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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 | |
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 | |
c035a008 AE |
152 | 'key_cannot_encrypt' is set to True if pubkeys or sigs' keys in the payload |
153 | piece are not capable of encryption. This could happen if a key is revoked | |
154 | or expired, for instance. | |
155 | ||
def9196c AE |
156 | 'keys' is a list of fingerprints of keys obtained in public key blocks. |
157 | """ | |
158 | ||
7d0b91d2 AE |
159 | decrypted = False |
160 | ||
161 | plainobj = None | |
162 | sigs = [] | |
b4c116d5 | 163 | sigkey_missing = False |
c035a008 | 164 | key_cannot_encrypt = False |
7d0b91d2 | 165 | keys = [] |
38738401 | 166 | |
38738401 | 167 | |
d873ff48 | 168 | class ReplyInfo (object): |
def9196c AE |
169 | """ |
170 | ReplyInfo contains details that edward uses in generating its reply. | |
171 | ||
172 | Instances of this class contain information about whether a message was | |
173 | successfully encrypted or signed, and whether a public key was attached, or | |
174 | retrievable, from the local GPG store. It stores the fingerprints of | |
175 | potential encryption key candidates and the message (if any at all) to | |
176 | quote in edward's reply. | |
177 | ||
178 | 'replies' points one of the dictionaries of translated replies. | |
179 | ||
180 | 'target_key' refers to the fingerprint of a key used to sign encrypted | |
181 | data. This is the preferred key, if it is set, and if is available. | |
182 | ||
183 | 'fallback_target_key' referst to the fingerprint of a key used to sign | |
184 | unencrypted data; alternatively it may be a public key attached to the | |
185 | message. | |
186 | ||
ca37d0cb AE |
187 | 'encrypt_to_key' the key object to use when encrypting edward's reply |
188 | ||
def9196c AE |
189 | 'msg_to_quote' refers to the part of a message which edward should quote in |
190 | his reply. This should remain as None if there was no encrypted and singed | |
191 | part. This is to avoid making edward a service for decrypting other | |
192 | people's messages to edward. | |
193 | ||
b4c116d5 | 194 | 'decrypt_success' is set to True if edward could decrypt part of the |
def9196c AE |
195 | message. |
196 | ||
def9196c AE |
197 | 'sig_success' is set to True if edward could to some extent verify the |
198 | signature of a signed part of the message to edward. | |
199 | ||
c035a008 AE |
200 | 'key_can_encrypt' is set to True if a key which can be encrypted to has |
201 | been found. | |
202 | ||
32a8996f AE |
203 | 'sig_failure' is set to True if edward could not verify a siganture. |
204 | ||
b4c116d5 AE |
205 | 'pubkey_success' is set to True if edward successfully imported a public |
206 | key. | |
207 | ||
208 | 'sigkey_missing' is set to True if edward doesn't have the public key | |
209 | needed for signature verification. | |
210 | ||
c035a008 AE |
211 | 'key_cannot_encrypt' is set to True if pubkeys or sig's keys in a payload |
212 | piece of the message are not capable of encryption. | |
213 | ||
b4c116d5 AE |
214 | 'have_repy_key' is set to True if edward has a public key to encrypt its |
215 | reply to. | |
def9196c AE |
216 | """ |
217 | ||
7d0b91d2 | 218 | replies = None |
6906d46d | 219 | |
7d0b91d2 AE |
220 | target_key = None |
221 | fallback_target_key = None | |
ca37d0cb | 222 | encrypt_to_key = None |
7d0b91d2 | 223 | msg_to_quote = "" |
d873ff48 | 224 | |
b4c116d5 | 225 | decrypt_success = False |
7d0b91d2 | 226 | sig_success = False |
b4c116d5 | 227 | pubkey_success = False |
c035a008 | 228 | key_can_encrypt = False |
b4c116d5 | 229 | |
4e2c66f7 | 230 | decrypt_failure = False |
32a8996f | 231 | sig_failure = False |
b4c116d5 | 232 | sigkey_missing = False |
c035a008 | 233 | key_cannot_encrypt = False |
371911ad | 234 | |
b4c116d5 | 235 | have_reply_key = False |
d873ff48 | 236 | |
38738401 | 237 | |
0bec96d6 AE |
238 | def main (): |
239 | ||
def9196c AE |
240 | """ |
241 | This is the main function for edward, a GPG reply bot. | |
242 | ||
243 | Edward responds to GPG-encrypted and signed mail, encrypting and signing | |
244 | the response if the user's public key is, or was, included in the message. | |
245 | ||
246 | Args: | |
247 | None | |
248 | ||
249 | Returns: | |
a3d6aff8 | 250 | Nothing |
def9196c AE |
251 | |
252 | Pre: | |
253 | Mime or plaintext email passing in through standard input. Portions of | |
254 | the email may be encrypted. If the To: address contains the text | |
255 | "edward-ja", then the reply will contain a reply written in the | |
256 | Japanese language. There are other languages as well. The default | |
257 | language is English. | |
258 | ||
259 | Post: | |
260 | A reply email will be printed to standard output. The contents of the | |
261 | reply email depends on whether the original email was encrypted or not, | |
262 | has or doesn't have a signature, whether a public key used in the | |
263 | original message is provided or locally stored, and the language | |
264 | implied by the To: address in the original email. | |
265 | """ | |
266 | ||
60ccbaf4 | 267 | print_reply_only = handle_args() |
0bec96d6 | 268 | |
0a064403 AE |
269 | gpgme_ctx = get_gpg_context(edward_config.gnupghome, |
270 | edward_config.sign_with_key) | |
271 | ||
85a829fc AE |
272 | email_bytes = sys.stdin.buffer.read() |
273 | email_struct = parse_pgp_mime(email_bytes, gpgme_ctx) | |
adcef2f7 | 274 | |
85a829fc | 275 | email_to, email_from, email_subject = email_to_from_subject(email_bytes) |
60ccbaf4 | 276 | lang, reply_from = import_lang_pick_address(email_to, edward_config.hostname) |
fafa21c3 | 277 | |
d873ff48 AE |
278 | replyinfo_obj = ReplyInfo() |
279 | replyinfo_obj.replies = lang.replies | |
280 | ||
281 | prepare_for_reply(email_struct, replyinfo_obj) | |
ca37d0cb | 282 | get_key_from_fp(replyinfo_obj, gpgme_ctx) |
d873ff48 | 283 | reply_plaintext = write_reply(replyinfo_obj) |
adcef2f7 | 284 | |
2007103e | 285 | reply_mime = generate_encrypted_mime(reply_plaintext, email_from, \ |
ca37d0cb | 286 | email_subject, replyinfo_obj.encrypt_to_key, |
2007103e | 287 | gpgme_ctx) |
1fccb295 | 288 | |
60ccbaf4 AE |
289 | if print_reply_only == True: |
290 | print(reply_mime) | |
291 | else: | |
292 | send_reply(reply_mime, email_subject, email_from, reply_from) | |
c96f3837 | 293 | |
0bec96d6 | 294 | |
0a064403 | 295 | def get_gpg_context (gnupghome, sign_with_key_fp): |
a3d6aff8 AE |
296 | """ |
297 | This function returns the GPG context needed for encryption and signing. | |
298 | ||
299 | The context is needed by other functions which use GPG functionality. | |
300 | ||
301 | Args: | |
302 | gnupghome: The path to "~/.gnupg/" or its alternative. | |
303 | sign_with_key: The fingerprint of the key to sign with | |
304 | ||
