DES算法的C语言实现，带有详细注释，02年所写，在我的另一个文件加密程序中使用过，在此摘出来也可以作为其他加密程序的内核。-DES algorithm realize the C language, with detailed notes, written in 2002, in my other file encryption procedures used in this pick up can also be used as other encryption core.