SSL_CTX_CONFIG

Section: OpenSSL (3)
Updated: 2021-03-26
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NAME

SSL_CTX_config, SSL_config - configure SSL_CTX or SSL structure

SYNOPSIS

 #include <openssl/ssl.h>

 int SSL_CTX_config(SSL_CTX *ctx, const char *name);
 int SSL_config(SSL *s, const char *name);

DESCRIPTION

The functions SSL_CTX_config() and SSL_config() configure an SSL_CTX or SSL structure using the configuration name.

NOTES

By calling SSL_CTX_config() or SSL_config() an application can perform many complex tasks based on the contents of the configuration file: greatly simplifying application configuration code. A degree of future proofing can also be achieved: an application can support configuration features in newer versions of OpenSSL automatically.

A configuration file must have been previously loaded, for example using CONF_modules_load_file(). See config(5) for details of the configuration file syntax.

RETURN VALUES

SSL_CTX_config() and SSL_config() return 1 for success or 0 if an error occurred.

EXAMPLES

If the file ``config.cnf'' contains the following:

 testapp = test_sect

 [test_sect]
 # list of configuration modules

 ssl_conf = ssl_sect

 [ssl_sect]
 server = server_section

 [server_section]
 RSA.Certificate = server-rsa.pem
 ECDSA.Certificate = server-ecdsa.pem
 Ciphers = ALL:!RC4

An application could call:

 if (CONF_modules_load_file("config.cnf", "testapp", 0) <= 0) {
     fprintf(stderr, "Error processing config file\n");
     goto err;
 }

 ctx = SSL_CTX_new(TLS_server_method());

 if (SSL_CTX_config(ctx, "server") == 0) {
     fprintf(stderr, "Error configuring server.\n");
     goto err;
 }

In this example two certificates and the cipher list are configured without the need for any additional application code.

HISTORY

The SSL_CTX_config() and SSL_config() functions were added in OpenSSL 1.1.0.

COPYRIGHT

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