1 /* notmuch - Not much of an email program, (just index and search)
3 * Copyright © 2012 Jameson Rollins
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: Jameson Rollins <jrollins@finestructure.net>
23 #define unused(x) x __attribute__ ((unused))
25 #define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
28 _notmuch_crypto_cleanup (unused(_notmuch_crypto_t *crypto))
33 _notmuch_crypto_decrypt (bool *attempted,
34 notmuch_decryption_policy_t decrypt,
35 notmuch_message_t *message,
36 GMimeMultipartEncrypted *part,
37 GMimeDecryptResult **decrypt_result,
40 GMimeObject *ret = NULL;
42 if (decrypt == NOTMUCH_DECRYPT_FALSE)
45 /* try decryption with session key if one is stashed */
47 notmuch_message_properties_t *list = NULL;
49 for (list = notmuch_message_get_properties (message, "session-key", TRUE);
50 notmuch_message_properties_valid (list); notmuch_message_properties_move_to_next (list)) {
57 ret = g_mime_multipart_encrypted_decrypt (part,
59 notmuch_message_properties_value (list),
65 notmuch_message_properties_destroy (list);
75 if (decrypt == NOTMUCH_DECRYPT_AUTO)
80 GMimeDecryptFlags flags = GMIME_DECRYPT_NONE;
81 if (decrypt == NOTMUCH_DECRYPT_TRUE && decrypt_result)
82 flags |= GMIME_DECRYPT_EXPORT_SESSION_KEY;
83 ret = g_mime_multipart_encrypted_decrypt (part, flags, NULL,
89 _notmuch_message_crypto_destructor (_notmuch_message_crypto_t *msg_crypto)
93 if (msg_crypto->sig_list)
94 g_object_unref (msg_crypto->sig_list);
95 if (msg_crypto->payload_subject)
96 talloc_free (msg_crypto->payload_subject);
100 _notmuch_message_crypto_t *
101 _notmuch_message_crypto_new (void *ctx)
103 _notmuch_message_crypto_t *ret = talloc_zero (ctx, _notmuch_message_crypto_t);
105 talloc_set_destructor (ret, _notmuch_message_crypto_destructor);
110 _notmuch_message_crypto_potential_sig_list (_notmuch_message_crypto_t *msg_crypto, GMimeSignatureList *sigs)
113 return NOTMUCH_STATUS_NULL_POINTER;
115 /* Signatures that arrive after a payload part during DFS are not
116 * part of the cryptographic envelope: */
117 if (msg_crypto->payload_encountered)
118 return NOTMUCH_STATUS_SUCCESS;
120 if (msg_crypto->sig_list)
121 g_object_unref (msg_crypto->sig_list);
123 /* This signature list needs to persist as long as the _n_m_crypto
124 * object survives. Increasing its reference counter prevents
125 * garbage-collection until after _n_m_crypto_destroy is
127 msg_crypto->sig_list = sigs;
131 if (msg_crypto->decryption_status == NOTMUCH_MESSAGE_DECRYPTED_FULL)
132 msg_crypto->signature_encrypted = true;
134 return NOTMUCH_STATUS_SUCCESS;
139 _notmuch_message_crypto_potential_payload (_notmuch_message_crypto_t *msg_crypto, GMimeObject *payload, GMimeObject *parent, int childnum)
141 const char *protected_headers = NULL;
142 const char *forwarded = NULL;
143 const char *subject = NULL;
145 if (! msg_crypto || ! payload)
146 return NOTMUCH_STATUS_NULL_POINTER;
148 /* only fire on the first payload part encountered */
149 if (msg_crypto->payload_encountered)
150 return NOTMUCH_STATUS_SUCCESS;
152 /* the first child of multipart/encrypted that matches the
153 * encryption protocol should be "control information" metadata,
154 * not payload. So we skip it. (see
155 * https://tools.ietf.org/html/rfc1847#page-8) */
156 if (parent && GMIME_IS_MULTIPART_ENCRYPTED (parent) && childnum == GMIME_MULTIPART_ENCRYPTED_VERSION) {
157 const char *enc_type = g_mime_object_get_content_type_parameter (parent, "protocol");
158 GMimeContentType *ct = g_mime_object_get_content_type (payload);
159 if (ct && enc_type) {
160 const char *part_type = g_mime_content_type_get_mime_type (ct);
161 if (part_type && strcmp (part_type, enc_type) == 0)
162 return NOTMUCH_STATUS_SUCCESS;
166 msg_crypto->payload_encountered = true;
168 /* don't bother recording anything if there is no cryptographic
170 if ((msg_crypto->decryption_status != NOTMUCH_MESSAGE_DECRYPTED_FULL) &&
171 (msg_crypto->sig_list == NULL))
172 return NOTMUCH_STATUS_SUCCESS;
174 /* Verify that this payload has headers that are intended to be
175 * exported to the larger message: */
177 /* Consider a payload that uses Alexei Melinkov's forwarded="no" for
178 * message/global or message/rfc822:
179 * https://tools.ietf.org/html/draft-melnikov-smime-header-signing-05#section-4 */
180 forwarded = g_mime_object_get_content_type_parameter (payload, "forwarded");
181 if (GMIME_IS_MESSAGE_PART (payload) && forwarded && strcmp (forwarded, "no") == 0) {
182 GMimeMessage *message = g_mime_message_part_get_message (GMIME_MESSAGE_PART (payload));
183 subject = g_mime_message_get_subject (message);
184 /* FIXME: handle more than just Subject: at some point */
186 /* Consider "memoryhole"-style protected headers as practiced by Enigmail and K-9 */
187 protected_headers = g_mime_object_get_content_type_parameter (payload, "protected-headers");
188 if (protected_headers && strcasecmp ("v1", protected_headers) == 0)
189 subject = g_mime_object_get_header (payload, "Subject");
190 /* FIXME: handle more than just Subject: at some point */
194 if (msg_crypto->payload_subject)
195 talloc_free (msg_crypto->payload_subject);
196 msg_crypto->payload_subject = talloc_strdup (msg_crypto, subject);
199 return NOTMUCH_STATUS_SUCCESS;
204 _notmuch_message_crypto_successful_decryption (_notmuch_message_crypto_t *msg_crypto)
207 return NOTMUCH_STATUS_NULL_POINTER;
209 /* see the rationale for different values of
210 * _notmuch_message_decryption_status_t in util/crypto.h */
211 if (! msg_crypto->payload_encountered)
212 msg_crypto->decryption_status = NOTMUCH_MESSAGE_DECRYPTED_FULL;
213 else if (msg_crypto->decryption_status == NOTMUCH_MESSAGE_DECRYPTED_NONE)
214 msg_crypto->decryption_status = NOTMUCH_MESSAGE_DECRYPTED_PARTIAL;
216 return NOTMUCH_STATUS_SUCCESS;