DES算法

发表时间：2003-9-21 12:47:10 [回复]

　楼主

现在网上的DES加密算法大都有问题，有幸在BBS上找到一个，但接口不够好。下面这一个是用MFC的CSTRING封装了一次的。
下面这两个是关键
---------------------------------------
CString SEncrypt(CString);
CString SDecrypt(CString);
---------------------------------------
int main()
{
CString aa,bb,cc;
aa = "kingwind";
unsigned long s1,s2;
s1 = 30;
s2 = 100;

    CPackage_Encoder coder1,coder2;

    const char k1[256]="dsa3425Hello";
coder1.SetKey(k1);
coder2.SetKey(k1);

cout<<"明文："<<aa<<endl;

bb = coder1.SEncrypt(aa);
cout<<"密文："<<bb<<endl;

cc = coder2.SDecrypt(bb);
cout<<"明文："<<cc<<endl;

    return 0;
};

俱怀逸兴壮思飞
欲上青天揽明月

作者：lanjingquan
专家分：500

发表时间：2003-9-21 12:41:34 [回复]

　第1楼

// DesCode.h: interface for the CDesCode class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_DESCODE_H__C03E92C7_2754_4B05_B19D_59D86587C26D__INCLUDED_)
#define AFX_DESCODE_H__C03E92C7_2754_4B05_B19D_59D86587C26D__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include "AFX.h"

typedef union{
        unsigned char byte[8];
        struct
{
                unsigned long low;
                unsigned long high;
        }dword;
}SBitBlock;

//static
extern void deskey (unsigned char const *key, int decryptf, unsigned long *outbuf);
//static
extern void desDES (unsigned char const inblock[8], unsigned char outblock[8], unsigned long const *keys);

class CDES_Encoder
{
private:
// Data:16 48-bit k[i], calculated from "key", use low 6-bit in each byte
        SBitBlock encrypt_k[16],decrypt_k[16];
public:
// Functions:SetKey,Encrypt,Decrypt
        inline void SetKey(const SBitBlock& key);       //calculate k[i]
        inline void Encrypt(SBitBlock& destination, const SBitBlock& source)const;
        inline void Decrypt(SBitBlock& destination, const SBitBlock& source)const;
};

inline void CDES_Encoder::SetKey(const SBitBlock& key)
{
        deskey((unsigned char const*)(&key),0,(unsigned long*)encrypt_k);
        deskey((unsigned char const*)(&key),1,(unsigned long*)decrypt_k);
};

inline void CDES_Encoder::Encrypt(SBitBlock& destination, const SBitBlock& source)const
{
        desDES((unsigned char const*)(&source),(unsigned char*)(&destination),(unsigned long const*)encrypt_k);
};

inline void CDES_Encoder::Decrypt(SBitBlock& destination, const SBitBlock& source)const
{
        desDES((unsigned char const*)(&source),(unsigned char*)(&destination),(unsigned long const*)decrypt_k);
};

// Below defines the package encryption and decryption class
class CPackage_Encoder{
private:
// Data: a DES coder and package seed
        CDES_Encoder theDEScoder;
        SBitBlock seed;
public:
// Functions: SetKey,SetSeed,GetSeed,Encrypt,Decrypt
        void SetKey(const char* password);
        inline void SetSeed(unsigned long lo,unsigned long hi);
        inline void GetSeed(unsigned long& lo,unsigned long& hi)const;
CString SEncrypt(CString);
CString SDecrypt(CString);
        int Encrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize)const;
        int Decrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize);
};

inline void CPackage_Encoder::SetSeed(unsigned long lo,unsigned long hi)
{
        seed.dword.low=lo;
        seed.dword.high=hi;
};

inline void CPackage_Encoder::GetSeed(unsigned long& lo,unsigned long& hi)const
{
        lo=seed.dword.low;
        hi=seed.dword.high;
};
#endif // !defined(AFX_DESCODE_H__C03E92C7_2754_4B05_B19D_59D86587C26D__INCLUDED_)

俱怀逸兴壮思飞
欲上青天揽明月

此帖尚未评分

作者：lanjingquan
专家分：500

发表时间：2003-9-21 12:42:56 [回复]

　第2楼

// DesCode.cpp: implementation of the CDesCode class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "hotel.h"
#include "DesCode.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

#define word32 unsigned long
#define byte unsigned char

extern void deskey (unsigned char const *key, int decryptf, unsigned long  *outbuf);
extern void desDES (unsigned char const inblock[8], unsigned char outblock[8], unsigned long  const *keys);

/* The size of a scheduled DES key */
#define DES_KEYWORDS 32
#define DES_KEYBYTES (sizeof(word32)*DES_KEYWORDS)
static word32 const bigbyte[24] = {
                0x800000L,              0x400000L,              0x200000L,              0x100000L,
                0x80000L,               0x40000L,               0x20000L,               0x10000L,
                0x8000L,                0x4000L,                0x2000L,                0x1000L,
                0x800L,                 0x400L,                 0x200L,                 0x100L,
                0x80L,                  0x40L,                  0x20L,                  0x10L,
                0x8L,                   0x4L,                   0x2L,                   0x1L    };
/* Use the key schedule specified in the Standard (ANSI X3.92-1981). */
static byte const pc1[56] = {
        56, 48, 40, 32, 24, 16, 8,              0, 57, 49, 41, 33, 25, 17,
        9, 1, 58, 50, 42, 34, 26,               18, 10, 2, 59, 51, 43, 35,
        62, 54, 46, 38, 30, 22, 14,             6, 61, 53, 45, 37, 29, 21,
        13, 5, 60, 52, 44, 36, 28,              20, 12, 4, 27, 19, 11, 3 };
static byte const totrot[16] = {
        1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28 };
static byte const pc2[48] = {
                13, 16, 10, 23, 0, 4,    2, 27, 14, 5, 20, 9,
                22, 18, 11, 3, 25, 7,   15, 6, 26, 19, 12, 1,
                40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
                43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31 };
/*
* This is a less-that-brilliant key scheduling routine.
* It could stand optimization some time.
*
* cookey "cooks" the key into the desired form, from the basic one that
* has the keys for S-boxes 1 through 8 in adjacent words of the
* "raw" array. I.e. the bits start out like this:
* xxxxxxxx111111222222333333444444
* xxxxxxxx555555666666777777888888
* We actually want the keys to look like this:
* 111111xx333333xx555555xx777777xx
* 222222xx444444xx666666xx888888xx
* Where the "xx" patterns are set to 01020300 for use by the s-box
* lookup code in the main encrypt loop.
*/
static void
cookey (word32 *raw, word32 *cooked)
{
                int i;
                for (i = 0; i < 16; i++, raw += 2, cooked += 2) {
                                cooked[0] = (raw[0] & 0x00fc0000L) << 8;
                                cooked[0] |= (raw[0] & 0x00000fc0L) << 12;
                                cooked[0] |= (raw[1] & 0x00fc0000L) >> 8;
                                cooked[0] |= (raw[1] & 0x00000fc0L) >> 4;
                                cooked[0] |= 0x01020300;
                                cooked[1] = (raw[0] & 0x0003f000L) << 14;
                                cooked[1] |= (raw[0] & 0x0000003fL) << 18;
                                cooked[1] |= (raw[1] & 0x0003f000L) >> 2;
                                cooked[1] |= (raw[1] & 0x0000003fL) << 2;
                                cooked[1] |= 0x01020300;
                }
                return;
}

