+ /* don't bother recording anything if there is no cryptographic
+ * envelope: */
+ if ((msg_crypto->decryption_status != NOTMUCH_MESSAGE_DECRYPTED_FULL) &&
+ (msg_crypto->sig_list == NULL))
+ return false;
+
+ /* Verify that this payload has headers that are intended to be
+ * exported to the larger message: */
+
+ /* Consider a payload that uses Alexei Melinkov's forwarded="no" for
+ * message/global or message/rfc822:
+ * https://tools.ietf.org/html/draft-melnikov-smime-header-signing-05#section-4 */
+ forwarded = g_mime_object_get_content_type_parameter (part, "forwarded");
+ if (GMIME_IS_MESSAGE_PART (part) && forwarded && strcmp (forwarded, "no") == 0) {
+ GMimeMessage *message = g_mime_message_part_get_message (GMIME_MESSAGE_PART (part));
+ subject = g_mime_message_get_subject (message);
+ /* FIXME: handle more than just Subject: at some point */
+ } else {
+ /* Consider "memoryhole"-style protected headers as practiced by Enigmail and K-9 */
+ protected_headers = g_mime_object_get_content_type_parameter (part, "protected-headers");
+ if (protected_headers && strcasecmp ("v1", protected_headers) == 0)
+ subject = g_mime_object_get_header (part, "Subject");
+ /* FIXME: handle more than just Subject: at some point */
+ }
+
+ if (subject) {
+ if (msg_crypto->payload_subject)
+ talloc_free (msg_crypto->payload_subject);
+ msg_crypto->payload_subject = talloc_strdup (msg_crypto, subject);
+ }
+
+ return true;