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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 | |
dfe75896 | 29 | * http://agpl.fsf.org/emailselfdefense.fsf.org/edward/PREVIOUS-20150530/edward.tar.gz |
8bdfb6d4 AE |
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 |
a9eaa792 | 40 | import smtplib |
adcef2f7 | 41 | import importlib |
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 | ||
c00930e9 AE |
95 | The 'filename', 'content_type', 'content_disposition' and |
96 | 'description_list' come from the mime part parameters. | |
97 | ||
def9196c AE |
98 | """ |
99 | ||
7d0b91d2 AE |
100 | multipart = False |
101 | subparts = [] | |
56578eaf | 102 | |
7d0b91d2 AE |
103 | payload_bytes = None |
104 | payload_pieces = [] | |
56578eaf | 105 | |
7d0b91d2 AE |
106 | filename = None |
107 | content_type = None | |
c00930e9 | 108 | content_disposition = None |
7d0b91d2 | 109 | description_list = None |
56578eaf AE |
110 | |
111 | ||
112 | class PayloadPiece (object): | |
def9196c AE |
113 | """ |
114 | PayloadPiece represents a complte or sub-section of a mime part. | |
115 | ||
116 | Instances of this class are often strung together within one or more arrays | |
117 | pointed to by each instance of the EddyMsg class. | |
118 | ||
0fd3389f AE |
119 | 'piece_type' refers to an enum whose value describes the content of |
120 | 'string'. Examples include TxtType.pubkey, for public keys, and | |
121 | TxtType.message, for encrypted data (or armored signatures until they are | |
122 | known to be such.) Some of the names derive from the header and footer of | |
123 | each of these ascii-encoded gpg blocks. | |
def9196c AE |
124 | |
125 | 'string' contains some string of text, such as non-GPG text, an encrypted | |
126 | block of text, a signature, or a public key. | |
127 | ||
128 | 'gpg_data' points to any instances of GPGData that have been created based | |
129 | on the contents of 'string'. | |
130 | """ | |
131 | ||
7d0b91d2 AE |
132 | piece_type = None |
133 | string = None | |
134 | gpg_data = None | |
56578eaf AE |
135 | |
136 | ||
38738401 | 137 | class GPGData (object): |
def9196c AE |
138 | """ |
139 | GPGData holds info from decryption, sig. verification, and/or pub. keys. | |
140 | ||
141 | Instances of this class contain decrypted information, signature | |
142 | fingerprints and/or fingerprints of processed and imported public keys. | |
143 | ||
144 | 'decrypted' is set to True if 'plainobj' was created from encrypted data. | |
145 | ||
146 | 'plainobj' points to any decrypted, or signed part of, a GPG signature. It | |
147 | is intended to be an instance of the EddyMsg class. | |
148 | ||
149 | 'sigs' is a list of fingerprints of keys used to sign the data in plainobj. | |
150 | ||
b4c116d5 AE |
151 | 'sigkey_missing' is set to True if edward doesn't have the key it needs to |
152 | verify the signature on a block of text. | |
9af26cb8 | 153 | |
c035a008 | 154 | 'key_cannot_encrypt' is set to True if pubkeys or sigs' keys in the payload |
e6d33a68 | 155 | piece are not capable of encryption, are revoked or expired, for instance. |
c035a008 | 156 | |
def9196c AE |
157 | 'keys' is a list of fingerprints of keys obtained in public key blocks. |
158 | """ | |
159 | ||
7d0b91d2 AE |
160 | decrypted = False |
161 | ||
162 | plainobj = None | |
163 | sigs = [] | |
b4c116d5 | 164 | sigkey_missing = False |
c035a008 | 165 | key_cannot_encrypt = False |
7d0b91d2 | 166 | keys = [] |
38738401 | 167 | |
38738401 | 168 | |
d873ff48 | 169 | class ReplyInfo (object): |
def9196c AE |
170 | """ |
171 | ReplyInfo contains details that edward uses in generating its reply. | |
172 | ||
173 | Instances of this class contain information about whether a message was | |
174 | successfully encrypted or signed, and whether a public key was attached, or | |
175 | retrievable, from the local GPG store. It stores the fingerprints of | |
176 | potential encryption key candidates and the message (if any at all) to | |
177 | quote in edward's reply. | |
178 | ||
179 | 'replies' points one of the dictionaries of translated replies. | |
180 | ||
181 | 'target_key' refers to the fingerprint of a key used to sign encrypted | |
182 | data. This is the preferred key, if it is set, and if is available. | |
183 | ||
184 | 'fallback_target_key' referst to the fingerprint of a key used to sign | |
185 | unencrypted data; alternatively it may be a public key attached to the | |
186 | message. | |
187 | ||
ca37d0cb AE |
188 | 'encrypt_to_key' the key object to use when encrypting edward's reply |
189 | ||
def9196c AE |
190 | 'msg_to_quote' refers to the part of a message which edward should quote in |
191 | his reply. This should remain as None if there was no encrypted and singed | |
192 | part. This is to avoid making edward a service for decrypting other | |
193 | people's messages to edward. | |
194 | ||
b4c116d5 | 195 | 'decrypt_success' is set to True if edward could decrypt part of the |
def9196c AE |
196 | message. |
197 | ||
def9196c AE |
198 | 'sig_success' is set to True if edward could to some extent verify the |
199 | signature of a signed part of the message to edward. | |
200 | ||
c035a008 AE |
201 | 'key_can_encrypt' is set to True if a key which can be encrypted to has |
202 | been found. | |
203 | ||
32a8996f AE |
204 | 'sig_failure' is set to True if edward could not verify a siganture. |
205 | ||
b4c116d5 AE |
206 | 'pubkey_success' is set to True if edward successfully imported a public |
207 | key. | |
208 | ||
209 | 'sigkey_missing' is set to True if edward doesn't have the public key | |
210 | needed for signature verification. | |
211 | ||
c035a008 AE |
212 | 'key_cannot_encrypt' is set to True if pubkeys or sig's keys in a payload |
213 | piece of the message are not capable of encryption. | |
214 | ||
b4c116d5 AE |
215 | 'have_repy_key' is set to True if edward has a public key to encrypt its |
216 | reply to. | |
def9196c AE |
217 | """ |
218 | ||
7d0b91d2 | 219 | replies = None |
6906d46d | 220 | |
7d0b91d2 AE |
221 | target_key = None |
222 | fallback_target_key = None | |
ca37d0cb | 223 | encrypt_to_key = None |
7d0b91d2 | 224 | msg_to_quote = "" |
d873ff48 | 225 | |
b4c116d5 | 226 | decrypt_success = False |
7d0b91d2 | 227 | sig_success = False |
b4c116d5 | 228 | pubkey_success = False |
c035a008 | 229 | key_can_encrypt = False |
b4c116d5 | 230 | |
4e2c66f7 | 231 | decrypt_failure = False |
32a8996f | 232 | sig_failure = False |
b4c116d5 | 233 | sigkey_missing = False |
c035a008 | 234 | key_cannot_encrypt = False |
371911ad | 235 | |
b4c116d5 | 236 | have_reply_key = False |
d873ff48 | 237 | |
38738401 | 238 | |
0bec96d6 AE |
239 | def main (): |
240 | ||
def9196c AE |
241 | """ |
242 | This is the main function for edward, a GPG reply bot. | |
243 | ||
244 | Edward responds to GPG-encrypted and signed mail, encrypting and signing | |
245 | the response if the user's public key is, or was, included in the message. | |
246 | ||
247 | Args: | |
248 | None | |
249 | ||
250 | Returns: | |
a3d6aff8 | 251 | Nothing |
def9196c AE |
252 | |
253 | Pre: | |
254 | Mime or plaintext email passing in through standard input. Portions of | |
255 | the email may be encrypted. If the To: address contains the text | |
256 | "edward-ja", then the reply will contain a reply written in the | |