305 | Returns: | |
306 | A gpgme context to be used for GPG functions. | |
307 | ||
308 | Post: | |
309 | the 'armor' flag is set to True and the list of signing keys contains | |
310 | the single specified key | |
311 | """ | |
0a064403 AE |
312 | |
313 | os.environ['GNUPGHOME'] = gnupghome | |
314 | ||
315 | gpgme_ctx = gpgme.Context() | |
316 | gpgme_ctx.armor = True | |
317 | ||
318 | try: | |
319 | sign_with_key = gpgme_ctx.get_key(sign_with_key_fp) | |
5f6f32b1 | 320 | except gpgme.GpgmeError: |
0a064403 AE |
321 | error("unable to load signing key. is the gnupghome " |
322 | + "and signing key properly set in the edward_config.py?") | |
323 | exit(1) | |
324 | ||
325 | gpgme_ctx.signers = [sign_with_key] | |
326 | ||
327 | return gpgme_ctx | |
328 | ||
329 | ||
85a829fc | 330 | def parse_pgp_mime (email_bytes, gpgme_ctx): |
a3d6aff8 AE |
331 | """Parses the email for mime payloads and decrypts/verfies signatures. |
332 | ||
333 | This function creates a representation of a mime or plaintext email with | |
334 | the EddyMsg class. It then splits each mime payload into one or more pieces | |
335 | which may be plain text or GPG data. It then decrypts encrypted parts and | |
336 | does some very basic signature verification on those parts. | |
337 | ||
338 | Args: | |
85a829fc | 339 | email_bytes: an email message in byte string format |
a3d6aff8 AE |
340 | gpgme_ctx: a gpgme context |
341 | ||
342 | Returns: | |
343 | A message as an instance of EddyMsg | |
344 | ||
345 | Post: | |
346 | the returned EddyMsg instance has split, decrypted, verified and pubkey | |
347 | imported payloads | |
348 | """ | |
394a1476 | 349 | |
85a829fc | 350 | email_struct = email.parser.BytesParser().parsebytes(email_bytes) |
394a1476 | 351 | |
928e3819 AE |
352 | eddymsg_obj = parse_mime(email_struct) |
353 | split_payloads(eddymsg_obj) | |
354 | gpg_on_payloads(eddymsg_obj, gpgme_ctx) | |
8bb4b0d5 | 355 | |
928e3819 | 356 | return eddymsg_obj |
0bec96d6 | 357 | |
0bec96d6 | 358 | |
56578eaf | 359 | def parse_mime(msg_struct): |
a3d6aff8 AE |
360 | """Translates python's email.parser format into an EddyMsg format |
361 | ||
362 | If the message is multi-part, then a recursive object is created, where | |
363 | each sub-part is also a EddyMsg instance. | |
364 | ||
365 | Args: | |
366 | msg_struct: an email parsed with email.parser.Parser(), which can be | |
367 | multi-part | |
368 | ||
369 | Returns: | |
370 | an instance of EddyMsg, potentially a recursive one. | |
371 | """ | |
0bec96d6 | 372 | |
928e3819 | 373 | eddymsg_obj = EddyMsg() |
8bb4b0d5 | 374 | |
56578eaf AE |
375 | if msg_struct.is_multipart() == True: |
376 | payloads = msg_struct.get_payload() | |
0bec96d6 | 377 | |
928e3819 AE |
378 | eddymsg_obj.multipart = True |
379 | eddymsg_obj.subparts = list(map(parse_mime, payloads)) | |
dd11a483 | 380 | |
56578eaf | 381 | else: |
928e3819 | 382 | eddymsg_obj = get_subpart_data(msg_struct) |
394a1476 | 383 | |
928e3819 | 384 | return eddymsg_obj |
c267c233 | 385 | |
80119cab | 386 | |
2f4102b9 | 387 | def scan_and_split (payload_piece, match_name, pattern): |
a3d6aff8 AE |
388 | """This splits the payloads of an EddyMsg object into GPG and text parts. |
389 | ||
390 | An EddyMsg object's payload_pieces starts off as a list containing a single | |
391 | PayloadPiece object. This function returns a list of these objects which | |
392 | have been split into GPG data and regular text, if such splits need to be/ | |
393 | can be made. | |
394 | ||
395 | Args: | |
396 | payload_piece: a single payload or a split part of a payload | |
2f4102b9 | 397 | match_name: the type of data to try to spit out from the payload piece |
a3d6aff8 AE |
398 | pattern: the search pattern to be used for finding that type of data |
399 | ||
400 | Returns: | |
401 | a list of objects of the PayloadPiece class, in the order that the | |
402 | string part of payload_piece originally was, broken up according to | |
403 | matches specified by 'pattern'. | |
404 | """ | |
cf75de65 | 405 | |
a5d37d44 | 406 | # don't try to re-split pieces containing gpg data |
0fd3389f | 407 | if payload_piece.piece_type != TxtType.text: |
a5d37d44 AE |
408 | return [payload_piece] |
409 | ||
56578eaf AE |
410 | flags = re.DOTALL | re.MULTILINE |
411 | matches = re.search("(?P<beginning>.*?)(?P<match>" + pattern + | |
412 | ")(?P<rest>.*)", payload_piece.string, flags=flags) | |
86663388 | 413 | |
56578eaf AE |
414 | if matches == None: |
415 | pieces = [payload_piece] | |
c96f3837 | 416 | |
56578eaf | 417 | else: |
d437f8b2 | 418 | |
56578eaf AE |
419 | beginning = PayloadPiece() |
420 | beginning.string = matches.group('beginning') | |
421 | beginning.piece_type = payload_piece.piece_type | |
d437f8b2 | 422 | |
56578eaf AE |
423 | match = PayloadPiece() |
424 | match.string = matches.group('match') | |
2f4102b9 | 425 | match.piece_type = match_name |
d437f8b2 | 426 | |
56578eaf AE |
427 | rest = PayloadPiece() |
428 | rest.string = matches.group('rest') | |
429 | rest.piece_type = payload_piece.piece_type | |
d437f8b2 | 430 | |
2f4102b9 | 431 | more_pieces = scan_and_split(rest, match_name, pattern) |
4615b156 | 432 | pieces = [beginning, match ] + more_pieces |
d437f8b2 | 433 | |
56578eaf | 434 | return pieces |
d437f8b2 | 435 | |
d437f8b2 | 436 | |
56578eaf | 437 | def get_subpart_data (part): |
a3d6aff8 AE |
438 | """This function grabs information from a single part mime object. |
439 | ||
440 | It copies needed data from a single part email.parser.Parser() object over | |
441 | to an EddyMsg object. | |
442 | ||
443 | Args: | |
444 | part: a non-multi-part mime.parser.Parser() object | |
445 | ||
446 | Returns: | |
447 | a single-part EddyMsg() object | |
448 | """ | |
0bec96d6 | 449 | |
6d8faaa7 | 450 | obj = EddyMsg() |
56578eaf | 451 | |
84ff9773 AE |
452 | mime_decoded_bytes = part.get_payload(decode=True) |
453 | charset = part.get_content_charset() | |
56578eaf AE |
454 | |
455 | # your guess is as good as a-myy-ee-ine... | |
6d8faaa7 AE |
456 | if charset == None: |
457 | charset = 'utf-8' | |
56578eaf | 458 | |
84ff9773 AE |
459 | payload_string = part.as_string() |
460 | if payload_string != None: | |
461 | obj.payload_bytes = payload_string.encode(charset) | |
462 | ||
463 | obj.filename = part.get_filename() | |
464 | obj.content_type = part.get_content_type() | |
465 | obj.description_list = part['content-description'] | |
466 | ||
6d8faaa7 | 467 | if mime_decoded_bytes != None: |
0eb75d9c AE |
468 | try: |
469 | payload = PayloadPiece() | |
6d8faaa7 | 470 | payload.string = mime_decoded_bytes.decode(charset) |
0fd3389f | 471 | payload.piece_type = TxtType.text |
0eb75d9c AE |
472 | |
473 | obj.payload_pieces = [payload] | |
474 | except UnicodeDecodeError: | |
475 | pass | |
56578eaf AE |
476 | |
477 | return obj | |
