938 | return reply_plain |
56578eaf AE |
939 | |
940 | ||
8f61c66a | 941 | def add_gpg_key (key_block, gpgme_ctx): |
39e2c525 AE |
942 | """Adds a GPG pubkey to the local keystore |
943 | ||
944 | This adds keys received through email into the key store so they can be | |
945 | used later. | |
946 | ||
947 | Args: | |
948 | key_block: the string form of the ascii-armored public key block | |
949 | gpgme_ctx: the gpgme context | |
950 | ||
951 | Returns: | |
952 | the fingerprint(s) of the imported key(s) | |
953 | """ | |
c267c233 | 954 | |
8f61c66a | 955 | fp = io.BytesIO(key_block.encode('ascii')) |
c267c233 | 956 | |
89c08329 AE |
957 | try: |
958 | result = gpgme_ctx.import_(fp) | |
959 | imports = result.imports | |
960 | except gpgme.GpgmeError: | |
961 | imports = [] | |
c267c233 | 962 | |
f8ee6bd3 | 963 | key_fingerprints = [] |
c267c233 | 964 | |
8f61c66a AE |
965 | if imports != []: |
966 | for import_ in imports: | |
967 | fingerprint = import_[0] | |
f8ee6bd3 | 968 | key_fingerprints += [fingerprint] |
c267c233 | 969 | |
e49673aa | 970 | debug("added gpg key: " + fingerprint) |
ec1e779a | 971 | |
f8ee6bd3 | 972 | return key_fingerprints |
ec1e779a AE |
973 | |
974 | ||
3a753fd0 | 975 | def verify_sig_message (msg_block, gpgme_ctx): |
39e2c525 AE |
976 | """Verifies the signature of a signed, ascii-armored block of text. |
977 | ||
978 | It encodes the string into ascii, since binary GPG files are currently | |
979 | unsupported, and alternative, the ascii-armored format is encodable into | |
980 | ascii. | |
981 | ||
982 | Args: | |
983 | msg_block: a GPG Message block in string form. It may be encrypted or | |
984 | not. If it is encrypted, it will return empty results. | |
985 | gpgme_ctx: the gpgme context | |
986 | ||
987 | Returns: | |
988 | A tuple of the plaintext of the signed part and the list of | |
989 | fingerprints of keys signing the data. If verification failed, perhaps | |
990 | because the message was also encrypted, then empty results are | |
991 | returned. | |
992 | """ | |
3a753fd0 AE |
993 | |
994 | block_b = io.BytesIO(msg_block.encode('ascii')) | |
995 | plain_b = io.BytesIO() | |
996 | ||
997 | try: | |
998 | sigs = gpgme_ctx.verify(block_b, None, plain_b) | |
5f6f32b1 | 999 | except gpgme.GpgmeError: |
3a753fd0 AE |
1000 | return ("",[]) |
1001 | ||
1002 | plaintext = plain_b.getvalue().decode('utf-8') | |
1003 | ||
1004 | fingerprints = [] | |
1005 | for sig in sigs: | |
1006 | fingerprints += [sig.fpr] | |
1007 | return (plaintext, fingerprints) | |
1008 | ||
1009 | ||
101d54a8 | 1010 | def verify_detached_signature (detached_sig, plaintext_bytes, gpgme_ctx): |
39e2c525 AE |
1011 | """Verifies the signature of a detached signature. |
1012 | ||
1013 | This requires the signature part and the signed part as separate arguments. | |
1014 | ||
1015 | Args: | |
1016 | detached_sig: the signature part of the detached signature | |
1017 | plaintext_bytes: the byte form of the message being signed. | |
1018 | gpgme_ctx: the gpgme context | |
1019 | ||
1020 | Returns: | |
1021 | A list of signing fingerprints if the signature verification was | |
1022 | sucessful. Otherwise, an empty list is returned. | |
1023 | """ | |
101d54a8 AE |
1024 | |
1025 | detached_sig_fp = io.BytesIO(detached_sig.encode('ascii')) | |
1026 | plaintext_fp = io.BytesIO(plaintext_bytes) | |
101d54a8 | 1027 | |
ff7aeb3d AE |
1028 | try: |
1029 | result = gpgme_ctx.verify(detached_sig_fp, plaintext_fp, None) | |
1030 | except gpgme.GpgmeError: | |
1031 | return [] | |
101d54a8 AE |
1032 | |
1033 | sig_fingerprints = [] | |
1034 | for res_ in result: | |
1035 | sig_fingerprints += [res_.fpr] | |
1036 | ||
1037 | return sig_fingerprints | |
1038 | ||
1039 | ||
5b3053c1 | 1040 | def decrypt_block (msg_block, gpgme_ctx): |
