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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 | ||
34 | import sys | |
0bec96d6 AE |
35 | import gpgme |
36 | import re | |
37 | import io | |
40c37ab3 | 38 | import os |
0bec96d6 | 39 | |
8bdfb6d4 AE |
40 | import email.parser |
41 | import email.message | |
42 | import email.encoders | |
43 | ||
44 | from email.mime.multipart import MIMEMultipart | |
45 | from email.mime.application import MIMEApplication | |
46 | from email.mime.nonmultipart import MIMENonMultipart | |
47 | ||
40c37ab3 | 48 | import edward_config |
c96f3837 | 49 | |
38738401 AE |
50 | match_types = [('clearsign', |
51 | '-----BEGIN PGP SIGNED MESSAGE-----.*?-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----'), | |
52 | ('message', | |
56578eaf AE |
53 | '-----BEGIN PGP MESSAGE-----.*?-----END PGP MESSAGE-----'), |
54 | ('pubkey', | |
55 | '-----BEGIN PGP PUBLIC KEY BLOCK-----.*?-----END PGP PUBLIC KEY BLOCK-----'), | |
56 | ('detachedsig', | |
38738401 | 57 | '-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----')] |
56578eaf AE |
58 | |
59 | ||
60 | class EddyMsg (object): | |
61 | def __init__(self): | |
62 | self.multipart = False | |
63 | self.subparts = [] | |
64 | ||
65 | self.charset = None | |
66 | self.payload_bytes = None | |
67 | self.payload_pieces = [] | |
68 | ||
69 | self.filename = None | |
70 | self.content_type = None | |
71 | self.description_list = None | |
72 | ||
73 | ||
74 | class PayloadPiece (object): | |
75 | def __init__(self): | |
76 | self.piece_type = None | |
77 | self.string = None | |
78 | self.gpg_data = None | |
79 | ||
80 | ||
38738401 AE |
81 | class GPGData (object): |
82 | def __init__(self): | |
83 | self.decrypted = False | |
84 | ||
85 | self.plainobj = None | |
86 | self.sigs = [] | |
87 | self.keys = [] | |
88 | ||
89 | ||
0bec96d6 AE |
90 | def main (): |
91 | ||
20f6e7c5 | 92 | handle_args() |
0bec96d6 | 93 | |
0a064403 AE |
94 | gpgme_ctx = get_gpg_context(edward_config.gnupghome, |
95 | edward_config.sign_with_key) | |
96 | ||
c96f3837 | 97 | email_text = sys.stdin.read() |
38738401 | 98 | result = parse_pgp_mime(email_text, gpgme_ctx) |
56578eaf | 99 | email_from, email_subject = email_from_subject(email_text) |
fafa21c3 | 100 | |
1fccb295 AE |
101 | print(flatten_eddy(result)) |
102 | ||
56578eaf AE |
103 | # encrypt_to_key = choose_reply_encryption_key(gpgme_ctx, fingerprints) |
104 | # | |
bf79a93e AE |
105 | # reply_mime = generate_encrypted_mime(plaintext, email_from, \ |
106 | # email_subject, encrypt_to_key, | |
107 | # gpgme_ctx) | |
c96f3837 | 108 | |
0bec96d6 | 109 | |
0a064403 AE |
110 | def get_gpg_context (gnupghome, sign_with_key_fp): |
111 | ||
112 | os.environ['GNUPGHOME'] = gnupghome | |
113 | ||
114 | gpgme_ctx = gpgme.Context() | |
115 | gpgme_ctx.armor = True | |
116 | ||
117 | try: | |
118 | sign_with_key = gpgme_ctx.get_key(sign_with_key_fp) | |
119 | except: | |
120 | error("unable to load signing key. is the gnupghome " | |
121 | + "and signing key properly set in the edward_config.py?") | |
122 | exit(1) | |
123 | ||
124 | gpgme_ctx.signers = [sign_with_key] | |
125 | ||
126 | return gpgme_ctx | |
127 | ||
128 | ||
38738401 | 129 | def parse_pgp_mime (email_text, gpgme_ctx): |
394a1476 AE |
130 | |
131 | email_struct = email.parser.Parser().parsestr(email_text) | |
