Commit | Line | Data |
---|---|---|
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 | |
01ceaec3 | 54 | langs = ["de", "el", "en", "es", "fr", "it", "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 | ||
b4c116d5 AE |
149 | 'sigkey_missing' is set to True if edward doesn't have the key it needs to |
150 | verify the signature on a block of text. | |
9af26cb8 | 151 | |
def9196c AE |
152 | 'keys' is a list of fingerprints of keys obtained in public key blocks. |
153 | """ | |
154 | ||
7d0b91d2 AE |
155 | decrypted = False |
156 | ||
157 | plainobj = None | |
158 | sigs = [] | |
b4c116d5 | 159 | sigkey_missing = False |
7d0b91d2 | 160 | keys = [] |
38738401 | 161 | |
38738401 | 162 | |
d873ff48 | 163 | class ReplyInfo (object): |
def9196c AE |
164 | """ |
165 | ReplyInfo contains details that edward uses in generating its reply. | |
166 | ||
167 | Instances of this class contain information about whether a message was | |
168 | successfully encrypted or signed, and whether a public key was attached, or | |
169 | retrievable, from the local GPG store. It stores the fingerprints of | |
170 | potential encryption key candidates and the message (if any at all) to | |
171 | quote in edward's reply. | |
172 | ||
173 | 'replies' points one of the dictionaries of translated replies. | |
174 | ||
175 | 'target_key' refers to the fingerprint of a key used to sign encrypted | |
176 | data. This is the preferred key, if it is set, and if is available. | |
177 | ||
178 | 'fallback_target_key' referst to the fingerprint of a key used to sign | |
179 | unencrypted data; alternatively it may be a public key attached to the | |
180 | message. | |
181 | ||
ca37d0cb AE |
182 | 'encrypt_to_key' the key object to use when encrypting edward's reply |
183 | ||
def9196c AE |
184 | 'msg_to_quote' refers to the part of a message which edward should quote in |
185 | his reply. This should remain as None if there was no encrypted and singed | |
186 | part. This is to avoid making edward a service for decrypting other | |
187 | people's messages to edward. | |
188 | ||
b4c116d5 | 189 | 'decrypt_success' is set to True if edward could decrypt part of the |
def9196c AE |
190 | message. |
191 | ||
def9196c AE |
192 | 'sig_success' is set to True if edward could to some extent verify the |
193 | signature of a signed part of the message to edward. | |
194 | ||
32a8996f AE |
195 | 'sig_failure' is set to True if edward could not verify a siganture. |
196 | ||
b4c116d5 AE |
197 | 'pubkey_success' is set to True if edward successfully imported a public |
198 | key. | |
199 | ||
200 | 'sigkey_missing' is set to True if edward doesn't have the public key | |
201 | needed for signature verification. | |
202 | ||
203 | 'have_repy_key' is set to True if edward has a public key to encrypt its | |
204 | reply to. | |
def9196c AE |
205 | """ |
206 | ||
7d0b91d2 | 207 | replies = None |
6906d46d | 208 | |
7d0b91d2 AE |
209 | target_key = None |
210 | fallback_target_key = None | |
ca37d0cb | 211 | encrypt_to_key = None |
7d0b91d2 | 212 | msg_to_quote = "" |
d873ff48 | 213 | |
b4c116d5 | 214 | decrypt_success = False |
7d0b91d2 | 215 | sig_success = False |
b4c116d5 AE |
216 | pubkey_success = False |
217 | ||
32a8996f | 218 | sig_failure = False |
b4c116d5 AE |
219 | sigkey_missing = False |
220 | have_reply_key = False | |
d873ff48 | 221 | |
38738401 | 222 | |
0bec96d6 AE |
223 | def main (): |
224 | ||
def9196c AE |
225 | """ |
226 | This is the main function for edward, a GPG reply bot. | |
227 | ||
228 | Edward responds to GPG-encrypted and signed mail, encrypting and signing | |
229 | the response if the user's public key is, or was, included in the message. | |
230 | ||
231 | Args: | |
232 | None | |
233 | ||
234 | Returns: | |
a3d6aff8 | 235 | Nothing |
def9196c AE |
236 | |
237 | Pre: | |
238 | Mime or plaintext email passing in through standard input. Portions of | |
239 | the email may be encrypted. If the To: address contains the text | |
240 | "edward-ja", then the reply will contain a reply written in the | |
241 | Japanese language. There are other languages as well. The default | |
242 | language is English. | |
243 | ||
244 | Post: | |
245 | A reply email will be printed to standard output. The contents of the | |
246 | reply email depends on whether the original email was encrypted or not, | |
247 | has or doesn't have a signature, whether a public key used in the | |
248 | original message is provided or locally stored, and the language | |
249 | implied by the To: address in the original email. | |
250 | """ | |
251 | ||
60ccbaf4 | 252 | print_reply_only = handle_args() |
0bec96d6 | 253 | |
0a064403 AE |
254 | gpgme_ctx = get_gpg_context(edward_config.gnupghome, |
255 | edward_config.sign_with_key) | |
256 | ||
c96f3837 | 257 | email_text = sys.stdin.read() |
adcef2f7 AE |
258 | email_struct = parse_pgp_mime(email_text, gpgme_ctx) |
259 | ||
260 | email_to, email_from, email_subject = email_to_from_subject(email_text) | |
60ccbaf4 | 261 | lang, reply_from = import_lang_pick_address(email_to, edward_config.hostname) |
fafa21c3 | 262 | |
d873ff48 AE |
263 | replyinfo_obj = ReplyInfo() |
264 | replyinfo_obj.replies = lang.replies | |
265 | ||
266 | prepare_for_reply(email_struct, replyinfo_obj) | |
ca37d0cb | 267 | get_key_from_fp(replyinfo_obj, gpgme_ctx) |
d873ff48 | 268 | reply_plaintext = write_reply(replyinfo_obj) |
adcef2f7 | 269 | |
2007103e | 270 | reply_mime = generate_encrypted_mime(reply_plaintext, email_from, \ |
ca37d0cb | 271 | email_subject, replyinfo_obj.encrypt_to_key, |
2007103e | 272 | gpgme_ctx) |
1fccb295 | 273 | |
60ccbaf4 AE |
274 | if print_reply_only == True: |
275 | print(reply_mime) | |
276 | else: | |
277 | send_reply(reply_mime, email_subject, email_from, reply_from) | |
c96f3837 | 278 | |
0bec96d6 | 279 | |
0a064403 | 280 | def get_gpg_context (gnupghome, sign_with_key_fp): |
a3d6aff8 AE |
281 | """ |
282 | This function returns the GPG context needed for encryption and signing. | |
283 | ||
284 | The context is needed by other functions which use GPG functionality. | |
285 | ||
286 | Args: | |
287 | gnupghome: The path to "~/.gnupg/" or its alternative. | |
288 | sign_with_key: The fingerprint of the key to sign with | |
289 | ||
