对文件的加密解密 实现的源代码
/* D3DES (V5.09) - * * A portable, public domain, version of the Data Encryption Standard. * * Written with Symantec's THINK (Lightspeed) C by Richard Outerbridge. * Thanks to: Dan Hoey for his excellent Initial and Inverse permutation * code; Jim Gillogly & Phil Karn for the DES key schedule