pub unsafe extern "C" fn cipher_auth_decrypt(
    ctx: *mut cipher_context_t,
    iv: *const c_uchar,
    iv_len: usize,
    ad: *const c_uchar,
    ad_len: usize,
    input: *const c_uchar,
    ilen: usize,
    output: *mut c_uchar,
    olen: *mut usize,
    tag: *const c_uchar,
    tag_len: usize
) -> c_int