void deskey (byte const *key, int decryptf, word32 *outbuf)
{
                int i, j, l, m, n;
                byte pc1m[56], pcr[56];
                word32 kn[32];

                for (j = 0; j < 56; j++) {
                        l = pc1[j];
                        m = l & 07;
                        pc1m[j] = ( key[l >> 3] >> (~l & 7) ) & 1;
                }
                for (i = 0; i < 16; i++ ) {
                                m = (decryptf ? 15-i : i) << 1;
                                n = m + 1;
                                kn[m] = kn[n] = 0L;
                                for (j = 0; j < 28; j++) {
                                                l = j + totrot[i];
                                                if (l >= 28)
                                                        l -= 28;
                                                pcr[j] = pc1m[l];
                                }
                                for (j = 28; j < 56; j++) {
                                                l = j + totrot[i];
                                                if (l >= 56)
                                                        l -= 28;
                                                pcr[j] = pc1m[l];
                                }
                                for (j = 0; j < 24; j++) {
                                                if (pcr[pc2[j]])
                                                        kn[m] |= bigbyte[j];
                                                if (pcr[pc2[j+24]])
                                                                kn[n] |= bigbyte[j];
                                }
                }
                cookey(kn, outbuf);
                return;
}
/* S-boxes 1, 3, 5, 7, plus P permutation, rotated */
static word32 const SP0[512] = {
                0x00404100, 0x00000000, 0x00004000, 0x00404101,
                0x00404001, 0x00004101, 0x00000001, 0x00004000,
                0x00000100, 0x00404100, 0x00404101, 0x00000100,
                0x00400101, 0x00404001, 0x00400000, 0x00000001,
                0x00000101, 0x00400100, 0x00400100, 0x00004100,
                0x00004100, 0x00404000, 0x00404000, 0x00400101,
                0x00004001, 0x00400001, 0x00400001, 0x00004001,
                0x00000000, 0x00000101, 0x00004101, 0x00400000,
                0x00004000, 0x00404101, 0x00000001, 0x00404000,
                0x00404100, 0x00400000, 0x00400000, 0x00000100,
                0x00404001, 0x00004000, 0x00004100, 0x00400001,
                0x00000100, 0x00000001, 0x00400101, 0x00004101,
                0x00404101, 0x00004001, 0x00404000, 0x00400101,
                0x00400001, 0x00000101, 0x00004101, 0x00404100,
                0x00000101, 0x00400100, 0x00400100, 0x00000000,
                0x00004001, 0x00004100, 0x00000000, 0x00404001,
                0x00000082, 0x02008080, 0x00000000, 0x02008002,
                0x02000080, 0x00000000, 0x00008082, 0x02000080,
                0x00008002, 0x02000002, 0x02000002, 0x00008000,
                0x02008082, 0x00008002, 0x02008000, 0x00000082,
                0x02000000, 0x00000002, 0x02008080, 0x00000080,
                0x00008080, 0x02008000, 0x02008002, 0x00008082,
                0x02000082, 0x00008080, 0x00008000, 0x02000082,
                0x00000002, 0x02008082, 0x00000080, 0x02000000,
                0x02008080, 0x02000000, 0x00008002, 0x00000082,
                0x00008000, 0x02008080, 0x02000080, 0x00000000,
                0x00000080, 0x00008002, 0x02008082, 0x02000080,
                0x02000002, 0x00000080, 0x00000000, 0x02008002,
                0x02000082, 0x00008000, 0x02000000, 0x02008082,
                0x00000002, 0x00008082, 0x00008080, 0x02000002,
                0x02008000, 0x02000082, 0x00000082, 0x02008000,
                0x00008082, 0x00000002, 0x02008002, 0x00008080,
                0x00000040, 0x00820040, 0x00820000, 0x10800040,
                0x00020000, 0x00000040, 0x10000000, 0x00820000,
                0x10020040, 0x00020000, 0x00800040, 0x10020040,
                0x10800040, 0x10820000, 0x00020040, 0x10000000,
                0x00800000, 0x10020000, 0x10020000, 0x00000000,
                0x10000040, 0x10820040, 0x10820040, 0x00800040,
                0x10820000, 0x10000040, 0x00000000, 0x10800000,
                0x00820040, 0x00800000, 0x10800000, 0x00020040,
                0x00020000, 0x10800040, 0x00000040, 0x00800000,
                0x10000000, 0x00820000, 0x10800040, 0x10020040,
                0x00800040, 0x10000000, 0x10820000, 0x00820040,
                0x10020040, 0x00000040, 0x00800000, 0x10820000,
                0x10820040, 0x00020040, 0x10800000, 0x10820040,
                0x00820000, 0x00000000, 0x10020000, 0x10800000,
                0x00020040, 0x00800040, 0x10000040, 0x00020000,
                0x00000000, 0x10020000, 0x00820040, 0x10000040,
                0x00080000, 0x81080000, 0x81000200, 0x00000000,
                0x00000200, 0x81000200, 0x80080200, 0x01080200,
                0x81080200, 0x00080000, 0x00000000, 0x81000000,
                0x80000000, 0x01000000, 0x81080000, 0x80000200,
                0x01000200, 0x80080200, 0x80080000, 0x01000200,
                0x81000000, 0x01080000, 0x01080200, 0x80080000,
                0x01080000, 0x00000200, 0x80000200, 0x81080200,
                0x00080200, 0x80000000, 0x01000000, 0x00080200,
                0x01000000, 0x00080200, 0x00080000, 0x81000200,
