Adding Post-Handshake message handling.

Change-Id: I5cc194fc0a3ba8283049078e5671c924ee23036c
Reviewed-on: https://boringssl-review.googlesource.com/8980
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
diff --git a/ssl/tls13_both.c b/ssl/tls13_both.c
index 7b276df..1f60453 100644
--- a/ssl/tls13_both.c
+++ b/ssl/tls13_both.c
@@ -452,3 +452,18 @@
 
   return 1;
 }
+
+int tls13_post_handshake(SSL *ssl) {
+  if (ssl->s3->tmp.message_type == SSL3_MT_NEW_SESSION_TICKET &&
+      !ssl->server) {
+    // TODO(svaldez): Handle NewSessionTicket.
+    return 1;
+  }
+
+  // TODO(svaldez): Handle post-handshake authentication.
+  // TODO(svaldez): Handle KeyUpdate.
+
+  ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
+  OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
+  return 0;
+}