The NewSessionTicket message is not optional.

Per RFC 4507, section 3.3:

   This message [NewSessionTicket] MUST be sent if the
   server included a SessionTicket extension in the ServerHello.  This
   message MUST NOT be sent if the server did not include a
   SessionTicket extension in the ServerHello.

The presence of the NewSessionTicket message should be determined
entirely from the ServerHello without probing.

RT#4389

Reviewed-by: Emilia Käsper <emilia@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>

diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index 4ede88ea2b2bdbc88336ceff8e332c3f01ba0558..8da3e9b622c53830c607d2c999d8c4329971836b 100644 (file)
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -341,9 +341,11 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
         break;
 
     case TLS_ST_CW_FINISHED:
-        if (mt == SSL3_MT_NEWSESSION_TICKET && s->tlsext_ticket_expected) {
-            st->hand_state = TLS_ST_CR_SESSION_TICKET;
-            return 1;
+        if (s->tlsext_ticket_expected) {
+            if (mt == SSL3_MT_NEWSESSION_TICKET) {
+                st->hand_state = TLS_ST_CR_SESSION_TICKET;
+                return 1;
+            }
         } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
             st->hand_state = TLS_ST_CR_CHANGE;
             return 1;