                0x81000200, 0x81080000, 0x81080000, 0x80000000,
                0x80080000, 0x01000000, 0x01000200, 0x00080000,
                0x01080200, 0x80000200, 0x80080200, 0x01080200,
                0x80000200, 0x81000000, 0x81080200, 0x01080000,
                0x00080200, 0x00000000, 0x80000000, 0x81080200,
                0x00000000, 0x80080200, 0x01080000, 0x00000200,
                0x81000000, 0x01000200, 0x00000200, 0x80080000 };
/* S-boxes 2, 4, 6, 8, plus P permutation, rotated */
static word32 const SP1[512] = {
                0x20042008, 0x20002000, 0x00002000, 0x00042008,
                0x00040000, 0x00000008, 0x20040008, 0x20002008,
                0x20000008, 0x20042008, 0x20042000, 0x20000000,
                0x20002000, 0x00040000, 0x00000008, 0x20040008,
                0x00042000, 0x00040008, 0x20002008, 0x00000000,
                0x20000000, 0x00002000, 0x00042008, 0x20040000,
                0x00040008, 0x20000008, 0x00000000, 0x00042000,
                0x00002008, 0x20042000, 0x20040000, 0x00002008,
                0x00000000, 0x00042008, 0x20040008, 0x00040000,
                0x20002008, 0x20040000, 0x20042000, 0x00002000,
                0x20040000, 0x20002000, 0x00000008, 0x20042008,
                0x00042008, 0x00000008, 0x00002000, 0x20000000,
                0x00002008, 0x20042000, 0x00040000, 0x20000008,
                0x00040008, 0x20002008, 0x20000008, 0x00040008,
                0x00042000, 0x00000000, 0x20002000, 0x00002008,
                0x20000000, 0x20040008, 0x20042008, 0x00042000,
                0x40200800, 0x40000820, 0x40000820, 0x00000020,
                0x00200820, 0x40200020, 0x40200000, 0x40000800,
                0x00000000, 0x00200800, 0x00200800, 0x40200820,
                0x40000020, 0x00000000, 0x00200020, 0x40200000,
                0x40000000, 0x00000800, 0x00200000, 0x40200800,
                0x00000020, 0x00200000, 0x40000800, 0x00000820,
                0x40200020, 0x40000000, 0x00000820, 0x00200020,
                0x00000800, 0x00200820, 0x40200820, 0x40000020,
                0x00200020, 0x40200000, 0x00200800, 0x40200820,
                0x40000020, 0x00000000, 0x00000000, 0x00200800,
                0x00000820, 0x00200020, 0x40200020, 0x40000000,
                0x40200800, 0x40000820, 0x40000820, 0x00000020,
                0x40200820, 0x40000020, 0x40000000, 0x00000800,
                0x40200000, 0x40000800, 0x00200820, 0x40200020,
                0x40000800, 0x00000820, 0x00200000, 0x40200800,
                0x00000020, 0x00200000, 0x00000800, 0x00200820,
                        0x08000004, 0x08100000, 0x00001000, 0x08101004,
                        0x08100000, 0x00000004, 0x08101004, 0x00100000,
                        0x08001000, 0x00101004, 0x00100000, 0x08000004,
                        0x00100004, 0x08001000, 0x08000000, 0x00001004,
                        0x00000000, 0x00100004, 0x08001004, 0x00001000,
                        0x00101000, 0x08001004, 0x00000004, 0x08100004,
                        0x08100004, 0x00000000, 0x00101004, 0x08101000,
                        0x00001004, 0x00101000, 0x08101000, 0x08000000,
                        0x08001000, 0x00000004, 0x08100004, 0x00101000,
                        0x08101004, 0x00100000, 0x00001004, 0x08000004,
                        0x00100000, 0x08001000, 0x08000000, 0x00001004,
                        0x08000004, 0x08101004, 0x00101000, 0x08100000,
                        0x00101004, 0x08101000, 0x00000000, 0x08100004,
                        0x00000004, 0x00001000, 0x08100000, 0x00101004,
                        0x00001000, 0x00100004, 0x08001004, 0x00000000,
                        0x08101000, 0x08000000, 0x00100004, 0x08001004,
                        0x04000410, 0x00000400, 0x00010000, 0x04010410,
                        0x04000000, 0x04000410, 0x00000010, 0x04000000,
                        0x00010010, 0x04010000, 0x04010410, 0x00010400,
                        0x04010400, 0x00010410, 0x00000400, 0x00000010,
                        0x04010000, 0x04000010, 0x04000400, 0x00000410,
                        0x00010400, 0x00010010, 0x04010010, 0x04010400,
                        0x00000410, 0x00000000, 0x00000000, 0x04010010,
                        0x04000010, 0x04000400, 0x00010410, 0x00010000,
                        0x00010410, 0x00010000, 0x04010400, 0x00000400,
                        0x00000010, 0x04010010, 0x00000400, 0x00010410,
                        0x04000400, 0x00000010, 0x04000010, 0x04010000,
                        0x04010010, 0x04000000, 0x00010000, 0x04000410,
                        0x00000000, 0x04010410, 0x00010010, 0x04000010,
                        0x04010000, 0x04000400, 0x04000410, 0x00000000,
                        0x04010410, 0x00010400, 0x00010400, 0x00000410,
                        0x00000410, 0x00010010, 0x04000000, 0x04010400 };
/*
* This encryption function is fairly clever in the way it does its
* s-box lookup. The S-boxes are indexed by bytes, rather than
* words, because that's faster on many machines, and shifting
* everything two bits to do the multiply by 4 is trivial.
* Then, the indexing into the various S boxes is done by
* adding the appropriate offset bits into the key array, so the
* addition is done by the XOR with the key rather than having to
* be done explicitly here.
*/
void desDES (byte const inblock[8], byte outblock[8], word32 const *keys)
{
                word32 s, t, right, leftt;
                int round;

