Function nginx::RSA_generate_key

pub unsafe extern "C" fn RSA_generate_key(
    bits: c_int, 
    e: c_ulong, 
    callback: Option<unsafe extern "C" fn(arg1: c_int, arg2: c_int, arg3: *mut c_void)>, 
    cb_arg: *mut c_void
) -> *mut RSA