执行 $ python gen_salt.py 后结果形式如下[4, 30, 42, -124, -120, -75, 77, 38, -112, 35, 4, -19, -9, -83, 122, -115, -34, 44, -95, -31, -102, -94, -85, -20, -73, 126, -16, 28, 20, -54]