257 | Japanese language. There are other languages as well. The default | |
258 | language is English. | |
259 | ||
260 | Post: | |
261 | A reply email will be printed to standard output. The contents of the | |
262 | reply email depends on whether the original email was encrypted or not, | |
263 | has or doesn't have a signature, whether a public key used in the | |
264 | original message is provided or locally stored, and the language | |
265 | implied by the To: address in the original email. | |
266 | """ | |
267 | ||
60ccbaf4 | 268 | print_reply_only = handle_args() |
0bec96d6 | 269 | |
0a064403 AE |
270 | gpgme_ctx = get_gpg_context(edward_config.gnupghome, |
271 | edward_config.sign_with_key) | |
272 | ||
85a829fc AE |
273 | email_bytes = sys.stdin.buffer.read() |
274 | email_struct = parse_pgp_mime(email_bytes, gpgme_ctx) | |
adcef2f7 | 275 | |
85a829fc | 276 | email_to, email_from, email_subject = email_to_from_subject(email_bytes) |
60ccbaf4 | 277 | lang, reply_from = import_lang_pick_address(email_to, edward_config.hostname) |
fafa21c3 | 278 | |
d873ff48 AE |
279 | replyinfo_obj = ReplyInfo() |
280 | replyinfo_obj.replies = lang.replies | |
281 | ||
282 | prepare_for_reply(email_struct, replyinfo_obj) | |
ca37d0cb | 283 | get_key_from_fp(replyinfo_obj, gpgme_ctx) |
d873ff48 | 284 | reply_plaintext = write_reply(replyinfo_obj) |
adcef2f7 | 285 | |
2007103e | 286 | reply_mime = generate_encrypted_mime(reply_plaintext, email_from, \ |
ca37d0cb | 287 | email_subject, replyinfo_obj.encrypt_to_key, |
2007103e | 288 | gpgme_ctx) |
1fccb295 | 289 | |
60ccbaf4 AE |
290 | if print_reply_only == True: |
291 | print(reply_mime) | |
292 | else: | |
ba34a33c | 293 | send_reply(reply_mime, email_from, reply_from) |
c96f3837 | 294 | |
0bec96d6 | 295 | |
0a064403 | 296 | def get_gpg_context (gnupghome, sign_with_key_fp): |
a3d6aff8 AE |
297 | """ |
298 | This function returns the GPG context needed for encryption and signing. | |
299 | ||
300 | The context is needed by other functions which use GPG functionality. | |
301 | ||
302 | Args: | |
303 | gnupghome: The path to "~/.gnupg/" or its alternative. | |
304 | sign_with_key: The fingerprint of the key to sign with | |
305 | ||
306 | Returns: | |
307 | A gpgme context to be used for GPG functions. | |
308 | ||
309 | Post: | |
310 | the 'armor' flag is set to True and the list of signing keys contains | |
311 | the single specified key | |
312 | """ | |
0a064403 AE |
313 | |
314 | os.environ['GNUPGHOME'] = gnupghome | |
315 | ||
316 | gpgme_ctx = gpgme.Context() | |
317 | gpgme_ctx.armor = True | |
318 | ||
319 | try: | |
320 | sign_with_key = gpgme_ctx.get_key(sign_with_key_fp) | |
5f6f32b1 | 321 | except gpgme.GpgmeError: |
0a064403 AE |
322 | error("unable to load signing key. is the gnupghome " |
323 | + "and signing key properly set in the edward_config.py?") | |
324 | exit(1) | |
325 | ||
326 | gpgme_ctx.signers = [sign_with_key] | |
327 | ||
328 | return gpgme_ctx | |
329 | ||
330 | ||
85a829fc | 331 | def parse_pgp_mime (email_bytes, gpgme_ctx): |
a3d6aff8 AE |
332 | """Parses the email for mime payloads and decrypts/verfies signatures. |
333 | ||
334 | This function creates a representation of a mime or plaintext email with | |
335 | the EddyMsg class. It then splits each mime payload into one or more pieces | |
336 | which may be plain text or GPG data. It then decrypts encrypted parts and | |
337 | does some very basic signature verification on those parts. | |
338 | ||
339 | Args: | |
85a829fc | 340 | email_bytes: an email message in byte string format |
a3d6aff8 AE |
341 | gpgme_ctx: a gpgme context |
342 | ||
343 | Returns: | |
344 | A message as an instance of EddyMsg | |
345 | ||
346 | Post: | |
347 | the returned EddyMsg instance has split, decrypted, verified and pubkey | |
348 | imported payloads | |
349 | """ | |
394a1476 | 350 | |
85a829fc | 351 | email_struct = email.parser.BytesParser().parsebytes(email_bytes) |
394a1476 | 352 | |
928e3819 AE |
353 | eddymsg_obj = parse_mime(email_struct) |
354 | split_payloads(eddymsg_obj) | |
355 | gpg_on_payloads(eddymsg_obj, gpgme_ctx) | |
8bb4b0d5 | 356 | |
928e3819 | 357 | return eddymsg_obj |
0bec96d6 | 358 | |
0bec96d6 | 359 | |
56578eaf | 360 | def parse_mime(msg_struct): |
a3d6aff8 AE |
361 | """Translates python's email.parser format into an EddyMsg format |
362 | ||
363 | If the message is multi-part, then a recursive object is created, where | |
364 | each sub-part is also a EddyMsg instance. | |
365 | ||
366 | Args: | |
3dad6a92 | 367 | msg_struct: an email parsed with email.parser.BytesParser(), which can be |
a3d6aff8 AE |
368 | multi-part |
369 | ||
370 | Returns: | |
371 | an instance of EddyMsg, potentially a recursive one. | |
372 | """ | |
0bec96d6 | 373 | |
158ddbca | 374 | eddymsg_obj = get_subpart_data(msg_struct) |
8bb4b0d5 | 375 | |
56578eaf AE |
376 | if msg_struct.is_multipart() == True: |
377 | payloads = msg_struct.get_payload() | |
0bec96d6 | 378 | |
928e3819 AE |
379 | eddymsg_obj.multipart = True |
380 | eddymsg_obj.subparts = list(map(parse_mime, payloads)) | |
dd11a483 | 381 | |
928e3819 | 382 | return eddymsg_obj |
c267c233 | 383 | |
80119cab | 384 | |
2f4102b9 | 385 | def scan_and_split (payload_piece, match_name, pattern): |
a3d6aff8 AE |
386 | """This splits the payloads of an EddyMsg object into GPG and text parts. |
387 | ||
388 | An EddyMsg object's payload_pieces starts off as a list containing a single | |
389 | PayloadPiece object. This function returns a list of these objects which | |
390 | have been split into GPG data and regular text, if such splits need to be/ | |
391 | can be made. | |
392 | ||
393 | Args: | |
394 | payload_piece: a single payload or a split part of a payload | |
2f4102b9 | 395 | match_name: the type of data to try to spit out from the payload piece |
a3d6aff8 AE |
396 | pattern: the search pattern to be used for finding that type of data |
397 | ||
398 | Returns: | |
399 | a list of objects of the PayloadPiece class, in the order that the | |
400 | string part of payload_piece originally was, broken up according to | |
401 | matches specified by 'pattern'. | |
402 | """ | |
cf75de65 | 403 | |
a5d37d44 | 404 | # don't try to re-split pieces containing gpg data |
0fd3389f | 405 | if payload_piece.piece_type != TxtType.text: |
a5d37d44 AE |
406 | return [payload_piece] |
407 | ||
56578eaf AE |
408 | flags = re.DOTALL | re.MULTILINE |
409 | matches = re.search("(?P<beginning>.*?)(?P<match>" + pattern + | |
410 | ")(?P<rest>.*)", payload_piece.string, flags=flags) | |
86663388 | 411 | |
56578eaf AE |
412 | if matches == None: |
413 | pieces = [payload_piece] | |
c96f3837 | 414 | |
56578eaf | 415 | else: |
d437f8b2 | 416 | |
56578eaf AE |
417 | beginning = PayloadPiece() |
418 | beginning.string = matches.group('beginning') | |
419 | beginning.piece_type = payload_piece.piece_type | |
d437f8b2 | 420 | |
56578eaf AE |
421 | match = PayloadPiece() |
422 | match.string = matches.group('match') | |
2f4102b9 | 423 | match.piece_type = match_name |
d437f8b2 | 424 | |
56578eaf AE |
425 | rest = PayloadPiece() |
426 | rest.string = matches.group('rest') | |
427 | rest.piece_type = payload_piece.piece_type | |
d437f8b2 | 428 | |
2f4102b9 | 429 | more_pieces = scan_and_split(rest, match_name, pattern) |