290 | Returns: | |
291 | A gpgme context to be used for GPG functions. | |
292 | ||
293 | Post: | |
294 | the 'armor' flag is set to True and the list of signing keys contains | |
295 | the single specified key | |
296 | """ | |
0a064403 AE |
297 | |
298 | os.environ['GNUPGHOME'] = gnupghome | |
299 | ||
300 | gpgme_ctx = gpgme.Context() | |
301 | gpgme_ctx.armor = True | |
302 | ||
303 | try: | |
304 | sign_with_key = gpgme_ctx.get_key(sign_with_key_fp) | |
5f6f32b1 | 305 | except gpgme.GpgmeError: |
0a064403 AE |
306 | error("unable to load signing key. is the gnupghome " |
307 | + "and signing key properly set in the edward_config.py?") | |
308 | exit(1) | |
309 | ||
310 | gpgme_ctx.signers = [sign_with_key] | |
311 | ||
312 | return gpgme_ctx | |
313 | ||
314 | ||
38738401 | 315 | def parse_pgp_mime (email_text, gpgme_ctx): |
a3d6aff8 AE |
316 | """Parses the email for mime payloads and decrypts/verfies signatures. |
317 | ||
318 | This function creates a representation of a mime or plaintext email with | |
319 | the EddyMsg class. It then splits each mime payload into one or more pieces | |
320 | which may be plain text or GPG data. It then decrypts encrypted parts and | |
321 | does some very basic signature verification on those parts. | |
322 | ||
323 | Args: | |
324 | email_text: an email message in string format | |
325 | gpgme_ctx: a gpgme context | |
326 | ||
327 | Returns: | |
328 | A message as an instance of EddyMsg | |
329 | ||
330 | Post: | |
331 | the returned EddyMsg instance has split, decrypted, verified and pubkey | |
332 | imported payloads | |
333 | """ | |
394a1476 AE |
334 | |
335 | email_struct = email.parser.Parser().parsestr(email_text) | |
336 | ||
928e3819 AE |
337 | eddymsg_obj = parse_mime(email_struct) |
338 | split_payloads(eddymsg_obj) | |
339 | gpg_on_payloads(eddymsg_obj, gpgme_ctx) | |
8bb4b0d5 | 340 | |
928e3819 | 341 | return eddymsg_obj |
0bec96d6 | 342 | |
0bec96d6 | 343 | |
56578eaf | 344 | def parse_mime(msg_struct): |
a3d6aff8 AE |
345 | """Translates python's email.parser format into an EddyMsg format |
346 | ||
347 | If the message is multi-part, then a recursive object is created, where | |
348 | each sub-part is also a EddyMsg instance. | |
349 | ||
350 | Args: | |
351 | msg_struct: an email parsed with email.parser.Parser(), which can be | |
352 | multi-part | |
353 | ||
354 | Returns: | |
355 | an instance of EddyMsg, potentially a recursive one. | |
356 | """ | |
0bec96d6 | 357 | |
928e3819 | 358 | eddymsg_obj = EddyMsg() |
8bb4b0d5 | 359 | |
56578eaf AE |
360 | if msg_struct.is_multipart() == True: |
361 | payloads = msg_struct.get_payload() | |
0bec96d6 | 362 | |
928e3819 AE |
363 | eddymsg_obj.multipart = True |
364 | eddymsg_obj.subparts = list(map(parse_mime, payloads)) | |
dd11a483 | 365 | |
56578eaf | 366 | else: |
928e3819 | 367 | eddymsg_obj = get_subpart_data(msg_struct) |
394a1476 | 368 | |
928e3819 | 369 | return eddymsg_obj |
c267c233 | 370 | |
80119cab | 371 | |
2f4102b9 | 372 | def scan_and_split (payload_piece, match_name, pattern): |
a3d6aff8 AE |
373 | """This splits the payloads of an EddyMsg object into GPG and text parts. |
374 | ||
375 | An EddyMsg object's payload_pieces starts off as a list containing a single | |
376 | PayloadPiece object. This function returns a list of these objects which | |
377 | have been split into GPG data and regular text, if such splits need to be/ | |
378 | can be made. | |
379 | ||
380 | Args: | |
381 | payload_piece: a single payload or a split part of a payload | |
2f4102b9 | 382 | match_name: the type of data to try to spit out from the payload piece |
a3d6aff8 AE |
383 | pattern: the search pattern to be used for finding that type of data |
384 | ||
385 | Returns: | |
386 | a list of objects of the PayloadPiece class, in the order that the | |
387 | string part of payload_piece originally was, broken up according to | |
388 | matches specified by 'pattern'. | |
389 | """ | |
cf75de65 | 390 | |
a5d37d44 | 391 | # don't try to re-split pieces containing gpg data |
0fd3389f | 392 | if payload_piece.piece_type != TxtType.text: |
a5d37d44 AE |
393 | return [payload_piece] |
394 | ||
56578eaf AE |
395 | flags = re.DOTALL | re.MULTILINE |
396 | matches = re.search("(?P<beginning>.*?)(?P<match>" + pattern + | |
397 | ")(?P<rest>.*)", payload_piece.string, flags=flags) | |
86663388 | 398 | |
56578eaf AE |
399 | if matches == None: |
400 | pieces = [payload_piece] | |
c96f3837 | 401 | |
56578eaf | 402 | else: |
d437f8b2 | 403 | |
56578eaf AE |
404 | beginning = PayloadPiece() |
405 | beginning.string = matches.group('beginning') | |
406 | beginning.piece_type = payload_piece.piece_type | |
d437f8b2 | 407 | |
56578eaf AE |
408 | match = PayloadPiece() |
409 | match.string = matches.group('match') | |
2f4102b9 | 410 | match.piece_type = match_name |
d437f8b2 | 411 | |
56578eaf AE |
412 | rest = PayloadPiece() |
413 | rest.string = matches.group('rest') | |
414 | rest.piece_type = payload_piece.piece_type | |
d437f8b2 | 415 | |
2f4102b9 | 416 | more_pieces = scan_and_split(rest, match_name, pattern) |
4615b156 | 417 | pieces = [beginning, match ] + more_pieces |
d437f8b2 | 418 | |
56578eaf | 419 | return pieces |
d437f8b2 | 420 | |
d437f8b2 | 421 | |
56578eaf | 422 | def get_subpart_data (part): |
a3d6aff8 AE |
423 | """This function grabs information from a single part mime object. |
424 | ||
425 | It copies needed data from a single part email.parser.Parser() object over | |
426 | to an EddyMsg object. | |
427 | ||
428 | Args: | |
429 | part: a non-multi-part mime.parser.Parser() object | |
430 | ||
431 | Returns: | |
432 | a single-part EddyMsg() object | |
433 | """ | |
0bec96d6 | 434 | |
6d8faaa7 | 435 | obj = EddyMsg() |
56578eaf | 436 | |
84ff9773 AE |
437 | mime_decoded_bytes = part.get_payload(decode=True) |
438 | charset = part.get_content_charset() | |
56578eaf AE |
439 | |
440 | # your guess is as good as a-myy-ee-ine... | |
6d8faaa7 AE |
441 | if charset == None: |
442 | charset = 'utf-8' | |
56578eaf | 443 | |
84ff9773 AE |
444 | payload_string = part.as_string() |
445 | if payload_string != None: | |
446 | obj.payload_bytes = payload_string.encode(charset) | |
447 | ||
448 | obj.filename = part.get_filename() | |
