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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 | |
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 | ||
b4c116d5 AE |
195 | 'pubkey_success' is set to True if edward successfully imported a public |
196 | key. | |
197 | ||
198 | 'sigkey_missing' is set to True if edward doesn't have the public key | |
199 | needed for signature verification. | |
200 | ||
201 | 'have_repy_key' is set to True if edward has a public key to encrypt its | |
202 | reply to. | |
def9196c AE |
203 | """ |
204 | ||
7d0b91d2 | 205 | replies = None |
6906d46d | 206 | |
7d0b91d2 AE |
207 | target_key = None |
208 | fallback_target_key = None | |
ca37d0cb | 209 | encrypt_to_key = None |
7d0b91d2 | 210 | msg_to_quote = "" |
d873ff48 | 211 | |
b4c116d5 | 212 | decrypt_success = False |
7d0b91d2 | 213 | sig_success = False |
b4c116d5 AE |
214 | pubkey_success = False |
215 | ||
216 | sigkey_missing = False | |
217 | have_reply_key = False | |
d873ff48 | 218 | |
38738401 | 219 | |
0bec96d6 AE |
220 | def main (): |
221 | ||
def9196c AE |
222 | """ |
223 | This is the main function for edward, a GPG reply bot. | |
224 | ||
225 | Edward responds to GPG-encrypted and signed mail, encrypting and signing | |
226 | the response if the user's public key is, or was, included in the message. | |
227 | ||
228 | Args: | |
229 | None | |
230 | ||
231 | Returns: | |
a3d6aff8 | 232 | Nothing |
def9196c AE |
233 | |
234 | Pre: | |
235 | Mime or plaintext email passing in through standard input. Portions of | |
236 | the email may be encrypted. If the To: address contains the text | |
237 | "edward-ja", then the reply will contain a reply written in the | |
238 | Japanese language. There are other languages as well. The default | |
239 | language is English. | |
240 | ||
241 | Post: | |
242 | A reply email will be printed to standard output. The contents of the | |
243 | reply email depends on whether the original email was encrypted or not, | |
244 | has or doesn't have a signature, whether a public key used in the | |
245 | original message is provided or locally stored, and the language | |
246 | implied by the To: address in the original email. | |
247 | """ | |
248 | ||
60ccbaf4 | 249 | print_reply_only = handle_args() |
0bec96d6 | 250 | |
0a064403 AE |
251 | gpgme_ctx = get_gpg_context(edward_config.gnupghome, |
252 | edward_config.sign_with_key) | |
253 | ||
c96f3837 | 254 | email_text = sys.stdin.read() |
adcef2f7 AE |
255 | email_struct = parse_pgp_mime(email_text, gpgme_ctx) |
256 | ||
257 | email_to, email_from, email_subject = email_to_from_subject(email_text) | |
60ccbaf4 | 258 | lang, reply_from = import_lang_pick_address(email_to, edward_config.hostname) |
fafa21c3 | 259 | |
d873ff48 AE |
260 | replyinfo_obj = ReplyInfo() |
261 | replyinfo_obj.replies = lang.replies | |
262 | ||
263 | prepare_for_reply(email_struct, replyinfo_obj) | |
ca37d0cb | 264 | get_key_from_fp(replyinfo_obj, gpgme_ctx) |
d873ff48 | 265 | reply_plaintext = write_reply(replyinfo_obj) |
adcef2f7 | 266 | |
2007103e | 267 | reply_mime = generate_encrypted_mime(reply_plaintext, email_from, \ |
ca37d0cb | 268 | email_subject, replyinfo_obj.encrypt_to_key, |
2007103e | 269 | gpgme_ctx) |
1fccb295 | 270 | |
60ccbaf4 AE |
271 | if print_reply_only == True: |
272 | print(reply_mime) | |
273 | else: | |
274 | send_reply(reply_mime, email_subject, email_from, reply_from) | |
c96f3837 | 275 | |
0bec96d6 | 276 | |
0a064403 | 277 | def get_gpg_context (gnupghome, sign_with_key_fp): |
a3d6aff8 AE |
278 | """ |
279 | This function returns the GPG context needed for encryption and signing. | |
280 | ||
281 | The context is needed by other functions which use GPG functionality. | |
282 | ||
283 | Args: | |
284 | gnupghome: The path to "~/.gnupg/" or its alternative. | |
285 | sign_with_key: The fingerprint of the key to sign with | |
286 | ||
287 | Returns: | |
288 | A gpgme context to be used for GPG functions. | |
289 | ||
290 | Post: | |
291 | the 'armor' flag is set to True and the list of signing keys contains | |
292 | the single specified key | |
293 | """ | |
0a064403 AE |
294 | |
295 | os.environ['GNUPGHOME'] = gnupghome | |
296 | ||
297 | gpgme_ctx = gpgme.Context() | |
298 | gpgme_ctx.armor = True | |
299 | ||
300 | try: | |
301 | sign_with_key = gpgme_ctx.get_key(sign_with_key_fp) | |
5f6f32b1 | 302 | except gpgme.GpgmeError: |
0a064403 AE |
303 | error("unable to load signing key. is the gnupghome " |
304 | + "and signing key properly set in the edward_config.py?") | |
305 | exit(1) | |
306 | ||
307 | gpgme_ctx.signers = [sign_with_key] | |
308 | ||
309 | return gpgme_ctx | |
310 | ||
311 | ||
38738401 | 312 | def parse_pgp_mime (email_text, gpgme_ctx): |
a3d6aff8 AE |
313 | """Parses the email for mime payloads and decrypts/verfies signatures. |
314 | ||
315 | This function creates a representation of a mime or plaintext email with | |
316 | the EddyMsg class. It then splits each mime payload into one or more pieces | |
317 | which may be plain text or GPG data. It then decrypts encrypted parts and | |
318 | does some very basic signature verification on those parts. | |
319 | ||
320 | Args: | |
321 | email_text: an email message in string format | |
322 | gpgme_ctx: a gpgme context | |
323 | ||
324 | Returns: | |
325 | A message as an instance of EddyMsg | |
326 | ||
327 | Post: | |
328 | the returned EddyMsg instance has split, decrypted, verified and pubkey | |
329 | imported payloads | |
330 | """ | |
394a1476 AE |
331 | |
332 | email_struct = email.parser.Parser().parsestr(email_text) | |
333 | ||
928e3819 AE |
334 | eddymsg_obj = parse_mime(email_struct) |
335 | split_payloads(eddymsg_obj) | |
336 | gpg_on_payloads(eddymsg_obj, gpgme_ctx) | |
8bb4b0d5 | 337 | |
928e3819 | 338 | return eddymsg_obj |
0bec96d6 | 339 | |
0bec96d6 | 340 | |
56578eaf | 341 | def parse_mime(msg_struct): |
a3d6aff8 AE |