4615b156 | 430 | pieces = [beginning, match ] + more_pieces |
d437f8b2 | 431 | |
56578eaf | 432 | return pieces |
d437f8b2 | 433 | |
d437f8b2 | 434 | |
56578eaf | 435 | def get_subpart_data (part): |
a32a1e11 | 436 | """This function grabs information from a mime part. |
a3d6aff8 | 437 | |
3dad6a92 | 438 | It copies needed data from an email.parser.BytesParser() object over to an |
a32a1e11 | 439 | EddyMsg object. |
a3d6aff8 AE |
440 | |
441 | Args: | |
3dad6a92 | 442 | part: an email.parser.BytesParser() object |
a3d6aff8 AE |
443 | |
444 | Returns: | |
a32a1e11 | 445 | an EddyMsg() object |
a3d6aff8 | 446 | """ |
0bec96d6 | 447 | |
6d8faaa7 | 448 | obj = EddyMsg() |
56578eaf | 449 | |
84ff9773 AE |
450 | mime_decoded_bytes = part.get_payload(decode=True) |
451 | charset = part.get_content_charset() | |
56578eaf AE |
452 | |
453 | # your guess is as good as a-myy-ee-ine... | |
6d8faaa7 AE |
454 | if charset == None: |
455 | charset = 'utf-8' | |
56578eaf | 456 | |
84ff9773 AE |
457 | payload_string = part.as_string() |
458 | if payload_string != None: | |
9c348860 AE |
459 | # convert each isolated carriage return or line feed to carriage return + line feed |
460 | payload_string_crlf = re.sub(r'\n', '\r\n', re.sub(r'\r', '\n', re.sub(r'\r\n', '\n', payload_string))) | |
461 | obj.payload_bytes = payload_string_crlf.encode(charset) | |
84ff9773 AE |
462 | |
463 | obj.filename = part.get_filename() | |
464 | obj.content_type = part.get_content_type() | |
c00930e9 | 465 | obj.content_disposition = part['content-disposition'] |
84ff9773 AE |
466 | obj.description_list = part['content-description'] |
467 | ||
6d8faaa7 | 468 | if mime_decoded_bytes != None: |
0eb75d9c AE |
469 | try: |
470 | payload = PayloadPiece() | |
6d8faaa7 | 471 | payload.string = mime_decoded_bytes.decode(charset) |
0fd3389f | 472 | payload.piece_type = TxtType.text |
0eb75d9c AE |
473 | |
474 | obj.payload_pieces = [payload] | |
475 | except UnicodeDecodeError: | |
476 | pass | |
56578eaf AE |
477 | |
478 | return obj | |
479 | ||
480 | ||
928e3819 | 481 | def do_to_eddys_pieces (function_to_do, eddymsg_obj, data): |
a3d6aff8 AE |
482 | """A function which maps another function onto a message's subparts. |
483 | ||
484 | This is a higer-order function which recursively performs a specified | |
485 | function on each subpart of a multi-part message. Each single-part sub-part | |
486 | has the function applied to it. This function also works if the part passed | |
487 | in is single-part. | |
488 | ||
489 | Args: | |
490 | function_to_do: function to perform on sub-parts | |
491 | eddymsg_obj: a single part or multi-part EddyMsg object | |
492 | data: a second argument to pass to 'function_to_do' | |
493 | ||
494 | Returns: | |
495 | Nothing | |
496 | ||
497 | Post: | |
498 | The passed-in EddyMsg object is transformed recursively on its | |
499 | sub-parts according to 'function_to_do'. | |
500 | """ | |
56578eaf | 501 | |
928e3819 AE |
502 | if eddymsg_obj.multipart == True: |
503 | for sub in eddymsg_obj.subparts: | |
d873ff48 | 504 | do_to_eddys_pieces(function_to_do, sub, data) |
394a1476 | 505 | else: |
928e3819 | 506 | function_to_do(eddymsg_obj, data) |
dd11a483 AE |
507 | |
508 | ||
928e3819 | 509 | def split_payloads (eddymsg_obj): |
a3d6aff8 AE |
510 | """Splits all (sub-)payloads of a message into GPG data and regular text. |
511 | ||
512 | Recursively performs payload splitting on all sub-parts of an EddyMsg | |
513 | object into the various GPG data types, such as GPG messages, public key | |
514 | blocks and signed text. | |
515 | ||
516 | Args: | |
517 | eddymsg_obj: an instance of EddyMsg | |
518 | ||
519 | Returns: | |
520 | Nothing | |
521 | ||
522 | Pre: | |
523 | The EddyMsg object has payloads that are unsplit (by may be split).. | |
524 | ||
525 | Post: | |
526 | The EddyMsg object's payloads are all split into GPG and non-GPG parts. | |
527 | """ | |
a5d37d44 | 528 | |
2f4102b9 AE |
529 | for match_pair in match_pairs: |
530 | do_to_eddys_pieces(split_payload_pieces, eddymsg_obj, match_pair) | |
a5d37d44 | 531 | |
a5d37d44 | 532 | |
2f4102b9 | 533 | def split_payload_pieces (eddymsg_obj, match_pair): |
a3d6aff8 AE |
534 | """A helper function for split_payloads(); works on PayloadPiece objects. |
535 | ||
536 | This function splits up PayloadPiece objects into multipe PayloadPiece | |
537 | objects and replaces the EddyMsg object's previous list of payload pieces | |
538 | with the new split up one. | |
539 | ||
540 | Args: | |
541 | eddymsg_obj: a single-part EddyMsg object. | |
2f4102b9 | 542 | match_pair: a tuple from the match_pairs list, which specifies a match |
a3d6aff8 AE |
543 | name and a match pattern. |
544 | ||
545 | Returns: | |
546 | Nothing | |
547 | ||
548 | Pre: | |
549 | The payload piece(s) of an EddyMsg object may be already split or | |
550 | unsplit. | |
551 | ||
552 | Post: | |
553 | The EddyMsg object's payload piece(s) are split into a list of pieces | |
2f4102b9 | 554 | if matches of the match_pair are found. |
a3d6aff8 | 555 | """ |
a5d37d44 | 556 | |
2f4102b9 | 557 | (match_name, pattern) = match_pair |
a5d37d44 AE |
558 | |
559 | new_pieces_list = [] | |
928e3819 | 560 | for piece in eddymsg_obj.payload_pieces: |
a5d37d44 AE |
561 | new_pieces_list += scan_and_split(piece, match_name, pattern) |
562 | ||
928e3819 | 563 | eddymsg_obj.payload_pieces = new_pieces_list |
a5d37d44 AE |
564 | |
565 | ||
928e3819 | 566 | def gpg_on_payloads (eddymsg_obj, gpgme_ctx, prev_parts=[]): |
a3d6aff8 AE |
567 | """Performs GPG operations on the GPG parts of the message |
568 | ||
569 | This function decrypts text, verifies signatures, and imports public keys | |
570 | included in an email. | |
571 | ||
572 | Args: | |
573 | eddymsg_obj: an EddyMsg object with its payload_pieces split into GPG | |
574 | and non-GPG sections by split_payloads() | |
575 | gpgme_ctx: a gpgme context | |
576 | ||
577 | prev_parts: a list of mime parts that occur before the eddymsg_obj | |
578 | part, under the same multi-part mime part. This is used for | |
579 | verifying detached signatures. For the root mime part, this should | |
580 | be an empty list, which is the default value if this paramater is | |
581 | omitted. | |
582 | ||
583 | Return: | |
584 | Nothing | |
585 | ||
586 | Pre: | |
587 | eddymsg_obj should have its payloads split into gpg and non-gpg pieces. | |
588 | ||
589 | Post: | |
c035a008 AE |
590 | Decryption, verification and key imports occur. the gpg_data members of |
591 | PayloadPiece objects get filled in with GPGData objects with some of | |
592 | their attributes set. | |
a3d6aff8 | 593 | """ |
38738401 | 594 | |
928e3819 | 595 | if eddymsg_obj.multipart == True: |
101d54a8 | 596 | prev_parts=[] |
928e3819 | 597 | for sub in eddymsg_obj.subparts: |
101d54a8 AE |
598 | gpg_on_payloads (sub, gpgme_ctx, prev_parts) |
599 | prev_parts += [sub] | |
38738401 | 600 | |
d873ff48 | 601 | return |
38738401 | 602 | |
928e3819 | 603 | for piece in eddymsg_obj.payload_pieces: |
38738401 | 604 | |
0fd3389f | 605 | if piece.piece_type == TxtType.text: |
38738401 AE |
606 | # don't transform the plaintext. |
607 | pass | |
608 | ||
0fd3389f | 609 | elif piece.piece_type == TxtType.message: |
b4c116d5 AE |
610 | piece.gpg_data = GPGData() |
611 | ||