449 | obj.content_type = part.get_content_type() | |
450 | obj.description_list = part['content-description'] | |
451 | ||
6d8faaa7 | 452 | if mime_decoded_bytes != None: |
0eb75d9c AE |
453 | try: |
454 | payload = PayloadPiece() | |
6d8faaa7 | 455 | payload.string = mime_decoded_bytes.decode(charset) |
0fd3389f | 456 | payload.piece_type = TxtType.text |
0eb75d9c AE |
457 | |
458 | obj.payload_pieces = [payload] | |
459 | except UnicodeDecodeError: | |
460 | pass | |
56578eaf AE |
461 | |
462 | return obj | |
463 | ||
464 | ||
928e3819 | 465 | def do_to_eddys_pieces (function_to_do, eddymsg_obj, data): |
a3d6aff8 AE |
466 | """A function which maps another function onto a message's subparts. |
467 | ||
468 | This is a higer-order function which recursively performs a specified | |
469 | function on each subpart of a multi-part message. Each single-part sub-part | |
470 | has the function applied to it. This function also works if the part passed | |
471 | in is single-part. | |
472 | ||
473 | Args: | |
474 | function_to_do: function to perform on sub-parts | |
475 | eddymsg_obj: a single part or multi-part EddyMsg object | |
476 | data: a second argument to pass to 'function_to_do' | |
477 | ||
478 | Returns: | |
479 | Nothing | |
480 | ||
481 | Post: | |
482 | The passed-in EddyMsg object is transformed recursively on its | |
483 | sub-parts according to 'function_to_do'. | |
484 | """ | |
56578eaf | 485 | |
928e3819 AE |
486 | if eddymsg_obj.multipart == True: |
487 | for sub in eddymsg_obj.subparts: | |
d873ff48 | 488 | do_to_eddys_pieces(function_to_do, sub, data) |
394a1476 | 489 | else: |
928e3819 | 490 | function_to_do(eddymsg_obj, data) |
dd11a483 AE |
491 | |
492 | ||
928e3819 | 493 | def split_payloads (eddymsg_obj): |
a3d6aff8 AE |
494 | """Splits all (sub-)payloads of a message into GPG data and regular text. |
495 | ||
496 | Recursively performs payload splitting on all sub-parts of an EddyMsg | |
497 | object into the various GPG data types, such as GPG messages, public key | |
498 | blocks and signed text. | |
499 | ||
500 | Args: | |
501 | eddymsg_obj: an instance of EddyMsg | |
502 | ||
503 | Returns: | |
504 | Nothing | |
505 | ||
506 | Pre: | |
507 | The EddyMsg object has payloads that are unsplit (by may be split).. | |
508 | ||
509 | Post: | |
510 | The EddyMsg object's payloads are all split into GPG and non-GPG parts. | |
511 | """ | |
a5d37d44 | 512 | |
2f4102b9 AE |
513 | for match_pair in match_pairs: |
514 | do_to_eddys_pieces(split_payload_pieces, eddymsg_obj, match_pair) | |
a5d37d44 | 515 | |
a5d37d44 | 516 | |
2f4102b9 | 517 | def split_payload_pieces (eddymsg_obj, match_pair): |
a3d6aff8 AE |
518 | """A helper function for split_payloads(); works on PayloadPiece objects. |
519 | ||
520 | This function splits up PayloadPiece objects into multipe PayloadPiece | |
521 | objects and replaces the EddyMsg object's previous list of payload pieces | |
522 | with the new split up one. | |
523 | ||
524 | Args: | |
525 | eddymsg_obj: a single-part EddyMsg object. | |
2f4102b9 | 526 | match_pair: a tuple from the match_pairs list, which specifies a match |
a3d6aff8 AE |
527 | name and a match pattern. |
528 | ||
529 | Returns: | |
530 | Nothing | |
531 | ||
532 | Pre: | |
533 | The payload piece(s) of an EddyMsg object may be already split or | |
534 | unsplit. | |
535 | ||
536 | Post: | |
537 | The EddyMsg object's payload piece(s) are split into a list of pieces | |
2f4102b9 | 538 | if matches of the match_pair are found. |
a3d6aff8 | 539 | """ |
a5d37d44 | 540 | |
2f4102b9 | 541 | (match_name, pattern) = match_pair |
a5d37d44 AE |
542 | |
543 | new_pieces_list = [] | |
928e3819 | 544 | for piece in eddymsg_obj.payload_pieces: |
a5d37d44 AE |
545 | new_pieces_list += scan_and_split(piece, match_name, pattern) |
546 | ||
928e3819 | 547 | eddymsg_obj.payload_pieces = new_pieces_list |
a5d37d44 AE |
548 | |
549 | ||
928e3819 | 550 | def gpg_on_payloads (eddymsg_obj, gpgme_ctx, prev_parts=[]): |
a3d6aff8 AE |
551 | """Performs GPG operations on the GPG parts of the message |
552 | ||
553 | This function decrypts text, verifies signatures, and imports public keys | |
554 | included in an email. | |
555 | ||
556 | Args: | |
557 | eddymsg_obj: an EddyMsg object with its payload_pieces split into GPG | |
558 | and non-GPG sections by split_payloads() | |
559 | gpgme_ctx: a gpgme context | |
560 | ||
561 | prev_parts: a list of mime parts that occur before the eddymsg_obj | |
562 | part, under the same multi-part mime part. This is used for | |
563 | verifying detached signatures. For the root mime part, this should | |
564 | be an empty list, which is the default value if this paramater is | |
565 | omitted. | |
566 | ||
567 | Return: | |
568 | Nothing | |
569 | ||
570 | Pre: | |
571 | eddymsg_obj should have its payloads split into gpg and non-gpg pieces. | |
572 | ||
573 | Post: | |
574 | Decryption, verification and key imports occur. the gpg_data member of | |
575 | PayloadPiece objects get filled in with GPGData objects. | |
576 | """ | |
38738401 | 577 | |
928e3819 | 578 | if eddymsg_obj.multipart == True: |
101d54a8 | 579 | prev_parts=[] |
928e3819 | 580 | for sub in eddymsg_obj.subparts: |
101d54a8 AE |
581 | gpg_on_payloads (sub, gpgme_ctx, prev_parts) |
582 | prev_parts += [sub] | |
38738401 | 583 | |
d873ff48 | 584 | return |
38738401 | 585 | |
928e3819 | 586 | for piece in eddymsg_obj.payload_pieces: |
38738401 | 587 | |
0fd3389f | 588 | if piece.piece_type == TxtType.text: |
38738401 AE |
589 | # don't transform the plaintext. |
590 | pass | |
591 | ||
0fd3389f | 592 | elif piece.piece_type == TxtType.message: |
b4c116d5 AE |
593 | piece.gpg_data = GPGData() |
594 | ||
595 | (plaintext, sigs, sigkey_missing) = decrypt_block(piece.string, gpgme_ctx) | |
596 | ||
597 | piece.gpg_data.sigkey_missing = sigkey_missing | |
38738401 AE |
598 | |
599 | if plaintext: | |
b23e171d | 600 | piece.gpg_data.decrypted = True |
38738401 AE |
601 | piece.gpg_data.sigs = sigs |
602 | # recurse! | |
603 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
3a753fd0 AE |
604 | continue |
605 | ||
606 | # if not encrypted, check to see if this is an armored signature. | |
b4c116d5 AE |
607 | (plaintext, sigs, sigkey_missing) = verify_sig_message(piece.string, gpgme_ctx) |