39e2c525 AE |
1041 | """Decrypts a block of GPG text, and verifies any included sigatures. |
1042 | ||
1043 | Some encypted messages have embeded signatures, so those are verified too. | |
1044 | ||
1045 | Args: | |
1046 | msg_block: the encrypted(/signed) text | |
1047 | gpgme_ctx: the gpgme context | |
1048 | ||
1049 | Returns: | |
1050 | A tuple of plaintext and signatures, if the decryption and signature | |
1051 | verification were successful, respectively. | |
1052 | """ | |
0bec96d6 | 1053 | |
5b3053c1 | 1054 | block_b = io.BytesIO(msg_block.encode('ascii')) |
0bec96d6 AE |
1055 | plain_b = io.BytesIO() |
1056 | ||
afc1f64c AE |
1057 | try: |
1058 | sigs = gpgme_ctx.decrypt_verify(block_b, plain_b) | |
5f6f32b1 | 1059 | except gpgme.GpgmeError: |
afc1f64c | 1060 | return ("",[]) |
0bec96d6 | 1061 | |
6aa41372 | 1062 | plaintext = plain_b.getvalue().decode('utf-8') |
cbdf22c1 AE |
1063 | |
1064 | fingerprints = [] | |
1065 | for sig in sigs: | |
1066 | fingerprints += [sig.fpr] | |
1067 | return (plaintext, fingerprints) | |
0bec96d6 AE |
1068 | |
1069 | ||
dd2b62d7 AE |
1070 | def email_to_from_subject (email_text): |
1071 | """Returns the values of the email's To:, From: and Subject: fields | |
fafa21c3 | 1072 | |
dd2b62d7 | 1073 | Returns this information from an email. |
fafa21c3 | 1074 | |
dd2b62d7 AE |
1075 | Args: |
1076 | email_text: the string form of the email | |
fafa21c3 | 1077 | |
dd2b62d7 AE |
1078 | Returns: |
1079 | the email To:, From:, and Subject: fields as strings | |
1080 | """ | |
d65993b8 AE |
1081 | |
1082 | email_struct = email.parser.Parser().parsestr(email_text) | |
1083 | ||
1084 | email_to = email_struct['To'] | |
1085 | email_from = email_struct['From'] | |
1086 | email_subject = email_struct['Subject'] | |
1087 | ||
1088 | return email_to, email_from, email_subject | |
1089 | ||
1090 | ||
bb27d257 AE |
1091 | def import_lang_pick_address(email_to, hostname): |
1092 | """Imports language file for i18n support; makes reply from address | |
dd2b62d7 AE |
1093 | |
1094 | The language imported depends on the To: address of the email received by | |
1095 | edward. an -en ending implies the English language, whereas a -ja ending | |
1096 | implies Japanese. The list of supported languages is listed in the 'langs' | |
bb27d257 AE |
1097 | list at the beginning of the program. This function also chooses the |
1098 | language-dependent address which can be used as the From address in the | |
1099 | reply email. | |
dd2b62d7 AE |
1100 | |
1101 | Args: | |
1102 | email_to: the string containing the email address that the mail was | |
bb27d257 AE |
1103 | sent to. |
1104 | hostname: the hostname part of the reply email's from address | |
dd2b62d7 AE |
1105 | |
1106 | Returns: | |
1107 | the reference to the imported language module. The only variable in | |
1108 | this file is the 'replies' dictionary. | |
1109 | """ | |
adcef2f7 | 1110 | |
bb27d257 AE |
1111 | # default |
1112 | use_lang = "en" | |
daed5f10 | 1113 | |
5250b3b8 AE |
1114 | if email_to != None: |
1115 | for lang in langs: | |
1116 | if "edward-" + lang in email_to: | |
bb27d257 AE |
1117 | use_lang = lang |
1118 | break | |
adcef2f7 | 1119 | |
bb27d257 AE |
1120 | lang_mod_name = "lang." + re.sub('-', '_', use_lang) |
1121 | lang_module = importlib.import_module(lang_mod_name) | |
1122 | ||
60ccbaf4 | 1123 | reply_from = "edward-" + use_lang + "@" + hostname |
bb27d257 | 1124 | |
60ccbaf4 | 1125 | return lang_module, reply_from |
adcef2f7 AE |
1126 | |
1127 | ||
cfb03389 | 1128 | def generate_encrypted_mime (plaintext, email_to, email_subject, encrypt_to_key, |
0a064403 | 1129 | gpgme_ctx): |
dd2b62d7 AE |
1130 | """This function creates the mime email reply. It can encrypt the email. |