342 | """Translates python's email.parser format into an EddyMsg format |
343 | ||
344 | If the message is multi-part, then a recursive object is created, where | |
345 | each sub-part is also a EddyMsg instance. | |
346 | ||
347 | Args: | |
348 | msg_struct: an email parsed with email.parser.Parser(), which can be | |
349 | multi-part | |
350 | ||
351 | Returns: | |
352 | an instance of EddyMsg, potentially a recursive one. | |
353 | """ | |
0bec96d6 | 354 | |
928e3819 | 355 | eddymsg_obj = EddyMsg() |
8bb4b0d5 | 356 | |
56578eaf AE |
357 | if msg_struct.is_multipart() == True: |
358 | payloads = msg_struct.get_payload() | |
0bec96d6 | 359 | |
928e3819 AE |
360 | eddymsg_obj.multipart = True |
361 | eddymsg_obj.subparts = list(map(parse_mime, payloads)) | |
dd11a483 | 362 | |
56578eaf | 363 | else: |
928e3819 | 364 | eddymsg_obj = get_subpart_data(msg_struct) |
394a1476 | 365 | |
928e3819 | 366 | return eddymsg_obj |
c267c233 | 367 | |
80119cab | 368 | |
2f4102b9 | 369 | def scan_and_split (payload_piece, match_name, pattern): |
a3d6aff8 AE |
370 | """This splits the payloads of an EddyMsg object into GPG and text parts. |
371 | ||
372 | An EddyMsg object's payload_pieces starts off as a list containing a single | |
373 | PayloadPiece object. This function returns a list of these objects which | |
374 | have been split into GPG data and regular text, if such splits need to be/ | |
375 | can be made. | |
376 | ||
377 | Args: | |
378 | payload_piece: a single payload or a split part of a payload | |
2f4102b9 | 379 | match_name: the type of data to try to spit out from the payload piece |
a3d6aff8 AE |
380 | pattern: the search pattern to be used for finding that type of data |
381 | ||
382 | Returns: | |
383 | a list of objects of the PayloadPiece class, in the order that the | |
384 | string part of payload_piece originally was, broken up according to | |
385 | matches specified by 'pattern'. | |
386 | """ | |
cf75de65 | 387 | |
a5d37d44 | 388 | # don't try to re-split pieces containing gpg data |
0fd3389f | 389 | if payload_piece.piece_type != TxtType.text: |
a5d37d44 AE |
390 | return [payload_piece] |
391 | ||
56578eaf AE |
392 | flags = re.DOTALL | re.MULTILINE |
393 | matches = re.search("(?P<beginning>.*?)(?P<match>" + pattern + | |
394 | ")(?P<rest>.*)", payload_piece.string, flags=flags) | |
86663388 | 395 | |
56578eaf AE |
396 | if matches == None: |
397 | pieces = [payload_piece] | |
c96f3837 | 398 | |
56578eaf | 399 | else: |
d437f8b2 | 400 | |
56578eaf AE |
401 | beginning = PayloadPiece() |
402 | beginning.string = matches.group('beginning') | |
403 | beginning.piece_type = payload_piece.piece_type | |
d437f8b2 | 404 | |
56578eaf AE |
405 | match = PayloadPiece() |
406 | match.string = matches.group('match') | |
2f4102b9 | 407 | match.piece_type = match_name |
d437f8b2 | 408 | |
56578eaf AE |
409 | rest = PayloadPiece() |
410 | rest.string = matches.group('rest') | |
411 | rest.piece_type = payload_piece.piece_type | |
d437f8b2 | 412 | |
2f4102b9 | 413 | more_pieces = scan_and_split(rest, match_name, pattern) |
4615b156 | 414 | pieces = [beginning, match ] + more_pieces |
d437f8b2 | 415 | |
56578eaf | 416 | return pieces |
d437f8b2 | 417 | |
d437f8b2 | 418 | |
56578eaf | 419 | def get_subpart_data (part): |
a3d6aff8 AE |
420 | """This function grabs information from a single part mime object. |
421 | ||
422 | It copies needed data from a single part email.parser.Parser() object over | |
423 | to an EddyMsg object. | |
424 | ||
425 | Args: | |
426 | part: a non-multi-part mime.parser.Parser() object | |
427 | ||
428 | Returns: | |
429 | a single-part EddyMsg() object | |
430 | """ | |
0bec96d6 | 431 | |
6d8faaa7 AE |
432 | charset = part.get_content_charset() |
433 | mime_decoded_bytes = part.get_payload(decode=True) | |
0bec96d6 | 434 | |
6d8faaa7 AE |
435 | obj = EddyMsg() |
436 | obj.payload_bytes = part.as_bytes() | |
56578eaf AE |
437 | |
438 | obj.filename = part.get_filename() | |
439 | obj.content_type = part.get_content_type() | |
440 | obj.description_list = part['content-description'] | |
441 | ||
442 | # your guess is as good as a-myy-ee-ine... | |
6d8faaa7 AE |
443 | if charset == None: |
444 | charset = 'utf-8' | |
56578eaf | 445 | |
6d8faaa7 | 446 | if mime_decoded_bytes != None: |
0eb75d9c AE |
447 | try: |
448 | payload = PayloadPiece() | |
6d8faaa7 | 449 | payload.string = mime_decoded_bytes.decode(charset) |
0fd3389f | 450 | payload.piece_type = TxtType.text |
0eb75d9c AE |
451 | |
452 | obj.payload_pieces = [payload] | |
453 | except UnicodeDecodeError: | |
454 | pass | |
56578eaf AE |
455 | |
456 | return obj | |
457 | ||
458 | ||
928e3819 | 459 | def do_to_eddys_pieces (function_to_do, eddymsg_obj, data): |
a3d6aff8 AE |
460 | """A function which maps another function onto a message's subparts. |
461 | ||
462 | This is a higer-order function which recursively performs a specified | |
463 | function on each subpart of a multi-part message. Each single-part sub-part | |
464 | has the function applied to it. This function also works if the part passed | |
465 | in is single-part. | |
466 | ||
467 | Args: | |
468 | function_to_do: function to perform on sub-parts | |
469 | eddymsg_obj: a single part or multi-part EddyMsg object | |
470 | data: a second argument to pass to 'function_to_do' | |
471 | ||
472 | Returns: | |
473 | Nothing | |
474 | ||
475 | Post: | |
476 | The passed-in EddyMsg object is transformed recursively on its | |
477 | sub-parts according to 'function_to_do'. | |
478 | """ | |
56578eaf | 479 | |
928e3819 AE |
480 | if eddymsg_obj.multipart == True: |
481 | for sub in eddymsg_obj.subparts: | |
d873ff48 | 482 | do_to_eddys_pieces(function_to_do, sub, data) |
394a1476 | 483 | else: |
928e3819 | 484 | function_to_do(eddymsg_obj, data) |
dd11a483 AE |
485 | |
486 | ||
928e3819 | 487 | def split_payloads (eddymsg_obj): |
a3d6aff8 AE |
488 | """Splits all (sub-)payloads of a message into GPG data and regular text. |