608 | ||
609 | piece.gpg_data.sigkey_missing = sigkey_missing | |
3a753fd0 AE |
610 | |
611 | if plaintext: | |
0fd3389f | 612 | piece.piece_type = TxtType.signature |
3a753fd0 AE |
613 | piece.gpg_data.sigs = sigs |
614 | # recurse! | |
615 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
129543c3 | 616 | |
0fd3389f | 617 | elif piece.piece_type == TxtType.pubkey: |
f8ee6bd3 | 618 | key_fps = add_gpg_key(piece.string, gpgme_ctx) |
8f61c66a | 619 | |
f8ee6bd3 | 620 | if key_fps != []: |
8f61c66a | 621 | piece.gpg_data = GPGData() |
f8ee6bd3 | 622 | piece.gpg_data.keys = key_fps |
129543c3 | 623 | |
0fd3389f | 624 | elif piece.piece_type == TxtType.detachedsig: |
b4c116d5 AE |
625 | piece.gpg_data = GPGData() |
626 | ||
101d54a8 | 627 | for prev in prev_parts: |
b4c116d5 AE |
628 | (sig_fps, sigkey_missing) = verify_detached_signature(piece.string, prev.payload_bytes, gpgme_ctx) |
629 | ||
630 | piece.gpg_data.sigkey_missing = sigkey_missing | |
101d54a8 | 631 | |
6d240f68 | 632 | if sig_fps != []: |
6d240f68 AE |
633 | piece.gpg_data.sigs = sig_fps |
634 | piece.gpg_data.plainobj = prev | |
635 | break | |
7e18f14d | 636 | |
38738401 AE |
637 | else: |
638 | pass | |
639 | ||
640 | ||
928e3819 | 641 | def prepare_for_reply (eddymsg_obj, replyinfo_obj): |
67691346 AE |
642 | """Updates replyinfo_obj with info on the message's GPG success/failures |
643 | ||
644 | This function marks replyinfo_obj with information about whether encrypted | |
645 | text in eddymsg_obj was successfully decrypted, signatures were verified | |
646 | and whether a public key was found or not. | |
647 | ||
648 | Args: | |
649 | eddymsg_obj: a message in the EddyMsg format | |
650 | replyinfo_obj: an instance of ReplyInfo | |
651 | ||
652 | Returns: | |
653 | Nothing | |
654 | ||
655 | Pre: | |
656 | eddymsg_obj has had its gpg_data created by gpg_on_payloads | |
657 | ||
658 | Post: | |
659 | replyinfo_obj has been updated with info about decryption/sig | |
660 | verififcation status, etc. However the desired key isn't imported until | |
661 | later, so the success or failure of that updates the values set here. | |
662 | """ | |
dd11a483 | 663 | |
928e3819 | 664 | do_to_eddys_pieces(prepare_for_reply_pieces, eddymsg_obj, replyinfo_obj) |
56578eaf | 665 | |
928e3819 | 666 | def prepare_for_reply_pieces (eddymsg_obj, replyinfo_obj): |
67691346 AE |
667 | """A helper function for prepare_for_reply |
668 | ||
669 | It updates replyinfo_obj with GPG success/failure information, when | |
670 | supplied a single-part EddyMsg object. | |
671 | ||
672 | Args: | |
673 | eddymsg_obj: a single-part message in the EddyMsg format | |
674 | replyinfo_obj: an object which holds information about the message's | |
675 | GPG status | |
676 | ||
677 | Returns: | |
678 | Nothing | |
679 | ||
680 | Pre: | |
681 | eddymsg_obj is a single-part message. (it may be a part of a multi-part | |
682 | message.) It has had its gpg_data created by gpg_on_payloads if it has | |
683 | gpg data. | |
684 | ||
685 | Post: | |
686 | replyinfo_obj has been updated with gpg success/failure information | |
687 | """ | |
56578eaf | 688 | |
928e3819 | 689 | for piece in eddymsg_obj.payload_pieces: |
0fd3389f | 690 | if piece.piece_type == TxtType.text: |
d873ff48 AE |
691 | # don't quote the plaintext part. |
692 | pass | |
693 | ||
0fd3389f | 694 | elif piece.piece_type == TxtType.message: |
05683768 | 695 | prepare_for_reply_message(piece, replyinfo_obj) |
d873ff48 | 696 | |
0fd3389f | 697 | elif piece.piece_type == TxtType.pubkey: |
05683768 | 698 | prepare_for_reply_pubkey(piece, replyinfo_obj) |
6906d46d | 699 | |
0fd3389f AE |
700 | elif (piece.piece_type == TxtType.detachedsig) \ |
701 | or (piece.piece_type == TxtType.signature): | |
05683768 | 702 | prepare_for_reply_sig(piece, replyinfo_obj) |
d873ff48 | 703 | |
d873ff48 | 704 | |
05683768 | 705 | def prepare_for_reply_message (piece, replyinfo_obj): |
67691346 AE |
706 | """Helper function for prepare_for_reply() |
707 | ||
708 | This function is called when the piece_type of a payload piece is | |
9af26cb8 AE |
709 | TxtType.message, or GPG Message block. This should be encrypted text. If |
710 | the encryted block is correclty signed, a sig will be attached to | |
711 | .target_key unless there is already one there. | |
67691346 AE |
712 | |
713 | Args: | |
714 | piece: a PayloadPiece object. | |
715 | replyinfo_obj: object which gets updated with decryption status, etc. | |
716 | ||
67691346 AE |
717 | Returns: |
718 | Nothing | |
719 | ||
720 | Pre: | |
0fd3389f | 721 | the piece.payload_piece value should be TxtType.message. |
67691346 AE |
722 | |
723 | Post: | |
b4c116d5 AE |
724 | replyinfo_obj gets updated with decryption status, signing status, a |
725 | potential signing key, and posession status of the public key for the | |
726 | signature. | |
67691346 | 727 | """ |
44fe39b7 | 728 | |
b4c116d5 | 729 | if piece.gpg_data == None or piece.gpg_data.plainobj == None: |
05683768 AE |
730 | return |
731 | ||
b4c116d5 | 732 | replyinfo_obj.decrypt_success = True |
05683768 AE |
733 | |
734 | # we already have a key (and a message) | |
735 | if replyinfo_obj.target_key != None: | |
736 | return | |
737 | ||
738 | if piece.gpg_data.sigs != []: | |
739 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
59003069 | 740 | replyinfo_obj.sig_success = True |
05683768 | 741 | get_signed_part = False |
b4c116d5 | 742 | |
05683768 | 743 | else: |
b4c116d5 AE |
744 | if piece.gpg_data.sigkey_missing == True: |
745 | replyinfo_obj.sigkey_missing = True | |
9af26cb8 | 746 | |
05683768 AE |
747 | # only include a signed message in the reply. |
748 | get_signed_part = True | |
749 | ||
8c3e5397 | 750 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, get_signed_part) |
05683768 AE |
751 | |
752 | # to catch public keys in encrypted blocks | |
753 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
754 | ||
755 | ||
756 | def prepare_for_reply_pubkey (piece, replyinfo_obj): | |
67691346 AE |
757 | """Helper function for prepare_for_reply(). Marks pubkey import status. |
758 | ||
759 | Marks replyinfo_obj with pub key import status. | |
760 | ||
761 | Args: | |
762 | piece: a PayloadPiece object | |
