Correct TLSv1.3 sequence number increment and wrapping check.

Fix proposed by tb@

1 files changed, 3 insertions, 3 deletions

diff --git a/src/lib/libssl/tls13_record_layer.c b/src/lib/libssl/tls13_record_layer.c
index 1ad8ed33f1..341bceeabc 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 1.28 2020/02/18 16:12:14 tb Exp $ */
+/* $OpenBSD: tls13_record_layer.c,v 1.29 2020/03/13 16:03:27 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -166,7 +166,7 @@ tls13_record_layer_rbuf(struct tls13_record_layer *rl, CBS *cbs)
         CBS_dup(&rl->rbuf_cbs, cbs);
 }
 
-static int
+int
 tls13_record_layer_inc_seq_num(uint8_t *seq_num)
 {
         size_t i;
@@ -177,7 +177,7 @@ tls13_record_layer_inc_seq_num(uint8_t *seq_num)
         }
 
         /* RFC 8446 section 5.3 - sequence numbers must not wrap. */
-        return (i != 0 || seq_num[0] != 0);
+        return (i != 0 || ++seq_num[0] != 0);
 }
 
 static int