489 | ||
490 | Recursively performs payload splitting on all sub-parts of an EddyMsg | |
491 | object into the various GPG data types, such as GPG messages, public key | |
492 | blocks and signed text. | |
493 | ||
494 | Args: | |
495 | eddymsg_obj: an instance of EddyMsg | |
496 | ||
497 | Returns: | |
498 | Nothing | |
499 | ||
500 | Pre: | |
501 | The EddyMsg object has payloads that are unsplit (by may be split).. | |
502 | ||
503 | Post: | |
504 | The EddyMsg object's payloads are all split into GPG and non-GPG parts. | |
505 | """ | |
a5d37d44 | 506 | |
2f4102b9 AE |
507 | for match_pair in match_pairs: |
508 | do_to_eddys_pieces(split_payload_pieces, eddymsg_obj, match_pair) | |
a5d37d44 | 509 | |
a5d37d44 | 510 | |
2f4102b9 | 511 | def split_payload_pieces (eddymsg_obj, match_pair): |
a3d6aff8 AE |
512 | """A helper function for split_payloads(); works on PayloadPiece objects. |
513 | ||
514 | This function splits up PayloadPiece objects into multipe PayloadPiece | |
515 | objects and replaces the EddyMsg object's previous list of payload pieces | |
516 | with the new split up one. | |
517 | ||
518 | Args: | |
519 | eddymsg_obj: a single-part EddyMsg object. | |
2f4102b9 | 520 | match_pair: a tuple from the match_pairs list, which specifies a match |
a3d6aff8 AE |
521 | name and a match pattern. |
522 | ||
523 | Returns: | |
524 | Nothing | |
525 | ||
526 | Pre: | |
527 | The payload piece(s) of an EddyMsg object may be already split or | |
528 | unsplit. | |
529 | ||
530 | Post: | |
531 | The EddyMsg object's payload piece(s) are split into a list of pieces | |
2f4102b9 | 532 | if matches of the match_pair are found. |
a3d6aff8 | 533 | """ |
a5d37d44 | 534 | |
2f4102b9 | 535 | (match_name, pattern) = match_pair |
a5d37d44 AE |
536 | |
537 | new_pieces_list = [] | |
928e3819 | 538 | for piece in eddymsg_obj.payload_pieces: |
a5d37d44 AE |
539 | new_pieces_list += scan_and_split(piece, match_name, pattern) |
540 | ||
928e3819 | 541 | eddymsg_obj.payload_pieces = new_pieces_list |
a5d37d44 AE |
542 | |
543 | ||
928e3819 | 544 | def gpg_on_payloads (eddymsg_obj, gpgme_ctx, prev_parts=[]): |
a3d6aff8 AE |
545 | """Performs GPG operations on the GPG parts of the message |
546 | ||
547 | This function decrypts text, verifies signatures, and imports public keys | |
548 | included in an email. | |
549 | ||
550 | Args: | |
551 | eddymsg_obj: an EddyMsg object with its payload_pieces split into GPG | |
552 | and non-GPG sections by split_payloads() | |
553 | gpgme_ctx: a gpgme context | |
554 | ||
555 | prev_parts: a list of mime parts that occur before the eddymsg_obj | |
556 | part, under the same multi-part mime part. This is used for | |
557 | verifying detached signatures. For the root mime part, this should | |
558 | be an empty list, which is the default value if this paramater is | |
559 | omitted. | |
560 | ||
561 | Return: | |
562 | Nothing | |
563 | ||
564 | Pre: | |
565 | eddymsg_obj should have its payloads split into gpg and non-gpg pieces. | |
566 | ||
567 | Post: | |
568 | Decryption, verification and key imports occur. the gpg_data member of | |
569 | PayloadPiece objects get filled in with GPGData objects. | |
570 | """ | |
38738401 | 571 | |
928e3819 | 572 | if eddymsg_obj.multipart == True: |
101d54a8 | 573 | prev_parts=[] |
928e3819 | 574 | for sub in eddymsg_obj.subparts: |
101d54a8 AE |
575 | gpg_on_payloads (sub, gpgme_ctx, prev_parts) |
576 | prev_parts += [sub] | |
38738401 | 577 | |
d873ff48 | 578 | return |
38738401 | 579 | |
928e3819 | 580 | for piece in eddymsg_obj.payload_pieces: |
38738401 | 581 | |
0fd3389f | 582 | if piece.piece_type == TxtType.text: |
38738401 AE |
583 | # don't transform the plaintext. |
584 | pass | |
585 | ||
0fd3389f | 586 | elif piece.piece_type == TxtType.message: |
b4c116d5 AE |
587 | piece.gpg_data = GPGData() |
588 | ||
589 | (plaintext, sigs, sigkey_missing) = decrypt_block(piece.string, gpgme_ctx) | |
590 | ||
591 | piece.gpg_data.sigkey_missing = sigkey_missing | |
38738401 AE |
592 | |
593 | if plaintext: | |
b23e171d | 594 | piece.gpg_data.decrypted = True |
38738401 AE |
595 | piece.gpg_data.sigs = sigs |
596 | # recurse! | |
597 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
3a753fd0 AE |
598 | continue |
599 | ||
600 | # if not encrypted, check to see if this is an armored signature. | |
b4c116d5 AE |
601 | (plaintext, sigs, sigkey_missing) = verify_sig_message(piece.string, gpgme_ctx) |
602 | ||
603 | piece.gpg_data.sigkey_missing = sigkey_missing | |
3a753fd0 AE |
604 | |
605 | if plaintext: | |
0fd3389f | 606 | piece.piece_type = TxtType.signature |
3a753fd0 AE |
607 | piece.gpg_data.sigs = sigs |
608 | # recurse! | |
609 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext, gpgme_ctx) | |
129543c3 | 610 | |
0fd3389f | 611 | elif piece.piece_type == TxtType.pubkey: |
f8ee6bd3 | 612 | key_fps = add_gpg_key(piece.string, gpgme_ctx) |
8f61c66a | 613 | |
f8ee6bd3 | 614 | if key_fps != []: |
8f61c66a | 615 | piece.gpg_data = GPGData() |
f8ee6bd3 | 616 | piece.gpg_data.keys = key_fps |
129543c3 | 617 | |
0fd3389f | 618 | elif piece.piece_type == TxtType.detachedsig: |
b4c116d5 AE |
619 | piece.gpg_data = GPGData() |
620 | ||
101d54a8 | 621 | for prev in prev_parts: |
b4c116d5 AE |
622 | (sig_fps, sigkey_missing) = verify_detached_signature(piece.string, prev.payload_bytes, gpgme_ctx) |
623 | ||
624 | piece.gpg_data.sigkey_missing = sigkey_missing | |
101d54a8 | 625 | |
6d240f68 | 626 | if sig_fps != []: |
6d240f68 AE |
627 | piece.gpg_data.sigs = sig_fps |
628 | piece.gpg_data.plainobj = prev | |
629 | break | |
7e18f14d | 630 | |
38738401 AE |
631 | else: |
632 | pass | |
633 | ||
634 | ||
928e3819 | 635 | def prepare_for_reply (eddymsg_obj, replyinfo_obj): |
67691346 AE |
636 | """Updates replyinfo_obj with info on the message's GPG success/failures |
637 | ||
638 | This function marks replyinfo_obj with information about whether encrypted | |