763 | replyinfo_obj: a ReplyInfo object | |
764 | ||
765 | Pre: | |
0fd3389f | 766 | piece.piece_type should be set to TxtType.pubkey . |
67691346 AE |
767 | |
768 | Post: | |
769 | replyinfo_obj has its fields updated. | |
770 | """ | |
05683768 AE |
771 | |
772 | if piece.gpg_data == None or piece.gpg_data.keys == []: | |
b4c116d5 | 773 | pass |
05683768 | 774 | else: |
b4c116d5 | 775 | replyinfo_obj.pubkey_success = True |
05683768 | 776 | |
3ceb92e5 AE |
777 | # prefer public key as a fallback for the encrypted reply |
778 | replyinfo_obj.fallback_target_key = piece.gpg_data.keys[0] | |
05683768 AE |
779 | |
780 | ||
781 | def prepare_for_reply_sig (piece, replyinfo_obj): | |
67691346 AE |
782 | """Helper function for prepare_for_reply(). Marks sig verification status. |
783 | ||
784 | Marks replyinfo_obj with signature verification status. | |
785 | ||
786 | Args: | |
787 | piece: a PayloadPiece object | |
788 | replyinfo_obj: a ReplyInfo object | |
789 | ||
790 | Pre: | |
0fd3389f AE |
791 | piece.piece_type should be set to TxtType.signature, or |
792 | TxtType.detachedsig . | |
67691346 AE |
793 | |
794 | Post: | |
795 | replyinfo_obj has its fields updated. | |
796 | """ | |
05683768 AE |
797 | |
798 | if piece.gpg_data == None or piece.gpg_data.sigs == []: | |
32a8996f | 799 | replyinfo_obj.sig_failure = True |
b4c116d5 AE |
800 | |
801 | if piece.gpg_data.sigkey_missing == True: | |
802 | replyinfo_obj.sigkey_missing = True | |
803 | ||
05683768 AE |
804 | else: |
805 | replyinfo_obj.sig_success = True | |
806 | ||
807 | if replyinfo_obj.fallback_target_key == None: | |
808 | replyinfo_obj.fallback_target_key = piece.gpg_data.sigs[0] | |
6906d46d AE |
809 | |
810 | ||
8c3e5397 AE |
811 | def flatten_decrypted_payloads (eddymsg_obj, replyinfo_obj, get_signed_part): |
812 | """For creating a string representation of a signed, encrypted part. | |
39e2c525 | 813 | |
8c3e5397 AE |
814 | When given a decrypted payload, it will add either the plaintext or signed |
815 | plaintext to the reply message, depeding on 'get_signed_part'. This is | |
816 | useful for ensuring that the reply message only comes from a signed and | |
817 | ecrypted GPG message. It also sets the target_key for encrypting the reply | |
818 | if it's told to get signed text only. | |
39e2c525 AE |
819 | |
820 | Args: | |
821 | eddymsg_obj: the message in EddyMsg format created by decrypting GPG | |
822 | text | |
8c3e5397 AE |
823 | replyinfo_obj: a ReplyInfo object for holding the message to quote and |
824 | the target_key to encrypt to. | |
39e2c525 AE |
825 | get_signed_part: True if we should only include text that contains a |
826 | further signature. If False, then include plain text. | |
827 | ||
828 | Returns: | |
8c3e5397 | 829 | Nothing |
39e2c525 AE |
830 | |
831 | Pre: | |
832 | The EddyMsg instance passed in should be a piece.gpg_data.plainobj | |
833 | which represents decrypted text. It may or may not be signed on that | |
834 | level. | |
d873ff48 | 835 | |
8c3e5397 AE |
836 | Post: |
837 | the ReplyInfo instance may have a new 'target_key' set and its | |
838 | 'msg_to_quote' will be updated with (possibly signed) plaintext, if any | |
839 | could be found. | |
840 | """ | |
d873ff48 | 841 | |
0aa88c27 | 842 | if eddymsg_obj == None: |
8c3e5397 | 843 | return |
0aa88c27 | 844 | |
0402995a | 845 | # recurse on multi-part mime |
928e3819 AE |
846 | if eddymsg_obj.multipart == True: |
847 | for sub in eddymsg_obj.subparts: | |
8c3e5397 | 848 | flatten_decrypted_payloads(sub, replyinfo_obj, get_signed_part) |
d873ff48 | 849 | |
928e3819 | 850 | for piece in eddymsg_obj.payload_pieces: |
0402995a | 851 | if (get_signed_part): |
0fd3389f AE |
852 | if ((piece.piece_type == TxtType.detachedsig) \ |
853 | or (piece.piece_type == TxtType.signature)) \ | |
b4c116d5 AE |
854 | and (piece.gpg_data != None) \ |
855 | and (piece.gpg_data.plainobj != None): | |
8c3e5397 AE |
856 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, False) |
857 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
c3d417bf AE |
858 | break |
859 | else: | |
0fd3389f | 860 | if piece.piece_type == TxtType.text: |
8c3e5397 | 861 | replyinfo_obj.msg_to_quote += piece.string |
d873ff48 AE |
862 | |
863 | ||
013f7cb8 | 864 | def get_key_from_fp (replyinfo_obj, gpgme_ctx): |
39e2c525 AE |
865 | """Obtains a public key object from a key fingerprint |
866 | ||
ca37d0cb AE |
867 | If the .target_key is not set, then we use .fallback_target_key, if |
868 | available. | |
39e2c525 AE |
869 | |
870 | Args: | |
871 | replyinfo_obj: ReplyInfo instance | |
872 | gpgme_ctx: the gpgme context | |
873 | ||
874 | Return: | |
875 | The key object of the key of either the target_key or the fallback one | |
876 | if .target_key is not set. If the key cannot be loaded, then return | |
877 | None. | |
878 | ||
879 | Pre: | |
880 | Loading a key requires that we have the public key imported. This | |
881 | requires that they email contains the pub key block, or that it was | |
882 | previously sent to edward. | |
883 | ||
884 | Post: | |
ca37d0cb AE |
885 | If the key can be loaded, then replyinfo_obj.reply_to_key points to the |
886 | public key object. If the key cannot be loaded, then the replyinfo_obj | |
887 | is marked as having no public key available. | |
39e2c525 | 888 | """ |
013f7cb8 | 889 | |
ca37d0cb AE |
890 | for key in (replyinfo_obj.target_key, replyinfo_obj.fallback_target_key): |
891 | if key != None: | |
892 | try: | |
893 | encrypt_to_key = gpgme_ctx.get_key(key) | |
894 | replyinfo_obj.encrypt_to_key = encrypt_to_key | |
b4c116d5 | 895 | replyinfo_obj.have_reply_key = True |
ca37d0cb | 896 | return |
013f7cb8 | 897 | |
ca37d0cb AE |
898 | except gpgme.GpgmeError: |
899 | pass | |
013f7cb8 | 900 | |
013f7cb8 | 901 | |
d873ff48 | 902 | def write_reply (replyinfo_obj): |
39e2c525 AE |
903 | """Write the reply email body about the GPG successes/failures. |
904 | ||
905 | The reply is about whether decryption, sig verification and key | |
906 | import/loading was successful or failed. If text was successfully decrypted | |
907 | and verified, then the first instance of such text will be included in | |
908 | quoted form. | |
909 | ||
910 | Args: | |
911 | replyinfo_obj: contains details of GPG processing status | |
