Correct legacy fallback for TLSv1.3 client.

When falling back to the legacy TLS client, in the case where a server has
sent a TLS record that contains more than one handshake message, we also
need to stash the unprocessed record data for later processing. Otherwise
we end up with missing handshake data.

ok beck@ tb@

1 files changed, 7 insertions, 1 deletions

diff --git a/src/lib/libssl/tls13_record_layer.c b/src/lib/libssl/tls13_record_layer.c
index e1007b3f7b..a6b00a83b3 100644
--- a/src/lib/libssl/tls13_record_layer.c
+++ b/src/lib/libssl/tls13_record_layer.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_record_layer.c,v 1.17 2020/01/20 22:04:17 beck Exp $ */
+/* $OpenBSD: tls13_record_layer.c,v 1.18 2020/01/21 12:08:04 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -154,6 +154,12 @@ tls13_record_layer_free(struct tls13_record_layer *rl)
         freezero(rl, sizeof(struct tls13_record_layer));
 }
 
+void
+tls13_record_layer_rbuf(struct tls13_record_layer *rl, CBS *cbs)
+{
+        CBS_dup(&rl->rbuf_cbs, cbs);
+}
+
 static int
 tls13_record_layer_inc_seq_num(uint8_t *seq_num)
 {