639 | text in eddymsg_obj was successfully decrypted, signatures were verified | |
640 | and whether a public key was found or not. | |
641 | ||
642 | Args: | |
643 | eddymsg_obj: a message in the EddyMsg format | |
644 | replyinfo_obj: an instance of ReplyInfo | |
645 | ||
646 | Returns: | |
647 | Nothing | |
648 | ||
649 | Pre: | |
650 | eddymsg_obj has had its gpg_data created by gpg_on_payloads | |
651 | ||
652 | Post: | |
653 | replyinfo_obj has been updated with info about decryption/sig | |
654 | verififcation status, etc. However the desired key isn't imported until | |
655 | later, so the success or failure of that updates the values set here. | |
656 | """ | |
dd11a483 | 657 | |
928e3819 | 658 | do_to_eddys_pieces(prepare_for_reply_pieces, eddymsg_obj, replyinfo_obj) |
56578eaf | 659 | |
928e3819 | 660 | def prepare_for_reply_pieces (eddymsg_obj, replyinfo_obj): |
67691346 AE |
661 | """A helper function for prepare_for_reply |
662 | ||
663 | It updates replyinfo_obj with GPG success/failure information, when | |
664 | supplied a single-part EddyMsg object. | |
665 | ||
666 | Args: | |
667 | eddymsg_obj: a single-part message in the EddyMsg format | |
668 | replyinfo_obj: an object which holds information about the message's | |
669 | GPG status | |
670 | ||
671 | Returns: | |
672 | Nothing | |
673 | ||
674 | Pre: | |
675 | eddymsg_obj is a single-part message. (it may be a part of a multi-part | |
676 | message.) It has had its gpg_data created by gpg_on_payloads if it has | |
677 | gpg data. | |
678 | ||
679 | Post: | |
680 | replyinfo_obj has been updated with gpg success/failure information | |
681 | """ | |
56578eaf | 682 | |
928e3819 | 683 | for piece in eddymsg_obj.payload_pieces: |
0fd3389f | 684 | if piece.piece_type == TxtType.text: |
d873ff48 AE |
685 | # don't quote the plaintext part. |
686 | pass | |
687 | ||
0fd3389f | 688 | elif piece.piece_type == TxtType.message: |
05683768 | 689 | prepare_for_reply_message(piece, replyinfo_obj) |
d873ff48 | 690 | |
0fd3389f | 691 | elif piece.piece_type == TxtType.pubkey: |
05683768 | 692 | prepare_for_reply_pubkey(piece, replyinfo_obj) |
6906d46d | 693 | |
0fd3389f AE |
694 | elif (piece.piece_type == TxtType.detachedsig) \ |
695 | or (piece.piece_type == TxtType.signature): | |
05683768 | 696 | prepare_for_reply_sig(piece, replyinfo_obj) |
d873ff48 | 697 | |
d873ff48 | 698 | |
05683768 | 699 | def prepare_for_reply_message (piece, replyinfo_obj): |
67691346 AE |
700 | """Helper function for prepare_for_reply() |
701 | ||
702 | This function is called when the piece_type of a payload piece is | |
9af26cb8 AE |
703 | TxtType.message, or GPG Message block. This should be encrypted text. If |
704 | the encryted block is correclty signed, a sig will be attached to | |
705 | .target_key unless there is already one there. | |
67691346 AE |
706 | |
707 | Args: | |
708 | piece: a PayloadPiece object. | |
709 | replyinfo_obj: object which gets updated with decryption status, etc. | |
710 | ||
67691346 AE |
711 | Returns: |
712 | Nothing | |
713 | ||
714 | Pre: | |
0fd3389f | 715 | the piece.payload_piece value should be TxtType.message. |
67691346 AE |
716 | |
717 | Post: | |
b4c116d5 AE |
718 | replyinfo_obj gets updated with decryption status, signing status, a |
719 | potential signing key, and posession status of the public key for the | |
720 | signature. | |
67691346 | 721 | """ |
44fe39b7 | 722 | |
b4c116d5 | 723 | if piece.gpg_data == None or piece.gpg_data.plainobj == None: |
05683768 AE |
724 | return |
725 | ||
b4c116d5 | 726 | replyinfo_obj.decrypt_success = True |
05683768 AE |
727 | |
728 | # we already have a key (and a message) | |
729 | if replyinfo_obj.target_key != None: | |
730 | return | |
731 | ||
732 | if piece.gpg_data.sigs != []: | |
733 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
59003069 | 734 | replyinfo_obj.sig_success = True |
05683768 | 735 | get_signed_part = False |
b4c116d5 | 736 | |
05683768 | 737 | else: |
b4c116d5 AE |
738 | if piece.gpg_data.sigkey_missing == True: |
739 | replyinfo_obj.sigkey_missing = True | |
9af26cb8 | 740 | |
05683768 AE |
741 | # only include a signed message in the reply. |
742 | get_signed_part = True | |
743 | ||
8c3e5397 | 744 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, get_signed_part) |
05683768 AE |
745 | |
746 | # to catch public keys in encrypted blocks | |
747 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
748 | ||
749 | ||
750 | def prepare_for_reply_pubkey (piece, replyinfo_obj): | |
67691346 AE |
751 | """Helper function for prepare_for_reply(). Marks pubkey import status. |
752 | ||
753 | Marks replyinfo_obj with pub key import status. | |
754 | ||
755 | Args: | |
756 | piece: a PayloadPiece object | |
757 | replyinfo_obj: a ReplyInfo object | |
758 | ||
759 | Pre: | |
0fd3389f | 760 | piece.piece_type should be set to TxtType.pubkey . |
67691346 AE |
761 | |
762 | Post: | |
763 | replyinfo_obj has its fields updated. | |
764 | """ | |
05683768 AE |
765 | |
766 | if piece.gpg_data == None or piece.gpg_data.keys == []: | |
b4c116d5 | 767 | pass |
05683768 | 768 | else: |
b4c116d5 | 769 | replyinfo_obj.pubkey_success = True |
05683768 | 770 | |
3ceb92e5 AE |
771 | # prefer public key as a fallback for the encrypted reply |
772 | replyinfo_obj.fallback_target_key = piece.gpg_data.keys[0] | |
05683768 AE |
773 | |
774 | ||
775 | def prepare_for_reply_sig (piece, replyinfo_obj): | |
67691346 AE |
776 | """Helper function for prepare_for_reply(). Marks sig verification status. |
777 | ||
778 | Marks replyinfo_obj with signature verification status. | |
779 | ||
780 | Args: | |
781 | piece: a PayloadPiece object | |
782 | replyinfo_obj: a ReplyInfo object | |
783 | ||
784 | Pre: | |
0fd3389f AE |
785 | piece.piece_type should be set to TxtType.signature, or |
786 | TxtType.detachedsig . | |
67691346 AE |
787 | |
788 | Post: | |
789 | replyinfo_obj has its fields updated. | |
790 | """ | |
