Updated: 2022/Sep/29

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SSL_CTX_use_serverinfo(3)           OpenSSL          SSL_CTX_use_serverinfo(3)



NAME
       SSL_CTX_use_serverinfo_ex, SSL_CTX_use_serverinfo,
       SSL_CTX_use_serverinfo_file - use serverinfo extension

LIBRARY
       libcrypto, -lcrypto

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 an 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>.



3.0.12                            2023-05-07         SSL_CTX_use_serverinfo(3)