                leftt    = ((word32)inblock[0] << 24)
        | ((word32)inblock[1] << 16)
        | ((word32)inblock[2] << 8)
        | (word32)inblock[3];
                right    = ((word32)inblock[4] << 24)
        | ((word32)inblock[5] << 16)
        | ((word32)inblock[6] << 8)
        | (word32)inblock[7];
                /* Initial permutation IP */
                t = ((leftt >> 4) ^ right) & 0x0f0f0f0fL;
                right ^= t;
                leftt ^= (t << 4);
                t = ((leftt >> 16) ^ right) & 0x0000ffffL;
                right ^= t;
                leftt ^= (t << 16);
                t = ((right >> 2) ^ leftt) & 0x33333333L;
                leftt ^= t;
                right ^= (t << 2);
                t = ((right >> 8) ^ leftt) & 0x00ff00ffL;
                leftt ^= t;
                right ^= (t << 8);
                leftt = ((leftt >> 1) | (leftt << 31));
                t = (leftt ^ right) & 0x55555555L;
                leftt ^= t;
                right ^= t;
                right = ((right >> 1) | (right << 31));
                for (round = 0; round < 8; round++) {
                                s = (right & 0xfcfcfcfc) ^ keys[0];
                                t = (((right >> 28) | (right << 4)) & 0xfcfcfcfc)
                                        ^ keys[1];
                                leftt ^= *(word32 *)((char *)SP0+( s & 0x3fc))
                                ^ *(word32 *)((char *)SP0+((s >> 8 ) & 0x3fc))
                                ^ *(word32 *)((char *)SP0+((s >> 16) & 0x3fc))
                                ^ *(word32 *)((char *)SP0+((s >> 24) & 0x0fc))
                                ^ *(word32 *)((char *)SP1+( t & 0x3fc))
                                ^ *(word32 *)((char *)SP1+((t >> 8 ) & 0x3fc))
                                ^ *(word32 *)((char *)SP1+((t >> 16) & 0x3fc))
                                ^ *(word32 *)((char *)SP1+((t >> 24) & 0x0fc));
                                s = (leftt & 0xfcfcfcfc) ^ keys[2];
                        t = (((leftt >> 28) | (leftt << 4)) & 0xfcfcfcfc)
                                ^ keys[3];
                        right ^= *(word32 *)((char *)SP0+( s & 0x3fc))
                        ^ *(word32 *)((char *)SP0+((s >> 8 ) & 0x3fc))
                        ^ *(word32 *)((char *)SP0+((s >> 16) & 0x3fc))
                        ^ *(word32 *)((char *)SP0+((s >> 24) & 0x0fc))
                        ^ *(word32 *)((char *)SP1+( t & 0x3fc))
                        ^ *(word32 *)((char *)SP1+((t >> 8 ) & 0x3fc))
                        ^ *(word32 *)((char *)SP1+((t >> 16) & 0x3fc))
                        ^ *(word32 *)((char *)SP1+((t >> 24) & 0x0fc));
                        keys += 4;
        };
/* Inverse IP */
leftt = ((leftt << 1) | (leftt >> 31));
                t = (leftt ^ right) & 0x55555555L;
                leftt ^= t;
                right ^= t;
                right = ((right << 1) | (right >> 31));
                t = ((leftt >> 8) ^ right) & 0x00ff00ffL;
                right ^= t;
                leftt ^= (t << 8);
                t = ((leftt >> 2) ^ right) & 0x33333333L;
                right ^= t;
                leftt ^= (t << 2);
                t = ((right >> 16) ^ leftt) & 0x0000ffffL;
                leftt ^= t;
                right ^= (t << 16);
                t = ((right >> 4) ^ leftt) & 0x0f0f0f0fL;
                leftt ^= t;
                right ^= (t << 4);
outblock[0] = (byte)(right >> 24);
outblock[1] = (byte)(right >> 16);
outblock[2] = (byte)(right >> 8);
outblock[3] = (byte)(right );
outblock[4] = (byte)(leftt >> 24);
outblock[5] = (byte)(leftt >> 16);
outblock[6] = (byte)(leftt >> 8);
outblock[7] = (byte)(leftt      );
return;
};
#undef word32
#undef byte
/******************************************************
   The Below Code (Package Coder) is Writen In "C++"
*******************************************************/
void CPackage_Encoder::SetKey(const char* password){
        unsigned i=0;
        SBitBlock key;
        key.dword.low=0x476226E8;
        key.dword.high=0x87F5F4AD;
        while(password[i]){
                key.byte[i%8]^=(password[i]+(i>>3)+37);
                i++;
        };
        theDEScoder.SetKey(key);
        SetSeed(0x31A68E0D,0x6508CB93);
};
int CPackage_Encoder::Encrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize)const{
        unsigned i,j;
        SBitBlock a,b;
        theDEScoder.Encrypt(a,seed);
        for(i=0;i<8;i++)destination[i]=a.byte[i];
        a.dword.low=seed.dword.low;
        a.dword.high=seed.dword.high;
        for(i=0,j=8;i<sourcesize;i++,j++){
                if((i%8)==0){
                        a.dword.low+=23;
                        a.dword.high-=71;
                        theDEScoder.Encrypt(b,a);
                };
                destination[j]=source[i]^b.byte[i%8];
        };
        return 0;
};
int CPackage_Encoder::Decrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize){
        unsigned i,j;
        SBitBlock a,b;
        if(sourcesize<8)return -201;    //Too Small Package
        for(i=0;i<8;i++)a.byte[i]=source[i];
        theDEScoder.Decrypt(seed,a);
        a.dword.low=seed.dword.low;
        a.dword.high=seed.dword.high;
        for(i=0,j=8;j<sourcesize;i++,j++){
                if((i%8)==0){
                        a.dword.low+=23;
                        a.dword.high-=71;
                        theDEScoder.Encrypt(b,a);
                };
                destination[i]=source[j]^b.byte[i%8];
        };
        return 0;
};

CString CPackage_Encoder::SEncrypt(CString s)
{
int z = s.GetLength();
CString sdet;
unsigned char * src = new unsigned char[z];
for(int i=0;i<z;i++)
src[i] = s[i];

unsigned char * det = new unsigned char[z+8];
Encrypt(det,src, z);

for(i=0;i<z+8;i++)
sdet += det[i];

delete[] det;
delete[] src;

return sdet;
}

CString CPackage_Encoder::SDecrypt(CString s)
{
int z = s.GetLength();
CString sdet;
unsigned char * src = new unsigned char[z+8];
for(int i=0;i<z;i++)
src[i] = s[i];

unsigned char * det = new unsigned char[z];
Decrypt(det,src, z);

for(i=0;i<z-8;i++)
sdet += det[i];

delete[] det;
delete[] src;

return sdet;
}

俱怀逸兴壮思飞
欲上青天揽明月

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作者：meteor135
专家分：4210

发表时间：2003-9-21 14:39:18 [回复]

　第3楼

楼主上面给出的文件不是一个完整的工程，因而无法简单的编译运行，我花了一点时间整理了一下，现重新贴在下面，请大家按要求进行即可，有什么问题请提出。

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作者：meteor135
专家分：4210

发表时间：2003-9-21 14:44:50 [回复]

　第4楼

/*
本项目由3个源文件（分别为下面的三个文件）组成，建立工程时首先需要用vc6.0打开Des.cpp文件，然后直接编译连接，会有两个错误，只需要在VC6.0的Setting中设置Using MFC as static/shared Library即可。
然后添加另外两个文件至工程（这一步可不要）。
再编译连接。
*/

