From: Mats Klepsland <mats.klepsland@gmail.com>
Date: Mon, 29 Oct 2018 20:20:33 +0000 (+0100)
Subject: app-layer-ssl: add 0-RTT support for TLSv1.3
X-Git-Tag: suricata-4.1.0~46
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3b73b7d542466ec0d6f4b581627bdc2581275596;p=thirdparty%2Fsuricata.git

app-layer-ssl: add 0-RTT support for TLSv1.3
---

diff --git a/src/app-layer-ssl.c b/src/app-layer-ssl.c
index d2a0cc3022..e9f431e6f8 100644
--- a/src/app-layer-ssl.c
+++ b/src/app-layer-ssl.c
@@ -2208,6 +2208,14 @@ static int SSLv3Decode(uint8_t direction, SSLState *ssl_state,
             break;
 
         case SSLV3_APPLICATION_PROTOCOL:
+            /* In TLSv1.3 early data (0-RTT) could be sent before the
+               handshake is complete (rfc8446, section 2.3). We should
+               therefore not mark the handshake as done before we have
+               seen the ServerHello record. */
+            if ((ssl_state->flags & SSL_AL_FLAG_EARLY_DATA) &&
+                    ((ssl_state->flags & SSL_AL_FLAG_STATE_SERVER_HELLO) == 0))
+                break;
+
             if ((ssl_state->flags & SSL_AL_FLAG_CLIENT_CHANGE_CIPHER_SPEC) &&
                 (ssl_state->flags & SSL_AL_FLAG_SERVER_CHANGE_CIPHER_SPEC)) {
 
@@ -2234,8 +2242,16 @@ static int SSLv3Decode(uint8_t direction, SSLState *ssl_state,
             break;
 
         case SSLV3_HANDSHAKE_PROTOCOL:
-            if (ssl_state->flags & SSL_AL_FLAG_CHANGE_CIPHER_SPEC)
-                break;
+            if (ssl_state->flags & SSL_AL_FLAG_CHANGE_CIPHER_SPEC) {
+                /* In TLSv1.3, ChangeCipherSpec is only used for middlebox
+                   compability (rfc8446, appendix D.4). */
+                if ((ssl_state->client_connp.version > TLS_VERSION_12) &&
+                       ((ssl_state->flags & SSL_AL_FLAG_STATE_SERVER_HELLO) == 0)) {
+                    /* do nothing */
+                } else {
+                    break;
+                }
+            }
 
             if (ssl_state->curr_connp->record_length < 4) {
                 SSLParserReset(ssl_state);