=pod

=head1 NAME

OPENSSL_config, OPENSSL_no_config - simple OpenSSL configuration functions

=head1 SYNOPSIS

 #include <openssl/conf.h>

 #if OPENSSL_API_COMPAT < 0x10100000L

 void OPENSSL_config(const char *appname);

 void OPENSSL_no_config(void);

 #endif

=head1 DESCRIPTION

OPENSSL_config() configures OpenSSL using the standard B<openssl.cnf> and

reads from the application section B<appname>. If B<appname> is NULL then

the default section, B<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.

If the application is built with B<OPENSSL_LOAD_CONF> defined, then a

call to OpenSSL_add_all_algorithms() will implicitly call OPENSSL_config()

first.

=head1 NOTES

The OPENSSL_config() function is designed to be a very simple "call it and

forget it" function.

It is however B<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, 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.

=head1 ENVIRONMENT

=over 4

=item B<OPENSSL_CONF>

The path to the config file.

Ignored in set-user-ID and set-group-ID programs.

=back

=head1 RETURN VALUES

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

=head1 SEE ALSO

L<config(5)>,

L<CONF_modules_load_file(3)>

=head1 HISTORY

The OPENSSL_no_config() and OPENSSL_config() functions were

deprecated in OpenSSL 1.1.0 by OPENSSL_init_crypto().

=head1 COPYRIGHT

Copyright 2004-2018 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

L<https://www.openssl.org/source/license.html>.

=cut