// DES.cpp : Defines the entry point for the console application.
//
#include <iostream.h>
#include "DesCode.h"

int main()
{
    CString aa,bb,cc;
    aa = "kingwind";

    CPackage_Encoder coder1,coder2;

    const char k1[256]="dsa3425Hello";
    coder1.SetKey(k1);
    coder2.SetKey(k1);

    cout<<"明文："<<aa<<endl;

    bb = coder1.SEncrypt(aa);
    cout<<"密文："<<bb<<endl;

    cc = coder2.SDecrypt(bb);
    cout<<"明文："<<cc<<endl;

    return 0;
}

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作者：meteor135
专家分：4210

发表时间：2003-9-21 14:45:35 [回复]

　第5楼

// DesCode.h: interface for the CDesCode class.
//
//////////////////////////////////////////////////////////////////////

#pragma once
#include <afx.h>

typedef union
{
    unsigned char byte[8];
    struct
    {
        unsigned long low;
        unsigned long high;
    }dword;
}SBitBlock;

extern void deskey (unsigned char const *key, int decryptf, unsigned long *outbuf);
extern void desDES (unsigned char const inblock[8], unsigned char outblock[8], unsigned long const *keys);

class CDES_Encoder
{
private:
    // Data:16 48-bit k[i], calculated from "key", use low 6-bit in each byte
    SBitBlock encrypt_k[16],decrypt_k[16];
public:
    inline void SetKey(const SBitBlock& key);       //calculate k[i]
    inline void Encrypt(SBitBlock& destination, const SBitBlock& source)const;
    inline void Decrypt(SBitBlock& destination, const SBitBlock& source)const;
};

// Below defines the package encryption and decryption class
class CPackage_Encoder
{
private:
    // Data: a DES coder and package seed
    CDES_Encoder theDEScoder;
    SBitBlock seed;
public:
    void SetKey(const char* password);
    inline void SetSeed(unsigned long lo,unsigned long hi);
    inline void GetSeed(unsigned long& lo,unsigned long& hi) const;
    int Encrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize)const;
    int Decrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize);
    CString SEncrypt(CString);
    CString SDecrypt(CString);
};

inline void CDES_Encoder::SetKey(const SBitBlock& key)
{
    deskey((unsigned char const*)(&key),0,(unsigned long*)encrypt_k);
    deskey((unsigned char const*)(&key),1,(unsigned long*)decrypt_k);
}

inline void CDES_Encoder::Encrypt(SBitBlock& destination, const SBitBlock& source)const
{
    desDES((unsigned char const*)(&source),(unsigned char*)(&destination),(unsigned long const*)encrypt_k);
}

inline void CDES_Encoder::Decrypt(SBitBlock& destination, const SBitBlock& source)const
{
    desDES((unsigned char const*)(&source),(unsigned char*)(&destination),(unsigned long const*)decrypt_k);
}

inline void CPackage_Encoder::SetSeed(unsigned long lo,unsigned long hi)
{
    seed.dword.low=lo;
    seed.dword.high=hi;
}

inline void CPackage_Encoder::GetSeed(unsigned long& lo,unsigned long& hi)const
{
    lo=seed.dword.low;
    hi=seed.dword.high;
}

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作者：meteor135
专家分：4210

发表时间：2003-9-21 14:47:44 [回复]

　第6楼

// DesCode.cpp: implementation of the CDesCode class.
//
//////////////////////////////////////////////////////////////////////

#include "DesCode.h"

#define word32 unsigned long
#define byte unsigned char

extern void deskey (unsigned char const *key, int decryptf, unsigned long  *outbuf);
extern void desDES (unsigned char const inblock[8], unsigned char outblock[8], unsigned long  const *keys);

/* The size of a scheduled DES key */
#define DES_KEYWORDS 32
#define DES_KEYBYTES (sizeof(word32)*DES_KEYWORDS)
static word32 const bigbyte[24] =
{
    0x800000L,              0x400000L,              0x200000L,              0x100000L,
    0x80000L,               0x40000L,               0x20000L,               0x10000L,
    0x8000L,                0x4000L,                0x2000L,                0x1000L,
    0x800L,                 0x400L,                 0x200L,                 0x100L,
    0x80L,                  0x40L,                  0x20L,                  0x10L,
    0x8L,                   0x4L,                   0x2L,                   0x1L
};
/* Use the key schedule specified in the Standard (ANSI X3.92-1981). */
static byte const pc1[56] =
{
    56, 48, 40, 32, 24, 16, 8,
    0, 57, 49, 41, 33, 25, 17,
    9, 1, 58, 50, 42, 34, 26,
    18, 10, 2, 59, 51, 43, 35,
    62, 54, 46, 38, 30, 22, 14,
    6, 61, 53, 45, 37, 29, 21,
    13, 5, 60, 52, 44, 36, 28,
    20, 12, 4, 27, 19, 11, 3
};
static byte const totrot[16] =
{
    1, 2, 4, 6, 8, 10, 12, 14,
    15, 17, 19, 21, 23, 25, 27, 28
};
static byte const pc2[48] =
{
    13, 16, 10, 23, 0, 4,
    2, 27, 14, 5, 20, 9,
    22, 18, 11, 3, 25, 7,
    15, 6, 26, 19, 12, 1,
    40, 51, 30, 36, 46, 54,
    29, 39, 50, 44, 32, 47,
    43, 48, 38, 55, 33, 52,
    45, 41, 49, 35, 28, 31
};
/*
* This is a less-that-brilliant key scheduling routine.
* It could stand optimization some time.
*
* cookey "cooks" the key into the desired form, from the basic one that
* has the keys for S-boxes 1 through 8 in adjacent words of the
* "raw" array. I.e. the bits start out like this:
* xxxxxxxx111111222222333333444444
* xxxxxxxx555555666666777777888888
* We actually want the keys to look like this:
* 111111xx333333xx555555xx777777xx
* 222222xx444444xx666666xx888888xx
* Where the "xx" patterns are set to 01020300 for use by the s-box
* lookup code in the main encrypt loop.
*/
static void cookey (word32 *raw, word32 *cooked)
{
    for (int i = 0; i < 16; i++, raw += 2, cooked += 2)
    {
        cooked[0] = (raw[0] & 0x00fc0000L) << 8;
        cooked[0] |= (raw[0] & 0x00000fc0L) << 12;
        cooked[0] |= (raw[1] & 0x00fc0000L) >> 8;
        cooked[0] |= (raw[1] & 0x00000fc0L) >> 4;
        cooked[0] |= 0x01020300;

