OPENSSL_config(3) OpenSSL OPENSSL_config(3)
NAME
OPENSSL_config, OPENSSL_no_config - simple OpenSSL configuration
functions
SYNOPSIS
#include <openssl/conf.h>
void OPENSSL_config(const char *appname);
void OPENSSL_no_config(void);
DESCRIPTION
OPENSSL_config() configures OpenSSL using the standard openssl.cnf and
reads from the application section appname. If appname is NULL then the
default section, openssl_conf, will be 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().
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
1.0.2k 2017-01-26 OPENSSL_config(3)