openssl Getting started with openssl (De-)Initialization of openssl library

Example

Overview

Openssl consists of 2 libraries: libcrypto and libssl. Before openssl API can be used in an application, mandatory initialization procedures are expected to be performed. Once application is done with openssl related work, it is expected to cleanup allocated resources.

Code below does complete initialization, however, developer is free to initialize only openssl stuff he is interested in.

Initialize libcrypto

ERR_load_crypto_strings();
OpenSSL_add_all_algorithms();
OPENSSL_config(NULL); // Load default configuration (e.g. openssl.conf)

Initialize libssl

OPENSSL_init_ssl(0, NULL);

Deinitialize

CONF_modules_unload(1);
EVP_cleanup();
CRYPTO_cleanup_all_ex_data();
ERR_remove_state();
ERR_free_strings();