1=pod
2
3=head1 NAME
4
5SSL_set_num_tickets,
6SSL_get_num_tickets,
7SSL_CTX_set_num_tickets,
8SSL_CTX_get_num_tickets
9- control the number of TLSv1.3 session tickets that are issued
10
11=head1 SYNOPSIS
12
13 #include <openssl/ssl.h>
14
15 int SSL_set_num_tickets(SSL *s, size_t num_tickets);
16 size_t SSL_get_num_tickets(SSL *s);
17 int SSL_CTX_set_num_tickets(SSL_CTX *ctx, size_t num_tickets);
18 size_t SSL_CTX_get_num_tickets(SSL_CTX *ctx);
19
20=head1 DESCRIPTION
21
22SSL_CTX_set_num_tickets() and SSL_set_num_tickets() can be called for a server
23application and set the number of TLSv1.3 session tickets that will be sent to
24the client after a full handshake. Set the desired value (which could be 0) in
25the B<num_tickets> argument. Typically these functions should be called before
26the start of the handshake.
27
28The default number of tickets is 2; the default number of tickets sent following
29a resumption handshake is 1 but this cannot be changed using these functions.
30The number of tickets following a resumption handshake can be reduced to 0 using
31custom session ticket callbacks (see L<SSL_CTX_set_session_ticket_cb(3)>).
32
33Tickets are also issued on receipt of a post-handshake certificate from the
34client following a request by the server using
35L<SSL_verify_client_post_handshake(3)>. These new tickets will be associated
36with the updated client identity (i.e. including their certificate and
37verification status). The number of tickets issued will normally be the same as
38was used for the initial handshake. If the initial handshake was a full
39handshake then SSL_set_num_tickets() can be called again prior to calling
40SSL_verify_client_post_handshake() to update the number of tickets that will be
41sent.
42
43SSL_CTX_get_num_tickets() and SSL_get_num_tickets() return the number of
44tickets set by a previous call to SSL_CTX_set_num_tickets() or
45SSL_set_num_tickets(), or 2 if no such call has been made.
46
47=head1 RETURN VALUES
48
49SSL_CTX_set_num_tickets() and SSL_set_num_tickets() return 1 on success or 0 on
50failure.
51
52SSL_CTX_get_num_tickets() and SSL_get_num_tickets() return the number of tickets
53that have been previously set.
54
55=head1 HISTORY
56
57These functions were added in OpenSSL 1.1.1.
58
59=head1 COPYRIGHT
60
61Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
62
63Licensed under the OpenSSL license (the "License").  You may not use
64this file except in compliance with the License.  You can obtain a copy
65in the file LICENSE in the source distribution or at
66L<https://www.openssl.org/source/license.html>.
67
68=cut
69