1 /* notmuch - Not much of an email program, (just index and search)
3 * Copyright © 2019 Daniel Kahn Gillmor
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see https://www.gnu.org/licenses/ .
18 * Authors: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
26 _notmuch_crypto_payload_has_legacy_display (GMimeObject *payload)
28 GMimeMultipart *mpayload;
29 const char *protected_header_parameter;
30 GMimeTextPart *legacy_display;
31 char *legacy_display_header_text = NULL;
32 GMimeStream *stream = NULL;
33 GMimeParser *parser = NULL;
34 GMimeObject *legacy_header_object = NULL, *first;
35 GMimeHeaderList *legacy_display_headers = NULL, *protected_headers = NULL;
38 if (! g_mime_content_type_is_type (g_mime_object_get_content_type (payload),
39 "multipart", "mixed"))
41 protected_header_parameter = g_mime_object_get_content_type_parameter (payload, "protected-headers");
42 if ((! protected_header_parameter) || strcmp (protected_header_parameter, "v1"))
44 if (! GMIME_IS_MULTIPART (payload))
46 mpayload = GMIME_MULTIPART (payload);
49 if (g_mime_multipart_get_count (mpayload) != 2)
51 first = g_mime_multipart_get_part (mpayload, 0);
52 /* Early implementations that generated "Legacy Display" parts used
53 Content-Type: text/rfc822-headers, but text/plain is more widely
54 rendered, so it is now the standard choice. We accept either as a
55 Legacy Display part. */
56 if (! (g_mime_content_type_is_type (g_mime_object_get_content_type (first),
58 g_mime_content_type_is_type (g_mime_object_get_content_type (first),
59 "text", "rfc822-headers")))
61 protected_header_parameter = g_mime_object_get_content_type_parameter (first, "protected-headers");
62 if ((! protected_header_parameter) || strcmp (protected_header_parameter, "v1"))
64 if (! GMIME_IS_TEXT_PART (first))
67 /* ensure that the headers in the first part all match the values
68 * found in the payload's own protected headers! if they don't,
69 * we should not treat this as a valid "legacy-display" part.
71 * Crafting a GMimeHeaderList object from the content of the
72 * text/rfc822-headers part is pretty clumsy; we should probably
73 * push something into GMime that makes this a one-shot
75 if ((protected_headers = g_mime_object_get_header_list (payload), protected_headers) &&
76 (legacy_display = GMIME_TEXT_PART (first), legacy_display) &&
77 (legacy_display_header_text = g_mime_text_part_get_text (legacy_display), legacy_display_header_text) &&
78 (stream = g_mime_stream_mem_new_with_buffer (legacy_display_header_text, strlen (legacy_display_header_text)), stream) &&
79 (g_mime_stream_write (stream, "\r\n\r\n", 4) == 4) &&
80 (g_mime_stream_seek (stream, 0, GMIME_STREAM_SEEK_SET) == 0) &&
81 (parser = g_mime_parser_new_with_stream (stream), parser) &&
82 (legacy_header_object = g_mime_parser_construct_part (parser, NULL), legacy_header_object) &&
83 (legacy_display_headers = g_mime_object_get_header_list (legacy_header_object), legacy_display_headers)) {
84 /* walk through legacy_display_headers, comparing them against
85 * their values in the protected_headers: */
87 for (int i = 0; i < g_mime_header_list_get_count (legacy_display_headers); i++) {
88 GMimeHeader *dh = g_mime_header_list_get_header_at (legacy_display_headers, i);
93 GMimeHeader *ph = g_mime_header_list_get_header (protected_headers, g_mime_header_get_name (dh));
98 const char *dhv = g_mime_header_get_value (dh);
99 const char *phv = g_mime_header_get_value (ph);
100 if (dhv == NULL || phv == NULL || strcmp (dhv, phv)) {
108 if (legacy_display_header_text)
109 g_free (legacy_display_header_text);
111 g_object_unref (stream);
113 g_object_unref (parser);
114 if (legacy_header_object)
115 g_object_unref (legacy_header_object);
121 _notmuch_repair_crypto_payload_skip_legacy_display (GMimeObject *payload)
123 if (_notmuch_crypto_payload_has_legacy_display (payload)) {
124 return g_mime_multipart_get_part (GMIME_MULTIPART (payload), 1);
131 * https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling-00#section-4.1.1 */
133 _notmuch_is_mixed_up_mangled (GMimeObject *part)
135 GMimeMultipart *mpart = NULL;
136 GMimeObject *parts[3] = {NULL, NULL, NULL};
137 GMimeContentType *type = NULL;
138 char *prelude_string = NULL;
139 bool prelude_is_empty;
143 type = g_mime_object_get_content_type (part);
146 if (! g_mime_content_type_is_type (type, "multipart", "mixed"))
148 if (! GMIME_IS_MULTIPART (part)) /* probably impossible */
150 mpart = GMIME_MULTIPART (part);
153 if (g_mime_multipart_get_count (mpart) != 3)
155 parts[0] = g_mime_multipart_get_part (mpart, 0);
156 if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[0]),
159 if (! GMIME_IS_TEXT_PART (parts[0]))
161 parts[1] = g_mime_multipart_get_part (mpart, 1);
162 if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[1]),
163 "application", "pgp-encrypted"))
165 parts[2] = g_mime_multipart_get_part (mpart, 2);
166 if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[2]),
167 "application", "octet-stream"))
170 /* Is parts[0] length 0? */
171 prelude_string = g_mime_text_part_get_text (GMIME_TEXT_PART (parts[0]));
172 prelude_is_empty = (prelude_string[0] == '\0');
173 g_free (prelude_string);
174 if (! prelude_is_empty)
177 /* FIXME: after decoding and stripping whitespace, is parts[1]
178 * subpart just "Version: 1" ? */
180 /* FIXME: can we determine that parts[2] subpart is *only* PGP
181 * encrypted data? I tried g_mime_part_get_openpgp_data () but
182 * found https://github.com/jstedfast/gmime/issues/60 */
189 * https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling-00#section-4.1.2 */
191 _notmuch_repair_mixed_up_mangled (GMimeObject *part)
193 GMimeMultipart *mpart = NULL, *mpart_ret = NULL;
194 GMimeObject *ret = NULL;
196 if (! _notmuch_is_mixed_up_mangled (part))
198 mpart = GMIME_MULTIPART (part);
199 ret = GMIME_OBJECT (g_mime_multipart_encrypted_new ());
202 mpart_ret = GMIME_MULTIPART (ret);
203 if (mpart_ret == NULL) {
204 g_object_unref (ret);
207 g_mime_object_set_content_type_parameter (ret, "protocol", "application/pgp-encrypted");
209 g_mime_multipart_insert (mpart_ret, 0, g_mime_multipart_get_part (mpart, 1));
210 g_mime_multipart_insert (mpart_ret, 1, g_mime_multipart_get_part (mpart, 2));