用c++实现des算法 整体思路 用key.cpp 文件来产生秘钥，用ringfuction.cpp文件来实现轮函数，用main.c来实现加密和解密。有关函数见三个文件里的具体实现。 -With c++ To achieve the overall outlook des algorithm key.cpp document used to generate secret keys, used to achieve ringfuction.cpp paper round fun