pub unsafe extern "C" fn EVP_PKEY_meth_get_sign(
pmeth: *const evp_pkey_method_st,
psign_init: *mut Option<unsafe extern "C" fn(*mut evp_pkey_ctx_st) -> i32>,
psign: *mut Option<unsafe extern "C" fn(*mut evp_pkey_ctx_st, *mut u8, *mut usize, *const u8, usize) -> i32>,
)