/usr/man2/cat.3/SSL_CTX_set_tlsext_servername_callback.3.Z

NAME

       SSL_CTX_set_tlsext_servername_callback, SSL_CTX_set_tlsext_server-
       name_arg, SSL_get_servername_type, SSL_get_servername - handle server
       name indication (SNI)

SYNOPSIS

        #include <openssl/ssl.h>

        long SSL_CTX_set_tlsext_servername_callback(SSL_CTX *ctx,
                                          int (*cb)(SSL *, int *, void *));
        long SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);

        const char *SSL_get_servername(const SSL *s, const int type);
        int SSL_get_servername_type(const SSL *s);

DESCRIPTION

       SSL_CTX_set_tlsext_servername_callback() sets the application callback
       cb used by a server to perform any actions or configuration required
       based on the servername extension received in the incoming connection.
       When cb is NULL, SNI is not used. The arg value is a pointer which is
       passed to the application callback.

       SSL_CTX_set_tlsext_servername_arg() sets a context-specific argument to
       be passed into the callback for this SSL_CTX.

       SSL_get_servername() returns a servername extension value of the speci-
       fied type if provided in the Client Hello or NULL.

       SSL_get_servername_type() returns the servername type or -1 if no
       servername is present. Currently the only supported type (defined in
       RFC3546) is TLSEXT_NAMETYPE_host_name.

NOTES

       The ALPN and SNI callbacks are both executed during Client Hello pro-
       cessing.  The servername callback is executed first, followed by the
       ALPN callback.

RETURN VALUES

       SSL_CTX_set_tlsext_servername_callback() and SSL_CTX_set_tlsext_server-
       name_arg() both always return 1 indicating success.

SEE ALSO

       ssl(7), SSL_CTX_set_alpn_select_cb(3), SSL_get0_alpn_selected(3)

COPYRIGHT

       Copyright 2017 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
       <https://www.openssl.org/source/license.html>.

1.0.2t                            201SSL_CTX_set_tlsext_servername_callback(3)
See also SSL_CTX_set_tlsext_servername_arg(3)
See also SSL_get_servername(3)
See also SSL_get_servername_type(3)