pub unsafe extern "C" fn ECDH_compute_key(
out: *mut c_void,
outlen: usize,
pub_key: *const ec_point_st,
ecdh: *const ec_key_st,
KDF: Option<unsafe extern "C" fn(*const c_void, usize, *mut c_void, *mut usize) -> *mut c_void>,
) -> i32