132 | ||
56578eaf AE |
133 | eddy_obj = parse_mime(email_struct) |
134 | eddy_obj = split_payloads(eddy_obj) | |
8f61c66a | 135 | eddy_obj = gpg_on_payloads(eddy_obj, gpgme_ctx) |
8bb4b0d5 | 136 | |
56578eaf | 137 | return eddy_obj |
0bec96d6 | 138 | |
0bec96d6 | 139 | |
56578eaf | 140 | def parse_mime(msg_struct): |
0bec96d6 | 141 | |
56578eaf | 142 | eddy_obj = EddyMsg() |
8bb4b0d5 | 143 | |
56578eaf AE |
144 | if msg_struct.is_multipart() == True: |
145 | payloads = msg_struct.get_payload() | |
0bec96d6 | 146 | |
56578eaf | 147 | eddy_obj.multipart = True |
dd11a483 AE |
148 | eddy_obj.subparts = list(map(parse_mime, payloads)) |
149 | ||
56578eaf AE |
150 | else: |
151 | eddy_obj = get_subpart_data(msg_struct) | |
394a1476 | 152 | |
56578eaf | 153 | return eddy_obj |
c267c233 | 154 | |
80119cab | 155 | |
56578eaf | 156 | def scan_and_split (payload_piece, match_type, pattern): |
cf75de65 | 157 | |
a5d37d44 AE |
158 | # don't try to re-split pieces containing gpg data |
159 | if payload_piece.piece_type != "text": | |
160 | return [payload_piece] | |
161 | ||
56578eaf AE |
162 | flags = re.DOTALL | re.MULTILINE |
163 | matches = re.search("(?P<beginning>.*?)(?P<match>" + pattern + | |
164 | ")(?P<rest>.*)", payload_piece.string, flags=flags) | |
86663388 | 165 | |
56578eaf AE |
166 | if matches == None: |
167 | pieces = [payload_piece] | |
c96f3837 | 168 | |
56578eaf | 169 | else: |
d437f8b2 | 170 | |
56578eaf AE |
171 | beginning = PayloadPiece() |
172 | beginning.string = matches.group('beginning') | |
173 | beginning.piece_type = payload_piece.piece_type | |
d437f8b2 | 174 | |
56578eaf AE |
175 | match = PayloadPiece() |
176 | match.string = matches.group('match') | |
177 | match.piece_type = match_type | |
d437f8b2 | 178 | |
56578eaf AE |
179 | rest = PayloadPiece() |
180 | rest.string = matches.group('rest') | |
181 | rest.piece_type = payload_piece.piece_type | |
d437f8b2 | 182 | |
56578eaf | 183 | more_pieces = scan_and_split(rest, match_type, pattern) |
4615b156 | 184 | pieces = [beginning, match ] + more_pieces |
d437f8b2 | 185 | |
56578eaf | 186 | return pieces |
d437f8b2 | 187 | |
d437f8b2 | 188 | |
56578eaf | 189 | def get_subpart_data (part): |
0bec96d6 | 190 | |
56578eaf | 191 | obj = EddyMsg() |
0bec96d6 | 192 | |
56578eaf AE |
193 | obj.charset = part.get_content_charset() |
194 | obj.payload_bytes = part.get_payload(decode=True) | |
195 | ||
196 | obj.filename = part.get_filename() | |
197 | obj.content_type = part.get_content_type() | |
198 | obj.description_list = part['content-description'] | |
199 | ||
200 | # your guess is as good as a-myy-ee-ine... | |
201 | if obj.charset == None: | |
202 | obj.charset = 'utf-8' | |
203 | ||
204 | if obj.payload_bytes != None: | |
0eb75d9c AE |
205 | try: |
206 | payload = PayloadPiece() | |
207 | payload.string = obj.payload_bytes.decode(obj.charset) | |
208 | payload.piece_type = 'text' | |
209 | ||
210 | obj.payload_pieces = [payload] | |
211 | except UnicodeDecodeError: | |
212 | pass | |
56578eaf AE |
213 | |
214 | return obj | |
215 | ||
216 | ||
dd11a483 | 217 | def do_to_eddys_pieces (function_to_do, eddy_obj, data): |
56578eaf | 218 | |
e33518c8 AE |
219 | if eddy_obj == None: |
220 | return [] | |
221 | ||
56578eaf | 222 | if eddy_obj.multipart == True: |
dd11a483 AE |
223 | result_list = [] |
