SSL_SESSION_get0_hostname, SSL_SESSION_set1_hostname, SSL_SESSION_get0_alpn_selected,

       Copyright 2016-2025 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (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
       <https://www.openssl.org/source/license.html>.

3.5.0                                              2025-06-04                    SSL_SESSION_GET0_HOSTNAME(3SSL)

SSL_SESSION_get0_hostname() retrieves the SNI value that was sent by the client when the session was
       created if it was accepted by the server. Otherwise NULL is returned.

       The value returned is a pointer to memory maintained within s and should not be free'd.

       SSL_SESSION_set1_hostname() sets the SNI value for the hostname to a copy of the string provided in
       hostname.

       SSL_SESSION_get0_alpn_selected() retrieves the selected ALPN protocol for this session and its associated
       length in bytes. The returned value of *alpn is a pointer to memory maintained within s and should not be
       free'd.

       SSL_SESSION_set1_alpn_selected() sets the ALPN protocol for this session to the value in alpn which
       should be of length len bytes. A copy of the input value is made, and the caller retains ownership of the
       memory pointed to by alpn.

       The SSL_SESSION_set1_hostname(), SSL_SESSION_get0_alpn_selected() and SSL_SESSION_set1_alpn_selected()
       functions were added in OpenSSL 1.1.1.

       SSL_SESSION_get0_hostname, SSL_SESSION_set1_hostname, SSL_SESSION_get0_alpn_selected,
       SSL_SESSION_set1_alpn_selected - get and set SNI and ALPN data associated with a session

SSL_SESSION_get0_hostname() returns either a string or NULL based on if there is the SNI value sent by
       client.

       SSL_SESSION_set1_hostname() returns 1 on success or 0 on error.

       SSL_SESSION_set1_alpn_selected() returns 1 on success or 0 on error.

ssl(7), d2i_SSL_SESSION(3), SSL_SESSION_get_time(3), SSL_SESSION_free(3)

        #include <openssl/ssl.h>

        const char *SSL_SESSION_get0_hostname(const SSL_SESSION *s);
        int SSL_SESSION_set1_hostname(SSL_SESSION *s, const char *hostname);

        void SSL_SESSION_get0_alpn_selected(const SSL_SESSION *s,
                                            const unsigned char **alpn,
                                            size_t *len);
        int SSL_SESSION_set1_alpn_selected(SSL_SESSION *s, const unsigned char *alpn,
                                           size_t len);