/usr/man/cat.3/SSL_CTX_set_tlsext_servername_callback.3

SSL_CTX_set_tlsext_servername_callback(3OpenSSSSL_CTX_set_tlsext_servername_callback(3)

NAME

     SSL_CTX_set_tlsext_servername_callback,
     SSL_CTX_set_tlsext_servername_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 specified 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 processing.  The servername callback is executed
     first, followed by the ALPN callback.

RETURN VALUES

     SSL_CTX_set_tlsext_servername_callback() and
     SSL_CTX_set_tlsext_servername_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.

1.0.2t               Last change: 2019-09-10                    1

SSL_CTX_set_tlsext_servername_callback(3OpenSSSSL_CTX_set_tlsext_servername_callback(3)

     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               Last change: 2019-09-10                    2

See also SSL_CTX_set_tlsext_servername_arg(3)
See also SSL_get_servername(3)
See also SSL_get_servername_type(3)