Add read and write support to tls_buffer.

tls_buffer was original created for a specific use case, namely reading in
length prefixed messages. This adds read and write support, along with a
capacity limit, allowing it to be used in additional use cases.

ok beck@ tb@

1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libssl/tls13_record.c b/src/lib/libssl/tls13_record.c
index 2c744668e5..dbc835c546 100644
--- a/src/lib/libssl/tls13_record.c
+++ b/src/lib/libssl/tls13_record.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_record.c,v 1.9 2021/10/23 13:12:14 jsing Exp $ */
+/* $OpenBSD: tls13_record.c,v 1.10 2022/07/22 19:33:53 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -134,7 +134,8 @@ tls13_record_recv(struct tls13_record *rec, tls_read_cb wire_read,
                     TLS13_RECORD_HEADER_LEN, wire_read, wire_arg)) <= 0)
                         return ret;
 
-                tls_buffer_cbs(rec->buf, &cbs);
+                if (!tls_buffer_data(rec->buf, &cbs))
+                        return TLS13_IO_FAILURE;
 
                 if (!CBS_get_u8(&cbs, &content_type))
                         return TLS13_IO_FAILURE;