Manpages - SSL_CTX_config.3ssl

SSL_CTX_config, SSL_config - configure SSL_CTX or SSL structure

#include <openssl/ssl.h> int SSL_CTX_config(SSL_CTX *ctx, const char *name); int SSL_config(SSL *s, const char *name);

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

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.

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

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.

config (5), SSL_CONF_cmd (3), CONF_modules_load_file (3)

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

Copyright 2015-2019 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 https://www.openssl.org/source/license.html.