util/repair: identify and repair "Mixed Up" mangled messages

[notmuch] / util / repair.c

diff --git a/util/repair.c b/util/repair.c
index 629e6f232e090371595e3924464e38d75df7fe61..9fba97b7a67fa56e6f4a7a96beddccfbe0a231ac 100644 (file)
--- a/util/repair.c
+++ b/util/repair.c
@@ -120,3 +120,87 @@ _notmuch_repair_crypto_payload_skip_legacy_display (GMimeObject *payload)
        return payload;
     }
 }
+
+/* see
+ * https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling-00#section-4.1.1 */
+static bool
+_notmuch_is_mixed_up_mangled (GMimeObject *part)
+{
+    GMimeMultipart *mpart = NULL;
+    GMimeObject *parts[3] = {NULL, NULL, NULL};
+    GMimeContentType *type = NULL;
+    char *prelude_string = NULL;
+    bool prelude_is_empty;
+
+    if (part == NULL)
+       return false;
+    type = g_mime_object_get_content_type (part);
+    if (type == NULL)
+       return false;
+    if (! g_mime_content_type_is_type (type, "multipart", "mixed"))
+       return false;
+    if (! GMIME_IS_MULTIPART (part)) /* probably impossible */
+       return false;
+    mpart = GMIME_MULTIPART (part);
+    if (mpart == NULL)
+       return false;
+    if (g_mime_multipart_get_count (mpart) != 3)
+       return false;
+    parts[0] = g_mime_multipart_get_part (mpart, 0);
+    if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[0]),
+                                      "text", "plain"))
+       return false;
+    if (! GMIME_IS_TEXT_PART (parts[0]))
+       return false;
+    parts[1] = g_mime_multipart_get_part (mpart, 1);
+    if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[1]),
+                                      "application", "pgp-encrypted"))
+       return false;
+    parts[2] = g_mime_multipart_get_part (mpart, 2);
+    if (! g_mime_content_type_is_type (g_mime_object_get_content_type (parts[2]),
+                                      "application", "octet-stream"))
+       return false;
+
+    /* Is parts[0] length 0? */
+    prelude_string = g_mime_text_part_get_text (GMIME_TEXT_PART (parts[0]));
+    prelude_is_empty = (prelude_string[0] == '\0');
+    g_free (prelude_string);
+    if (! prelude_is_empty)
+       return false;
+
+    /* FIXME: after decoding and stripping whitespace, is parts[1]
+     * subpart just "Version: 1" ? */
+
+    /* FIXME: can we determine that parts[2] subpart is *only* PGP
+     * encrypted data?  I tried g_mime_part_get_openpgp_data () but
+     * found https://github.com/jstedfast/gmime/issues/60 */
+
+    return true;
+}
+
+
+/* see
+ * https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling-00#section-4.1.2 */
+GMimeObject *
+_notmuch_repair_mixed_up_mangled (GMimeObject *part)
+{
+    GMimeMultipart *mpart = NULL, *mpart_ret = NULL;
+    GMimeObject *ret = NULL;
+
+    if (! _notmuch_is_mixed_up_mangled (part))
+       return NULL;
+    mpart = GMIME_MULTIPART (part);
+    ret = GMIME_OBJECT (g_mime_multipart_encrypted_new ());
+    if (ret == NULL)
+       return NULL;
+    mpart_ret = GMIME_MULTIPART (ret);
+    if (mpart_ret == NULL) {
+       g_object_unref (ret);
+       return NULL;
+    }
+    g_mime_object_set_content_type_parameter (ret, "protocol", "application/pgp-encrypted");
+
+    g_mime_multipart_insert (mpart_ret, 0, g_mime_multipart_get_part (mpart, 1));
+    g_mime_multipart_insert (mpart_ret, 1, g_mime_multipart_get_part (mpart, 2));
+    return ret;
+}