SSL_get_current_cipher() returns a pointer to an SSL_CIPHER object
containing the description of the actually used cipher of a
connection established with the ssl
object.
SSL_get_cipher() and SSL_get_cipher_name() are identical macros to
obtain the name of the currently used cipher. SSL_get_cipher_bits()
is a macro to obtain the number of secret/algorithm bits used and
SSL_get_cipher_version() returns the protocol name. See SSL_CIPHER_get_name(3)
for more details.
RETURN VALUES
SSL_get_current_cipher() returns the cipher actually used or NULL,
when no session has been established.