OPENSSL_config(3SSL)                         OpenSSL                         OPENSSL_config(3SSL)



NAME
       OPENSSL_config, OPENSSL_no_config - simple OpenSSL configuration functions

SYNOPSIS
        #include <openssl/conf.h>

        void OPENSSL_config(const char *config_name);
        void OPENSSL_no_config(void);

DESCRIPTION
       OPENSSL_config() configures OpenSSL using the standard openssl.cnf configuration file name
       using config_name. If config_name is NULL then the file specified in the environment
       variable OPENSSL_CONF will be used, and if that is not set then a system default location
       is used.  Errors are silently ignored.  Multiple calls have no effect.

       OPENSSL_no_config() disables configuration. If called before OPENSSL_config() no
       configuration takes place.

NOTES
       The OPENSSL_config() function is designed to be a very simple "call it and forget it"
       function.  It is however much better than nothing. Applications which need finer control
       over their configuration functionality should use the configuration functions such as
       CONF_modules_load() directly. This function is deprecated and its use should be avoided.
       Applications should instead call CONF_modules_load() during initialization (that is before
       starting any threads).

       There are several reasons why calling the OpenSSL configuration routines is advisable. For
       example new ENGINE functionality was added to OpenSSL 0.9.7.  In OpenSSL 0.9.7 control
       functions can be supported by ENGINEs, this can be used (among other things) to load
       dynamic ENGINEs from shared libraries (DSOs).  However very few applications currently
       support the control interface and so very few can load and use dynamic ENGINEs. Equally in
       future more sophisticated ENGINEs will require certain control operations to customize
       them. If an application calls OPENSSL_config() it doesn't need to know or care about
       ENGINE control operations because they can be performed by editing a configuration file.

       Applications should free up configuration at application closedown by calling
       CONF_modules_free().

RESTRICTIONS
       The OPENSSL_config() function is designed to be a very simple "call it and forget it"
       function. As a result its behaviour is somewhat limited. It ignores all errors silently
       and it can only load from the standard configuration file location for example.

       It is however much better than nothing. Applications which need finer control over their
       configuration functionality should use the configuration functions such as
       CONF_load_modules() directly.

RETURN VALUES
       Neither OPENSSL_config() nor OPENSSL_no_config() return a value.

SEE ALSO
       conf(5), CONF_load_modules_file(3), CONF_modules_free(3)

HISTORY
       OPENSSL_config() and OPENSSL_no_config() first appeared in OpenSSL 0.9.7



1.0.1t                                      2016-05-03                       OPENSSL_config(3SSL)