The following top-level framework functions provide generic initialization and cleanup necessary to implement cryptographic functionality in OpenSSL.
void OpenSSL_add_all_ciphers ();
OpenSSL_add_all_ciphers () loads all of the symmetric encryption algorithms that OpenSSL was compiled with into the global object hashtable.
void OpenSSL_add_all_digests();
OpenSSL_add_all_digests () loads all of the message digest algorithms that OpenSSL was compiled with into the global object hashtable.
void OpenSSL_add_all_algorithms();
OpenSSL_add_all_algorithms () is a simple wrapper to both of these functions, loading all symmetric encryption and message digest algorithms that OpenSSL was compiled with into the global object hashtable.
void EVP_cleanup();
EVP_cleanup () clears the state for any existing symmetric or message digest algorithms and clears out the object hashtable.