1131 | ||
1132 | If the encrypt_key is included, then the email is encrypted and signed. | |
1133 | Otherwise it is unencrypted. | |
1134 | ||
1135 | Args: | |
1136 | plaintext: the plaintext body of the message to create. | |
cfb03389 | 1137 | email_to: the email address to reply to |
dd2b62d7 AE |
1138 | email_subject: the subject to use in reply |
1139 | encrypt_to_key: the key object to use for encrypting the email. (or | |
1140 | None) | |
1141 | gpgme_ctx: the gpgme context | |
1142 | ||
1143 | Returns | |
1144 | A string version of the mime message, possibly encrypted and signed. | |
1145 | """ | |
1da9b527 | 1146 | |
e5dd6f23 | 1147 | if (encrypt_to_key != None): |
8bdfb6d4 | 1148 | |
e5dd6f23 AE |
1149 | # quoted printable encoding lets most ascii characters look normal |
1150 | # before the mime message is decoded. | |
1151 | char_set = email.charset.Charset("utf-8") | |
1152 | char_set.body_encoding = email.charset.QP | |
216708e9 | 1153 | |
e5dd6f23 AE |
1154 | # MIMEText doesn't allow setting the text encoding |
1155 | # so we use MIMENonMultipart. | |
1156 | plaintext_mime = MIMENonMultipart('text', 'plain') | |
1157 | plaintext_mime.set_payload(plaintext, charset=char_set) | |
8bdfb6d4 AE |
1158 | |
1159 | encrypted_text = encrypt_sign_message(plaintext_mime.as_string(), | |
1160 | encrypt_to_key, | |
40c37ab3 | 1161 | gpgme_ctx) |
8bdfb6d4 | 1162 | |
e5dd6f23 AE |
1163 | control_mime = MIMEApplication("Version: 1", |
1164 | _subtype='pgp-encrypted', | |
1165 | _encoder=email.encoders.encode_7or8bit) | |
1166 | control_mime['Content-Description'] = 'PGP/MIME version identification' | |
1167 | control_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1168 | |
e5dd6f23 AE |
1169 | encoded_mime = MIMEApplication(encrypted_text, |
1170 | _subtype='octet-stream; name="encrypted.asc"', | |
1171 | _encoder=email.encoders.encode_7or8bit) | |
1172 | encoded_mime['Content-Description'] = 'OpenPGP encrypted message' | |
1173 | encoded_mime['Content-Disposition'] = 'inline; filename="encrypted.asc"' | |
1174 | encoded_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1175 | |
e5dd6f23 AE |
1176 | message_mime = MIMEMultipart(_subtype="encrypted", protocol="application/pgp-encrypted") |
1177 | message_mime.attach(control_mime) | |
1178 | message_mime.attach(encoded_mime) | |
1179 | message_mime['Content-Disposition'] = 'inline' | |
216708e9 | 1180 | |
e5dd6f23 AE |
1181 | else: |
1182 | message_mime = MIMEText(plaintext) | |
2007103e | 1183 | |
cfb03389 | 1184 | message_mime['To'] = email_to |
2007103e AE |
1185 | message_mime['Subject'] = email_subject |
1186 | ||
1187 | reply = message_mime.as_string() | |
1da9b527 AE |
1188 | |
1189 | return reply | |
1190 | ||
1191 | ||
60ccbaf4 AE |
1192 | def send_reply(email_txt, subject, reply_to, reply_from): |
1193 | ||
1194 | email_bytes = email_txt.encode('ascii') | |
1195 | ||
1196 | p = subprocess.Popen(["/usr/sbin/sendmail", "-f", reply_from, "-F", "Edward, GPG Bot", "-i", reply_to], stdin=subprocess.PIPE) | |
1197 | ||
1198 | (stdout, stderr) = p.communicate(email_bytes) | |
1199 | ||
1200 | if stdout != None: | |
1201 | debug("sendmail stdout: " + str(stdout)) | |
1202 | if stderr != None: | |
1203 | error("sendmail stderr: " + str(stderr)) | |
1204 | ||
1205 | ||
f87041f8 | 1206 | def email_quote_text (text): |
dd2b62d7 AE |
1207 | """Quotes input text by inserting "> "s |
1208 | ||
1209 | This is useful for quoting a text for the reply message. It inserts "> " | |
1210 | strings at the beginning of lines. | |
1211 | ||
1212 | Args: | |
1213 | text: plain text to quote | |
1214 | ||
1215 | Returns: | |
1216 | Quoted text | |
1217 | """ | |
f87041f8 AE |
1218 | |
1219 | quoted_message = re.sub(r'^', r'> ', text, flags=re.MULTILINE) | |