478 | ||
479 | ||
928e3819 | 480 | def do_to_eddys_pieces (function_to_do, eddymsg_obj, data): |
a3d6aff8 AE |
481 | """A function which maps another function onto a message's subparts. |
482 | ||
483 | This is a higer-order function which recursively performs a specified | |
484 | function on each subpart of a multi-part message. Each single-part sub-part | |
485 | has the function applied to it. This function also works if the part passed | |
486 | in is single-part. | |
487 | ||
488 | Args: | |
489 | function_to_do: function to perform on sub-parts | |
490 | eddymsg_obj: a single part or multi-part EddyMsg object | |
491 | data: a second argument to pass to 'function_to_do' | |
492 | ||
493 | Returns: | |
494 | Nothing | |
495 | ||
496 | Post: | |
497 | The passed-in EddyMsg object is transformed recursively on its | |
498 | sub-parts according to 'function_to_do'. | |
499 | """ | |
56578eaf | 500 | |
928e3819 AE |
501 | if eddymsg_obj.multipart == True: |
502 | for sub in eddymsg_obj.subparts: | |
d873ff48 | 503 | do_to_eddys_pieces(function_to_do, sub, data) |
394a1476 | 504 | else: |
928e3819 | 505 | function_to_do(eddymsg_obj, data) |
dd11a483 AE |
506 | |
507 | ||
928e3819 | 508 | def split_payloads (eddymsg_obj): |
a3d6aff8 AE |
509 | """Splits all (sub-)payloads of a message into GPG data and regular text. |
510 | ||
511 | Recursively performs payload splitting on all sub-parts of an EddyMsg | |
512 | object into the various GPG data types, such as GPG messages, public key | |
513 | blocks and signed text. | |
514 | ||
515 | Args: | |
516 | eddymsg_obj: an instance of EddyMsg | |
517 | ||
518 | Returns: | |
519 | Nothing | |
520 | ||
521 | Pre: | |
522 | The EddyMsg object has payloads that are unsplit (by may be split).. | |
523 | ||
524 | Post: | |
525 | The EddyMsg object's payloads are all split into GPG and non-GPG parts. | |
526 | """ | |
a5d37d44 | 527 | |
2f4102b9 AE |
528 | for match_pair in match_pairs: |
529 | do_to_eddys_pieces(split_payload_pieces, eddymsg_obj, match_pair) | |
a5d37d44 | 530 | |
a5d37d44 | 531 | |
2f4102b9 | 532 | def split_payload_pieces (eddymsg_obj, match_pair): |
a3d6aff8 AE |
533 | """A helper function for split_payloads(); works on PayloadPiece objects. |
534 | ||
535 | This function splits up PayloadPiece objects into multipe PayloadPiece | |
536 | objects and replaces the EddyMsg object's previous list of payload pieces | |
537 | with the new split up one. | |
538 | ||
539 | Args: | |
540 | eddymsg_obj: a single-part EddyMsg object. | |
2f4102b9 | 541 | match_pair: a tuple from the match_pairs list, which specifies a match |
a3d6aff8 AE |
542 | name and a match pattern. |
543 | ||
544 | Returns: | |
545 | Nothing | |
546 | ||
547 | Pre: | |
548 | The payload piece(s) of an EddyMsg object may be already split or | |
549 | unsplit. | |
550 | ||
551 | Post: | |
552 | The EddyMsg object's payload piece(s) are split into a list of pieces | |
2f4102b9 | 553 | if matches of the match_pair are found. |
a3d6aff8 | 554 | """ |
a5d37d44 | 555 | |
2f4102b9 | 556 | (match_name, pattern) = match_pair |
a5d37d44 AE |
557 | |
558 | new_pieces_list = [] | |
928e3819 | 559 | for piece in eddymsg_obj.payload_pieces: |
a5d37d44 AE |
560 | new_pieces_list += scan_and_split(piece, match_name, pattern) |
561 | ||
928e3819 | 562 | eddymsg_obj.payload_pieces = new_pieces_list |
a5d37d44 AE |
563 | |
564 | ||
928e3819 | 565 | def gpg_on_payloads (eddymsg_obj, gpgme_ctx, prev_parts=[]): |
a3d6aff8 AE |
566 | """Performs GPG operations on the GPG parts of the message |
567 | ||
568 | This function decrypts text, verifies signatures, and imports public keys | |
569 | included in an email. | |
570 | ||
571 | Args: | |
572 | eddymsg_obj: an EddyMsg object with its payload_pieces split into GPG | |
573 | and non-GPG sections by split_payloads() | |
574 | gpgme_ctx: a gpgme context | |
575 | ||
576 | prev_parts: a list of mime parts that occur before the eddymsg_obj | |
577 | part, under the same multi-part mime part. This is used for | |
578 | verifying detached signatures. For the root mime part, this should | |
579 | be an empty list, which is the default value if this paramater is | |
580 | omitted. | |
581 | ||
582 | Return: | |
583 | Nothing | |
584 | ||
585 | Pre: | |
586 | eddymsg_obj should have its payloads split into gpg and non-gpg pieces. | |
587 | ||
588 | Post: | |
c035a008 AE |
589 | Decryption, verification and key imports occur. the gpg_data members of |
590 | PayloadPiece objects get filled in with GPGData objects with some of | |
591 | their attributes set. | |
a3d6aff8 | 592 | """ |
38738401 | 593 | |
928e3819 | 594 | if eddymsg_obj.multipart == True: |
101d54a8 | 595 | prev_parts=[] |
928e3819 | 596 | for sub in eddymsg_obj.subparts: |
101d54a8 AE |
597 | gpg_on_payloads (sub, gpgme_ctx, prev_parts) |
598 | prev_parts += [sub] | |
38738401 | 599 | |
d873ff48 | 600 | return |
38738401 | 601 | |
928e3819 | 602 | for piece in eddymsg_obj.payload_pieces: |
38738401 | 603 | |
0fd3389f | 604 | if piece.piece_type == TxtType.text: |
38738401 AE |
605 | # don't transform the plaintext. |
606 | pass | |
607 | ||
0fd3389f | 608 | elif piece.piece_type == TxtType.message: |
b4c116d5 AE |
609 | piece.gpg_data = GPGData() |
610 | ||
c035a008 | 611 | (plaintext_b, sigs, sigkey_missing, key_cannot_encrypt) = decrypt_block(piece.string, gpgme_ctx) |
b4c116d5 AE |
612 | |
613 | piece.gpg_data.sigkey_missing = sigkey_missing | |
c035a008 | 614 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt |
38738401 | 615 | |
85a829fc | 616 | if plaintext_b: |
b23e171d | 617 | piece.gpg_data.decrypted = True |
38738401 AE |
618 | piece.gpg_data.sigs = sigs |
619 | # recurse! | |
85a829fc | 620 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext_b, gpgme_ctx) |
3a753fd0 AE |
621 | continue |
622 | ||
623 | # if not encrypted, check to see if this is an armored signature. | |
c035a008 | 624 | (plaintext_b, sigs, sigkey_missing, key_cannot_encrypt) = verify_sig_message(piece.string, gpgme_ctx) |
b4c116d5 AE |
625 | |
626 | piece.gpg_data.sigkey_missing = sigkey_missing | |
c035a008 | 627 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt |
3a753fd0 | 628 | |
85a829fc | 629 | if plaintext_b: |
0fd3389f | 630 | piece.piece_type = TxtType.signature |
3a753fd0 AE |
631 | piece.gpg_data.sigs = sigs |
632 | # recurse! | |
85a829fc | 633 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext_b, gpgme_ctx) |
129543c3 | 634 | |
0fd3389f | 635 | elif piece.piece_type == TxtType.pubkey: |
c035a008 AE |
636 | piece.gpg_data = GPGData() |
637 | ||
638 | (key_fps, key_cannot_encrypt) = add_gpg_key(piece.string, gpgme_ctx) | |
639 | ||
640 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt | |
8f61c66a | 641 | |
f8ee6bd3 | 642 | if key_fps != []: |