c035a008 | 612 | (plaintext_b, sigs, sigkey_missing, key_cannot_encrypt) = decrypt_block(piece.string, gpgme_ctx) |
b4c116d5 AE |
613 | |
614 | piece.gpg_data.sigkey_missing = sigkey_missing | |
c035a008 | 615 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt |
38738401 | 616 | |
85a829fc | 617 | if plaintext_b: |
b23e171d | 618 | piece.gpg_data.decrypted = True |
38738401 AE |
619 | piece.gpg_data.sigs = sigs |
620 | # recurse! | |
85a829fc | 621 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext_b, gpgme_ctx) |
3a753fd0 AE |
622 | continue |
623 | ||
624 | # if not encrypted, check to see if this is an armored signature. | |
c035a008 | 625 | (plaintext_b, sigs, sigkey_missing, key_cannot_encrypt) = verify_sig_message(piece.string, gpgme_ctx) |
b4c116d5 AE |
626 | |
627 | piece.gpg_data.sigkey_missing = sigkey_missing | |
c035a008 | 628 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt |
3a753fd0 | 629 | |
85a829fc | 630 | if plaintext_b: |
0fd3389f | 631 | piece.piece_type = TxtType.signature |
3a753fd0 AE |
632 | piece.gpg_data.sigs = sigs |
633 | # recurse! | |
85a829fc | 634 | piece.gpg_data.plainobj = parse_pgp_mime(plaintext_b, gpgme_ctx) |
129543c3 | 635 | |
0fd3389f | 636 | elif piece.piece_type == TxtType.pubkey: |
c035a008 AE |
637 | piece.gpg_data = GPGData() |
638 | ||
639 | (key_fps, key_cannot_encrypt) = add_gpg_key(piece.string, gpgme_ctx) | |
640 | ||
641 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt | |
8f61c66a | 642 | |
f8ee6bd3 | 643 | if key_fps != []: |
f8ee6bd3 | 644 | piece.gpg_data.keys = key_fps |
129543c3 | 645 | |
0fd3389f | 646 | elif piece.piece_type == TxtType.detachedsig: |
b4c116d5 AE |
647 | piece.gpg_data = GPGData() |
648 | ||
101d54a8 | 649 | for prev in prev_parts: |
c035a008 | 650 | (sig_fps, sigkey_missing, key_cannot_encrypt) = verify_detached_signature(piece.string, prev.payload_bytes, gpgme_ctx) |
b4c116d5 AE |
651 | |
652 | piece.gpg_data.sigkey_missing = sigkey_missing | |
c035a008 | 653 | piece.gpg_data.key_cannot_encrypt = key_cannot_encrypt |
101d54a8 | 654 | |
6d240f68 | 655 | if sig_fps != []: |
6d240f68 AE |
656 | piece.gpg_data.sigs = sig_fps |
657 | piece.gpg_data.plainobj = prev | |
658 | break | |
7e18f14d | 659 | |
38738401 AE |
660 | else: |
661 | pass | |
662 | ||
663 | ||
928e3819 | 664 | def prepare_for_reply (eddymsg_obj, replyinfo_obj): |
67691346 AE |
665 | """Updates replyinfo_obj with info on the message's GPG success/failures |
666 | ||
667 | This function marks replyinfo_obj with information about whether encrypted | |
668 | text in eddymsg_obj was successfully decrypted, signatures were verified | |
669 | and whether a public key was found or not. | |
670 | ||
671 | Args: | |
672 | eddymsg_obj: a message in the EddyMsg format | |
673 | replyinfo_obj: an instance of ReplyInfo | |
674 | ||
675 | Returns: | |
676 | Nothing | |
677 | ||
678 | Pre: | |
679 | eddymsg_obj has had its gpg_data created by gpg_on_payloads | |
680 | ||
681 | Post: | |
682 | replyinfo_obj has been updated with info about decryption/sig | |
683 | verififcation status, etc. However the desired key isn't imported until | |
684 | later, so the success or failure of that updates the values set here. | |
685 | """ | |
dd11a483 | 686 | |
928e3819 | 687 | do_to_eddys_pieces(prepare_for_reply_pieces, eddymsg_obj, replyinfo_obj) |
56578eaf | 688 | |
928e3819 | 689 | def prepare_for_reply_pieces (eddymsg_obj, replyinfo_obj): |
67691346 AE |
690 | """A helper function for prepare_for_reply |
691 | ||
692 | It updates replyinfo_obj with GPG success/failure information, when | |
693 | supplied a single-part EddyMsg object. | |
694 | ||
695 | Args: | |
696 | eddymsg_obj: a single-part message in the EddyMsg format | |
697 | replyinfo_obj: an object which holds information about the message's | |
698 | GPG status | |
699 | ||
700 | Returns: | |
701 | Nothing | |
702 | ||
703 | Pre: | |
704 | eddymsg_obj is a single-part message. (it may be a part of a multi-part | |
705 | message.) It has had its gpg_data created by gpg_on_payloads if it has | |
706 | gpg data. | |
707 | ||
708 | Post: | |
709 | replyinfo_obj has been updated with gpg success/failure information | |
710 | """ | |
56578eaf | 711 | |
928e3819 | 712 | for piece in eddymsg_obj.payload_pieces: |
0fd3389f | 713 | if piece.piece_type == TxtType.text: |
d873ff48 AE |
714 | # don't quote the plaintext part. |
715 | pass | |
716 | ||
0fd3389f | 717 | elif piece.piece_type == TxtType.message: |
05683768 | 718 | prepare_for_reply_message(piece, replyinfo_obj) |
d873ff48 | 719 | |
0fd3389f | 720 | elif piece.piece_type == TxtType.pubkey: |
05683768 | 721 | prepare_for_reply_pubkey(piece, replyinfo_obj) |
6906d46d | 722 | |
0fd3389f AE |
723 | elif (piece.piece_type == TxtType.detachedsig) \ |
724 | or (piece.piece_type == TxtType.signature): | |
05683768 | 725 | prepare_for_reply_sig(piece, replyinfo_obj) |
d873ff48 | 726 | |
d873ff48 | 727 | |
05683768 | 728 | def prepare_for_reply_message (piece, replyinfo_obj): |
67691346 AE |
729 | """Helper function for prepare_for_reply() |
730 | ||
731 | This function is called when the piece_type of a payload piece is | |
9af26cb8 AE |
732 | TxtType.message, or GPG Message block. This should be encrypted text. If |
733 | the encryted block is correclty signed, a sig will be attached to | |
734 | .target_key unless there is already one there. | |
67691346 AE |
735 | |
736 | Args: | |
737 | piece: a PayloadPiece object. | |
738 | replyinfo_obj: object which gets updated with decryption status, etc. | |
739 | ||
67691346 AE |
740 | Returns: |
741 | Nothing | |
742 | ||
743 | Pre: | |
0fd3389f | 744 | the piece.payload_piece value should be TxtType.message. |
67691346 AE |
745 | |
746 | Post: | |
b4c116d5 | 747 | replyinfo_obj gets updated with decryption status, signing status, a |
c035a008 AE |
748 | potential signing key, posession status of the public key for the |
749 | signature and encryption capability status if that key is missing. | |
67691346 | 750 | """ |
44fe39b7 | 751 | |
c035a008 | 752 | if piece.gpg_data.plainobj == None: |
4e2c66f7 | 753 | replyinfo_obj.decrypt_failure = True |
05683768 AE |
754 | return |
755 | ||
b4c116d5 | 756 | replyinfo_obj.decrypt_success = True |
05683768 AE |
757 | |
758 | # we already have a key (and a message) | |
759 | if replyinfo_obj.target_key != None: | |
760 | return | |
761 | ||
c035a008 | 762 | if piece.gpg_data.sigs == []: |
b4c116d5 AE |
763 | if piece.gpg_data.sigkey_missing == True: |
764 | replyinfo_obj.sigkey_missing = True | |
9af26cb8 | 765 | |
c035a008 AE |
766 | if piece.gpg_data.key_cannot_encrypt == True: |
767 | replyinfo_obj.key_cannot_encrypt = True | |
768 | ||
05683768 AE |
769 | # only include a signed message in the reply. |
770 | get_signed_part = True | |
771 | ||
c035a008 AE |
772 | else: |
773 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
774 | replyinfo_obj.sig_success = True | |
775 | get_signed_part = False | |
776 | ||
8c3e5397 | 777 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, get_signed_part) |
05683768 AE |
778 | |
779 | # to catch public keys in encrypted blocks | |
780 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
781 | ||
782 | ||
783 | def prepare_for_reply_pubkey (piece, replyinfo_obj): | |
67691346 AE |
