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