5 OPENSSL_config, OPENSSL_no_config - simple OpenSSL configuration functions
9 #include <openssl/conf.h>
11 void OPENSSL_config(const char *config_name);
12 void OPENSSL_no_config(void);
16 OPENSSL_config() configures OpenSSL using the standard B<openssl.cnf>
17 configuration file name using B<config_name>. If B<config_name> is NULL then
18 the file specified in the environment variable B<OPENSSL_CONF> will be used,
19 and if that is not set then a system default location is used.
20 In case of error, a message is printed to B<stderr> and the routine
22 Multiple calls have no effect.
24 OPENSSL_no_config() disables configuration. If called before OPENSSL_config()
25 no configuration takes place.
27 Applications should free up configuration at application closedown by calling
30 If the application is built with B<OPENSSL_LOAD_CONF> defined, then a
31 call to OpenSSL_add_all_algorithms() will implicitly call OPENSSL_config()
36 The OPENSSL_config() function is designed to be a very simple "call it and
38 It is however B<much> better than nothing. Applications which need finer
39 control over their configuration functionality should use the configuration
40 functions such as CONF_modules_load() directly.
42 It is B<strongly> recommended that B<all> new applications call
43 CONF_modules_load() during
44 initialization (that is before starting any threads).
46 There are several reasons why calling the OpenSSL configuration routines is
47 advisable. For example new ENGINE functionality was added to OpenSSL 0.9.7.
48 In OpenSSL 0.9.7 control functions can be supported by ENGINEs, this can be
49 used (among other things) to load dynamic ENGINEs from shared libraries (DSOs).
50 However very few applications currently support the control interface and so
51 very few can load and use dynamic ENGINEs. Equally in future more sophisticated
52 ENGINEs will require certain control operations to customize them. If an
53 application calls OPENSSL_config() it doesn't need to know or care about
54 ENGINE control operations because they can be performed by editing a
59 Neither OPENSSL_config() nor OPENSSL_no_config() return a value.
64 L<CONF_modules_load_file(3)|CONF_modules_load_file(3)>,
65 L<CONF_modules_free(3)|CONF_modules_free(3)>
69 OPENSSL_config() and OPENSSL_no_config() first appeared in OpenSSL 0.9.7