        cooked[1] = (raw[0] & 0x0003f000L) << 14;
        cooked[1] |= (raw[0] & 0x0000003fL) << 18;
        cooked[1] |= (raw[1] & 0x0003f000L) >> 2;
        cooked[1] |= (raw[1] & 0x0000003fL) << 2;
        cooked[1] |= 0x01020300;
    }
}

void deskey (byte const *key, int decryptf, word32 *outbuf)
{
    int i, j, l, m, n;
    byte pc1m[56], pcr[56];
    word32 kn[32];

    for (j = 0; j < 56; j++)
    {
        l = pc1[j];
        m = l & 07;
        pc1m[j] = ( key[l >> 3] >> (~l & 7) ) & 1;
    }

    for (i = 0; i < 16; i++ )
    {
        m = (decryptf ? 15-i : i) << 1;
        n = m + 1;
        kn[m] = kn[n] = 0L;
        for (j = 0; j < 28; j++)
        {
            l = j + totrot[i];
            if (l >= 28)
                l -= 28;
            pcr[j] = pc1m[l];
        }
        for (j = 28; j < 56; j++)
        {
            l = j + totrot[i];
            if (l >= 56)
                l -= 28;
            pcr[j] = pc1m[l];
        }
        for (j = 0; j < 24; j++)
        {
            if (pcr[pc2[j]])
                kn[m] |= bigbyte[j];
            if (pcr[pc2[j+24]])
                kn[n] |= bigbyte[j];
        }
    }
    cookey(kn, outbuf);
}

/* S-boxes 1, 3, 5, 7, plus P permutation, rotated */
static word32 const SP0[512] =
{
    0x00404100, 0x00000000, 0x00004000, 0x00404101,
    0x00404001, 0x00004101, 0x00000001, 0x00004000,
    0x00000100, 0x00404100, 0x00404101, 0x00000100,
    0x00400101, 0x00404001, 0x00400000, 0x00000001,
    0x00000101, 0x00400100, 0x00400100, 0x00004100,
    0x00004100, 0x00404000, 0x00404000, 0x00400101,
    0x00004001, 0x00400001, 0x00400001, 0x00004001,
    0x00000000, 0x00000101, 0x00004101, 0x00400000,
    0x00004000, 0x00404101, 0x00000001, 0x00404000,
    0x00404100, 0x00400000, 0x00400000, 0x00000100,
    0x00404001, 0x00004000, 0x00004100, 0x00400001,
    0x00000100, 0x00000001, 0x00400101, 0x00004101,
    0x00404101, 0x00004001, 0x00404000, 0x00400101,
    0x00400001, 0x00000101, 0x00004101, 0x00404100,
    0x00000101, 0x00400100, 0x00400100, 0x00000000,
    0x00004001, 0x00004100, 0x00000000, 0x00404001,
    0x00000082, 0x02008080, 0x00000000, 0x02008002,
    0x02000080, 0x00000000, 0x00008082, 0x02000080,
    0x00008002, 0x02000002, 0x02000002, 0x00008000,
    0x02008082, 0x00008002, 0x02008000, 0x00000082,
    0x02000000, 0x00000002, 0x02008080, 0x00000080,
    0x00008080, 0x02008000, 0x02008002, 0x00008082,
    0x02000082, 0x00008080, 0x00008000, 0x02000082,
    0x00000002, 0x02008082, 0x00000080, 0x02000000,
    0x02008080, 0x02000000, 0x00008002, 0x00000082,
    0x00008000, 0x02008080, 0x02000080, 0x00000000,
    0x00000080, 0x00008002, 0x02008082, 0x02000080,
    0x02000002, 0x00000080, 0x00000000, 0x02008002,
    0x02000082, 0x00008000, 0x02000000, 0x02008082,
    0x00000002, 0x00008082, 0x00008080, 0x02000002,
    0x02008000, 0x02000082, 0x00000082, 0x02008000,
    0x00008082, 0x00000002, 0x02008002, 0x00008080,
    0x00000040, 0x00820040, 0x00820000, 0x10800040,
    0x00020000, 0x00000040, 0x10000000, 0x00820000,
    0x10020040, 0x00020000, 0x00800040, 0x10020040,
    0x10800040, 0x10820000, 0x00020040, 0x10000000,
    0x00800000, 0x10020000, 0x10020000, 0x00000000,
    0x10000040, 0x10820040, 0x10820040, 0x00800040,
    0x10820000, 0x10000040, 0x00000000, 0x10800000,
    0x00820040, 0x00800000, 0x10800000, 0x00020040,
    0x00020000, 0x10800040, 0x00000040, 0x00800000,
    0x10000000, 0x00820000, 0x10800040, 0x10020040,
    0x00800040, 0x10000000, 0x10820000, 0x00820040,
    0x10020040, 0x00000040, 0x00800000, 0x10820000,
    0x10820040, 0x00020040, 0x10800000, 0x10820040,
    0x00820000, 0x00000000, 0x10020000, 0x10800000,
    0x00020040, 0x00800040, 0x10000040, 0x00020000,
    0x00000000, 0x10020000, 0x00820040, 0x10000040,
    0x00080000, 0x81080000, 0x81000200, 0x00000000,
    0x00000200, 0x81000200, 0x80080200, 0x01080200,
    0x81080200, 0x00080000, 0x00000000, 0x81000000,
    0x80000000, 0x01000000, 0x81080000, 0x80000200,
    0x01000200, 0x80080200, 0x80080000, 0x01000200,
    0x81000000, 0x01080000, 0x01080200, 0x80080000,
    0x01080000, 0x00000200, 0x80000200, 0x81080200,
    0x00080200, 0x80000000, 0x01000000, 0x00080200,
    0x01000000, 0x00080200, 0x00080000, 0x81000200,
    0x81000200, 0x81080000, 0x81080000, 0x80000000,
    0x80080000, 0x01000000, 0x01000200, 0x00080000,
    0x01080200, 0x80000200, 0x80080200, 0x01080200,
    0x80000200, 0x81000000, 0x81080200, 0x01080000,
    0x00080200, 0x00000000, 0x80000000, 0x81080200,
    0x00000000, 0x80080200, 0x01080000, 0x00000200,
    0x81000000, 0x01000200, 0x00000200, 0x80080000
};
/* S-boxes 2, 4, 6, 8, plus P permutation, rotated */
static word32 const SP1[512] =
{
    0x20042008, 0x20002000, 0x00002000, 0x00042008,
    0x00040000, 0x00000008, 0x20040008, 0x20002008,
    0x20000008, 0x20042008, 0x20042000, 0x20000000,
    0x20002000, 0x00040000, 0x00000008, 0x20040008,
    0x00042000, 0x00040008, 0x20002008, 0x00000000,
    0x20000000, 0x00002000, 0x00042008, 0x20040000,
    0x00040008, 0x20000008, 0x00000000, 0x00042000,
    0x00002008, 0x20042000, 0x20040000, 0x00002008,
    0x00000000, 0x00042008, 0x20040008, 0x00040000,
    0x20002008, 0x20040000, 0x20042000, 0x00002000,
    0x20040000, 0x20002000, 0x00000008, 0x20042008,
    0x00042008, 0x00000008, 0x00002000, 0x20000000,
    0x00002008, 0x20042000, 0x00040000, 0x20000008,
    0x00040008, 0x20002008, 0x20000008, 0x00040008,
    0x00042000, 0x00000000, 0x20002000, 0x00002008,
    0x20000000, 0x20040008, 0x20042008, 0x00042000,
    0x40200800, 0x40000820, 0x40000820, 0x00000020,
    0x00200820, 0x40200020, 0x40200000, 0x40000800,
    0x00000000, 0x00200800, 0x00200800, 0x40200820,
    0x40000020, 0x00000000, 0x00200020, 0x40200000,
    0x40000000, 0x00000800, 0x00200000, 0x40200800,
    0x00000020, 0x00200000, 0x40000800, 0x00000820,
    0x40200020, 0x40000000, 0x00000820, 0x00200020,
    0x00000800, 0x00200820, 0x40200820, 0x40000020,
    0x00200020, 0x40200000, 0x00200800, 0x40200820,
    0x40000020, 0x00000000, 0x00000000, 0x00200800,
    0x00000820, 0x00200020, 0x40200020, 0x40000000,
    0x40200800, 0x40000820, 0x40000820, 0x00000020,
    0x40200820, 0x40000020, 0x40000000, 0x00000800,
    0x40200000, 0x40000800, 0x00200820, 0x40200020,
    0x40000800, 0x00000820, 0x00200000, 0x40200800,
    0x00000020, 0x00200000, 0x00000800, 0x00200820,
    0x08000004, 0x08100000, 0x00001000, 0x08101004,
    0x08100000, 0x00000004, 0x08101004, 0x00100000,
    0x08001000, 0x00101004, 0x00100000, 0x08000004,
    0x00100004, 0x08001000, 0x08000000, 0x00001004,
    0x00000000, 0x00100004, 0x08001004, 0x00001000,
    0x00101000, 0x08001004, 0x00000004, 0x08100004,
    0x08100004, 0x00000000, 0x00101004, 0x08101000,
    0x00001004, 0x00101000, 0x08101000, 0x08000000,
    0x08001000, 0x00000004, 0x08100004, 0x00101000,
    0x08101004, 0x00100000, 0x00001004, 0x08000004,
    0x00100000, 0x08001000, 0x08000000, 0x00001004,
    0x08000004, 0x08101004, 0x00101000, 0x08100000,
    0x00101004, 0x08101000, 0x00000000, 0x08100004,
    0x00000004, 0x00001000, 0x08100000, 0x00101004,
    0x00001000, 0x00100004, 0x08001004, 0x00000000,
    0x08101000, 0x08000000, 0x00100004, 0x08001004,
    0x04000410, 0x00000400, 0x00010000, 0x04010410,
    0x04000000, 0x04000410, 0x00000010, 0x04000000,
    0x00010010, 0x04010000, 0x04010410, 0x00010400,
    0x04010400, 0x00010410, 0x00000400, 0x00000010,
    0x04010000, 0x04000010, 0x04000400, 0x00000410,
    0x00010400, 0x00010010, 0x04010010, 0x04010400,
    0x00000410, 0x00000000, 0x00000000, 0x04010010,
    0x04000010, 0x04000400, 0x00010410, 0x00010000,
    0x00010410, 0x00010000, 0x04010400, 0x00000400,
    0x00000010, 0x04010010, 0x00000400, 0x00010410,
    0x04000400, 0x00000010, 0x04000010, 0x04010000,
    0x04010010, 0x04000000, 0x00010000, 0x04000410,
    0x00000000, 0x04010410, 0x00010010, 0x04000010,
    0x04010000, 0x04000400, 0x04000410, 0x00000000,
    0x04010410, 0x00010400, 0x00010400, 0x00000410,
    0x00000410, 0x00010010, 0x04000000, 0x04010400
};