912 | ||
913 | Returns: | |
914 | the plaintext message to be sent to the user | |
915 | ||
916 | Pre: | |
917 | replyinfo_obj should be populated with info about GPG processing status. | |
918 | """ | |
d873ff48 AE |
919 | |
920 | reply_plain = "" | |
921 | ||
b4c116d5 | 922 | if replyinfo_obj.decrypt_success == True: |
234f607b | 923 | debug('decrypt success') |
d873ff48 | 924 | reply_plain += replyinfo_obj.replies['success_decrypt'] |
b4c116d5 | 925 | reply_plain += "\n\n" |
2694709a | 926 | |
b4c116d5 | 927 | if (replyinfo_obj.sig_success == True) and (replyinfo_obj.have_reply_key == True): |
234f607b | 928 | debug('message quoted') |
2694709a AE |
929 | quoted_text = email_quote_text(replyinfo_obj.msg_to_quote) |
930 | reply_plain += quoted_text | |
b4c116d5 | 931 | reply_plain += "\n\n" |
d873ff48 | 932 | |
b4c116d5 | 933 | else: |
234f607b | 934 | debug('decrypt failure') |
d873ff48 | 935 | reply_plain += replyinfo_obj.replies['failed_decrypt'] |
b4c116d5 | 936 | reply_plain += "\n\n" |
d873ff48 AE |
937 | |
938 | if replyinfo_obj.sig_success == True: | |
234f607b | 939 | debug('signature success') |
d873ff48 | 940 | reply_plain += replyinfo_obj.replies['sig_success'] |
b4c116d5 | 941 | reply_plain += "\n\n" |
d873ff48 | 942 | |
32a8996f | 943 | elif replyinfo_obj.sig_failure == True: |
234f607b | 944 | debug('signature failure') |
d873ff48 | 945 | reply_plain += replyinfo_obj.replies['sig_failure'] |
b4c116d5 | 946 | reply_plain += "\n\n" |
d873ff48 | 947 | |
b4c116d5 | 948 | if (replyinfo_obj.pubkey_success == True): |
234f607b | 949 | debug('public key received') |
b4c116d5 | 950 | reply_plain += replyinfo_obj.replies['public_key_received'] |
d873ff48 | 951 | reply_plain += "\n\n" |
d873ff48 | 952 | |
b4c116d5 | 953 | elif (replyinfo_obj.sigkey_missing == True): |
234f607b | 954 | debug('no public key') |
b4c116d5 | 955 | reply_plain += replyinfo_obj.replies['no_public_key'] |
d873ff48 | 956 | reply_plain += "\n\n" |
d873ff48 AE |
957 | |
958 | ||
d873ff48 | 959 | reply_plain += replyinfo_obj.replies['signature'] |
b4c116d5 | 960 | reply_plain += "\n\n" |
56578eaf | 961 | |
d873ff48 | 962 | return reply_plain |
56578eaf AE |
963 | |
964 | ||
8f61c66a | 965 | def add_gpg_key (key_block, gpgme_ctx): |
39e2c525 AE |
966 | """Adds a GPG pubkey to the local keystore |
967 | ||
968 | This adds keys received through email into the key store so they can be | |
969 | used later. | |
970 | ||
971 | Args: | |
972 | key_block: the string form of the ascii-armored public key block | |
973 | gpgme_ctx: the gpgme context | |
974 | ||
975 | Returns: | |
976 | the fingerprint(s) of the imported key(s) | |
977 | """ | |
c267c233 | 978 | |
8f61c66a | 979 | fp = io.BytesIO(key_block.encode('ascii')) |
c267c233 | 980 | |
89c08329 AE |
981 | try: |
982 | result = gpgme_ctx.import_(fp) | |
983 | imports = result.imports | |
984 | except gpgme.GpgmeError: | |
985 | imports = [] | |
c267c233 | 986 | |
f8ee6bd3 | 987 | key_fingerprints = [] |
c267c233 | 988 | |
8f61c66a AE |
989 | if imports != []: |
990 | for import_ in imports: | |
991 | fingerprint = import_[0] | |
f8ee6bd3 | 992 | key_fingerprints += [fingerprint] |
c267c233 | 993 | |
e49673aa | 994 | debug("added gpg key: " + fingerprint) |
ec1e779a | 995 | |
f8ee6bd3 | 996 | return key_fingerprints |
ec1e779a AE |
997 | |
998 | ||
3a753fd0 | 999 | def verify_sig_message (msg_block, gpgme_ctx): |
39e2c525 AE |
1000 | """Verifies the signature of a signed, ascii-armored block of text. |
1001 | ||
1002 | It encodes the string into ascii, since binary GPG files are currently | |
1003 | unsupported, and alternative, the ascii-armored format is encodable into | |
1004 | ascii. | |
1005 | ||
1006 | Args: | |
1007 | msg_block: a GPG Message block in string form. It may be encrypted or | |
1008 | not. If it is encrypted, it will return empty results. | |
1009 | gpgme_ctx: the gpgme context | |
1010 | ||
1011 | Returns: | |
9af26cb8 AE |
1012 | A tuple containing the plaintext of the signed part, the list of |
1013 | fingerprints of keys signing the data, and a boolean marking whether | |
b4c116d5 AE |
1014 | edward is missing all public keys for validating any of the signatures. |
1015 | If verification failed, perhaps because the message was also encrypted, | |
1016 | then empty results are returned. | |
39e2c525 | 1017 | """ |
3a753fd0 AE |
1018 | |
1019 | block_b = io.BytesIO(msg_block.encode('ascii')) | |
1020 | plain_b = io.BytesIO() | |
1021 | ||
1022 | try: | |
1023 | sigs = gpgme_ctx.verify(block_b, None, plain_b) | |
5f6f32b1 | 1024 | except gpgme.GpgmeError: |
b4c116d5 | 1025 | return ("",[],False) |
3a753fd0 AE |
1026 | |
1027 | plaintext = plain_b.getvalue().decode('utf-8') | |
1028 | ||
b4c116d5 | 1029 | sigkey_missing = False |
3a753fd0 AE |
1030 | fingerprints = [] |
1031 | for sig in sigs: | |
8f011cc9 | 1032 | if (sig.summary == 0) or (sig.summary & gpgme.SIGSUM_VALID != 0) or (sig.summary & gpgme.SIGSUM_GREEN != 0): |
9af26cb8 | 1033 | fingerprints += [sig.fpr] |
b4c116d5 AE |
1034 | sigkey_missing = False |
1035 | break | |
9af26cb8 | 1036 | else: |
b4c116d5 AE |
1037 | if (sig.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1038 | sigkey_missing = True | |
9af26cb8 | 1039 | |
b4c116d5 | 1040 | return (plaintext, fingerprints, sigkey_missing) |
3a753fd0 AE |
1041 | |
1042 | ||
101d54a8 | 1043 | def verify_detached_signature (detached_sig, plaintext_bytes, gpgme_ctx): |
39e2c525 AE |
1044 | """Verifies the signature of a detached signature. |
1045 | ||
1046 | This requires the signature part and the signed part as separate arguments. | |
1047 | ||
1048 | Args: | |
1049 | detached_sig: the signature part of the detached signature | |
1050 | plaintext_bytes: the byte form of the message being signed. | |
1051 | gpgme_ctx: the gpgme context | |
1052 | ||
1053 | Returns: | |
9af26cb8 | 1054 | A tuple containging a list of signing fingerprints if the signature |
b4c116d5 AE |
1055 | verification was sucessful, and a boolean marking whether edward is |
1056 | missing all public keys for validating any of the signatures. | |
1057 | Otherwise, a tuple containing an empty list and True are returned. | |
39e2c525 | 1058 | """ |
101d54a8 AE |
1059 | |
1060 | detached_sig_fp = io.BytesIO(detached_sig.encode('ascii')) | |
