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OPENSSL_INIT_SSL(3)                 OpenSSL                OPENSSL_INIT_SSL(3)
NAME
       OPENSSL_init_ssl - OpenSSL (libssl and libcrypto) initialisation
SYNOPSIS
        #include <openssl/ssl.h>
        int OPENSSL_init_ssl(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings);
DESCRIPTION
       During normal operation OpenSSL (libssl and libcrypto) will allocate
       various resources at start up that must, subsequently, be freed on
       close down of the library. Additionally some resources are allocated on
       a per thread basis (if the application is multi-threaded), and these
       resources must be freed prior to the thread closing.
       As of version 1.1.0 OpenSSL will automatically allocate all resources
       that it needs so no explicit initialisation is required. Similarly it
       will also automatically deinitialise as required.
       However, there may be situations when explicit initialisation is
       desirable or needed, for example when some nondefault initialisation is
       required. The function OPENSSL_init_ssl() can be used for this purpose.
       Calling this function will explicitly initialise BOTH libcrypto and
       libssl. To explicitly initialise ONLY libcrypto see the
       OPENSSL_init_crypto(3) function.
       Numerous internal OpenSSL functions call OPENSSL_init_ssl().
       Therefore, in order to perform nondefault initialisation,
       OPENSSL_init_ssl() MUST be called by application code prior to any
       other OpenSSL function calls.
       The opts parameter specifies which aspects of libssl and libcrypto
       should be initialised. Valid options for libcrypto are described on the
       OPENSSL_init_crypto(3) page. In addition to any libcrypto specific
       option the following libssl options can also be used:
       OPENSSL_INIT_NO_LOAD_SSL_STRINGS
           Suppress automatic loading of the libssl error strings. This option
           is not a default option. Once selected subsequent calls to
           OPENSSL_init_ssl() with the option OPENSSL_INIT_LOAD_SSL_STRINGS
           will be ignored.
       OPENSSL_INIT_LOAD_SSL_STRINGS
           Automatic loading of the libssl error strings. This option is a
           default option. Once selected subsequent calls to
           OPENSSL_init_ssl() with the option OPENSSL_INIT_LOAD_SSL_STRINGS
           will be ignored.
       OPENSSL_init_ssl() takes a settings parameter which can be used to set
       parameter values.  See OPENSSL_init_crypto(3) for details.
RETURN VALUES
       The function OPENSSL_init_ssl() returns 1 on success or 0 on error.
SEE ALSO
       OPENSSL_init_crypto(3)
HISTORY
       The OPENSSL_init_ssl() function was added in OpenSSL 1.1.0.
COPYRIGHT
       Copyright 2016-2020 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>;.
1.1.1k                            2021-03-25               OPENSSL_INIT_SSL(3)