f8ee6bd3 | 643 | piece.gpg_data.keys = key_fps |
129543c3 | 644 | |
0fd3389f | 645 | elif piece.piece_type == TxtType.detachedsig: |
b4c116d5 AE |
646 | piece.gpg_data = GPGData() |
647 | ||
101d54a8 | 648 | for prev in prev_parts: |
c035a008 | 649 | (sig_fps, sigkey_missing, key_cannot_encrypt) = verify_detached_signature(piece.string, prev.payload_bytes, gpgme_ctx) |
b4c116d5 AE |
650 | |
651 | piece.gpg_data.sigkey_missing = sigkey_missing | |
c035a008 | 652 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt |
101d54a8 | 653 | |
6d240f68 | 654 | if sig_fps != []: |
6d240f68 AE |
655 | piece.gpg_data.sigs = sig_fps |
656 | piece.gpg_data.plainobj = prev | |
657 | break | |
7e18f14d | 658 | |
38738401 AE |
659 | else: |
660 | pass | |
661 | ||
662 | ||
928e3819 | 663 | def prepare_for_reply (eddymsg_obj, replyinfo_obj): |
67691346 AE |
664 | """Updates replyinfo_obj with info on the message's GPG success/failures |
665 | ||
666 | This function marks replyinfo_obj with information about whether encrypted | |
667 | text in eddymsg_obj was successfully decrypted, signatures were verified | |
668 | and whether a public key was found or not. | |
669 | ||
670 | Args: | |
671 | eddymsg_obj: a message in the EddyMsg format | |
672 | replyinfo_obj: an instance of ReplyInfo | |
673 | ||
674 | Returns: | |
675 | Nothing | |
676 | ||
677 | Pre: | |
678 | eddymsg_obj has had its gpg_data created by gpg_on_payloads | |
679 | ||
680 | Post: | |
681 | replyinfo_obj has been updated with info about decryption/sig | |
682 | verififcation status, etc. However the desired key isn't imported until | |
683 | later, so the success or failure of that updates the values set here. | |
684 | """ | |
dd11a483 | 685 | |
928e3819 | 686 | do_to_eddys_pieces(prepare_for_reply_pieces, eddymsg_obj, replyinfo_obj) |
56578eaf | 687 | |
928e3819 | 688 | def prepare_for_reply_pieces (eddymsg_obj, replyinfo_obj): |
67691346 AE |
689 | """A helper function for prepare_for_reply |
690 | ||
691 | It updates replyinfo_obj with GPG success/failure information, when | |
692 | supplied a single-part EddyMsg object. | |
693 | ||
694 | Args: | |
695 | eddymsg_obj: a single-part message in the EddyMsg format | |
696 | replyinfo_obj: an object which holds information about the message's | |
697 | GPG status | |
698 | ||
699 | Returns: | |
700 | Nothing | |
701 | ||
702 | Pre: | |
703 | eddymsg_obj is a single-part message. (it may be a part of a multi-part | |
704 | message.) It has had its gpg_data created by gpg_on_payloads if it has | |
705 | gpg data. | |
706 | ||
707 | Post: | |
708 | replyinfo_obj has been updated with gpg success/failure information | |
709 | """ | |
56578eaf | 710 | |
928e3819 | 711 | for piece in eddymsg_obj.payload_pieces: |
0fd3389f | 712 | if piece.piece_type == TxtType.text: |
d873ff48 AE |
713 | # don't quote the plaintext part. |
714 | pass | |
715 | ||
0fd3389f | 716 | elif piece.piece_type == TxtType.message: |
05683768 | 717 | prepare_for_reply_message(piece, replyinfo_obj) |
d873ff48 | 718 | |
0fd3389f | 719 | elif piece.piece_type == TxtType.pubkey: |
05683768 | 720 | prepare_for_reply_pubkey(piece, replyinfo_obj) |
6906d46d | 721 | |
0fd3389f AE |
722 | elif (piece.piece_type == TxtType.detachedsig) \ |
723 | or (piece.piece_type == TxtType.signature): | |
05683768 | 724 | prepare_for_reply_sig(piece, replyinfo_obj) |
d873ff48 | 725 | |
d873ff48 | 726 | |
05683768 | 727 | def prepare_for_reply_message (piece, replyinfo_obj): |
67691346 AE |
728 | """Helper function for prepare_for_reply() |
729 | ||
730 | This function is called when the piece_type of a payload piece is | |
9af26cb8 AE |
731 | TxtType.message, or GPG Message block. This should be encrypted text. If |
732 | the encryted block is correclty signed, a sig will be attached to | |
733 | .target_key unless there is already one there. | |
67691346 AE |
734 | |
735 | Args: | |
736 | piece: a PayloadPiece object. | |
737 | replyinfo_obj: object which gets updated with decryption status, etc. | |
738 | ||
67691346 AE |
739 | Returns: |
740 | Nothing | |
741 | ||
742 | Pre: | |
0fd3389f | 743 | the piece.payload_piece value should be TxtType.message. |
67691346 AE |
744 | |
745 | Post: | |
b4c116d5 | 746 | replyinfo_obj gets updated with decryption status, signing status, a |
c035a008 AE |
747 | potential signing key, posession status of the public key for the |
748 | signature and encryption capability status if that key is missing. | |
67691346 | 749 | """ |
44fe39b7 | 750 | |
c035a008 | 751 | if piece.gpg_data.plainobj == None: |
4e2c66f7 | 752 | replyinfo_obj.decrypt_failure = True |
05683768 AE |
753 | return |
754 | ||
b4c116d5 | 755 | replyinfo_obj.decrypt_success = True |
05683768 AE |
756 | |
757 | # we already have a key (and a message) | |
758 | if replyinfo_obj.target_key != None: | |
759 | return | |
760 | ||
c035a008 | 761 | if piece.gpg_data.sigs == []: |
b4c116d5 AE |
762 | if piece.gpg_data.sigkey_missing == True: |
763 | replyinfo_obj.sigkey_missing = True | |
9af26cb8 | 764 | |
c035a008 AE |
765 | if piece.gpg_data.key_cannot_encrypt == True: |
766 | replyinfo_obj.key_cannot_encrypt = True | |
767 | ||
05683768 AE |
768 | # only include a signed message in the reply. |
769 | get_signed_part = True | |
770 | ||
c035a008 AE |
771 | else: |
772 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
773 | replyinfo_obj.sig_success = True | |
774 | get_signed_part = False | |
775 | ||
8c3e5397 | 776 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, get_signed_part) |
05683768 AE |
777 | |
778 | # to catch public keys in encrypted blocks | |
779 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
780 | ||
781 | ||
782 | def prepare_for_reply_pubkey (piece, replyinfo_obj): | |
67691346 AE |
783 | """Helper function for prepare_for_reply(). Marks pubkey import status. |
784 | ||
785 | Marks replyinfo_obj with pub key import status. | |
786 | ||
787 | Args: | |
788 | piece: a PayloadPiece object | |
789 | replyinfo_obj: a ReplyInfo object | |
790 | ||
791 | Pre: | |
0fd3389f | 792 | piece.piece_type should be set to TxtType.pubkey . |
67691346 AE |
793 | |
794 | Post: | |
795 | replyinfo_obj has its fields updated. | |
796 | """ | |
05683768 | 797 | |
c035a008 AE |
798 | if piece.gpg_data.keys == []: |
799 | if piece.gpg_data.key_cannot_encrypt == True: | |
800 | replyinfo_obj.key_cannot_encrypt = True | |
05683768 | 801 | else: |
b4c116d5 | 802 | replyinfo_obj.pubkey_success = True |
05683768 | 803 | |
3ceb92e5 AE |
804 | # prefer public key as a fallback for the encrypted reply |
805 | replyinfo_obj.fallback_target_key = piece.gpg_data.keys[0] | |
05683768 AE |
806 | |
807 | ||
808 | def prepare_for_reply_sig (piece, replyinfo_obj): | |
67691346 AE |
809 | """Helper function for prepare_for_reply(). Marks sig verification status. |