784 | """Helper function for prepare_for_reply(). Marks pubkey import status. |
785 | ||
786 | Marks replyinfo_obj with pub key import status. | |
787 | ||
788 | Args: | |
789 | piece: a PayloadPiece object | |
790 | replyinfo_obj: a ReplyInfo object | |
791 | ||
792 | Pre: | |
0fd3389f | 793 | piece.piece_type should be set to TxtType.pubkey . |
67691346 AE |
794 | |
795 | Post: | |
796 | replyinfo_obj has its fields updated. | |
797 | """ | |
05683768 | 798 | |
c035a008 AE |
799 | if piece.gpg_data.keys == []: |
800 | if piece.gpg_data.key_cannot_encrypt == True: | |
801 | replyinfo_obj.key_cannot_encrypt = True | |
05683768 | 802 | else: |
b4c116d5 | 803 | replyinfo_obj.pubkey_success = True |
05683768 | 804 | |
3ceb92e5 AE |
805 | # prefer public key as a fallback for the encrypted reply |
806 | replyinfo_obj.fallback_target_key = piece.gpg_data.keys[0] | |
05683768 AE |
807 | |
808 | ||
809 | def prepare_for_reply_sig (piece, replyinfo_obj): | |
67691346 AE |
810 | """Helper function for prepare_for_reply(). Marks sig verification status. |
811 | ||
812 | Marks replyinfo_obj with signature verification status. | |
813 | ||
814 | Args: | |
815 | piece: a PayloadPiece object | |
816 | replyinfo_obj: a ReplyInfo object | |
817 | ||
818 | Pre: | |
0fd3389f AE |
819 | piece.piece_type should be set to TxtType.signature, or |
820 | TxtType.detachedsig . | |
67691346 AE |
821 | |
822 | Post: | |
823 | replyinfo_obj has its fields updated. | |
824 | """ | |
05683768 | 825 | |
c035a008 | 826 | if piece.gpg_data.sigs == []: |
32a8996f | 827 | replyinfo_obj.sig_failure = True |
b4c116d5 AE |
828 | |
829 | if piece.gpg_data.sigkey_missing == True: | |
830 | replyinfo_obj.sigkey_missing = True | |
831 | ||
c035a008 AE |
832 | if piece.gpg_data.key_cannot_encrypt == True: |
833 | replyinfo_obj.key_cannot_encrypt = True | |
834 | ||
05683768 AE |
835 | else: |
836 | replyinfo_obj.sig_success = True | |
837 | ||
838 | if replyinfo_obj.fallback_target_key == None: | |
839 | replyinfo_obj.fallback_target_key = piece.gpg_data.sigs[0] | |
6906d46d | 840 | |
c230113e AE |
841 | if (piece.piece_type == TxtType.signature): |
842 | # to catch public keys in signature blocks | |
843 | prepare_for_reply(piece.gpg_data.plainobj, replyinfo_obj) | |
844 | ||
6906d46d | 845 | |
8c3e5397 AE |
846 | def flatten_decrypted_payloads (eddymsg_obj, replyinfo_obj, get_signed_part): |
847 | """For creating a string representation of a signed, encrypted part. | |
39e2c525 | 848 | |
8c3e5397 AE |
849 | When given a decrypted payload, it will add either the plaintext or signed |
850 | plaintext to the reply message, depeding on 'get_signed_part'. This is | |
851 | useful for ensuring that the reply message only comes from a signed and | |
852 | ecrypted GPG message. It also sets the target_key for encrypting the reply | |
853 | if it's told to get signed text only. | |
39e2c525 AE |
854 | |
855 | Args: | |
856 | eddymsg_obj: the message in EddyMsg format created by decrypting GPG | |
857 | text | |
8c3e5397 AE |
858 | replyinfo_obj: a ReplyInfo object for holding the message to quote and |
859 | the target_key to encrypt to. | |
39e2c525 AE |
860 | get_signed_part: True if we should only include text that contains a |
861 | further signature. If False, then include plain text. | |
862 | ||
863 | Returns: | |
8c3e5397 | 864 | Nothing |
39e2c525 AE |
865 | |
866 | Pre: | |
867 | The EddyMsg instance passed in should be a piece.gpg_data.plainobj | |
868 | which represents decrypted text. It may or may not be signed on that | |
869 | level. | |
d873ff48 | 870 | |
8c3e5397 AE |
871 | Post: |
872 | the ReplyInfo instance may have a new 'target_key' set and its | |
873 | 'msg_to_quote' will be updated with (possibly signed) plaintext, if any | |
874 | could be found. | |
875 | """ | |
d873ff48 | 876 | |
0aa88c27 | 877 | if eddymsg_obj == None: |
8c3e5397 | 878 | return |
0aa88c27 | 879 | |
0402995a | 880 | # recurse on multi-part mime |
928e3819 AE |
881 | if eddymsg_obj.multipart == True: |
882 | for sub in eddymsg_obj.subparts: | |
8c3e5397 | 883 | flatten_decrypted_payloads(sub, replyinfo_obj, get_signed_part) |
d873ff48 | 884 | |
928e3819 | 885 | for piece in eddymsg_obj.payload_pieces: |
0402995a | 886 | if (get_signed_part): |
0fd3389f AE |
887 | if ((piece.piece_type == TxtType.detachedsig) \ |
888 | or (piece.piece_type == TxtType.signature)) \ | |
b4c116d5 AE |
889 | and (piece.gpg_data != None) \ |
890 | and (piece.gpg_data.plainobj != None): | |
8c3e5397 AE |
891 | flatten_decrypted_payloads(piece.gpg_data.plainobj, replyinfo_obj, False) |
892 | replyinfo_obj.target_key = piece.gpg_data.sigs[0] | |
c3d417bf AE |
893 | break |
894 | else: | |
c00930e9 AE |
895 | if (eddymsg_obj.content_disposition == None \ |
896 | or not eddymsg_obj.content_disposition.startswith("attachment")) \ | |
897 | and piece.piece_type == TxtType.text: | |
8c3e5397 | 898 | replyinfo_obj.msg_to_quote += piece.string |
d873ff48 AE |
899 | |
900 | ||
013f7cb8 | 901 | def get_key_from_fp (replyinfo_obj, gpgme_ctx): |
39e2c525 AE |
902 | """Obtains a public key object from a key fingerprint |
903 | ||
ca37d0cb AE |
904 | If the .target_key is not set, then we use .fallback_target_key, if |
905 | available. | |
39e2c525 AE |
906 | |
907 | Args: | |
908 | replyinfo_obj: ReplyInfo instance | |
909 | gpgme_ctx: the gpgme context | |
910 | ||
911 | Return: | |
c035a008 | 912 | Nothing |
39e2c525 AE |
913 | |
914 | Pre: | |
915 | Loading a key requires that we have the public key imported. This | |
916 | requires that they email contains the pub key block, or that it was | |
917 | previously sent to edward. | |
918 | ||
919 | Post: | |
ca37d0cb AE |
920 | If the key can be loaded, then replyinfo_obj.reply_to_key points to the |
921 | public key object. If the key cannot be loaded, then the replyinfo_obj | |
c035a008 AE |
922 | is marked as having no public key available. If the key is not capable |
923 | of encryption, it will not be used, and replyinfo_obj will be marked | |
924 | accordingly. | |
39e2c525 | 925 | """ |
013f7cb8 | 926 | |
ca37d0cb AE |
927 | for key in (replyinfo_obj.target_key, replyinfo_obj.fallback_target_key): |
928 | if key != None: | |
929 | try: | |
930 | encrypt_to_key = gpgme_ctx.get_key(key) | |
c035a008 AE |
931 | |
932 | except gpgme.GpgmeError: | |
933 | continue | |
934 | ||
c5492aa9 | 935 | if is_key_usable(encrypt_to_key): |
ca37d0cb | 936 | replyinfo_obj.encrypt_to_key = encrypt_to_key |
b4c116d5 | 937 | replyinfo_obj.have_reply_key = True |
c035a008 | 938 | replyinfo_obj.key_can_encrypt = True |
ca37d0cb | 939 | return |
013f7cb8 | 940 | |
c035a008 AE |
941 | else: |
942 | replyinfo_obj.key_cannot_encrypt = True | |
943 | ||
013f7cb8 | 944 | |
013f7cb8 | 945 | |
d873ff48 | 946 | def write_reply (replyinfo_obj): |
39e2c525 AE |
947 | """Write the reply email body about the GPG successes/failures. |
948 | ||
949 | The reply is about whether decryption, sig verification and key | |
950 | import/loading was successful or failed. If text was successfully decrypted | |
951 | and verified, then the first instance of such text will be included in | |
952 | quoted form. | |
953 | ||
954 | Args: | |
955 | replyinfo_obj: contains details of GPG processing status | |
956 | ||
957 | Returns: | |
958 | the plaintext message to be sent to the user | |