/*
* This encryption function is fairly clever in the way it does its
* s-box lookup. The S-boxes are indexed by bytes, rather than
* words, because that's faster on many machines, and shifting
* everything two bits to do the multiply by 4 is trivial.
* Then, the indexing into the various S boxes is done by
* adding the appropriate offset bits into the key array, so the
* addition is done by the XOR with the key rather than having to
* be done explicitly here.
*/

void desDES (byte const inblock[8], byte outblock[8], word32 const *keys)
{
    word32 s, t, right, leftt;
    int round;

    leftt    = ((word32)inblock[0] << 24)
                | ((word32)inblock[1] << 16)
                | ((word32)inblock[2] << 8)
                | (word32)inblock[3];
    right    = ((word32)inblock[4] << 24)
                | ((word32)inblock[5] << 16)
                | ((word32)inblock[6] << 8)
                | (word32)inblock[7];

    /* Initial permutation IP */
    t = ((leftt >> 4) ^ right) & 0x0f0f0f0fL;
    right ^= t;
    leftt ^= (t << 4);
    t = ((leftt >> 16) ^ right) & 0x0000ffffL;
    right ^= t;
    leftt ^= (t << 16);
    t = ((right >> 2) ^ leftt) & 0x33333333L;
    leftt ^= t;
    right ^= (t << 2);
    t = ((right >> 8) ^ leftt) & 0x00ff00ffL;
    leftt ^= t;
    right ^= (t << 8);
    leftt = ((leftt >> 1) | (leftt << 31));
    t = (leftt ^ right) & 0x55555555L;
    leftt ^= t;
    right ^= t;
    right = ((right >> 1) | (right << 31));