810 | ||
811 | Marks replyinfo_obj with signature verification status. | |
812 | ||
813 | Args: | |
814 | piece: a PayloadPiece object | |
815 | replyinfo_obj: a ReplyInfo object | |
816 | ||
817 | Pre: | |
0fd3389f AE |
818 | piece.piece_type should be set to TxtType.signature, or |
819 | TxtType.detachedsig . | |
67691346 AE |
820 | |
821 | Post: | |
822 | replyinfo_obj has its fields updated. | |
823 | """ | |
05683768 | 824 | |
c035a008 | 825 | if piece.gpg_data.sigs == []: |
32a8996f | 826 | replyinfo_obj.sig_failure = True |
b4c116d5 AE |
827 | |
828 | if piece.gpg_data.sigkey_missing == True: | |
829 | replyinfo_obj.sigkey_missing = True | |
830 | ||
c035a008 AE |
831 | if piece.gpg_data.key_cannot_encrypt == True: |
832 | replyinfo_obj.key_cannot_encrypt = True | |
833 | ||
05683768 AE |
834 | else: |
835 | replyinfo_obj.sig_success = True | |
836 | ||
837 | if replyinfo_obj.fallback_target_key == None: | |
838 | replyinfo_obj.fallback_target_key = piece.gpg_data.sigs[0] | |
6906d46d | 839 | |
c230113e AE |
840 | if (piece.piece_type == TxtType.signature): |
841 | # to catch public keys in signature blocks | |
842 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
843 | ||
6906d46d | 844 | |
8c3e5397 AE |
845 | def flatten_decrypted_payloads (eddymsg_obj, replyinfo_obj, get_signed_part): |
846 | """For creating a string representation of a signed, encrypted part. | |
39e2c525 | 847 | |
8c3e5397 AE |
848 | When given a decrypted payload, it will add either the plaintext or signed |
849 | plaintext to the reply message, depeding on 'get_signed_part'. This is | |
850 | useful for ensuring that the reply message only comes from a signed and | |
851 | ecrypted GPG message. It also sets the target_key for encrypting the reply | |
852 | if it's told to get signed text only. | |
39e2c525 AE |
853 | |
854 | Args: | |
855 | eddymsg_obj: the message in EddyMsg format created by decrypting GPG | |
856 | text | |
8c3e5397 AE |
857 | replyinfo_obj: a ReplyInfo object for holding the message to quote and |
858 | the target_key to encrypt to. | |
39e2c525 AE |
859 | get_signed_part: True if we should only include text that contains a |
860 | further signature. If False, then include plain text. | |
861 | ||
862 | Returns: | |
8c3e5397 | 863 | Nothing |
39e2c525 AE |
864 | |
865 | Pre: | |
866 | The EddyMsg instance passed in should be a piece.gpg_data.plainobj | |
867 | which represents decrypted text. It may or may not be signed on that | |
868 | level. | |
d873ff48 | 869 | |
8c3e5397 AE |
870 | Post: |
871 | the ReplyInfo instance may have a new 'target_key' set and its | |
872 | 'msg_to_quote' will be updated with (possibly signed) plaintext, if any | |
873 | could be found. | |
874 | """ | |
d873ff48 | 875 | |
0aa88c27 | 876 | if eddymsg_obj == None: |
8c3e5397 | 877 | return |
0aa88c27 | 878 | |
0402995a | 879 | # recurse on multi-part mime |
928e3819 AE |
880 | if eddymsg_obj.multipart == True: |
881 | for sub in eddymsg_obj.subparts: | |
8c3e5397 | 882 | flatten_decrypted_payloads(sub, replyinfo_obj, get_signed_part) |
d873ff48 | 883 | |
928e3819 | 884 | for piece in eddymsg_obj.payload_pieces: |
0402995a | 885 | if (get_signed_part): |
0fd3389f AE |
886 | if ((piece.piece_type == TxtType.detachedsig) \ |
887 | or (piece.piece_type == TxtType.signature)) \ | |
b4c116d5 AE |
888 | and (piece.gpg_data != None) \ |
889 | and (piece.gpg_data.plainobj != None): | |
8c3e5397 AE |
890 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, False) |
891 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
c3d417bf AE |
892 | break |
893 | else: | |
0fd3389f | 894 | if piece.piece_type == TxtType.text: |
8c3e5397 | 895 | replyinfo_obj.msg_to_quote += piece.string |
d873ff48 AE |
896 | |
897 | ||
013f7cb8 | 898 | def get_key_from_fp (replyinfo_obj, gpgme_ctx): |
39e2c525 AE |
899 | """Obtains a public key object from a key fingerprint |
900 | ||
ca37d0cb AE |
901 | If the .target_key is not set, then we use .fallback_target_key, if |
902 | available. | |
39e2c525 AE |
903 | |
904 | Args: | |
905 | replyinfo_obj: ReplyInfo instance | |
906 | gpgme_ctx: the gpgme context | |
907 | ||
908 | Return: | |
c035a008 | 909 | Nothing |
39e2c525 AE |
910 | |
911 | Pre: | |
912 | Loading a key requires that we have the public key imported. This | |
913 | requires that they email contains the pub key block, or that it was | |
914 | previously sent to edward. | |
915 | ||
916 | Post: | |
ca37d0cb AE |
917 | If the key can be loaded, then replyinfo_obj.reply_to_key points to the |
918 | public key object. If the key cannot be loaded, then the replyinfo_obj | |
c035a008 AE |
919 | is marked as having no public key available. If the key is not capable |
920 | of encryption, it will not be used, and replyinfo_obj will be marked | |
921 | accordingly. | |
39e2c525 | 922 | """ |
013f7cb8 | 923 | |
ca37d0cb AE |
924 | for key in (replyinfo_obj.target_key, replyinfo_obj.fallback_target_key): |
925 | if key != None: | |
926 | try: | |
927 | encrypt_to_key = gpgme_ctx.get_key(key) | |
c035a008 AE |
928 | |
929 | except gpgme.GpgmeError: | |
930 | continue | |
931 | ||
932 | if encrypt_to_key.can_encrypt == True: | |
ca37d0cb | 933 | replyinfo_obj.encrypt_to_key = encrypt_to_key |
b4c116d5 | 934 | replyinfo_obj.have_reply_key = True |
c035a008 | 935 | replyinfo_obj.key_can_encrypt = True |
ca37d0cb | 936 | return |
013f7cb8 | 937 | |
c035a008 AE |
938 | else: |
939 | replyinfo_obj.key_cannot_encrypt = True | |
940 | ||
013f7cb8 | 941 | |
013f7cb8 | 942 | |
d873ff48 | 943 | def write_reply (replyinfo_obj): |
39e2c525 AE |
944 | """Write the reply email body about the GPG successes/failures. |
945 | ||
946 | The reply is about whether decryption, sig verification and key | |
947 | import/loading was successful or failed. If text was successfully decrypted | |
948 | and verified, then the first instance of such text will be included in | |
949 | quoted form. | |
950 | ||
951 | Args: | |
952 | replyinfo_obj: contains details of GPG processing status | |
953 | ||
954 | Returns: | |
955 | the plaintext message to be sent to the user | |
956 | ||
957 | Pre: | |
958 | replyinfo_obj should be populated with info about GPG processing status. | |
959 | """ | |
d873ff48 AE |
960 | |
961 | reply_plain = "" | |
962 | ||
cfcc211c AE |
963 | if (replyinfo_obj.pubkey_success == True): |
964 | reply_plain += replyinfo_obj.replies['greeting'] | |
965 | reply_plain += "\n\n" | |
966 | ||
371911ad | 967 | |
b4c116d5 | 968 | if replyinfo_obj.decrypt_success == True: |
234f607b | 969 | debug('decrypt success') |
d873ff48 | 970 | reply_plain += replyinfo_obj.replies['success_decrypt'] |
2694709a | 971 | |
b4c116d5 | 972 | if (replyinfo_obj.sig_success == True) and (replyinfo_obj.have_reply_key == True): |
234f607b | 973 | debug('message quoted') |
