net: tls: Add tls 1.3 support

TLS 1.3 has minor changes from TLS 1.2 at the record layer.

* Header now hardcodes the same version and application content type in
  the header.
* The real content type is appended after the data, before encryption (or
  after decryption).
* The IV is xored with the sequence number, instead of concatinating four
  bytes of IV with the explicit IV.
* Zero-padding:  No exlicit length is given, we search backwards from the
  end of the decrypted data for the first non-zero byte, which is the
  content type.  Currently recv supports reading zero-padding, but there
  is no way for send to add zero padding.

Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 0f028cfdf835..d1c2fd9a3f63 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -463,7 +463,8 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
         }
 
         /* check version */
-        if (crypto_info->version != TLS_1_2_VERSION) {
+        if (crypto_info->version != TLS_1_2_VERSION &&
+            crypto_info->version != TLS_1_3_VERSION) {
                 rc = -ENOTSUPP;
                 goto err_crypto_info;
         }