05683768 AE |
791 | |
792 | if piece.gpg_data == None or piece.gpg_data.sigs == []: | |
b4c116d5 AE |
793 | |
794 | if piece.gpg_data.sigkey_missing == True: | |
795 | replyinfo_obj.sigkey_missing = True | |
796 | ||
05683768 AE |
797 | else: |
798 | replyinfo_obj.sig_success = True | |
799 | ||
800 | if replyinfo_obj.fallback_target_key == None: | |
801 | replyinfo_obj.fallback_target_key = piece.gpg_data.sigs[0] | |
6906d46d AE |
802 | |
803 | ||
8c3e5397 AE |
804 | def flatten_decrypted_payloads (eddymsg_obj, replyinfo_obj, get_signed_part): |
805 | """For creating a string representation of a signed, encrypted part. | |
39e2c525 | 806 | |
8c3e5397 AE |
807 | When given a decrypted payload, it will add either the plaintext or signed |
808 | plaintext to the reply message, depeding on 'get_signed_part'. This is | |
809 | useful for ensuring that the reply message only comes from a signed and | |
810 | ecrypted GPG message. It also sets the target_key for encrypting the reply | |
811 | if it's told to get signed text only. | |
39e2c525 AE |
812 | |
813 | Args: | |
814 | eddymsg_obj: the message in EddyMsg format created by decrypting GPG | |
815 | text | |
8c3e5397 AE |
816 | replyinfo_obj: a ReplyInfo object for holding the message to quote and |
817 | the target_key to encrypt to. | |
39e2c525 AE |
818 | get_signed_part: True if we should only include text that contains a |
819 | further signature. If False, then include plain text. | |
820 | ||
821 | Returns: | |
8c3e5397 | 822 | Nothing |
39e2c525 AE |
823 | |
824 | Pre: | |
825 | The EddyMsg instance passed in should be a piece.gpg_data.plainobj | |
826 | which represents decrypted text. It may or may not be signed on that | |
827 | level. | |
d873ff48 | 828 | |
8c3e5397 AE |
829 | Post: |
830 | the ReplyInfo instance may have a new 'target_key' set and its | |
831 | 'msg_to_quote' will be updated with (possibly signed) plaintext, if any | |
832 | could be found. | |
833 | """ | |
d873ff48 | 834 | |
0aa88c27 | 835 | if eddymsg_obj == None: |
8c3e5397 | 836 | return |
0aa88c27 | 837 | |
0402995a | 838 | # recurse on multi-part mime |
928e3819 AE |
839 | if eddymsg_obj.multipart == True: |
840 | for sub in eddymsg_obj.subparts: | |
8c3e5397 | 841 | flatten_decrypted_payloads(sub, replyinfo_obj, get_signed_part) |
d873ff48 | 842 | |
928e3819 | 843 | for piece in eddymsg_obj.payload_pieces: |
0402995a | 844 | if (get_signed_part): |
0fd3389f AE |
845 | if ((piece.piece_type == TxtType.detachedsig) \ |
846 | or (piece.piece_type == TxtType.signature)) \ | |
b4c116d5 AE |
847 | and (piece.gpg_data != None) \ |
848 | and (piece.gpg_data.plainobj != None): | |
8c3e5397 AE |
849 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, False) |
850 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
c3d417bf AE |
851 | break |
852 | else: | |
0fd3389f | 853 | if piece.piece_type == TxtType.text: |
8c3e5397 | 854 | replyinfo_obj.msg_to_quote += piece.string |
d873ff48 AE |
855 | |
856 | ||
013f7cb8 | 857 | def get_key_from_fp (replyinfo_obj, gpgme_ctx): |
39e2c525 AE |
858 | """Obtains a public key object from a key fingerprint |
859 | ||
ca37d0cb AE |
860 | If the .target_key is not set, then we use .fallback_target_key, if |
861 | available. | |
39e2c525 AE |
862 | |
863 | Args: | |
864 | replyinfo_obj: ReplyInfo instance | |
865 | gpgme_ctx: the gpgme context | |
866 | ||
867 | Return: | |
868 | The key object of the key of either the target_key or the fallback one | |
869 | if .target_key is not set. If the key cannot be loaded, then return | |
870 | None. | |
871 | ||
872 | Pre: | |
873 | Loading a key requires that we have the public key imported. This | |
874 | requires that they email contains the pub key block, or that it was | |
875 | previously sent to edward. | |
876 | ||
877 | Post: | |
ca37d0cb AE |
878 | If the key can be loaded, then replyinfo_obj.reply_to_key points to the |
879 | public key object. If the key cannot be loaded, then the replyinfo_obj | |
880 | is marked as having no public key available. | |
39e2c525 | 881 | """ |
013f7cb8 | 882 | |
ca37d0cb AE |
883 | for key in (replyinfo_obj.target_key, replyinfo_obj.fallback_target_key): |
884 | if key != None: | |
885 | try: | |
886 | encrypt_to_key = gpgme_ctx.get_key(key) | |
887 | replyinfo_obj.encrypt_to_key = encrypt_to_key | |
b4c116d5 | 888 | replyinfo_obj.have_reply_key = True |
ca37d0cb | 889 | return |
013f7cb8 | 890 | |
ca37d0cb AE |
891 | except gpgme.GpgmeError: |
892 | pass | |
013f7cb8 | 893 | |
013f7cb8 | 894 | |
d873ff48 | 895 | def write_reply (replyinfo_obj): |
39e2c525 AE |
896 | """Write the reply email body about the GPG successes/failures. |
897 | ||
898 | The reply is about whether decryption, sig verification and key | |
899 | import/loading was successful or failed. If text was successfully decrypted | |
900 | and verified, then the first instance of such text will be included in | |
901 | quoted form. | |
902 | ||
903 | Args: | |
904 | replyinfo_obj: contains details of GPG processing status | |
905 | ||
906 | Returns: | |
907 | the plaintext message to be sent to the user | |
908 | ||
909 | Pre: | |
910 | replyinfo_obj should be populated with info about GPG processing status. | |
911 | """ | |
d873ff48 AE |
912 | |
913 | reply_plain = "" | |
914 | ||
b4c116d5 | 915 | if replyinfo_obj.decrypt_success == True: |
234f607b | 916 | debug('decrypt success') |
d873ff48 | 917 | reply_plain += replyinfo_obj.replies['success_decrypt'] |
b4c116d5 | 918 | reply_plain += "\n\n" |
2694709a | 919 | |
b4c116d5 | 920 | if (replyinfo_obj.sig_success == True) and (replyinfo_obj.have_reply_key == True): |
234f607b | 921 | debug('message quoted') |
2694709a AE |
922 | quoted_text = email_quote_text(replyinfo_obj.msg_to_quote) |
923 | reply_plain += quoted_text | |
b4c116d5 | 924 | reply_plain += "\n\n" |
d873ff48 | 925 | |
b4c116d5 | 926 | else: |
234f607b | 927 | debug('decrypt failure') |