1061 | plaintext_fp = io.BytesIO(plaintext_bytes) | |
101d54a8 | 1062 | |
ff7aeb3d AE |
1063 | try: |
1064 | result = gpgme_ctx.verify(detached_sig_fp, plaintext_fp, None) | |
1065 | except gpgme.GpgmeError: | |
b4c116d5 | 1066 | return ([],False) |
101d54a8 | 1067 | |
b4c116d5 | 1068 | sigkey_missing = False |
101d54a8 AE |
1069 | sig_fingerprints = [] |
1070 | for res_ in result: | |
8f011cc9 | 1071 | if (res_.summary == 0) or (res_.summary & gpgme.SIGSUM_VALID != 0) or (res_.summary & gpgme.SIGSUM_GREEN != 0): |
9af26cb8 | 1072 | sig_fingerprints += [res_.fpr] |
b4c116d5 AE |
1073 | sigkey_missing = False |
1074 | break | |
9af26cb8 | 1075 | else: |
b4c116d5 AE |
1076 | if (res_.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1077 | sigkey_missing = True | |
101d54a8 | 1078 | |
b4c116d5 | 1079 | return (sig_fingerprints, sigkey_missing) |
101d54a8 AE |
1080 | |
1081 | ||
5b3053c1 | 1082 | def decrypt_block (msg_block, gpgme_ctx): |
9af26cb8 | 1083 | """Decrypts a block of GPG text and verifies any included sigatures. |
39e2c525 AE |
1084 | |
1085 | Some encypted messages have embeded signatures, so those are verified too. | |
1086 | ||
1087 | Args: | |
1088 | msg_block: the encrypted(/signed) text | |
1089 | gpgme_ctx: the gpgme context | |
1090 | ||
1091 | Returns: | |
9af26cb8 AE |
1092 | A tuple containing plaintext, signatures (if the decryption and |
1093 | signature verification were successful, respectively), and a boolean | |
b4c116d5 AE |
1094 | marking whether edward is missing all public keys for validating any of |
1095 | the signatures. | |
39e2c525 | 1096 | """ |
0bec96d6 | 1097 | |
5b3053c1 | 1098 | block_b = io.BytesIO(msg_block.encode('ascii')) |
0bec96d6 AE |
1099 | plain_b = io.BytesIO() |
1100 | ||
afc1f64c AE |
1101 | try: |
1102 | sigs = gpgme_ctx.decrypt_verify(block_b, plain_b) | |
5f6f32b1 | 1103 | except gpgme.GpgmeError: |
b4c116d5 | 1104 | return ("",[],False) |
0bec96d6 | 1105 | |
6aa41372 | 1106 | plaintext = plain_b.getvalue().decode('utf-8') |
cbdf22c1 | 1107 | |
b4c116d5 | 1108 | sigkey_missing = False |
cbdf22c1 AE |
1109 | fingerprints = [] |
1110 | for sig in sigs: | |
8f011cc9 | 1111 | if (sig.summary == 0) or (sig.summary & gpgme.SIGSUM_VALID != 0) or (sig.summary & gpgme.SIGSUM_GREEN != 0): |
9af26cb8 | 1112 | fingerprints += [sig.fpr] |
b4c116d5 AE |
1113 | sigkey_missing = False |
1114 | break | |
9af26cb8 | 1115 | else: |
b4c116d5 AE |
1116 | if (sig.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1117 | sigkey_missing = True | |
9af26cb8 | 1118 | |
b4c116d5 | 1119 | return (plaintext, fingerprints, sigkey_missing) |
0bec96d6 AE |
1120 | |
1121 | ||
dd2b62d7 AE |
1122 | def email_to_from_subject (email_text): |
1123 | """Returns the values of the email's To:, From: and Subject: fields | |
fafa21c3 | 1124 | |
dd2b62d7 | 1125 | Returns this information from an email. |
fafa21c3 | 1126 | |
dd2b62d7 AE |
1127 | Args: |
1128 | email_text: the string form of the email | |
fafa21c3 | 1129 | |
dd2b62d7 AE |
1130 | Returns: |
1131 | the email To:, From:, and Subject: fields as strings | |
1132 | """ | |
d65993b8 AE |
1133 | |
1134 | email_struct = email.parser.Parser().parsestr(email_text) | |
1135 | ||
1136 | email_to = email_struct['To'] | |
1137 | email_from = email_struct['From'] | |
1138 | email_subject = email_struct['Subject'] | |
1139 | ||
1140 | return email_to, email_from, email_subject | |
1141 | ||
1142 | ||
bb27d257 AE |
1143 | def import_lang_pick_address(email_to, hostname): |
1144 | """Imports language file for i18n support; makes reply from address | |
dd2b62d7 AE |
1145 | |
1146 | The language imported depends on the To: address of the email received by | |
1147 | edward. an -en ending implies the English language, whereas a -ja ending | |
1148 | implies Japanese. The list of supported languages is listed in the 'langs' | |
bb27d257 AE |
1149 | list at the beginning of the program. This function also chooses the |
1150 | language-dependent address which can be used as the From address in the | |
1151 | reply email. | |
dd2b62d7 AE |
1152 | |
1153 | Args: | |
1154 | email_to: the string containing the email address that the mail was | |
bb27d257 AE |
1155 | sent to. |
1156 | hostname: the hostname part of the reply email's from address | |
dd2b62d7 AE |
1157 | |
1158 | Returns: | |
1159 | the reference to the imported language module. The only variable in | |
1160 | this file is the 'replies' dictionary. | |
1161 | """ | |
adcef2f7 | 1162 | |
bb27d257 AE |
1163 | # default |
1164 | use_lang = "en" | |
daed5f10 | 1165 | |
5250b3b8 AE |
1166 | if email_to != None: |
1167 | for lang in langs: | |
1168 | if "edward-" + lang in email_to: | |
bb27d257 AE |
1169 | use_lang = lang |
1170 | break | |
adcef2f7 | 1171 | |
bb27d257 AE |
1172 | lang_mod_name = "lang." + re.sub('-', '_', use_lang) |
1173 | lang_module = importlib.import_module(lang_mod_name) | |
1174 | ||
60ccbaf4 | 1175 | reply_from = "edward-" + use_lang + "@" + hostname |
bb27d257 | 1176 | |
60ccbaf4 | 1177 | return lang_module, reply_from |
adcef2f7 AE |
1178 | |
1179 | ||
cfb03389 | 1180 | def generate_encrypted_mime (plaintext, email_to, email_subject, encrypt_to_key, |
0a064403 | 1181 | gpgme_ctx): |
dd2b62d7 AE |
1182 | """This function creates the mime email reply. It can encrypt the email. |
1183 | ||
1184 | If the encrypt_key is included, then the email is encrypted and signed. | |
1185 | Otherwise it is unencrypted. | |
1186 | ||
1187 | Args: | |
1188 | plaintext: the plaintext body of the message to create. | |
cfb03389 | 1189 | email_to: the email address to reply to |
dd2b62d7 AE |
1190 | email_subject: the subject to use in reply |
1191 | encrypt_to_key: the key object to use for encrypting the email. (or | |
1192 | None) | |
1193 | gpgme_ctx: the gpgme context | |
1194 | ||
1195 | Returns | |
1196 | A string version of the mime message, possibly encrypted and signed. | |
1197 | """ | |
1da9b527 | 1198 | |
e5dd6f23 | 1199 | if (encrypt_to_key != None): |
8bdfb6d4 | 1200 | |
66a125ef AE |
1201 | plaintext_mime = MIMEText(plaintext) |
1202 | plaintext_mime.set_charset('utf-8') | |
8bdfb6d4 AE |
1203 | |
1204 | encrypted_text = encrypt_sign_message(plaintext_mime.as_string(), | |
