SSL_set_num_tickets, SSL_get_num_tickets, SSL_CTX_set_num_tickets,
       SSL_CTX_get_num_tickets - control the number of TLSv1.3 session tickets
       that are issued

        #include <openssl/ssl.h>

        int SSL_set_num_tickets(SSL *s, size_t num_tickets);
        size_t SSL_get_num_tickets(SSL *s);
        int SSL_CTX_set_num_tickets(SSL_CTX *ctx, size_t num_tickets);
        size_t SSL_CTX_get_num_tickets(SSL_CTX *ctx);

       SSL_CTX_set_num_tickets() and SSL_set_num_tickets() can be called for a
       server application and set the number of TLSv1.3 session tickets that
       will be sent to the client after a full handshake. Set the desired value
       (which could be 0) in the num_tickets argument. Typically these functions
       should be called before the start of the handshake.

       The default number of tickets is 2; the default number of tickets sent
       following a resumption handshake is 1 but this cannot be changed using
       these functions.  The number of tickets following a resumption handshake
       can be reduced to 0 using custom session ticket callbacks (see

       Tickets are also issued on receipt of a post-handshake certificate from
       the client following a request by the server using
       SSL_verify_client_post_handshake(3). These new tickets will be associated
       with the updated client identity (i.e. including their certificate and
       verification status). The number of tickets issued will normally be the
       same as was used for the initial handshake. If the initial handshake was
       a full handshake then SSL_set_num_tickets() can be called again prior to
       calling SSL_verify_client_post_handshake() to update the number of
       tickets that will be sent.

       SSL_CTX_get_num_tickets() and SSL_get_num_tickets() return the number of
       tickets set by a previous call to SSL_CTX_set_num_tickets() or
       SSL_set_num_tickets(), or 2 if no such call has been made.

       SSL_CTX_set_num_tickets() and SSL_set_num_tickets() return 1 on success
       or 0 on failure.

       SSL_CTX_get_num_tickets() and SSL_get_num_tickets() return the number of
       tickets that have been previously set.

       These functions were added in OpenSSL 1.1.1.

       Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use this
       file except in compliance with the License.  You can obtain a copy in the
       file LICENSE in the source distribution or at

1.1.1j                             2021-02-16         SSL_CTX_SET_NUM_TICKETS(3)