d873ff48 | 928 | reply_plain += replyinfo_obj.replies['failed_decrypt'] |
b4c116d5 | 929 | reply_plain += "\n\n" |
d873ff48 AE |
930 | |
931 | if replyinfo_obj.sig_success == True: | |
234f607b | 932 | debug('signature success') |
d873ff48 | 933 | reply_plain += replyinfo_obj.replies['sig_success'] |
b4c116d5 | 934 | reply_plain += "\n\n" |
d873ff48 | 935 | |
8329b828 | 936 | else: |
234f607b | 937 | debug('signature failure') |
d873ff48 | 938 | reply_plain += replyinfo_obj.replies['sig_failure'] |
b4c116d5 | 939 | reply_plain += "\n\n" |
d873ff48 | 940 | |
b4c116d5 | 941 | if (replyinfo_obj.pubkey_success == True): |
234f607b | 942 | debug('public key received') |
b4c116d5 | 943 | reply_plain += replyinfo_obj.replies['public_key_received'] |
d873ff48 | 944 | reply_plain += "\n\n" |
d873ff48 | 945 | |
b4c116d5 | 946 | elif (replyinfo_obj.sigkey_missing == True): |
234f607b | 947 | debug('no public key') |
b4c116d5 | 948 | reply_plain += replyinfo_obj.replies['no_public_key'] |
d873ff48 | 949 | reply_plain += "\n\n" |
d873ff48 AE |
950 | |
951 | ||
d873ff48 | 952 | reply_plain += replyinfo_obj.replies['signature'] |
b4c116d5 | 953 | reply_plain += "\n\n" |
56578eaf | 954 | |
d873ff48 | 955 | return reply_plain |
56578eaf AE |
956 | |
957 | ||
8f61c66a | 958 | def add_gpg_key (key_block, gpgme_ctx): |
39e2c525 AE |
959 | """Adds a GPG pubkey to the local keystore |
960 | ||
961 | This adds keys received through email into the key store so they can be | |
962 | used later. | |
963 | ||
964 | Args: | |
965 | key_block: the string form of the ascii-armored public key block | |
966 | gpgme_ctx: the gpgme context | |
967 | ||
968 | Returns: | |
969 | the fingerprint(s) of the imported key(s) | |
970 | """ | |
c267c233 | 971 | |
8f61c66a | 972 | fp = io.BytesIO(key_block.encode('ascii')) |
c267c233 | 973 | |
89c08329 AE |
974 | try: |
975 | result = gpgme_ctx.import_(fp) | |
976 | imports = result.imports | |
977 | except gpgme.GpgmeError: | |
978 | imports = [] | |
c267c233 | 979 | |
f8ee6bd3 | 980 | key_fingerprints = [] |
c267c233 | 981 | |
8f61c66a AE |
982 | if imports != []: |
983 | for import_ in imports: | |
984 | fingerprint = import_[0] | |
f8ee6bd3 | 985 | key_fingerprints += [fingerprint] |
c267c233 | 986 | |
e49673aa | 987 | debug("added gpg key: " + fingerprint) |
ec1e779a | 988 | |
f8ee6bd3 | 989 | return key_fingerprints |
ec1e779a AE |
990 | |
991 | ||
3a753fd0 | 992 | def verify_sig_message (msg_block, gpgme_ctx): |
39e2c525 AE |
993 | """Verifies the signature of a signed, ascii-armored block of text. |
994 | ||
995 | It encodes the string into ascii, since binary GPG files are currently | |
996 | unsupported, and alternative, the ascii-armored format is encodable into | |
997 | ascii. | |
998 | ||
999 | Args: | |
1000 | msg_block: a GPG Message block in string form. It may be encrypted or | |
1001 | not. If it is encrypted, it will return empty results. | |
1002 | gpgme_ctx: the gpgme context | |
1003 | ||
1004 | Returns: | |
9af26cb8 AE |
1005 | A tuple containing the plaintext of the signed part, the list of |
1006 | fingerprints of keys signing the data, and a boolean marking whether | |
b4c116d5 AE |
1007 | edward is missing all public keys for validating any of the signatures. |
1008 | If verification failed, perhaps because the message was also encrypted, | |
1009 | then empty results are returned. | |
39e2c525 | 1010 | """ |
3a753fd0 AE |
1011 | |
1012 | block_b = io.BytesIO(msg_block.encode('ascii')) | |
1013 | plain_b = io.BytesIO() | |
1014 | ||
1015 | try: | |
1016 | sigs = gpgme_ctx.verify(block_b, None, plain_b) | |
5f6f32b1 | 1017 | except gpgme.GpgmeError: |
b4c116d5 | 1018 | return ("",[],False) |
3a753fd0 AE |
1019 | |
1020 | plaintext = plain_b.getvalue().decode('utf-8') | |
1021 | ||
b4c116d5 | 1022 | sigkey_missing = False |
3a753fd0 AE |
1023 | fingerprints = [] |
1024 | for sig in sigs: | |
8f011cc9 | 1025 | if (sig.summary == 0) or (sig.summary & gpgme.SIGSUM_VALID != 0) or (sig.summary & gpgme.SIGSUM_GREEN != 0): |
9af26cb8 | 1026 | fingerprints += [sig.fpr] |
b4c116d5 AE |
1027 | sigkey_missing = False |
1028 | break | |
9af26cb8 | 1029 | else: |
b4c116d5 AE |
1030 | if (sig.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1031 | sigkey_missing = True | |
9af26cb8 | 1032 | |
b4c116d5 | 1033 | return (plaintext, fingerprints, sigkey_missing) |
3a753fd0 AE |
1034 | |
1035 | ||
101d54a8 | 1036 | def verify_detached_signature (detached_sig, plaintext_bytes, gpgme_ctx): |
39e2c525 AE |
1037 | """Verifies the signature of a detached signature. |
1038 | ||
1039 | This requires the signature part and the signed part as separate arguments. | |
1040 | ||
1041 | Args: | |
1042 | detached_sig: the signature part of the detached signature | |
1043 | plaintext_bytes: the byte form of the message being signed. | |
1044 | gpgme_ctx: the gpgme context | |
1045 | ||
1046 | Returns: | |
9af26cb8 | 1047 | A tuple containging a list of signing fingerprints if the signature |
b4c116d5 AE |
1048 | verification was sucessful, and a boolean marking whether edward is |
1049 | missing all public keys for validating any of the signatures. | |
1050 | Otherwise, a tuple containing an empty list and True are returned. | |
39e2c525 | 1051 | """ |
101d54a8 AE |
1052 | |
1053 | detached_sig_fp = io.BytesIO(detached_sig.encode('ascii')) | |
1054 | plaintext_fp = io.BytesIO(plaintext_bytes) | |
101d54a8 | 1055 | |
ff7aeb3d AE |
1056 | try: |
1057 | result = gpgme_ctx.verify(detached_sig_fp, plaintext_fp, None) | |
1058 | except gpgme.GpgmeError: | |
b4c116d5 | 1059 | return ([],False) |
101d54a8 | 1060 | |
b4c116d5 | 1061 | sigkey_missing = False |
101d54a8 AE |
1062 | sig_fingerprints = [] |
1063 | for res_ in result: | |
8f011cc9 | 1064 | if (res_.summary == 0) or (res_.summary & gpgme.SIGSUM_VALID != 0) or (res_.summary & gpgme.SIGSUM_GREEN != 0): |
9af26cb8 | 1065 | sig_fingerprints += [res_.fpr] |
b4c116d5 AE |
1066 | sigkey_missing = False |
