NAME

       SSL_CTX_use_serverinfo_ex, SSL_CTX_use_serverinfo, SSL_CTX_use_serverinfo_file - use
       serverinfo extension

SYNOPSIS

        #include <openssl/ssl.h>

        int SSL_CTX_use_serverinfo_ex(SSL_CTX *ctx, unsigned int version,
                                      const unsigned char *serverinfo,
                                      size_t serverinfo_length);

        int SSL_CTX_use_serverinfo(SSL_CTX *ctx, const unsigned char *serverinfo,
                                   size_t serverinfo_length);

        int SSL_CTX_use_serverinfo_file(SSL_CTX *ctx, const char *file);

DESCRIPTION

       These functions load "serverinfo" TLS extensions into the SSL_CTX. A "serverinfo"
       extension is returned in response to an empty ClientHello Extension.

       SSL_CTX_use_serverinfo_ex() loads one or more serverinfo extensions from a byte array into
       ctx. The version parameter specifies the format of the byte array provided in *serverinfo
       which is of length serverinfo_length.

       If version is SSL_SERVERINFOV2 then the extensions in the array must consist of a 4-byte
       context, a 2-byte Extension Type, a 2-byte length, and then length bytes of
       extension_data. The context and type values have the same meaning as for
       SSL_CTX_add_custom_ext(3). If serverinfo is being loaded for extensions to be added to a
       Certificate message, then the extension will only be added for the first certificate in
       the message (which is always the end-entity certificate).

       If version is SSL_SERVERINFOV1 then the extensions in the array must consist of a 2-byte
       Extension Type, a 2-byte length, and then length bytes of extension_data. The type value
       has the same meaning as for SSL_CTX_add_custom_ext(3). The following default context value
       will be used in this case:

        SSL_EXT_TLS1_2_AND_BELOW_ONLY | SSL_EXT_CLIENT_HELLO
        | SSL_EXT_TLS1_2_SERVER_HELLO | SSL_EXT_IGNORE_ON_RESUMPTION

       SSL_CTX_use_serverinfo() does the same thing as SSL_CTX_use_serverinfo_ex() except that
       there is no version parameter so a default version of SSL_SERVERINFOV1 is used instead.

       SSL_CTX_use_serverinfo_file() loads one or more serverinfo extensions from file into ctx.
       The extensions must be in PEM format.  Each extension must be in a format as described
       above for SSL_CTX_use_serverinfo_ex().  Each PEM extension name must begin with the phrase
       "BEGIN SERVERINFOV2 FOR " for SSL_SERVERINFOV2 data or "BEGIN SERVERINFO FOR " for
       SSL_SERVERINFOV1 data.

       If more than one certificate (RSA/DSA) is installed using SSL_CTX_use_certificate(), the
       serverinfo extension will be loaded into the last certificate installed.  If e.g. the last
       item was a RSA certificate, the loaded serverinfo extension data will be loaded for that
       certificate.  To use the serverinfo extension for multiple certificates,
       SSL_CTX_use_serverinfo() needs to be called multiple times, once after each time a
       certificate is loaded via a call to SSL_CTX_use_certificate().

RETURN VALUES

       On success, the functions return 1.  On failure, the functions return 0.  Check out the
       error stack to find out the reason.

SEE ALSO

       ssl(7)

COPYRIGHT

       Copyright 2013-2017 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>.