SSL_CTX_config, SSL_config - configure SSL_CTX or SSL structure

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       Licensed under the Apache License 2.0 (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>.

3.5.0                                              2025-06-04                               SSL_CTX_CONFIG(3SSL)

       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.

       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.

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

       SSL_CTX_config, SSL_config - configure SSL_CTX or SSL structure

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

ssl(7), config(5), SSL_CONF_cmd(3), CONF_modules_load_file(3)

        #include <openssl/ssl.h>

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