1067 | break | |
9af26cb8 | 1068 | else: |
b4c116d5 AE |
1069 | if (res_.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1070 | sigkey_missing = True | |
101d54a8 | 1071 | |
b4c116d5 | 1072 | return (sig_fingerprints, sigkey_missing) |
101d54a8 AE |
1073 | |
1074 | ||
5b3053c1 | 1075 | def decrypt_block (msg_block, gpgme_ctx): |
9af26cb8 | 1076 | """Decrypts a block of GPG text and verifies any included sigatures. |
39e2c525 AE |
1077 | |
1078 | Some encypted messages have embeded signatures, so those are verified too. | |
1079 | ||
1080 | Args: | |
1081 | msg_block: the encrypted(/signed) text | |
1082 | gpgme_ctx: the gpgme context | |
1083 | ||
1084 | Returns: | |
9af26cb8 AE |
1085 | A tuple containing plaintext, signatures (if the decryption and |
1086 | signature verification were successful, respectively), and a boolean | |
b4c116d5 AE |
1087 | marking whether edward is missing all public keys for validating any of |
1088 | the signatures. | |
39e2c525 | 1089 | """ |
0bec96d6 | 1090 | |
5b3053c1 | 1091 | block_b = io.BytesIO(msg_block.encode('ascii')) |
0bec96d6 AE |
1092 | plain_b = io.BytesIO() |
1093 | ||
afc1f64c AE |
1094 | try: |
1095 | sigs = gpgme_ctx.decrypt_verify(block_b, plain_b) | |
5f6f32b1 | 1096 | except gpgme.GpgmeError: |
b4c116d5 | 1097 | return ("",[],False) |
0bec96d6 | 1098 | |
6aa41372 | 1099 | plaintext = plain_b.getvalue().decode('utf-8') |
cbdf22c1 | 1100 | |
b4c116d5 | 1101 | sigkey_missing = False |
cbdf22c1 AE |
1102 | fingerprints = [] |
1103 | for sig in sigs: | |
8f011cc9 | 1104 | if (sig.summary == 0) or (sig.summary & gpgme.SIGSUM_VALID != 0) or (sig.summary & gpgme.SIGSUM_GREEN != 0): |
9af26cb8 | 1105 | fingerprints += [sig.fpr] |
b4c116d5 AE |
1106 | sigkey_missing = False |
1107 | break | |
9af26cb8 | 1108 | else: |
b4c116d5 AE |
1109 | if (sig.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1110 | sigkey_missing = True | |
9af26cb8 | 1111 | |
b4c116d5 | 1112 | return (plaintext, fingerprints, sigkey_missing) |
0bec96d6 AE |
1113 | |
1114 | ||
dd2b62d7 AE |
1115 | def email_to_from_subject (email_text): |
1116 | """Returns the values of the email's To:, From: and Subject: fields | |
fafa21c3 | 1117 | |
dd2b62d7 | 1118 | Returns this information from an email. |
fafa21c3 | 1119 | |
dd2b62d7 AE |
1120 | Args: |
1121 | email_text: the string form of the email | |
fafa21c3 | 1122 | |
dd2b62d7 AE |
1123 | Returns: |
1124 | the email To:, From:, and Subject: fields as strings | |
1125 | """ | |
d65993b8 AE |
1126 | |
1127 | email_struct = email.parser.Parser().parsestr(email_text) | |
1128 | ||
1129 | email_to = email_struct['To'] | |
1130 | email_from = email_struct['From'] | |
1131 | email_subject = email_struct['Subject'] | |
1132 | ||
1133 | return email_to, email_from, email_subject | |
1134 | ||
1135 | ||
bb27d257 AE |
1136 | def import_lang_pick_address(email_to, hostname): |
1137 | """Imports language file for i18n support; makes reply from address | |
dd2b62d7 AE |
1138 | |
1139 | The language imported depends on the To: address of the email received by | |
1140 | edward. an -en ending implies the English language, whereas a -ja ending | |
1141 | implies Japanese. The list of supported languages is listed in the 'langs' | |
bb27d257 AE |
1142 | list at the beginning of the program. This function also chooses the |
1143 | language-dependent address which can be used as the From address in the | |
1144 | reply email. | |
dd2b62d7 AE |
1145 | |
1146 | Args: | |
1147 | email_to: the string containing the email address that the mail was | |
bb27d257 AE |
1148 | sent to. |
1149 | hostname: the hostname part of the reply email's from address | |
dd2b62d7 AE |
1150 | |
1151 | Returns: | |
1152 | the reference to the imported language module. The only variable in | |
1153 | this file is the 'replies' dictionary. | |
1154 | """ | |
adcef2f7 | 1155 | |
bb27d257 AE |
1156 | # default |
1157 | use_lang = "en" | |
daed5f10 | 1158 | |
5250b3b8 AE |
1159 | if email_to != None: |
1160 | for lang in langs: | |
1161 | if "edward-" + lang in email_to: | |
bb27d257 AE |
1162 | use_lang = lang |
1163 | break | |
adcef2f7 | 1164 | |
bb27d257 AE |
1165 | lang_mod_name = "lang." + re.sub('-', '_', use_lang) |
1166 | lang_module = importlib.import_module(lang_mod_name) | |
1167 | ||
60ccbaf4 | 1168 | reply_from = "edward-" + use_lang + "@" + hostname |
bb27d257 | 1169 | |
60ccbaf4 | 1170 | return lang_module, reply_from |
adcef2f7 AE |
1171 | |
1172 | ||
cfb03389 | 1173 | def generate_encrypted_mime (plaintext, email_to, email_subject, encrypt_to_key, |
0a064403 | 1174 | gpgme_ctx): |
dd2b62d7 AE |
1175 | """This function creates the mime email reply. It can encrypt the email. |
1176 | ||
1177 | If the encrypt_key is included, then the email is encrypted and signed. | |
1178 | Otherwise it is unencrypted. | |
1179 | ||
1180 | Args: | |
1181 | plaintext: the plaintext body of the message to create. | |
cfb03389 | 1182 | email_to: the email address to reply to |
dd2b62d7 AE |
1183 | email_subject: the subject to use in reply |
1184 | encrypt_to_key: the key object to use for encrypting the email. (or | |
1185 | None) | |
1186 | gpgme_ctx: the gpgme context | |
1187 | ||
1188 | Returns | |
1189 | A string version of the mime message, possibly encrypted and signed. | |
1190 | """ | |
1da9b527 | 1191 | |
e5dd6f23 | 1192 | if (encrypt_to_key != None): |
8bdfb6d4 | 1193 | |
66a125ef AE |
1194 | plaintext_mime = MIMEText(plaintext) |
1195 | plaintext_mime.set_charset('utf-8') | |
8bdfb6d4 AE |
1196 | |
1197 | encrypted_text = encrypt_sign_message(plaintext_mime.as_string(), | |
1198 | encrypt_to_key, | |
40c37ab3 | 1199 | gpgme_ctx) |
8bdfb6d4 | 1200 | |
e5dd6f23 AE |
1201 | control_mime = MIMEApplication("Version: 1", |
1202 | _subtype='pgp-encrypted', | |
1203 | _encoder=email.encoders.encode_7or8bit) | |
1204 | control_mime['Content-Description'] = 'PGP/MIME version identification' | |