cfcc211c AE |
974 | reply_plain += replyinfo_obj.replies['space'] |
975 | reply_plain += replyinfo_obj.replies['quote_follows'] | |
976 | reply_plain += "\n\n" | |
2694709a AE |
977 | quoted_text = email_quote_text(replyinfo_obj.msg_to_quote) |
978 | reply_plain += quoted_text | |
cfcc211c AE |
979 | |
980 | reply_plain += "\n\n" | |
d873ff48 | 981 | |
4e2c66f7 | 982 | elif replyinfo_obj.decrypt_failure == True: |
234f607b | 983 | debug('decrypt failure') |
d873ff48 | 984 | reply_plain += replyinfo_obj.replies['failed_decrypt'] |
b4c116d5 | 985 | reply_plain += "\n\n" |
d873ff48 | 986 | |
371911ad | 987 | |
d873ff48 | 988 | if replyinfo_obj.sig_success == True: |
234f607b | 989 | debug('signature success') |
d873ff48 | 990 | reply_plain += replyinfo_obj.replies['sig_success'] |
b4c116d5 | 991 | reply_plain += "\n\n" |
d873ff48 | 992 | |
32a8996f | 993 | elif replyinfo_obj.sig_failure == True: |
234f607b | 994 | debug('signature failure') |
d873ff48 | 995 | reply_plain += replyinfo_obj.replies['sig_failure'] |
b4c116d5 | 996 | reply_plain += "\n\n" |
d873ff48 | 997 | |
371911ad | 998 | |
b4c116d5 | 999 | if (replyinfo_obj.pubkey_success == True): |
234f607b | 1000 | debug('public key received') |
b4c116d5 | 1001 | reply_plain += replyinfo_obj.replies['public_key_received'] |
d873ff48 | 1002 | reply_plain += "\n\n" |
d873ff48 | 1003 | |
b4c116d5 | 1004 | elif (replyinfo_obj.sigkey_missing == True): |
234f607b | 1005 | debug('no public key') |
b4c116d5 | 1006 | reply_plain += replyinfo_obj.replies['no_public_key'] |
d873ff48 | 1007 | reply_plain += "\n\n" |
d873ff48 | 1008 | |
c035a008 AE |
1009 | elif (replyinfo_obj.key_can_encrypt == False) \ |
1010 | and (replyinfo_obj.key_cannot_encrypt == True): | |
1011 | debug('bad public key') | |
1012 | reply_plain += replyinfo_obj.replies['no_public_key'] | |
1013 | reply_plain += "\n\n" | |
1014 | ||
d873ff48 | 1015 | |
4e2c66f7 AE |
1016 | if (reply_plain == ""): |
1017 | debug('plaintext message') | |
1018 | reply_plain += replyinfo_obj.replies['failed_decrypt'] | |
1019 | reply_plain += "\n\n" | |
1020 | ||
1021 | ||
d873ff48 | 1022 | reply_plain += replyinfo_obj.replies['signature'] |
b4c116d5 | 1023 | reply_plain += "\n\n" |
56578eaf | 1024 | |
d873ff48 | 1025 | return reply_plain |
56578eaf AE |
1026 | |
1027 | ||
8f61c66a | 1028 | def add_gpg_key (key_block, gpgme_ctx): |
39e2c525 AE |
1029 | """Adds a GPG pubkey to the local keystore |
1030 | ||
1031 | This adds keys received through email into the key store so they can be | |
1032 | used later. | |
1033 | ||
1034 | Args: | |
1035 | key_block: the string form of the ascii-armored public key block | |
1036 | gpgme_ctx: the gpgme context | |
1037 | ||
1038 | Returns: | |
c035a008 AE |
1039 | the fingerprint(s) of the imported key(s) which can be used for |
1040 | encryption, and a boolean marking whether none of the keys are capable | |
1041 | of encryption. | |
39e2c525 | 1042 | """ |
c267c233 | 1043 | |
8f61c66a | 1044 | fp = io.BytesIO(key_block.encode('ascii')) |
c267c233 | 1045 | |
89c08329 AE |
1046 | try: |
1047 | result = gpgme_ctx.import_(fp) | |
1048 | imports = result.imports | |
1049 | except gpgme.GpgmeError: | |
1050 | imports = [] | |
c267c233 | 1051 | |
f8ee6bd3 | 1052 | key_fingerprints = [] |
c035a008 AE |
1053 | key_cannot_encrypt = False |
1054 | ||
1055 | for import_res in imports: | |
1056 | fingerprint = import_res[0] | |
1057 | ||
1058 | try: | |
1059 | key_obj = gpgme_ctx.get_key(fingerprint) | |
1060 | except: | |
1061 | pass | |
c267c233 | 1062 | |
c035a008 | 1063 | if key_obj.can_encrypt == True: |
f8ee6bd3 | 1064 | key_fingerprints += [fingerprint] |
c035a008 | 1065 | key_cannot_encrypt = False |
c267c233 | 1066 | |
e49673aa | 1067 | debug("added gpg key: " + fingerprint) |
ec1e779a | 1068 | |
c035a008 AE |
1069 | elif key_fingerprints == []: |
1070 | key_cannot_encrypt = True | |
1071 | ||
1072 | return (key_fingerprints, key_cannot_encrypt) | |
ec1e779a AE |
1073 | |
1074 | ||
3a753fd0 | 1075 | def verify_sig_message (msg_block, gpgme_ctx): |
39e2c525 AE |
1076 | """Verifies the signature of a signed, ascii-armored block of text. |
1077 | ||
1078 | It encodes the string into ascii, since binary GPG files are currently | |
1079 | unsupported, and alternative, the ascii-armored format is encodable into | |
1080 | ascii. | |
1081 | ||
1082 | Args: | |
1083 | msg_block: a GPG Message block in string form. It may be encrypted or | |
1084 | not. If it is encrypted, it will return empty results. | |
1085 | gpgme_ctx: the gpgme context | |
1086 | ||
1087 | Returns: | |
85a829fc | 1088 | A tuple containing the plaintext bytes of the signed part, the list of |
c035a008 AE |
1089 | fingerprints of encryption-capable keys signing the data, a boolean |
1090 | marking whether edward is missing all public keys for validating any of | |
1091 | the signatures, and a boolean marking whether all sigs' keys are | |
1092 | incapable of encryption. If verification failed, perhaps because the | |
1093 | message was also encrypted, sensible default values are returned. | |
39e2c525 | 1094 | """ |
3a753fd0 AE |
1095 | |
1096 | block_b = io.BytesIO(msg_block.encode('ascii')) | |
1097 | plain_b = io.BytesIO() | |
1098 | ||
1099 | try: | |
1100 | sigs = gpgme_ctx.verify(block_b, None, plain_b) | |
5f6f32b1 | 1101 | except gpgme.GpgmeError: |
c035a008 | 1102 | return ("",[],False,False) |
3a753fd0 | 1103 | |
85a829fc | 1104 | plaintext_b = plain_b.getvalue() |
3a753fd0 | 1105 | |
c035a008 | 1106 | (fingerprints, sigkey_missing, key_cannot_encrypt) = get_signature_fp(sigs, gpgme_ctx) |
9af26cb8 | 1107 | |
c035a008 | 1108 | return (plaintext_b, fingerprints, sigkey_missing, key_cannot_encrypt) |
3a753fd0 AE |
1109 | |
1110 | ||
101d54a8 | 1111 | def verify_detached_signature (detached_sig, plaintext_bytes, gpgme_ctx): |
39e2c525 AE |
1112 | """Verifies the signature of a detached signature. |
1113 | ||
1114 | This requires the signature part and the signed part as separate arguments. | |
1115 | ||
1116 | Args: | |
1117 | detached_sig: the signature part of the detached signature | |
1118 | plaintext_bytes: the byte form of the message being signed. | |
1119 | gpgme_ctx: the gpgme context | |
1120 | ||
1121 | Returns: | |
c035a008 AE |
1122 | A tuple containging a list of encryption capable signing fingerprints |
1123 | if the signature verification was sucessful, a boolean marking whether | |
1124 | edward is missing all public keys for validating any of the signatures, | |
1125 | and a boolean marking whether all signing keys are incapable of | |
1126 | encryption. Otherwise, a tuple containing an empty list and True are | |
1127 | returned. | |
39e2c525 | 1128 | """ |
101d54a8 AE |
1129 | |
1130 | detached_sig_fp = io.BytesIO(detached_sig.encode('ascii')) | |
