pub unsafe extern "C" fn gcm_crypt_and_tag(
ctx: *mut gcm_context,
mode: c_int,
length: size_t,
iv: *const c_uchar,
iv_len: size_t,
add: *const c_uchar,
add_len: size_t,
input: *const c_uchar,
output: *mut c_uchar,
tag_len: size_t,
tag: *mut c_uchar
) -> c_int