224 | for sub in eddy_obj.subparts: | |
225 | result_list += do_to_eddys_pieces(function_to_do, sub, data) | |
394a1476 | 226 | else: |
a5d37d44 | 227 | result_list = [function_to_do(eddy_obj, data)] |
dd11a483 AE |
228 | |
229 | return result_list | |
230 | ||
231 | ||
a5d37d44 AE |
232 | def split_payloads (eddy_obj): |
233 | ||
234 | for match_type in match_types: | |
235 | do_to_eddys_pieces(split_payload_pieces, eddy_obj, match_type) | |
236 | ||
237 | return eddy_obj | |
238 | ||
239 | ||
240 | def split_payload_pieces (eddy_obj, match_type): | |
241 | ||
242 | (match_name, pattern) = match_type | |
243 | ||
244 | new_pieces_list = [] | |
245 | for piece in eddy_obj.payload_pieces: | |
246 | new_pieces_list += scan_and_split(piece, match_name, pattern) | |
247 | ||
248 | eddy_obj.payload_pieces = new_pieces_list | |
249 | ||
250 | ||
8f61c66a | 251 | def gpg_on_payloads (eddy_obj, gpgme_ctx): |
38738401 | 252 | |
8f61c66a | 253 | do_to_eddys_pieces(gpg_on_payload_pieces, eddy_obj, gpgme_ctx) |
38738401 AE |
254 | |
255 | return eddy_obj | |
256 | ||
257 | ||
8f61c66a | 258 | def gpg_on_payload_pieces (eddy_obj, gpgme_ctx): |
38738401 | 259 | |
a5d37d44 | 260 | for piece in eddy_obj.payload_pieces: |
38738401 AE |
261 | |
262 | if piece.piece_type == "text": | |
263 | # don't transform the plaintext. | |
264 | pass | |
265 | ||
266 | elif piece.piece_type == "message": | |
267 | (plaintext, sigs) = decrypt_block (piece.string, gpgme_ctx) | |
268 | ||
269 | if plaintext: | |
270 | piece.gpg_data = GPGData() | |
271 | piece.gpg_data.sigs = sigs | |
272 | # recurse! | |
273 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
129543c3 | 274 | |
8f61c66a AE |
275 | elif piece.piece_type == "pubkey": |
276 | fingerprints = add_gpg_key(piece.string, gpgme_ctx) | |
277 | ||
278 | if fingerprints != []: | |
279 | piece.gpg_data = GPGData() | |
280 | piece.gpg_data.keys = fingerprints | |
129543c3 AE |
281 | |
282 | elif piece.piece_type == "clearsign": | |
283 | (plaintext, fingerprints) = verify_clear_signature(piece.string, gpgme_ctx) | |
284 | ||
285 | if fingerprints != []: | |
286 | piece.gpg_data = GPGData() | |
287 | piece.gpg_data.sigs = fingerprints | |
288 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
289 | ||
38738401 AE |
290 | else: |
291 | pass | |
292 | ||
293 | ||
dd11a483 AE |
294 | def flatten_eddy (eddy_obj): |
295 | ||
296 | string = "\n".join(do_to_eddys_pieces(flatten_payload_pieces, eddy_obj, None)) | |
56578eaf AE |
297 | |
298 | return string | |
299 | ||
300 | ||
a5d37d44 | 301 | def flatten_payload_pieces (eddy_obj, _ignore): |
0bec96d6 | 302 | |
56578eaf | 303 | string = "" |
a5d37d44 | 304 | for piece in eddy_obj.payload_pieces: |
38738401 AE |
305 | if piece.piece_type == "text": |
306 | string += piece.string | |
efe7336d AE |
307 | elif piece.gpg_data == None: |
308 | string += "Hmmm... I wasn't able to get that part.\n" | |
38738401 AE |
309 | elif piece.piece_type == "message": |
310 | # recursive! | |
311 | string += flatten_eddy(piece.gpg_data.plainobj) | |
8f61c66a AE |
312 | elif piece.piece_type == "pubkey": |
313 | string += "thanks for your public key:" | |
314 | for key in piece.gpg_data.keys: | |
315 | string += "\n" + key | |
129543c3 AE |
316 | elif piece.piece_type == "clearsign": |
317 | string += "*** Begin signed part ***\n" | |