959 | ||
960 | Pre: | |
961 | replyinfo_obj should be populated with info about GPG processing status. | |
962 | """ | |
d873ff48 AE |
963 | |
964 | reply_plain = "" | |
965 | ||
cfcc211c AE |
966 | if (replyinfo_obj.pubkey_success == True): |
967 | reply_plain += replyinfo_obj.replies['greeting'] | |
968 | reply_plain += "\n\n" | |
969 | ||
371911ad | 970 | |
b4c116d5 | 971 | if replyinfo_obj.decrypt_success == True: |
234f607b | 972 | debug('decrypt success') |
d873ff48 | 973 | reply_plain += replyinfo_obj.replies['success_decrypt'] |
2694709a | 974 | |
b4c116d5 | 975 | if (replyinfo_obj.sig_success == True) and (replyinfo_obj.have_reply_key == True): |
234f607b | 976 | debug('message quoted') |
cfcc211c AE |
977 | reply_plain += replyinfo_obj.replies['space'] |
978 | reply_plain += replyinfo_obj.replies['quote_follows'] | |
979 | reply_plain += "\n\n" | |
2694709a AE |
980 | quoted_text = email_quote_text(replyinfo_obj.msg_to_quote) |
981 | reply_plain += quoted_text | |
cfcc211c AE |
982 | |
983 | reply_plain += "\n\n" | |
d873ff48 | 984 | |
4e2c66f7 | 985 | elif replyinfo_obj.decrypt_failure == True: |
234f607b | 986 | debug('decrypt failure') |
d873ff48 | 987 | reply_plain += replyinfo_obj.replies['failed_decrypt'] |
b4c116d5 | 988 | reply_plain += "\n\n" |
d873ff48 | 989 | |
371911ad | 990 | |
d873ff48 | 991 | if replyinfo_obj.sig_success == True: |
234f607b | 992 | debug('signature success') |
d873ff48 | 993 | reply_plain += replyinfo_obj.replies['sig_success'] |
b4c116d5 | 994 | reply_plain += "\n\n" |
d873ff48 | 995 | |
32a8996f | 996 | elif replyinfo_obj.sig_failure == True: |
234f607b | 997 | debug('signature failure') |
d873ff48 | 998 | reply_plain += replyinfo_obj.replies['sig_failure'] |
b4c116d5 | 999 | reply_plain += "\n\n" |
d873ff48 | 1000 | |
371911ad | 1001 | |
b4c116d5 | 1002 | if (replyinfo_obj.pubkey_success == True): |
234f607b | 1003 | debug('public key received') |
b4c116d5 | 1004 | reply_plain += replyinfo_obj.replies['public_key_received'] |
d873ff48 | 1005 | reply_plain += "\n\n" |
d873ff48 | 1006 | |
b4c116d5 | 1007 | elif (replyinfo_obj.sigkey_missing == True): |
234f607b | 1008 | debug('no public key') |
b4c116d5 | 1009 | reply_plain += replyinfo_obj.replies['no_public_key'] |
d873ff48 | 1010 | reply_plain += "\n\n" |
d873ff48 | 1011 | |
c035a008 AE |
1012 | elif (replyinfo_obj.key_can_encrypt == False) \ |
1013 | and (replyinfo_obj.key_cannot_encrypt == True): | |
1014 | debug('bad public key') | |
1015 | reply_plain += replyinfo_obj.replies['no_public_key'] | |
1016 | reply_plain += "\n\n" | |
1017 | ||
d873ff48 | 1018 | |
4e2c66f7 AE |
1019 | if (reply_plain == ""): |
1020 | debug('plaintext message') | |
1021 | reply_plain += replyinfo_obj.replies['failed_decrypt'] | |
1022 | reply_plain += "\n\n" | |
1023 | ||
1024 | ||
d873ff48 | 1025 | reply_plain += replyinfo_obj.replies['signature'] |
b4c116d5 | 1026 | reply_plain += "\n\n" |
56578eaf | 1027 | |
d873ff48 | 1028 | return reply_plain |
56578eaf AE |
1029 | |
1030 | ||
8f61c66a | 1031 | def add_gpg_key (key_block, gpgme_ctx): |
39e2c525 AE |
1032 | """Adds a GPG pubkey to the local keystore |
1033 | ||
1034 | This adds keys received through email into the key store so they can be | |
1035 | used later. | |
1036 | ||
1037 | Args: | |
1038 | key_block: the string form of the ascii-armored public key block | |
1039 | gpgme_ctx: the gpgme context | |
1040 | ||
1041 | Returns: | |
c035a008 AE |
1042 | the fingerprint(s) of the imported key(s) which can be used for |
1043 | encryption, and a boolean marking whether none of the keys are capable | |
1044 | of encryption. | |
39e2c525 | 1045 | """ |
c267c233 | 1046 | |
8f61c66a | 1047 | fp = io.BytesIO(key_block.encode('ascii')) |
c267c233 | 1048 | |
89c08329 AE |
1049 | try: |
1050 | result = gpgme_ctx.import_(fp) | |
1051 | imports = result.imports | |
1052 | except gpgme.GpgmeError: | |
1053 | imports = [] | |
c267c233 | 1054 | |
f8ee6bd3 | 1055 | key_fingerprints = [] |
c035a008 AE |
1056 | key_cannot_encrypt = False |
1057 | ||
1058 | for import_res in imports: | |
1059 | fingerprint = import_res[0] | |
1060 | ||
1061 | try: | |
1062 | key_obj = gpgme_ctx.get_key(fingerprint) | |
1063 | except: | |
494c6e50 | 1064 | key_obj = None |
c267c233 | 1065 | |
494c6e50 | 1066 | if key_obj != None and is_key_usable(key_obj): |
f8ee6bd3 | 1067 | key_fingerprints += [fingerprint] |
c035a008 | 1068 | key_cannot_encrypt = False |
c267c233 | 1069 | |
e49673aa | 1070 | debug("added gpg key: " + fingerprint) |
ec1e779a | 1071 | |
c035a008 AE |
1072 | elif key_fingerprints == []: |
1073 | key_cannot_encrypt = True | |
1074 | ||
1075 | return (key_fingerprints, key_cannot_encrypt) | |
ec1e779a AE |
1076 | |
1077 | ||
3a753fd0 | 1078 | def verify_sig_message (msg_block, gpgme_ctx): |
39e2c525 AE |
1079 | """Verifies the signature of a signed, ascii-armored block of text. |
1080 | ||
1081 | It encodes the string into ascii, since binary GPG files are currently | |
1082 | unsupported, and alternative, the ascii-armored format is encodable into | |
1083 | ascii. | |
1084 | ||
1085 | Args: | |
1086 | msg_block: a GPG Message block in string form. It may be encrypted or | |
1087 | not. If it is encrypted, it will return empty results. | |
1088 | gpgme_ctx: the gpgme context | |
1089 | ||
1090 | Returns: | |
85a829fc | 1091 | A tuple containing the plaintext bytes of the signed part, the list of |
c035a008 AE |
1092 | fingerprints of encryption-capable keys signing the data, a boolean |
1093 | marking whether edward is missing all public keys for validating any of | |
1094 | the signatures, and a boolean marking whether all sigs' keys are | |
1095 | incapable of encryption. If verification failed, perhaps because the | |
1096 | message was also encrypted, sensible default values are returned. | |
39e2c525 | 1097 | """ |
3a753fd0 AE |
1098 | |
1099 | block_b = io.BytesIO(msg_block.encode('ascii')) | |
1100 | plain_b = io.BytesIO() | |
1101 | ||
1102 | try: | |
1103 | sigs = gpgme_ctx.verify(block_b, None, plain_b) | |
5f6f32b1 | 1104 | except gpgme.GpgmeError: |
c035a008 | 1105 | return ("",[],False,False) |
3a753fd0 | 1106 | |
85a829fc | 1107 | plaintext_b = plain_b.getvalue() |
3a753fd0 | 1108 | |
c035a008 | 1109 | (fingerprints, sigkey_missing, key_cannot_encrypt) = get_signature_fp(sigs, gpgme_ctx) |
9af26cb8 | 1110 | |
c035a008 | 1111 | return (plaintext_b, fingerprints, sigkey_missing, key_cannot_encrypt) |
3a753fd0 AE |
1112 | |
1113 | ||
101d54a8 | 1114 | def verify_detached_signature (detached_sig, plaintext_bytes, gpgme_ctx): |
39e2c525 AE |
1115 | """Verifies the signature of a detached signature. |
1116 | ||
1117 | This requires the signature part and the signed part as separate arguments. | |
1118 | ||
1119 | Args: | |
1120 | detached_sig: the signature part of the detached signature | |
1121 | plaintext_bytes: the byte form of the message being signed. | |
1122 | gpgme_ctx: the gpgme context | |
1123 | ||
1124 | Returns: | |
c035a008 AE |
1125 | A tuple containging a list of encryption capable signing fingerprints |
1126 | if the signature verification was sucessful, a boolean marking whether | |
1127 | edward is missing all public keys for validating any of the signatures, | |
1128 | and a boolean marking whether all signing keys are incapable of | |
