* Authors: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
*/
+#include <stdbool.h>
#include "repair.h"
+
+
+static bool
+_notmuch_crypto_payload_has_legacy_display (GMimeObject *payload)
+{
+ GMimeMultipart *mpayload;
+ const char *protected_header_parameter;
+ GMimeTextPart *legacy_display;
+ char *legacy_display_header_text = NULL;
+ GMimeStream *stream = NULL;
+ GMimeParser *parser = NULL;
+ GMimeObject *legacy_header_object = NULL, *first;
+ GMimeHeaderList *legacy_display_headers = NULL, *protected_headers = NULL;
+ bool ret = false;
+
+ if (! g_mime_content_type_is_type (g_mime_object_get_content_type (payload),
+ "multipart", "mixed"))
+ return false;
+ protected_header_parameter = g_mime_object_get_content_type_parameter (payload, "protected-headers");
+ if ((! protected_header_parameter) || strcmp (protected_header_parameter, "v1"))
+ return false;
+ if (! GMIME_IS_MULTIPART (payload))
+ return false;
+ mpayload = GMIME_MULTIPART (payload);
+ if (mpayload == NULL)
+ return false;
+ if (g_mime_multipart_get_count (mpayload) != 2)
+ return false;
+ first = g_mime_multipart_get_part (mpayload, 0);
+ /* Early implementations that generated "Legacy Display" parts used
+ Content-Type: text/rfc822-headers, but text/plain is more widely
+ rendered, so it is now the standard choice. We accept either as a
+ Legacy Display part. */
+ if (! (g_mime_content_type_is_type (g_mime_object_get_content_type (first),
+ "text", "plain") ||
+ g_mime_content_type_is_type (g_mime_object_get_content_type (first),
+ "text", "rfc822-headers")))
+ return false;
+ protected_header_parameter = g_mime_object_get_content_type_parameter (first, "protected-headers");
+ if ((! protected_header_parameter) || strcmp (protected_header_parameter, "v1"))
+ return false;
+ if (! GMIME_IS_TEXT_PART (first))
+ return false;
+
+ /* ensure that the headers in the first part all match the values
+ * found in the payload's own protected headers! if they don't,
+ * we should not treat this as a valid "legacy-display" part.
+ *
+ * Crafting a GMimeHeaderList object from the content of the
+ * text/rfc822-headers part is pretty clumsy; we should probably
+ * push something into GMime that makes this a one-shot
+ * operation. */
+ if ((protected_headers = g_mime_object_get_header_list (payload), protected_headers) &&
+ (legacy_display = GMIME_TEXT_PART (first), legacy_display) &&
+ (legacy_display_header_text = g_mime_text_part_get_text (legacy_display), legacy_display_header_text) &&
+ (stream = g_mime_stream_mem_new_with_buffer (legacy_display_header_text, strlen (legacy_display_header_text)), stream) &&
+ (g_mime_stream_write (stream, "\r\n\r\n", 4) == 4) &&
+ (g_mime_stream_seek (stream, 0, GMIME_STREAM_SEEK_SET) == 0) &&
+ (parser = g_mime_parser_new_with_stream (stream), parser) &&
+ (legacy_header_object = g_mime_parser_construct_part (parser, NULL), legacy_header_object) &&
+ (legacy_display_headers = g_mime_object_get_header_list (legacy_header_object), legacy_display_headers)) {
+ /* walk through legacy_display_headers, comparing them against
+ * their values in the protected_headers: */
+ ret = true;
+ for (int i = 0; i < g_mime_header_list_get_count (legacy_display_headers); i++) {
+ GMimeHeader *dh = g_mime_header_list_get_header_at (legacy_display_headers, i);
+ if (dh == NULL) {
+ ret = false;
+ goto DONE;
+ }
+ GMimeHeader *ph = g_mime_header_list_get_header (protected_headers, g_mime_header_get_name (dh));
+ if (ph == NULL) {
+ ret = false;
+ goto DONE;
+ }
+ const char *dhv = g_mime_header_get_value (dh);
+ const char *phv = g_mime_header_get_value (ph);
+ if (dhv == NULL || phv == NULL || strcmp (dhv, phv)) {
+ ret = false;
+ goto DONE;
+ }
+ }
+ }
+
+ DONE:
+ if (legacy_display_header_text)
+ g_free (legacy_display_header_text);
+ if (stream)
+ g_object_unref (stream);
+ if (parser)
+ g_object_unref (parser);
+ if (legacy_header_object)
+ g_object_unref (legacy_header_object);
+
+ return ret;
+}
+
+GMimeObject *
+_notmuch_repair_crypto_payload_skip_legacy_display (GMimeObject *payload)
+{
+ if (_notmuch_crypto_payload_has_legacy_display (payload)) {
+ return g_mime_multipart_get_part (GMIME_MULTIPART (payload), 1);
+ } else {
+ 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;
+}
projects / notmuch / blobdiff