pub unsafe extern "C" fn ECDH_compute_key(
out: *mut c_void,
outlen: usize,
pub_key: *const EC_POINT,
priv_key: *const EC_KEY,
kdf: Option<unsafe extern "C" fn(in_: *const c_void, inlen: usize, out: *mut c_void, outlen: *mut usize) -> *mut c_void>,
) -> c_int