1129 | encryption. Otherwise, a tuple containing an empty list and True are | |
1130 | returned. | |
39e2c525 | 1131 | """ |
101d54a8 AE |
1132 | |
1133 | detached_sig_fp = io.BytesIO(detached_sig.encode('ascii')) | |
1134 | plaintext_fp = io.BytesIO(plaintext_bytes) | |
101d54a8 | 1135 | |
ff7aeb3d | 1136 | try: |
c035a008 | 1137 | sigs = gpgme_ctx.verify(detached_sig_fp, plaintext_fp, None) |
ff7aeb3d | 1138 | except gpgme.GpgmeError: |
c035a008 | 1139 | return ([],False,False) |
101d54a8 | 1140 | |
c035a008 | 1141 | (fingerprints, sigkey_missing, key_cannot_encrypt) = get_signature_fp(sigs, gpgme_ctx) |
101d54a8 | 1142 | |
c035a008 | 1143 | return (fingerprints, sigkey_missing, key_cannot_encrypt) |
101d54a8 AE |
1144 | |
1145 | ||
5b3053c1 | 1146 | def decrypt_block (msg_block, gpgme_ctx): |
9af26cb8 | 1147 | """Decrypts a block of GPG text and verifies any included sigatures. |
39e2c525 AE |
1148 | |
1149 | Some encypted messages have embeded signatures, so those are verified too. | |
1150 | ||
1151 | Args: | |
1152 | msg_block: the encrypted(/signed) text | |
1153 | gpgme_ctx: the gpgme context | |
1154 | ||
1155 | Returns: | |
c035a008 AE |
1156 | A tuple containing plaintext bytes, encryption-capable signatures (if |
1157 | decryption and signature verification were successful, respectively), a | |
1158 | boolean marking whether edward is missing all public keys for | |
1159 | validating any of the signatures, and a boolean marking whether all | |
1160 | signature keys are incapable of encryption. | |
39e2c525 | 1161 | """ |
0bec96d6 | 1162 | |
5b3053c1 | 1163 | block_b = io.BytesIO(msg_block.encode('ascii')) |
0bec96d6 AE |
1164 | plain_b = io.BytesIO() |
1165 | ||
afc1f64c AE |
1166 | try: |
1167 | sigs = gpgme_ctx.decrypt_verify(block_b, plain_b) | |
5f6f32b1 | 1168 | except gpgme.GpgmeError: |
c035a008 | 1169 | return ("",[],False,False) |
0bec96d6 | 1170 | |
85a829fc | 1171 | plaintext_b = plain_b.getvalue() |
cbdf22c1 | 1172 | |
c035a008 AE |
1173 | (fingerprints, sigkey_missing, key_cannot_encrypt) = get_signature_fp(sigs, gpgme_ctx) |
1174 | ||
1175 | return (plaintext_b, fingerprints, sigkey_missing, key_cannot_encrypt) | |
1176 | ||
1177 | ||
1178 | def get_signature_fp (sigs, gpgme_ctx): | |
1179 | """Selects valid signatures from output of gpgme signature verifying functions | |
1180 | ||
1181 | get_signature_fp returns a list of valid signature fingerprints if those | |
1182 | fingerprints are associated with available keys capable of encryption. | |
1183 | ||
1184 | Args: | |
1185 | sigs: a signature verification result object list | |
1186 | gpgme_ctx: a gpgme context | |
1187 | ||
1188 | Returns: | |
1189 | fingerprints: a list of fingerprints | |
1190 | sigkey_missing: a boolean marking whether public keys are missing for | |
1191 | all available signatures. | |
1192 | key_cannot_encrypt: a boolearn marking whether available public keys are | |
1193 | incapable of encryption. | |
1194 | """ | |
1195 | ||
b4c116d5 | 1196 | sigkey_missing = False |
c035a008 | 1197 | key_cannot_encrypt = False |
cbdf22c1 | 1198 | fingerprints = [] |
c035a008 | 1199 | |
cbdf22c1 | 1200 | for sig in sigs: |
8f011cc9 | 1201 | if (sig.summary == 0) or (sig.summary & gpgme.SIGSUM_VALID != 0) or (sig.summary & gpgme.SIGSUM_GREEN != 0): |
c035a008 AE |
1202 | try: |
1203 | key_obj = gpgme_ctx.get_key(sig.fpr) | |
1204 | except: | |
1205 | if fingerprints == []: | |
1206 | sigkey_missing = True | |
1207 | continue | |
1208 | ||
c5492aa9 | 1209 | if is_key_usable(key_obj): |
c035a008 AE |
1210 | fingerprints += [sig.fpr] |
1211 | key_cannot_encrypt = False | |
1212 | sigkey_missing = False | |
1213 | ||
1214 | elif fingerprints == []: | |
1215 | key_cannot_encrypt = True | |
1216 | ||
1217 | elif fingerprints == []: | |
b4c116d5 AE |
1218 | if (sig.summary & gpgme.SIGSUM_KEY_MISSING != 0): |
1219 | sigkey_missing = True | |
9af26cb8 | 1220 | |
c035a008 | 1221 | return (fingerprints, sigkey_missing, key_cannot_encrypt) |
0bec96d6 AE |
1222 | |
1223 | ||
c5492aa9 AE |
1224 | def is_key_usable (key_obj): |
1225 | """Returns boolean representing key usability regarding encryption | |
1226 | ||
1227 | Tests various feature of key and returns usability | |
1228 | ||
1229 | Args: | |
1230 | key_obj: a gpgme key object | |
1231 | ||
1232 | Returns: | |
1233 | A boolean representing key usability | |
1234 | """ | |
1235 | if key_obj.can_encrypt and not key_obj.invalid and not key_obj.expired \ | |
1236 | and not key_obj.revoked and not key_obj.disabled: | |
1237 | return True | |
1238 | else: | |
1239 | return False | |
1240 | ||
1241 | ||
85a829fc | 1242 | def email_to_from_subject (email_bytes): |
dd2b62d7 | 1243 | """Returns the values of the email's To:, From: and Subject: fields |
fafa21c3 | 1244 | |
dd2b62d7 | 1245 | Returns this information from an email. |
fafa21c3 | 1246 | |
dd2b62d7 | 1247 | Args: |
85a829fc | 1248 | email_bytes: the byte string form of the email |
fafa21c3 | 1249 | |
dd2b62d7 AE |
1250 | Returns: |
1251 | the email To:, From:, and Subject: fields as strings | |
1252 | """ | |
d65993b8 | 1253 | |
85a829fc | 1254 | email_struct = email.parser.BytesParser().parsebytes(email_bytes) |
d65993b8 AE |
1255 | |
1256 | email_to = email_struct['To'] | |
1257 | email_from = email_struct['From'] | |
1258 | email_subject = email_struct['Subject'] | |
1259 | ||
1260 | return email_to, email_from, email_subject | |
1261 | ||
1262 | ||
bb27d257 AE |
1263 | def import_lang_pick_address(email_to, hostname): |
1264 | """Imports language file for i18n support; makes reply from address | |
dd2b62d7 AE |
1265 | |
1266 | The language imported depends on the To: address of the email received by | |
1267 | edward. an -en ending implies the English language, whereas a -ja ending | |
1268 | implies Japanese. The list of supported languages is listed in the 'langs' | |
bb27d257 AE |
1269 | list at the beginning of the program. This function also chooses the |
1270 | language-dependent address which can be used as the From address in the | |
1271 | reply email. | |
dd2b62d7 AE |
1272 | |
1273 | Args: | |
1274 | email_to: the string containing the email address that the mail was | |
bb27d257 AE |
1275 | sent to. |
1276 | hostname: the hostname part of the reply email's from address | |
dd2b62d7 AE |
1277 | |
1278 | Returns: | |
1279 | the reference to the imported language module. The only variable in | |
1280 | this file is the 'replies' dictionary. | |
1281 | """ | |
adcef2f7 | 1282 | |
bb27d257 AE |
1283 | # default |
1284 | use_lang = "en" | |
daed5f10 | 1285 | |
5250b3b8 AE |
1286 | if email_to != None: |
1287 | for lang in langs: | |
1288 | if "edward-" + lang in email_to: | |
bb27d257 AE |
1289 | use_lang = lang |
1290 | break | |
adcef2f7 | 1291 | |
bb27d257 AE |
1292 | lang_mod_name = "lang." + re.sub('-', '_', use_lang) |
1293 | lang_module = importlib.import_module(lang_mod_name) | |
1294 | ||
60ccbaf4 | 1295 | reply_from = "edward-" + use_lang + "@" + hostname |
bb27d257 | 1296 | |
60ccbaf4 | 1297 | return lang_module, reply_from |
adcef2f7 AE |
1298 | |
1299 | ||
cfb03389 | 1300 | def generate_encrypted_mime (plaintext, email_to, email_subject, encrypt_to_key, |
0a064403 | 1301 | gpgme_ctx): |
dd2b62d7 AE |