1131 | plaintext_fp = io.BytesIO(plaintext_bytes) | |
101d54a8 | 1132 | |
ff7aeb3d | 1133 | try: |
c035a008 | 1134 | sigs = gpgme_ctx.verify(detached_sig_fp, plaintext_fp, None) |
ff7aeb3d | 1135 | except gpgme.GpgmeError: |
c035a008 | 1136 | return ([],False,False) |
101d54a8 | 1137 | |
c035a008 | 1138 | (fingerprints, sigkey_missing, key_cannot_encrypt) = get_signature_fp(sigs, gpgme_ctx) |
101d54a8 | 1139 | |
c035a008 | 1140 | return (fingerprints, sigkey_missing, key_cannot_encrypt) |
101d54a8 AE |
1141 | |
1142 | ||
5b3053c1 | 1143 | def decrypt_block (msg_block, gpgme_ctx): |
9af26cb8 | 1144 | """Decrypts a block of GPG text and verifies any included sigatures. |
39e2c525 AE |
1145 | |
1146 | Some encypted messages have embeded signatures, so those are verified too. | |
1147 | ||
1148 | Args: | |
1149 | msg_block: the encrypted(/signed) text | |
1150 | gpgme_ctx: the gpgme context | |
1151 | ||
1152 | Returns: | |
c035a008 AE |
1153 | A tuple containing plaintext bytes, encryption-capable signatures (if |
1154 | decryption and signature verification were successful, respectively), a | |
1155 | boolean marking whether edward is missing all public keys for | |
1156 | validating any of the signatures, and a boolean marking whether all | |
1157 | signature keys are incapable of encryption. | |
39e2c525 | 1158 | """ |
0bec96d6 | 1159 | |
5b3053c1 | 1160 | block_b = io.BytesIO(msg_block.encode('ascii')) |
0bec96d6 AE |
1161 | plain_b = io.BytesIO() |
1162 | ||
afc1f64c AE |
1163 | try: |
1164 | sigs = gpgme_ctx.decrypt_verify(block_b, plain_b) | |
5f6f32b1 | 1165 | except gpgme.GpgmeError: |
c035a008 | 1166 | return ("",[],False,False) |
0bec96d6 | 1167 | |
85a829fc | 1168 | plaintext_b = plain_b.getvalue() |
cbdf22c1 | 1169 | |
c035a008 AE |
1170 | (fingerprints, sigkey_missing, key_cannot_encrypt) = get_signature_fp(sigs, gpgme_ctx) |
1171 | ||
1172 | return (plaintext_b, fingerprints, sigkey_missing, key_cannot_encrypt) | |
1173 | ||
1174 | ||
1175 | def get_signature_fp (sigs, gpgme_ctx): | |
1176 | """Selects valid signatures from output of gpgme signature verifying functions | |
1177 | ||
1178 | get_signature_fp returns a list of valid signature fingerprints if those | |
1179 | fingerprints are associated with available keys capable of encryption. | |
1180 | ||
1181 | Args: | |
1182 | sigs: a signature verification result object list | |
1183 | gpgme_ctx: a gpgme context | |
1184 | ||
1185 | Returns: | |
1186 | fingerprints: a list of fingerprints | |
1187 | sigkey_missing: a boolean marking whether public keys are missing for | |
1188 | all available signatures. | |
1189 | key_cannot_encrypt: a boolearn marking whether available public keys are | |
1190 | incapable of encryption. | |
1191 | """ | |
1192 | ||
b4c116d5 | 1193 | sigkey_missing = False |
c035a008 | 1194 | key_cannot_encrypt = False |
cbdf22c1 | 1195 | fingerprints = [] |
c035a008 | 1196 | |
cbdf22c1 | 1197 | for sig in sigs: |
8f011cc9 | 1198 | if (sig.summary == 0) or (sig.summary & gpgme.SIGSUM_VALID != 0) or (sig.summary & gpgme.SIGSUM_GREEN != 0): |
c035a008 AE |
1199 | try: |
1200 | key_obj = gpgme_ctx.get_key(sig.fpr) | |
1201 | except: | |
1202 | if fingerprints == []: | |
1203 | sigkey_missing = True | |
1204 | continue | |
1205 | ||
1206 | if key_obj.can_encrypt == True: | |
1207 | fingerprints += [sig.fpr] | |
1208 | key_cannot_encrypt = False | |
1209 | sigkey_missing = False | |
1210 | ||
1211 | elif fingerprints == []: | |
1212 | key_cannot_encrypt = True | |
1213 | ||
1214 | elif fingerprints == []: | |
b4c116d5 AE |
1215 | if (sig.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1216 | sigkey_missing = True | |
9af26cb8 | 1217 | |
c035a008 | 1218 | return (fingerprints, sigkey_missing, key_cannot_encrypt) |
0bec96d6 AE |
1219 | |
1220 | ||
85a829fc | 1221 | def email_to_from_subject (email_bytes): |
dd2b62d7 | 1222 | """Returns the values of the email's To:, From: and Subject: fields |
fafa21c3 | 1223 | |
dd2b62d7 | 1224 | Returns this information from an email. |
fafa21c3 | 1225 | |
dd2b62d7 | 1226 | Args: |
85a829fc | 1227 | email_bytes: the byte string form of the email |
fafa21c3 | 1228 | |
dd2b62d7 AE |
1229 | Returns: |
1230 | the email To:, From:, and Subject: fields as strings | |
1231 | """ | |
d65993b8 | 1232 | |
85a829fc | 1233 | email_struct = email.parser.BytesParser().parsebytes(email_bytes) |
d65993b8 AE |
1234 | |
1235 | email_to = email_struct['To'] | |
1236 | email_from = email_struct['From'] | |
1237 | email_subject = email_struct['Subject'] | |
1238 | ||
1239 | return email_to, email_from, email_subject | |
1240 | ||
1241 | ||
bb27d257 AE |
1242 | def import_lang_pick_address(email_to, hostname): |
1243 | """Imports language file for i18n support; makes reply from address | |
dd2b62d7 AE |
1244 | |
1245 | The language imported depends on the To: address of the email received by | |
1246 | edward. an -en ending implies the English language, whereas a -ja ending | |
1247 | implies Japanese. The list of supported languages is listed in the 'langs' | |
bb27d257 AE |
1248 | list at the beginning of the program. This function also chooses the |
1249 | language-dependent address which can be used as the From address in the | |
1250 | reply email. | |
dd2b62d7 AE |
1251 | |
1252 | Args: | |
1253 | email_to: the string containing the email address that the mail was | |
bb27d257 AE |
1254 | sent to. |
1255 | hostname: the hostname part of the reply email's from address | |
dd2b62d7 AE |
1256 | |
1257 | Returns: | |
1258 | the reference to the imported language module. The only variable in | |
1259 | this file is the 'replies' dictionary. | |
1260 | """ | |
adcef2f7 | 1261 | |
bb27d257 AE |
1262 | # default |
1263 | use_lang = "en" | |
daed5f10 | 1264 | |
5250b3b8 AE |
1265 | if email_to != None: |
1266 | for lang in langs: | |
1267 | if "edward-" + lang in email_to: | |
bb27d257 AE |
1268 | use_lang = lang |
1269 | break | |
adcef2f7 | 1270 | |
bb27d257 AE |
1271 | lang_mod_name = "lang." + re.sub('-', '_', use_lang) |
1272 | lang_module = importlib.import_module(lang_mod_name) | |
1273 | ||
60ccbaf4 | 1274 | reply_from = "edward-" + use_lang + "@" + hostname |
bb27d257 | 1275 | |
60ccbaf4 | 1276 | return lang_module, reply_from |
adcef2f7 AE |
1277 | |
1278 | ||
cfb03389 | 1279 | def generate_encrypted_mime (plaintext, email_to, email_subject, encrypt_to_key, |
0a064403 | 1280 | gpgme_ctx): |
dd2b62d7 AE |
1281 | """This function creates the mime email reply. It can encrypt the email. |
1282 | ||
1283 | If the encrypt_key is included, then the email is encrypted and signed. | |
1284 | Otherwise it is unencrypted. | |
1285 | ||
1286 | Args: | |
1287 | plaintext: the plaintext body of the message to create. | |
cfb03389 | 1288 | email_to: the email address to reply to |
dd2b62d7 AE |
