pub unsafe extern "C" fn EVP_PKEY_meth_set_derive(
pmeth: *mut evp_pkey_method_st,
derive_init: Option<unsafe extern "C" fn(_: *mut evp_pkey_ctx_st) -> i32>,
derive: Option<unsafe extern "C" fn(_: *mut evp_pkey_ctx_st, _: *mut u8, _: *mut usize) -> i32>,
)