1205 | encrypt_to_key, | |
40c37ab3 | 1206 | gpgme_ctx) |
8bdfb6d4 | 1207 | |
e5dd6f23 AE |
1208 | control_mime = MIMEApplication("Version: 1", |
1209 | _subtype='pgp-encrypted', | |
1210 | _encoder=email.encoders.encode_7or8bit) | |
1211 | control_mime['Content-Description'] = 'PGP/MIME version identification' | |
1212 | control_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1213 | |
e5dd6f23 AE |
1214 | encoded_mime = MIMEApplication(encrypted_text, |
1215 | _subtype='octet-stream; name="encrypted.asc"', | |
1216 | _encoder=email.encoders.encode_7or8bit) | |
1217 | encoded_mime['Content-Description'] = 'OpenPGP encrypted message' | |
1218 | encoded_mime['Content-Disposition'] = 'inline; filename="encrypted.asc"' | |
1219 | encoded_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1220 | |
e5dd6f23 AE |
1221 | message_mime = MIMEMultipart(_subtype="encrypted", protocol="application/pgp-encrypted") |
1222 | message_mime.attach(control_mime) | |
1223 | message_mime.attach(encoded_mime) | |
1224 | message_mime['Content-Disposition'] = 'inline' | |
216708e9 | 1225 | |
e5dd6f23 AE |
1226 | else: |
1227 | message_mime = MIMEText(plaintext) | |
66a125ef | 1228 | message_mime.set_charset('utf-8') |
2007103e | 1229 | |
cfb03389 | 1230 | message_mime['To'] = email_to |
2007103e AE |
1231 | message_mime['Subject'] = email_subject |
1232 | ||
1233 | reply = message_mime.as_string() | |
1da9b527 AE |
1234 | |
1235 | return reply | |
1236 | ||
1237 | ||
60ccbaf4 AE |
1238 | def send_reply(email_txt, subject, reply_to, reply_from): |
1239 | ||
1240 | email_bytes = email_txt.encode('ascii') | |
1241 | ||
1242 | p = subprocess.Popen(["/usr/sbin/sendmail", "-f", reply_from, "-F", "Edward, GPG Bot", "-i", reply_to], stdin=subprocess.PIPE) | |
1243 | ||
1244 | (stdout, stderr) = p.communicate(email_bytes) | |
1245 | ||
1246 | if stdout != None: | |
1247 | debug("sendmail stdout: " + str(stdout)) | |
1248 | if stderr != None: | |
1249 | error("sendmail stderr: " + str(stderr)) | |
1250 | ||
1251 | ||
f87041f8 | 1252 | def email_quote_text (text): |
dd2b62d7 AE |
1253 | """Quotes input text by inserting "> "s |
1254 | ||
1255 | This is useful for quoting a text for the reply message. It inserts "> " | |
1256 | strings at the beginning of lines. | |
1257 | ||
1258 | Args: | |
1259 | text: plain text to quote | |
1260 | ||
1261 | Returns: | |
1262 | Quoted text | |
1263 | """ | |
f87041f8 AE |
1264 | |
1265 | quoted_message = re.sub(r'^', r'> ', text, flags=re.MULTILINE) | |
1266 | ||
1267 | return quoted_message | |
1268 | ||
1269 | ||
0a064403 | 1270 | def encrypt_sign_message (plaintext, encrypt_to_key, gpgme_ctx): |
dd2b62d7 AE |
1271 | """Encrypts and signs plaintext |
1272 | ||
1273 | This encrypts and signs a message. | |
1274 | ||
1275 | Args: | |
1276 | plaintext: text to sign and ecrypt | |
1277 | encrypt_to_key: the key object to encrypt to | |
1278 | gpgme_ctx: the gpgme context | |
1279 | ||
1280 | Returns: | |
1281 | An encrypted and signed string of text | |
1282 | """ | |
897cbaf6 | 1283 | |
b33f601b | 1284 | # the plaintext should be mime encoded in an ascii-compatible form |
6aa41372 | 1285 | plaintext_bytes = io.BytesIO(plaintext.encode('ascii')) |
1da9b527 AE |
1286 | encrypted_bytes = io.BytesIO() |
1287 | ||
897cbaf6 | 1288 | gpgme_ctx.encrypt_sign([encrypt_to_key], gpgme.ENCRYPT_ALWAYS_TRUST, |
1da9b527 AE |
1289 | plaintext_bytes, encrypted_bytes) |
1290 | ||
6aa41372 | 1291 | encrypted_txt = encrypted_bytes.getvalue().decode('ascii') |
1da9b527 AE |
1292 | return encrypted_txt |
1293 | ||
1294 | ||
0a064403 | 1295 | def error (error_msg): |
dd2b62d7 AE |
1296 | """Write an error message to stdout |
1297 | ||
1298 | The error message includes the program name. | |
1299 | ||
1300 | Args: | |
1301 | error_msg: the message to print | |
1302 | ||
1303 | Returns: | |
1304 | Nothing | |
1305 | ||
1306 | Post: | |
1307 | An error message is printed to stdout | |
1308 | """ | |
0a064403 | 1309 | |
e4fb2ab2 | 1310 | sys.stderr.write(progname + ": " + str(error_msg) + "\n") |
0a064403 AE |
1311 | |
1312 | ||
5e8f9094 | 1313 | def debug (debug_msg): |
dd2b62d7 AE |
1314 | """Writes a debug message to stdout if debug == True |
1315 | ||
1316 | If the debug option is set in edward_config.py, then the passed message | |
1317 | gets printed to stdout. | |
1318 | ||
1319 | Args: | |
1320 | debug_msg: the message to print to stdout | |
1321 | ||
1322 | Returns: | |
1323 | Nothing | |
1324 | ||
1325 | Post: | |
1326 | A debug message is printed to stdout | |
1327 | """ | |
5e8f9094 AE |
1328 | |
1329 | if edward_config.debug == True: | |
0a064403 | 1330 | error(debug_msg) |
5e8f9094 AE |
1331 | |
1332 | ||
20f6e7c5 | 1333 | def handle_args (): |
60ccbaf4 | 1334 | """Sets the progname variable and processes optional argument |
dd2b62d7 | 1335 | |
60ccbaf4 AE |
1336 | If there are more than two arguments then edward complains and quits. An |
1337 | single "-p" argument sets the print_reply_only option, which makes edward | |
1338 | print email replies instead of mailing them. | |
dd2b62d7 AE |
1339 | |
1340 | Args: | |
1341 | None | |
1342 | ||
1343 | Returns: | |
60ccbaf4 AE |
1344 | True if edward should print arguments instead of mailing them, |
1345 | otherwise it returns False. | |
dd2b62d7 AE |
1346 | |
1347 | Post: | |
60ccbaf4 AE |
1348 | Exits with error 1 if there are more than two arguments, otherwise |
1349 | returns the print_reply_only option. | |
dd2b62d7 | 1350 | """ |
20f6e7c5 | 1351 | |
a51cdb72 AE |
1352 | global progname |
1353 | progname = sys.argv[0] | |
1354 | ||
60ccbaf4 AE |
1355 | print_reply_only = False |
1356 | ||
1357 | if len(sys.argv) > 2: | |
1358 | print(progname + " usage: " + progname + " [-p]\n\n" \ | |
1359 | + " -p print reply message to stdout, do not mail it\n", \ | |
1360 | file=sys.stderr) | |
a51cdb72 | 1361 | exit(1) |
20f6e7c5 | 1362 | |
60ccbaf4 AE |
1363 | elif (len(sys.argv) == 2) and (sys.argv[1] == "-p"): |
1364 | print_reply_only = True | |
1365 | ||
1366 | return print_reply_only | |
1367 | ||
20f6e7c5 | 1368 | |
a51cdb72 | 1369 | if __name__ == "__main__": |
dd2b62d7 | 1370 | """Executes main if this file is not loaded interactively""" |
20f6e7c5 | 1371 | |
a51cdb72 | 1372 | main() |
0bec96d6 | 1373 |