1289 | email_subject: the subject to use in reply |
1290 | encrypt_to_key: the key object to use for encrypting the email. (or | |
1291 | None) | |
1292 | gpgme_ctx: the gpgme context | |
1293 | ||
1294 | Returns | |
1295 | A string version of the mime message, possibly encrypted and signed. | |
1296 | """ | |
1da9b527 | 1297 | |
59bc3fac AE |
1298 | plaintext_mime = MIMEText(plaintext) |
1299 | plaintext_mime.set_charset('utf-8') | |
8bdfb6d4 | 1300 | |
59bc3fac | 1301 | if (encrypt_to_key != None): |
8bdfb6d4 AE |
1302 | |
1303 | encrypted_text = encrypt_sign_message(plaintext_mime.as_string(), | |
1304 | encrypt_to_key, | |
40c37ab3 | 1305 | gpgme_ctx) |
8bdfb6d4 | 1306 | |
e5dd6f23 AE |
1307 | control_mime = MIMEApplication("Version: 1", |
1308 | _subtype='pgp-encrypted', | |
1309 | _encoder=email.encoders.encode_7or8bit) | |
1310 | control_mime['Content-Description'] = 'PGP/MIME version identification' | |
1311 | control_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1312 | |
e5dd6f23 AE |
1313 | encoded_mime = MIMEApplication(encrypted_text, |
1314 | _subtype='octet-stream; name="encrypted.asc"', | |
1315 | _encoder=email.encoders.encode_7or8bit) | |
1316 | encoded_mime['Content-Description'] = 'OpenPGP encrypted message' | |
1317 | encoded_mime['Content-Disposition'] = 'inline; filename="encrypted.asc"' | |
1318 | encoded_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1319 | |
e5dd6f23 AE |
1320 | message_mime = MIMEMultipart(_subtype="encrypted", protocol="application/pgp-encrypted") |
1321 | message_mime.attach(control_mime) | |
1322 | message_mime.attach(encoded_mime) | |
1323 | message_mime['Content-Disposition'] = 'inline' | |
216708e9 | 1324 | |
e5dd6f23 | 1325 | else: |
59bc3fac | 1326 | message_mime = plaintext_mime |
2007103e | 1327 | |
cfb03389 | 1328 | message_mime['To'] = email_to |
2007103e AE |
1329 | message_mime['Subject'] = email_subject |
1330 | ||
1331 | reply = message_mime.as_string() | |
1da9b527 AE |
1332 | |
1333 | return reply | |
1334 | ||
1335 | ||
60ccbaf4 AE |
1336 | def send_reply(email_txt, subject, reply_to, reply_from): |
1337 | ||
1338 | email_bytes = email_txt.encode('ascii') | |
1339 | ||
1340 | p = subprocess.Popen(["/usr/sbin/sendmail", "-f", reply_from, "-F", "Edward, GPG Bot", "-i", reply_to], stdin=subprocess.PIPE) | |
1341 | ||
1342 | (stdout, stderr) = p.communicate(email_bytes) | |
1343 | ||
1344 | if stdout != None: | |
1345 | debug("sendmail stdout: " + str(stdout)) | |
1346 | if stderr != None: | |
1347 | error("sendmail stderr: " + str(stderr)) | |
1348 | ||
1349 | ||
f87041f8 | 1350 | def email_quote_text (text): |
dd2b62d7 AE |
1351 | """Quotes input text by inserting "> "s |
1352 | ||
1353 | This is useful for quoting a text for the reply message. It inserts "> " | |
1354 | strings at the beginning of lines. | |
1355 | ||
1356 | Args: | |
1357 | text: plain text to quote | |
1358 | ||
1359 | Returns: | |
1360 | Quoted text | |
1361 | """ | |
f87041f8 AE |
1362 | |
1363 | quoted_message = re.sub(r'^', r'> ', text, flags=re.MULTILINE) | |
1364 | ||
1365 | return quoted_message | |
1366 | ||
1367 | ||
0a064403 | 1368 | def encrypt_sign_message (plaintext, encrypt_to_key, gpgme_ctx): |
dd2b62d7 AE |
1369 | """Encrypts and signs plaintext |
1370 | ||
1371 | This encrypts and signs a message. | |
1372 | ||
1373 | Args: | |
1374 | plaintext: text to sign and ecrypt | |
1375 | encrypt_to_key: the key object to encrypt to | |
1376 | gpgme_ctx: the gpgme context | |
1377 | ||
1378 | Returns: | |
1379 | An encrypted and signed string of text | |
1380 | """ | |
897cbaf6 | 1381 | |
b33f601b | 1382 | # the plaintext should be mime encoded in an ascii-compatible form |
6aa41372 | 1383 | plaintext_bytes = io.BytesIO(plaintext.encode('ascii')) |
1da9b527 AE |
1384 | encrypted_bytes = io.BytesIO() |
1385 | ||
897cbaf6 | 1386 | gpgme_ctx.encrypt_sign([encrypt_to_key], gpgme.ENCRYPT_ALWAYS_TRUST, |
1da9b527 AE |
1387 | plaintext_bytes, encrypted_bytes) |
1388 | ||
6aa41372 | 1389 | encrypted_txt = encrypted_bytes.getvalue().decode('ascii') |
1da9b527 AE |
1390 | return encrypted_txt |
1391 | ||
1392 | ||
0a064403 | 1393 | def error (error_msg): |
dd2b62d7 AE |
1394 | """Write an error message to stdout |
1395 | ||
1396 | The error message includes the program name. | |
1397 | ||
1398 | Args: | |
1399 | error_msg: the message to print | |
1400 | ||
1401 | Returns: | |
1402 | Nothing | |
1403 | ||
1404 | Post: | |
1405 | An error message is printed to stdout | |
1406 | """ | |
0a064403 | 1407 | |
e4fb2ab2 | 1408 | sys.stderr.write(progname + ": " + str(error_msg) + "\n") |
0a064403 AE |
1409 | |
1410 | ||
5e8f9094 | 1411 | def debug (debug_msg): |
dd2b62d7 AE |
1412 | """Writes a debug message to stdout if debug == True |
1413 | ||
1414 | If the debug option is set in edward_config.py, then the passed message | |
1415 | gets printed to stdout. | |
1416 | ||
1417 | Args: | |
1418 | debug_msg: the message to print to stdout | |
1419 | ||
1420 | Returns: | |
1421 | Nothing | |
1422 | ||
1423 | Post: | |
1424 | A debug message is printed to stdout | |
1425 | """ | |
5e8f9094 AE |
1426 | |
1427 | if edward_config.debug == True: | |
0a064403 | 1428 | error(debug_msg) |
5e8f9094 AE |
1429 | |
1430 | ||
20f6e7c5 | 1431 | def handle_args (): |
60ccbaf4 | 1432 | """Sets the progname variable and processes optional argument |
dd2b62d7 | 1433 | |
60ccbaf4 AE |
1434 | If there are more than two arguments then edward complains and quits. An |
1435 | single "-p" argument sets the print_reply_only option, which makes edward | |
1436 | print email replies instead of mailing them. | |
dd2b62d7 AE |
1437 | |
1438 | Args: | |
1439 | None | |
1440 | ||
1441 | Returns: | |
60ccbaf4 AE |
1442 | True if edward should print arguments instead of mailing them, |
1443 | otherwise it returns False. | |
dd2b62d7 AE |
1444 | |
1445 | Post: | |
60ccbaf4 AE |
1446 | Exits with error 1 if there are more than two arguments, otherwise |
1447 | returns the print_reply_only option. | |
dd2b62d7 | 1448 | """ |
20f6e7c5 | 1449 | |
a51cdb72 AE |
1450 | global progname |
1451 | progname = sys.argv[0] | |
1452 | ||
60ccbaf4 AE |
1453 | print_reply_only = False |
1454 | ||
1455 | if len(sys.argv) > 2: | |
1456 | print(progname + " usage: " + progname + " [-p]\n\n" \ | |
1457 | + " -p print reply message to stdout, do not mail it\n", \ | |
1458 | file=sys.stderr) | |
a51cdb72 | 1459 | exit(1) |
20f6e7c5 | 1460 | |
60ccbaf4 AE |
1461 | elif (len(sys.argv) == 2) and (sys.argv[1] == "-p"): |
1462 | print_reply_only = True | |
1463 | ||
1464 | return print_reply_only | |
1465 | ||
20f6e7c5 | 1466 | |
a51cdb72 | 1467 | if __name__ == "__main__": |
dd2b62d7 | 1468 | """Executes main if this file is not loaded interactively""" |
20f6e7c5 | 1469 | |
a51cdb72 | 1470 | main() |
0bec96d6 | 1471 |