318 | string += flatten_eddy(piece.gpg_data.plainobj) | |
319 | string += "\n*** End signed part ***" | |
56578eaf AE |
320 | |
321 | return string | |
322 | ||
323 | ||
8f61c66a | 324 | def add_gpg_key (key_block, gpgme_ctx): |
c267c233 | 325 | |
8f61c66a | 326 | fp = io.BytesIO(key_block.encode('ascii')) |
c267c233 | 327 | |
8f61c66a AE |
328 | result = gpgme_ctx.import_(fp) |
329 | imports = result.imports | |
c267c233 | 330 | |
8f61c66a | 331 | fingerprints = [] |
c267c233 | 332 | |
8f61c66a AE |
333 | if imports != []: |
334 | for import_ in imports: | |
335 | fingerprint = import_[0] | |
d0489345 | 336 | fingerprints += [fingerprint] |
c267c233 | 337 | |
e49673aa | 338 | debug("added gpg key: " + fingerprint) |
ec1e779a | 339 | |
d0489345 | 340 | return fingerprints |
ec1e779a AE |
341 | |
342 | ||
129543c3 | 343 | def verify_clear_signature (sig_block, gpgme_ctx): |
cf75de65 | 344 | |
129543c3 AE |
345 | # FIXME: this might require the un-decoded bytes |
346 | # or the correct re-encoding with the carset of the mime part. | |
347 | msg_fp = io.BytesIO(sig_block.encode('utf-8')) | |
348 | ptxt_fp = io.BytesIO() | |
cf75de65 | 349 | |
129543c3 | 350 | result = gpgme_ctx.verify(msg_fp, None, ptxt_fp) |
cf75de65 | 351 | |
129543c3 AE |
352 | # FIXME: this might require using the charset of the mime part. |
353 | plaintext = ptxt_fp.getvalue().decode('utf-8') | |
cf75de65 | 354 | |
129543c3 AE |
355 | fingerprints = [] |
356 | for res_ in result: | |
357 | fingerprints += [res_.fpr] | |
cf75de65 AE |
358 | |
359 | return plaintext, fingerprints | |
360 | ||
361 | ||
5b3053c1 | 362 | def decrypt_block (msg_block, gpgme_ctx): |
0bec96d6 | 363 | |
5b3053c1 | 364 | block_b = io.BytesIO(msg_block.encode('ascii')) |
0bec96d6 AE |
365 | plain_b = io.BytesIO() |
366 | ||
afc1f64c AE |
367 | try: |
368 | sigs = gpgme_ctx.decrypt_verify(block_b, plain_b) | |
369 | except: | |
370 | return ("",[]) | |
0bec96d6 | 371 | |
6aa41372 | 372 | plaintext = plain_b.getvalue().decode('utf-8') |
394a1476 | 373 | return (plaintext, sigs) |
0bec96d6 AE |
374 | |
375 | ||
d0489345 | 376 | def choose_reply_encryption_key (gpgme_ctx, fingerprints): |
fafa21c3 AE |
377 | |
378 | reply_key = None | |
d0489345 AE |
379 | for fp in fingerprints: |
380 | try: | |
381 | key = gpgme_ctx.get_key(fp) | |
382 | ||
383 | if (key.can_encrypt == True): | |
384 | reply_key = key | |
385 | break | |
386 | except: | |
387 | continue | |
388 | ||
fafa21c3 | 389 | |
216708e9 | 390 | return reply_key |
fafa21c3 AE |
391 | |
392 | ||
d65993b8 AE |
393 | def email_to_from_subject (email_text): |
394 | ||
395 | email_struct = email.parser.Parser().parsestr(email_text) | |
396 | ||
397 | email_to = email_struct['To'] | |
398 | email_from = email_struct['From'] | |
399 | email_subject = email_struct['Subject'] | |
400 | ||
401 | return email_to, email_from, email_subject | |
402 | ||
403 | ||
bf79a93e | 404 | def generate_encrypted_mime (plaintext, email_from, email_subject, encrypt_to_key, |
0a064403 | 405 | gpgme_ctx): |
1da9b527 | 406 | |
8bdfb6d4 | 407 | |
1da9b527 AE |
408 | reply = "To: " + email_from + "\n" |
409 | reply += "Subject: " + email_subject + "\n" | |
216708e9 AE |
410 | |
411 | if (encrypt_to_key != None): | |
412 | plaintext_reply = "thanks for the message!\n\n\n" | |
413 | plaintext_reply += email_quote_text(plaintext) | |
