diff options
| author | Joel Sing <jsing@cvs.openbsd.org> | 2020-08-11 19:25:41 +0000 |
|---|---|---|
| committer | Joel Sing <jsing@cvs.openbsd.org> | 2020-08-11 19:25:41 +0000 |
| commit | b00daf18ae2c4134de69b91a97e4d50838536ad4 (patch) | |
| tree | a88fe1ee94050cc0207feefbf4e2b9d6abd892f9 | |
| parent | 16d54354609ab15527fca926d25d13f212db57be (diff) | |
Send an unexpected message alert if no valid content type is found.
When record protection is engaged, the plaintext must be followed by a
non-zero content type and optional zero padding. If the plaintext is zero
length or only consists of zero bytes then it is not a valid message,
since the content type is unspecified.
ok tb@
| -rw-r--r-- | lib/libssl/tls13_record_layer.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/libssl/tls13_record_layer.c b/lib/libssl/tls13_record_layer.c index af4e7f24548..7093da48a7d 100644 --- a/lib/libssl/tls13_record_layer.c +++ b/lib/libssl/tls13_record_layer.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tls13_record_layer.c,v 1.51 2020/08/10 18:54:45 tb Exp $ */ +/* $OpenBSD: tls13_record_layer.c,v 1.52 2020/08/11 19:25:40 jsing Exp $ */ /* * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org> * @@ -576,8 +576,11 @@ tls13_record_layer_open_record_protected(struct tls13_record_layer *rl) inner_len = out_len - 1; while (inner_len >= 0 && content[inner_len] == 0) inner_len--; - if (inner_len < 0) + if (inner_len < 0) { + /* Unexpected message per RFC 8446 section 5.4. */ + rl->alert = TLS13_ALERT_UNEXPECTED_MESSAGE; goto err; + } if (inner_len > TLS13_RECORD_MAX_PLAINTEXT_LEN) { rl->alert = SSL_AD_RECORD_OVERFLOW; goto err; |