1302 | """This function creates the mime email reply. It can encrypt the email. |
1303 | ||
1304 | If the encrypt_key is included, then the email is encrypted and signed. | |
1305 | Otherwise it is unencrypted. | |
1306 | ||
1307 | Args: | |
1308 | plaintext: the plaintext body of the message to create. | |
cfb03389 | 1309 | email_to: the email address to reply to |
dd2b62d7 AE |
1310 | email_subject: the subject to use in reply |
1311 | encrypt_to_key: the key object to use for encrypting the email. (or | |
1312 | None) | |
1313 | gpgme_ctx: the gpgme context | |
1314 | ||
1315 | Returns | |
1316 | A string version of the mime message, possibly encrypted and signed. | |
1317 | """ | |
1da9b527 | 1318 | |
59bc3fac AE |
1319 | plaintext_mime = MIMEText(plaintext) |
1320 | plaintext_mime.set_charset('utf-8') | |
8bdfb6d4 | 1321 | |
59bc3fac | 1322 | if (encrypt_to_key != None): |
8bdfb6d4 AE |
1323 | |
1324 | encrypted_text = encrypt_sign_message(plaintext_mime.as_string(), | |
1325 | encrypt_to_key, | |
40c37ab3 | 1326 | gpgme_ctx) |
8bdfb6d4 | 1327 | |
e5dd6f23 AE |
1328 | control_mime = MIMEApplication("Version: 1", |
1329 | _subtype='pgp-encrypted', | |
1330 | _encoder=email.encoders.encode_7or8bit) | |
1331 | control_mime['Content-Description'] = 'PGP/MIME version identification' | |
1332 | control_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1333 | |
e5dd6f23 AE |
1334 | encoded_mime = MIMEApplication(encrypted_text, |
1335 | _subtype='octet-stream; name="encrypted.asc"', | |
1336 | _encoder=email.encoders.encode_7or8bit) | |
1337 | encoded_mime['Content-Description'] = 'OpenPGP encrypted message' | |
1338 | encoded_mime['Content-Disposition'] = 'inline; filename="encrypted.asc"' | |
1339 | encoded_mime.set_charset('us-ascii') | |
8bdfb6d4 | 1340 | |
e5dd6f23 AE |
1341 | message_mime = MIMEMultipart(_subtype="encrypted", protocol="application/pgp-encrypted") |
1342 | message_mime.attach(control_mime) | |
1343 | message_mime.attach(encoded_mime) | |
1344 | message_mime['Content-Disposition'] = 'inline' | |
216708e9 | 1345 | |
e5dd6f23 | 1346 | else: |
59bc3fac | 1347 | message_mime = plaintext_mime |
2007103e | 1348 | |
cfb03389 | 1349 | message_mime['To'] = email_to |
2007103e AE |
1350 | message_mime['Subject'] = email_subject |
1351 | ||
1352 | reply = message_mime.as_string() | |
1da9b527 AE |
1353 | |
1354 | return reply | |
1355 | ||
1356 | ||
ba34a33c AE |
1357 | def send_reply(email_txt, reply_to, reply_from): |
1358 | """Sends reply email | |
1359 | ||
1360 | Sent to original sender | |
1361 | ||
1362 | Args: | |
1363 | email_txt: message as a string | |
1364 | reply_to: recipient of reply | |
1365 | reply_from: edward's specific email address | |
1366 | ||
1367 | Post: | |
1368 | Email is sent | |
1369 | """ | |
1370 | ||
8ad5c922 AE |
1371 | if reply_to == None: |
1372 | error("*** ERROR: No one to send email to.") | |
1373 | exit(1) | |
60ccbaf4 | 1374 | |
a9eaa792 AE |
1375 | s = smtplib.SMTP('localhost') |
1376 | s.sendmail(reply_from, reply_to, email_txt) | |
1377 | s.quit() | |
60ccbaf4 AE |
1378 | |
1379 | ||
f87041f8 | 1380 | def email_quote_text (text): |
dd2b62d7 AE |
1381 | """Quotes input text by inserting "> "s |
1382 | ||
1383 | This is useful for quoting a text for the reply message. It inserts "> " | |
1384 | strings at the beginning of lines. | |
1385 | ||
1386 | Args: | |
1387 | text: plain text to quote | |
1388 | ||
1389 | Returns: | |
1390 | Quoted text | |
1391 | """ | |
f87041f8 AE |
1392 | |
1393 | quoted_message = re.sub(r'^', r'> ', text, flags=re.MULTILINE) | |
1394 | ||
1395 | return quoted_message | |
1396 | ||
1397 | ||
0a064403 | 1398 | def encrypt_sign_message (plaintext, encrypt_to_key, gpgme_ctx): |
dd2b62d7 AE |
1399 | """Encrypts and signs plaintext |
1400 | ||
1401 | This encrypts and signs a message. | |
1402 | ||
1403 | Args: | |
1404 | plaintext: text to sign and ecrypt | |
1405 | encrypt_to_key: the key object to encrypt to | |
1406 | gpgme_ctx: the gpgme context | |
1407 | ||
1408 | Returns: | |
1409 | An encrypted and signed string of text | |
1410 | """ | |
897cbaf6 | 1411 | |
b33f601b | 1412 | # the plaintext should be mime encoded in an ascii-compatible form |
6aa41372 | 1413 | plaintext_bytes = io.BytesIO(plaintext.encode('ascii')) |
1da9b527 AE |
1414 | encrypted_bytes = io.BytesIO() |
1415 | ||
897cbaf6 | 1416 | gpgme_ctx.encrypt_sign([encrypt_to_key], gpgme.ENCRYPT_ALWAYS_TRUST, |
1da9b527 AE |
1417 | plaintext_bytes, encrypted_bytes) |
1418 | ||
6aa41372 | 1419 | encrypted_txt = encrypted_bytes.getvalue().decode('ascii') |
1da9b527 AE |
1420 | return encrypted_txt |
1421 | ||
1422 | ||
0a064403 | 1423 | def error (error_msg): |
dd2b62d7 AE |
1424 | """Write an error message to stdout |
1425 | ||
1426 | The error message includes the program name. | |
1427 | ||
1428 | Args: | |
1429 | error_msg: the message to print | |
1430 | ||
1431 | Returns: | |
1432 | Nothing | |
1433 | ||
1434 | Post: | |
1435 | An error message is printed to stdout | |
1436 | """ | |
0a064403 | 1437 | |
e4fb2ab2 | 1438 | sys.stderr.write(progname + ": " + str(error_msg) + "\n") |
0a064403 AE |
1439 | |
1440 | ||
5e8f9094 | 1441 | def debug (debug_msg): |
dd2b62d7 AE |
1442 | """Writes a debug message to stdout if debug == True |
1443 | ||
1444 | If the debug option is set in edward_config.py, then the passed message | |
1445 | gets printed to stdout. | |
1446 | ||
1447 | Args: | |
1448 | debug_msg: the message to print to stdout | |
1449 | ||
1450 | Returns: | |
1451 | Nothing | |
1452 | ||
1453 | Post: | |
1454 | A debug message is printed to stdout | |
1455 | """ | |
5e8f9094 AE |
1456 | |
1457 | if edward_config.debug == True: | |
0a064403 | 1458 | error(debug_msg) |
5e8f9094 AE |
1459 | |
1460 | ||
20f6e7c5 | 1461 | def handle_args (): |
60ccbaf4 | 1462 | """Sets the progname variable and processes optional argument |
dd2b62d7 | 1463 | |
60ccbaf4 AE |
1464 | If there are more than two arguments then edward complains and quits. An |
1465 | single "-p" argument sets the print_reply_only option, which makes edward | |
1466 | print email replies instead of mailing them. | |
dd2b62d7 AE |
1467 | |
1468 | Args: | |
1469 | None | |
1470 | ||
1471 | Returns: | |
60ccbaf4 AE |
1472 | True if edward should print arguments instead of mailing them, |
1473 | otherwise it returns False. | |
dd2b62d7 AE |
1474 | |
1475 | Post: | |
60ccbaf4 AE |
1476 | Exits with error 1 if there are more than two arguments, otherwise |
1477 | returns the print_reply_only option. | |
dd2b62d7 | 1478 | """ |
20f6e7c5 | 1479 | |
a51cdb72 AE |
1480 | global progname |
1481 | progname = sys.argv[0] | |
1482 | ||
60ccbaf4 AE |
1483 | print_reply_only = False |
1484 | ||
1485 | if len(sys.argv) > 2: | |
1486 | print(progname + " usage: " + progname + " [-p]\n\n" \ | |
1487 | + " -p print reply message to stdout, do not mail it\n", \ | |
1488 | file=sys.stderr) | |
a51cdb72 | 1489 | exit(1) |
20f6e7c5 | 1490 | |
60ccbaf4 AE |
1491 | elif (len(sys.argv) == 2) and (sys.argv[1] == "-p"): |
1492 | print_reply_only = True | |
1493 | ||
1494 | return print_reply_only | |
1495 | ||
20f6e7c5 | 1496 | |
a51cdb72 | 1497 | if __name__ == "__main__": |
dd2b62d7 | 1498 | """Executes main if this file is not loaded interactively""" |
20f6e7c5 | 1499 | |
a51cdb72 | 1500 | main() |
0bec96d6 | 1501 |