    for (round = 0; round < 8; round++)
    {
        s = (right & 0xfcfcfcfc) ^ keys[0];
        t = (((right >> 28) | (right << 4)) & 0xfcfcfcfc) ^ keys[1];
        leftt ^= *(word32 *)((char *)SP0+( s & 0x3fc))
            ^ *(word32 *)((char *)SP0+((s >> 8 ) & 0x3fc))
            ^ *(word32 *)((char *)SP0+((s >> 16) & 0x3fc))
            ^ *(word32 *)((char *)SP0+((s >> 24) & 0x0fc))
            ^ *(word32 *)((char *)SP1+( t & 0x3fc))
            ^ *(word32 *)((char *)SP1+((t >> 8 ) & 0x3fc))
            ^ *(word32 *)((char *)SP1+((t >> 16) & 0x3fc))
            ^ *(word32 *)((char *)SP1+((t >> 24) & 0x0fc));
        s = (leftt & 0xfcfcfcfc) ^ keys[2];
        t = (((leftt >> 28) | (leftt << 4)) & 0xfcfcfcfc) ^ keys[3];
        right ^= *(word32 *)((char *)SP0+( s & 0x3fc))
            ^ *(word32 *)((char *)SP0+((s >> 8 ) & 0x3fc))
            ^ *(word32 *)((char *)SP0+((s >> 16) & 0x3fc))
            ^ *(word32 *)((char *)SP0+((s >> 24) & 0x0fc))
            ^ *(word32 *)((char *)SP1+( t & 0x3fc))
            ^ *(word32 *)((char *)SP1+((t >> 8 ) & 0x3fc))
            ^ *(word32 *)((char *)SP1+((t >> 16) & 0x3fc))
            ^ *(word32 *)((char *)SP1+((t >> 24) & 0x0fc));
        keys += 4;
    }
    /* Inverse IP */
    leftt = ((leftt << 1) | (leftt >> 31));
    t = (leftt ^ right) & 0x55555555L;
    leftt ^= t;
    right ^= t;
    right = ((right << 1) | (right >> 31));
    t = ((leftt >> 8) ^ right) & 0x00ff00ffL;
    right ^= t;
    leftt ^= (t << 8);
    t = ((leftt >> 2) ^ right) & 0x33333333L;
    right ^= t;
    leftt ^= (t << 2);
    t = ((right >> 16) ^ leftt) & 0x0000ffffL;
    leftt ^= t;
    right ^= (t << 16);
    t = ((right >> 4) ^ leftt) & 0x0f0f0f0fL;
    leftt ^= t;
    right ^= (t << 4);
    outblock[0] = (byte)(right >> 24);
    outblock[1] = (byte)(right >> 16);
    outblock[2] = (byte)(right >> 8);
    outblock[3] = (byte)(right );
    outblock[4] = (byte)(leftt >> 24);
    outblock[5] = (byte)(leftt >> 16);
    outblock[6] = (byte)(leftt >> 8);
    outblock[7] = (byte)(leftt      );
}

#undef word32
#undef byte

/******************************************************
The Below Code (Package Coder) is Writen In "C++"
*******************************************************/
void CPackage_Encoder::SetKey(const char* password)
{
    unsigned i=0;
    SBitBlock key;
    key.dword.low=0x476226E8;
    key.dword.high=0x87F5F4AD;
    while(password[i])
    {
        key.byte[i%8]^=(password[i]+(i>>3)+37);
        i++;
    }
    theDEScoder.SetKey(key);
    SetSeed(0x31A68E0D,0x6508CB93);
}

int CPackage_Encoder::Encrypt(unsigned char destination[], const unsigned char source[], unsigned sourcesize) const
{
    unsigned i,j;
    SBitBlock a,b;
    theDEScoder.Encrypt(a,seed);
    for(i=0;i<8;i++)
        destination[i]=a.byte[i];
    a.dword.low=seed.dword.low;
    a.dword.high=seed.dword.high;
    for(i=0,j=8;i<sourcesize;i++,j++)
    {
        if(i%8==0)
        {
            a.dword.low+=23;
            a.dword.high-=71;
            theDEScoder.Encrypt(b,a);
        }
        destination[j]=source[i]^b.byte[i%8];
    }
    return 0;
}

int CPackage_Encoder::Decrypt(unsigned char destination[],const unsigned char source[], unsigned sourcesize)
{
    unsigned i,j;
    SBitBlock a,b;
    if(sourcesize<8)
        return -201;    //Too Small Package
    for(i=0;i<8;i++)
        a.byte[i]=source[i];
    theDEScoder.Decrypt(seed,a);
    a.dword.low=seed.dword.low;
    a.dword.high=seed.dword.high;
    for(i=0,j=8;j<sourcesize;i++,j++)
    {
        if(i%8==0)
        {
            a.dword.low+=23;
            a.dword.high-=71;
            theDEScoder.Encrypt(b,a);
        }
        destination[i]=source[j]^b.byte[i%8];
    }
    return 0;
}

CString CPackage_Encoder::SEncrypt(CString s)
{
    int z = s.GetLength();
    CString sdet;
    unsigned char * src = new unsigned char[z];
    for(int i=0;i<z;i++)
        src[i] = s[i];

    unsigned char * det = new unsigned char[z+8];

    Encrypt(det,src, z);

    for(i=0;i<z+8;i++)
        sdet += det[i];

    delete[] det;
    delete[] src;

    return sdet;
}

CString CPackage_Encoder::SDecrypt(CString s)
{
    int z = s.GetLength();
    CString sdet;

    unsigned char * src = new unsigned char[z+8];
    for(int i=0;i<z;i++)
        src[i] = s[i];

    unsigned char * det = new unsigned char[z];
    Decrypt(det,src, z);

    for(i=0;i<z-8;i++)
        sdet += det[i];

    delete[] det;
    delete[] src;

    return sdet;
}

此帖尚未评分

作者：autuy123
专家分：0

发表时间：2003-9-21 18:04:46 [回复]

　第7楼

可以讲一讲，这些程序的作用吗？讲解的细一点？我们可以看懂呀！

此帖尚未评分

作者：月之影
专家分：80

发表时间：2003-9-22 18:44:32 [回复]

　第8楼

嗯咳...DES的全称好像应该是Data Encrytion Standard吧...
也就是【数据加密标准】......
由此来看DES加密算法大致就是一种按照DES标准制定的一套替换明文的加密算法...
明文一般按照n比特为单位进行加密（n通常等于64)，此算法用一个m比特的密钥作为参数...输出为p比特的密文
从数学的角度，我可以把它简化描述成一个线性时不变因果系统...
设明文为x，密文为y，密钥为m，h为特定的标准明文对于m加密输出的密文
则满足 y(m)=x(m)*h(m)的系统可以算是一个DES线性加密系统...

此帖尚未评分

作者：lanjingquan
专家分：500