1=pod
2
3=head1 NAME
4
5SSL_SESSION_get0_hostname,
6SSL_SESSION_set1_hostname,
7SSL_SESSION_get0_alpn_selected,
8SSL_SESSION_set1_alpn_selected
9- get and set SNI and ALPN data associated with a session
10
11=head1 SYNOPSIS
12
13 #include <openssl/ssl.h>
14
15 const char *SSL_SESSION_get0_hostname(const SSL_SESSION *s);
16 int SSL_SESSION_set1_hostname(SSL_SESSION *s, const char *hostname);
17
18 void SSL_SESSION_get0_alpn_selected(const SSL_SESSION *s,
19                                     const unsigned char **alpn,
20                                     size_t *len);
21 int SSL_SESSION_set1_alpn_selected(SSL_SESSION *s, const unsigned char *alpn,
22                                    size_t len);
23
24=head1 DESCRIPTION
25
26SSL_SESSION_get0_hostname() retrieves the SNI value that was sent by the
27client when the session was created if it was accepted by the server and TLSv1.2
28or below was negotiated. Otherwise NULL is returned. Note that in TLSv1.3 the
29SNI hostname is negotiated with each handshake including resumption handshakes
30and is therefore never associated with the session.
31
32The value returned is a pointer to memory maintained within B<s> and
33should not be free'd.
34
35SSL_SESSION_set1_hostname() sets the SNI value for the hostname to a copy of
36the string provided in hostname.
37
38SSL_SESSION_get0_alpn_selected() retrieves the selected ALPN protocol for this
39session and its associated length in bytes. The returned value of B<*alpn> is a
40pointer to memory maintained within B<s> and should not be free'd.
41
42SSL_SESSION_set1_alpn_selected() sets the ALPN protocol for this session to the
43value in B<alpn> which should be of length B<len> bytes. A copy of the input
44value is made, and the caller retains ownership of the memory pointed to by
45B<alpn>.
46
47=head1 RETURN VALUES
48
49SSL_SESSION_get0_hostname() returns either a string or NULL based on if there
50is the SNI value sent by client.
51
52SSL_SESSION_set1_hostname() returns 1 on success or 0 on error.
53
54SSL_SESSION_set1_alpn_selected() returns 1 on success or 0 on error.
55
56=head1 SEE ALSO
57
58L<ssl(7)>,
59L<d2i_SSL_SESSION(3)>,
60L<SSL_SESSION_get_time(3)>,
61L<SSL_SESSION_free(3)>
62
63=head1 HISTORY
64
65The SSL_SESSION_set1_hostname(), SSL_SESSION_get0_alpn_selected() and
66SSL_SESSION_set1_alpn_selected() functions were added in OpenSSL 1.1.1.
67
68=head1 COPYRIGHT
69
70Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
71
72Licensed under the Apache License 2.0 (the "License").  You may not use
73this file except in compliance with the License.  You can obtain a copy
74in the file LICENSE in the source distribution or at
75L<https://www.openssl.org/source/license.html>.
76
77=cut
78