def get_cipher_version(self):
cipher = _lib.SSL_get_current_cipher(self._ssl)<EOL>if cipher == _ffi.NULL:<EOL><INDENT>return None<EOL><DEDENT>else:<EOL><INDENT>version = _ffi.string(_lib.SSL_CIPHER_get_version(cipher))<EOL>return version.decode("<STR_LIT:utf-8>")<EOL><DEDENT>
Obtain the protocol version of the currently used cipher.

:returns: The protocol name of the currently used cipher
    or :obj:`None` if no connection has been established.
:rtype: :class:`unicode` or :class:`NoneType`

.. versionadded:: 0.15