SSL_get_version - get the protocol version of a connection.
#include <openssl/ssl.h>
const char *SSL_get_version(const SSL *ssl);
SSL_get_version()
returns the name of the protocol used for the
connection ssl. It should only be called after the initial handshake has been
completed. Prior to that the results returned from this function may be
unreliable.
The following strings can be returned:
The connection uses the SSLv2 protocol.
The connection uses the SSLv3 protocol.
The connection uses the TLSv1.0 protocol.
The connection uses the TLSv1.1 protocol.
The connection uses the TLSv1.2 protocol.
This indicates an unknown protocol version.