1220 | ||
1221 | return quoted_message | |
1222 | ||
1223 | ||
0a064403 | 1224 | def encrypt_sign_message (plaintext, encrypt_to_key, gpgme_ctx): |
dd2b62d7 AE |
1225 | """Encrypts and signs plaintext |
1226 | ||
1227 | This encrypts and signs a message. | |
1228 | ||
1229 | Args: | |
1230 | plaintext: text to sign and ecrypt | |
1231 | encrypt_to_key: the key object to encrypt to | |
1232 | gpgme_ctx: the gpgme context | |
1233 | ||
1234 | Returns: | |
1235 | An encrypted and signed string of text | |
1236 | """ | |
897cbaf6 | 1237 | |
b33f601b | 1238 | # the plaintext should be mime encoded in an ascii-compatible form |
6aa41372 | 1239 | plaintext_bytes = io.BytesIO(plaintext.encode('ascii')) |
1da9b527 AE |
1240 | encrypted_bytes = io.BytesIO() |
1241 | ||
897cbaf6 | 1242 | gpgme_ctx.encrypt_sign([encrypt_to_key], gpgme.ENCRYPT_ALWAYS_TRUST, |
1da9b527 AE |
1243 | plaintext_bytes, encrypted_bytes) |
1244 | ||
6aa41372 | 1245 | encrypted_txt = encrypted_bytes.getvalue().decode('ascii') |
1da9b527 AE |
1246 | return encrypted_txt |
1247 | ||
1248 | ||
0a064403 | 1249 | def error (error_msg): |
dd2b62d7 AE |
1250 | """Write an error message to stdout |
1251 | ||
1252 | The error message includes the program name. | |
1253 | ||
1254 | Args: | |
1255 | error_msg: the message to print | |
1256 | ||
1257 | Returns: | |
1258 | Nothing | |
1259 | ||
1260 | Post: | |
1261 | An error message is printed to stdout | |
1262 | """ | |
0a064403 | 1263 | |
e4fb2ab2 | 1264 | sys.stderr.write(progname + ": " + str(error_msg) + "\n") |
0a064403 AE |
1265 | |
1266 | ||
5e8f9094 | 1267 | def debug (debug_msg): |
dd2b62d7 AE |
1268 | """Writes a debug message to stdout if debug == True |
1269 | ||
1270 | If the debug option is set in edward_config.py, then the passed message | |
1271 | gets printed to stdout. | |
1272 | ||
1273 | Args: | |
1274 | debug_msg: the message to print to stdout | |
1275 | ||
1276 | Returns: | |
1277 | Nothing | |
1278 | ||
1279 | Post: | |
1280 | A debug message is printed to stdout | |
1281 | """ | |
5e8f9094 AE |
1282 | |
1283 | if edward_config.debug == True: | |
0a064403 | 1284 | error(debug_msg) |
5e8f9094 AE |
1285 | |
1286 | ||
20f6e7c5 | 1287 | def handle_args (): |
60ccbaf4 | 1288 | """Sets the progname variable and processes optional argument |
dd2b62d7 | 1289 | |
60ccbaf4 AE |
1290 | If there are more than two arguments then edward complains and quits. An |
1291 | single "-p" argument sets the print_reply_only option, which makes edward | |
1292 | print email replies instead of mailing them. | |
dd2b62d7 AE |
1293 | |
1294 | Args: | |
1295 | None | |
1296 | ||
1297 | Returns: | |
60ccbaf4 AE |
1298 | True if edward should print arguments instead of mailing them, |
1299 | otherwise it returns False. | |
dd2b62d7 AE |
1300 | |
1301 | Post: | |
60ccbaf4 AE |
1302 | Exits with error 1 if there are more than two arguments, otherwise |
1303 | returns the print_reply_only option. | |
dd2b62d7 | 1304 | """ |
20f6e7c5 | 1305 | |
a51cdb72 AE |
1306 | global progname |
1307 | progname = sys.argv[0] | |
1308 | ||
60ccbaf4 AE |
1309 | print_reply_only = False |
1310 | ||
1311 | if len(sys.argv) > 2: | |
1312 | print(progname + " usage: " + progname + " [-p]\n\n" \ | |
1313 | + " -p print reply message to stdout, do not mail it\n", \ | |
1314 | file=sys.stderr) | |
a51cdb72 | 1315 | exit(1) |
20f6e7c5 | 1316 | |
60ccbaf4 AE |
1317 | elif (len(sys.argv) == 2) and (sys.argv[1] == "-p"): |
1318 | print_reply_only = True | |
1319 | ||
1320 | return print_reply_only | |
1321 | ||
20f6e7c5 | 1322 | |
a51cdb72 | 1323 | if __name__ == "__main__": |
dd2b62d7 | 1324 | """Executes main if this file is not loaded interactively""" |
20f6e7c5 | 1325 | |
a51cdb72 | 1326 | main() |
0bec96d6 | 1327 |