1205 | control_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1206 | |
e5dd6f23 AE |
1207 | encoded_mime = MIMEApplication(encrypted_text, |
1208 | _subtype='octet-stream; name="encrypted.asc"', | |
1209 | _encoder=email.encoders.encode_7or8bit) | |
1210 | encoded_mime['Content-Description'] = 'OpenPGP encrypted message' | |
1211 | encoded_mime['Content-Disposition'] = 'inline; filename="encrypted.asc"' | |
1212 | encoded_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1213 | |
e5dd6f23 AE |
1214 | message_mime = MIMEMultipart(_subtype="encrypted", protocol="application/pgp-encrypted") |
1215 | message_mime.attach(control_mime) | |
1216 | message_mime.attach(encoded_mime) | |
1217 | message_mime['Content-Disposition'] = 'inline' | |
216708e9 | 1218 | |
e5dd6f23 AE |
1219 | else: |
1220 | message_mime = MIMEText(plaintext) | |
66a125ef | 1221 | message_mime.set_charset('utf-8') |
2007103e | 1222 | |
cfb03389 | 1223 | message_mime['To'] = email_to |
2007103e AE |
1224 | message_mime['Subject'] = email_subject |
1225 | ||
1226 | reply = message_mime.as_string() | |
1da9b527 AE |
1227 | |
1228 | return reply | |
1229 | ||
1230 | ||
60ccbaf4 AE |
1231 | def send_reply(email_txt, subject, reply_to, reply_from): |
1232 | ||
1233 | email_bytes = email_txt.encode('ascii') | |
1234 | ||
1235 | p = subprocess.Popen(["/usr/sbin/sendmail", "-f", reply_from, "-F", "Edward, GPG Bot", "-i", reply_to], stdin=subprocess.PIPE) | |
1236 | ||
1237 | (stdout, stderr) = p.communicate(email_bytes) | |
1238 | ||
1239 | if stdout != None: | |
1240 | debug("sendmail stdout: " + str(stdout)) | |
1241 | if stderr != None: | |
1242 | error("sendmail stderr: " + str(stderr)) | |
1243 | ||
1244 | ||
f87041f8 | 1245 | def email_quote_text (text): |
dd2b62d7 AE |
1246 | """Quotes input text by inserting "> "s |
1247 | ||
1248 | This is useful for quoting a text for the reply message. It inserts "> " | |
1249 | strings at the beginning of lines. | |
1250 | ||
1251 | Args: | |
1252 | text: plain text to quote | |
1253 | ||
1254 | Returns: | |
1255 | Quoted text | |
1256 | """ | |
f87041f8 AE |
1257 | |
1258 | quoted_message = re.sub(r'^', r'> ', text, flags=re.MULTILINE) | |
1259 | ||
1260 | return quoted_message | |
1261 | ||
1262 | ||
0a064403 | 1263 | def encrypt_sign_message (plaintext, encrypt_to_key, gpgme_ctx): |
dd2b62d7 AE |
1264 | """Encrypts and signs plaintext |
1265 | ||
1266 | This encrypts and signs a message. | |
1267 | ||
1268 | Args: | |
1269 | plaintext: text to sign and ecrypt | |
1270 | encrypt_to_key: the key object to encrypt to | |
1271 | gpgme_ctx: the gpgme context | |
1272 | ||
1273 | Returns: | |
1274 | An encrypted and signed string of text | |
1275 | """ | |
897cbaf6 | 1276 | |
b33f601b | 1277 | # the plaintext should be mime encoded in an ascii-compatible form |
6aa41372 | 1278 | plaintext_bytes = io.BytesIO(plaintext.encode('ascii')) |
1da9b527 AE |
1279 | encrypted_bytes = io.BytesIO() |
1280 | ||
897cbaf6 | 1281 | gpgme_ctx.encrypt_sign([encrypt_to_key], gpgme.ENCRYPT_ALWAYS_TRUST, |
1da9b527 AE |
1282 | plaintext_bytes, encrypted_bytes) |
1283 | ||
6aa41372 | 1284 | encrypted_txt = encrypted_bytes.getvalue().decode('ascii') |
1da9b527 AE |
1285 | return encrypted_txt |
1286 | ||
1287 | ||
0a064403 | 1288 | def error (error_msg): |
dd2b62d7 AE |
1289 | """Write an error message to stdout |
1290 | ||
1291 | The error message includes the program name. | |
1292 | ||
1293 | Args: | |
1294 | error_msg: the message to print | |
1295 | ||
1296 | Returns: | |
1297 | Nothing | |
1298 | ||
1299 | Post: | |
1300 | An error message is printed to stdout | |
1301 | """ | |
0a064403 | 1302 | |
e4fb2ab2 | 1303 | sys.stderr.write(progname + ": " + str(error_msg) + "\n") |
0a064403 AE |
1304 | |
1305 | ||
5e8f9094 | 1306 | def debug (debug_msg): |
dd2b62d7 AE |
1307 | """Writes a debug message to stdout if debug == True |
1308 | ||
1309 | If the debug option is set in edward_config.py, then the passed message | |
1310 | gets printed to stdout. | |
1311 | ||
1312 | Args: | |
1313 | debug_msg: the message to print to stdout | |
1314 | ||
1315 | Returns: | |
1316 | Nothing | |
1317 | ||
1318 | Post: | |
1319 | A debug message is printed to stdout | |
1320 | """ | |
5e8f9094 AE |
1321 | |
1322 | if edward_config.debug == True: | |
0a064403 | 1323 | error(debug_msg) |
5e8f9094 AE |
1324 | |
1325 | ||
20f6e7c5 | 1326 | def handle_args (): |
60ccbaf4 | 1327 | """Sets the progname variable and processes optional argument |
dd2b62d7 | 1328 | |
60ccbaf4 AE |
1329 | If there are more than two arguments then edward complains and quits. An |
1330 | single "-p" argument sets the print_reply_only option, which makes edward | |
1331 | print email replies instead of mailing them. | |
dd2b62d7 AE |
1332 | |
1333 | Args: | |
1334 | None | |
1335 | ||
1336 | Returns: | |
60ccbaf4 AE |
1337 | True if edward should print arguments instead of mailing them, |
1338 | otherwise it returns False. | |
dd2b62d7 AE |
1339 | |
1340 | Post: | |
60ccbaf4 AE |
1341 | Exits with error 1 if there are more than two arguments, otherwise |
1342 | returns the print_reply_only option. | |
dd2b62d7 | 1343 | """ |
20f6e7c5 | 1344 | |
a51cdb72 AE |
1345 | global progname |
1346 | progname = sys.argv[0] | |
1347 | ||
60ccbaf4 AE |
1348 | print_reply_only = False |
1349 | ||
1350 | if len(sys.argv) > 2: | |
1351 | print(progname + " usage: " + progname + " [-p]\n\n" \ | |
1352 | + " -p print reply message to stdout, do not mail it\n", \ | |
1353 | file=sys.stderr) | |
a51cdb72 | 1354 | exit(1) |
20f6e7c5 | 1355 | |
60ccbaf4 AE |
1356 | elif (len(sys.argv) == 2) and (sys.argv[1] == "-p"): |
1357 | print_reply_only = True | |
1358 | ||
1359 | return print_reply_only | |
1360 | ||
20f6e7c5 | 1361 | |
a51cdb72 | 1362 | if __name__ == "__main__": |
dd2b62d7 | 1363 | """Executes main if this file is not loaded interactively""" |
20f6e7c5 | 1364 | |
a51cdb72 | 1365 | main() |
0bec96d6 | 1366 |