414 | ||
8bdfb6d4 AE |
415 | # quoted printable encoding lets most ascii characters look normal |
416 | # before the decrypted mime message is decoded. | |
417 | char_set = email.charset.Charset("utf-8") | |
418 | char_set.body_encoding = email.charset.QP | |
419 | ||
420 | # MIMEText doesn't allow setting the text encoding | |
421 | # so we use MIMENonMultipart. | |
422 | plaintext_mime = MIMENonMultipart('text', 'plain') | |
423 | plaintext_mime.set_payload(plaintext_reply, charset=char_set) | |
424 | ||
425 | encrypted_text = encrypt_sign_message(plaintext_mime.as_string(), | |
426 | encrypt_to_key, | |
40c37ab3 | 427 | gpgme_ctx) |
8bdfb6d4 AE |
428 | |
429 | control_mime = MIMEApplication("Version: 1", | |
430 | _subtype='pgp-encrypted', | |
431 | _encoder=email.encoders.encode_7or8bit) | |
432 | control_mime['Content-Description'] = 'PGP/MIME version identification' | |
433 | control_mime.set_charset('us-ascii') | |
434 | ||
435 | encoded_mime = MIMEApplication(encrypted_text, | |
436 | _subtype='octet-stream; name="encrypted.asc"', | |
437 | _encoder=email.encoders.encode_7or8bit) | |
438 | encoded_mime['Content-Description'] = 'OpenPGP encrypted message' | |
439 | encoded_mime['Content-Disposition'] = 'inline; filename="encrypted.asc"' | |
440 | encoded_mime.set_charset('us-ascii') | |
441 | ||
442 | message_mime = MIMEMultipart(_subtype="encrypted", protocol="application/pgp-encrypted") | |
443 | message_mime.attach(control_mime) | |
444 | message_mime.attach(encoded_mime) | |
445 | message_mime['Content-Disposition'] = 'inline' | |
216708e9 | 446 | |
8bdfb6d4 | 447 | reply += message_mime.as_string() |
216708e9 AE |
448 | |
449 | else: | |
8bdfb6d4 | 450 | reply += "\n" |
216708e9 AE |
451 | reply += "Sorry, i couldn't find your key.\n" |
452 | reply += "I'll need that to encrypt a message to you." | |
1da9b527 AE |
453 | |
454 | return reply | |
455 | ||
456 | ||
f87041f8 AE |
457 | def email_quote_text (text): |
458 | ||
459 | quoted_message = re.sub(r'^', r'> ', text, flags=re.MULTILINE) | |
460 | ||
461 | return quoted_message | |
462 | ||
463 | ||
0a064403 | 464 | def encrypt_sign_message (plaintext, encrypt_to_key, gpgme_ctx): |
897cbaf6 | 465 | |
6aa41372 | 466 | plaintext_bytes = io.BytesIO(plaintext.encode('ascii')) |
1da9b527 AE |
467 | encrypted_bytes = io.BytesIO() |
468 | ||
897cbaf6 | 469 | gpgme_ctx.encrypt_sign([encrypt_to_key], gpgme.ENCRYPT_ALWAYS_TRUST, |
1da9b527 AE |
470 | plaintext_bytes, encrypted_bytes) |
471 | ||
6aa41372 | 472 | encrypted_txt = encrypted_bytes.getvalue().decode('ascii') |
1da9b527 AE |
473 | return encrypted_txt |
474 | ||
475 | ||
0a064403 AE |
476 | def error (error_msg): |
477 | ||
e4fb2ab2 | 478 | sys.stderr.write(progname + ": " + str(error_msg) + "\n") |
0a064403 AE |
479 | |
480 | ||
5e8f9094 AE |
481 | def debug (debug_msg): |
482 | ||
483 | if edward_config.debug == True: | |
0a064403 | 484 | error(debug_msg) |
5e8f9094 AE |
485 | |
486 | ||
20f6e7c5 AE |
487 | def handle_args (): |
488 | if __name__ == "__main__": | |
489 | ||
490 | global progname | |
491 | progname = sys.argv[0] | |
492 | ||
493 | if len(sys.argv) > 1: | |
494 | print(progname + ": error, this program doesn't " \ | |
495 | "need any arguments.", file=sys.stderr) | |
496 | exit(1) | |
497 | ||
498 | ||
0bec96d6 AE |
499 | main() |
500 |