三种算法，写了个统一接口调用。SHA、DES、RSA。一些地方借鉴了别人的写法。 SHA：安全哈希算法 DES:入口参数有三个:Key、Data、Mode-Three algorithms, wrote a unified interface. SHA, DES, RSA. Some places borrow writing. SHA: a secure hash algorithm DES: entrance there are three parameters: