C语言实现CBC模式DES加密

#define SECTION_SIZE 8 //每段密文字节数，DES为8个字节64位
#define GET_BIT(x,y) (x |((BYTE)0xff <<9-y) | ((BYTE)0xff >>y)) //将X的第Y位保留，其余位置1
#define FORM_DWORD(p1,p2,p3,p4)  ((((DWORD)p1) <<24) | (((DWORD)p2) <<16) | (((DWORD)p3) <<8) | ((DWORD)p4)) //四个字节形成一个双字
#define FORM_BYTE(x,y) ((BYTE)((x & ((DWORD)0xffffffff << 8*(4-y)) & ((DWORD)0xffffffff >> (y-1)*8)) >>(4-y)*8))//将双字X的第Y个字节提取出来
#define GET_BIT_LOW(x,y) ((x & ( (BYTE)0xff<<(8-y)) & (BYTE)0xff >> (y-1)) >> (8-y)) //拿到字节X的第Y位
//#define ENCRPT  //如果定义则为加密，无定义为解密
#define CHANGE  //未用

//------------------------------------------------------------------------------------------
BYTE DisPlaceIPTable[] = { 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
};
BYTE DisPlaceRIPTable[] = { 40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25
};
BYTE DisPlaceKEYTable[] = { 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4, };
BYTE MoveCount[] = { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };
BYTE PC_2[] = { 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 };
BYTE E_Table[] = { 32, 1, 2, 3, 4, 5,
4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13,
12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21,
20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1 };
BYTE S1[4][16] = { 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13};
BYTE S2[4][16] = { 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 };
BYTE S3[4][16] = { 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 };
BYTE S4[4][16] = { 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 };
BYTE S5[4][16] = { 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 };
BYTE S6[4][16] = { 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 };
BYTE S7[4][16] = { 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 };
BYTE S8[4][16] = { 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 };
BYTE result[] = { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 };
//---------------------------------------------------------------------------------
typedef struct _BIT
{
    BYTE a : 1;
    BYTE b : 1;
    BYTE c : 1;
    BYTE d : 1;
    BYTE e : 1;
    BYTE f : 1;
}BIT,*PBIT;
typedef struct _8_BIT
{
    BYTE a : 1;
    BYTE b : 1;
    BYTE c : 1;
    BYTE d : 1;
    BYTE e : 1;
    BYTE f : 1;
    BYTE g : 1;
    BYTE h : 1;
}E_BIT,*P4_BIT;

LPVOID  getTable(int index);
DWORD data_rl(DWORD x, BYTE y, BYTE z);
PBYTE SHL_Connect(PBYTE p1, PBYTE p2, int index);
void ExchangeDword(PVOID p1, PVOID p2);
void DisPlaceItem(PVOID fileVa, PBYTE KEY, int length);

// DESEncryption.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "windows.h"
#include "myEncpy.h"

int _tmain(int argc, _TCHAR* argv[])
{
    
    //get plaintext
    HANDLE hFile = CreateFile(L"d:\a.txt", GENERIC_ALL, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, NULL);
    if (hFile == INVALID_HANDLE_VALUE)
    {
        printf_s("can not create file...  d:a.txt");
        system("pause");
        return 0;
    }
    HANDLE hFileMapping = CreateFileMapping(hFile, 0, PAGE_READWRITE, 0, 0, L"myshare");
    if (hFileMapping == INVALID_HANDLE_VALUE)
    {
        printf_s("can not create filemapping");
        system("pause");
        return 0;
    }
    LPVOID fileVa = MapViewOfFile(hFileMapping, FILE_MAP_ALL_ACCESS, 0, 0, 0);
    if (fileVa == NULL)
    {
        printf_s("can not get mapview");
        system("pause");
        return 0;
    }
    //printf_s("%s
", fileVa);
    //使用内存映射打开大文件
    //---------------------------------------------------------------
    //get parameter,key,subkey
    BYTE KEY[8] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h' }; //定义密钥
    DisPlaceItem(KEY, DisPlaceKEYTable,7);
    PBYTE SubKey[16];
    BYTE C0[4] = { KEY[0], KEY[1], KEY[2], KEY[3]&0xf0 };
    BYTE D0[4] = { KEY[3] & 0x0f, KEY[4], KEY[5], KEY[6] };
    for (int i = 0; i < 16; i++)
    {
        PBYTE p = SHL_Connect(C0, D0, i);
        DisPlaceItem(p, PC_2, 6);
        SubKey[i] = p;  //生成16个子密钥
    }

    //-----------------
    // begain encryp
    BYTE CBC_IV[] = { 0x11, 0x32, 0x43, 0x54, 0x65, 0x76, 0x87, 0xa8 };//初始化向量 未向
    PBYTE fileOffset =(PBYTE)fileVa;  //明文起始位置
    DWORD fileSize = GetFileSize(hFile, 0); //得到明文大小

    
    for (DWORD index = 0; index < fileSize / SECTION_SIZE ; index ++) //目前只针对凑满8个字节的部分进行加密
    {
        fileOffset = fileOffset + index *SECTION_SIZE;
        
        //for (int i = 0; i < SECTION_SIZE; i++)
        //{
        //    *(fileOffset + i) ^= CBC_IV[i];
        //}
        
#ifdef CHANGE
        DisPlaceItem(fileOffset, DisPlaceIPTable, 8); //IP置换
#endif
        
#ifdef ENCRPT
        for (int j =0; j <16; j++)
        {
#else
        for (int j = 15; j >= 0; j--)
        {
#endif
            BYTE L0[4], R0[6];
            memcpy(L0, fileOffset, 4);
            memcpy(R0, fileOffset + 4, 4); //分别拿到左边右边4个字节
#ifdef ENCRPT
            if (j !=15)
#else
            if (j != 0)
#endif
                memcpy(fileOffset, R0, 4); //如果不是最后一次加密或者解密，则右边直接写回左边
            else
                memcpy(fileOffset + 4, R0, 4);
            DisPlaceItem(R0, E_Table, 6); //扩展置换
            PBYTE pbyte1 = SubKey[j];
            for (int i = 0; i < 6; i++)
            {
                R0[i] ^= pbyte1[i];  //与右边进行异或
            }
            //partion----------------------------------------
            BIT mybit[8] = {0};
            ///////////////////////
            BYTE t[48]; //把6字节分为6位一组共8组
            int tIndex = 1;
            int rIdex = 0;
            for (int i = 0; i < 48; i++)
            {
                BYTE a = R0[rIdex];
                t[i] = GET_BIT_LOW(R0[rIdex], tIndex);
                if (tIndex % 8 == 0)
                {
                    rIdex++;
                    tIndex = 1;
                }
                else
                {
                    tIndex++;
                }
            }
            tIndex = 0;
            for (int i = 0; i < 48; i+=6)
            {
                mybit[tIndex].a = t[i];
                mybit[tIndex].b = t[i+1];
                mybit[tIndex].c = t[i+2];
                mybit[tIndex].d = t[i+3];
                mybit[tIndex].e = t[i+4];
                mybit[tIndex].f = t[i+5];
                tIndex++;
            }
            //此时mybit里面放着分组之后的每一位
            ////////////////////////
            BYTE  Str[4];
            int EIndex = 0;
            BYTE(*tempTable)[16] = 0;
            for (char i = 0; i < 8; i += 2) //根据mybit拿到表中的数并 组合成str
            {
                tempTable = (BYTE(*)[16])getTable(i + 1);
                BYTE sum1 = tempTable[mybit[i].a*2 + mybit[i].f][mybit[i].b*8 + mybit[i].c*4 + mybit[i].d*2 + mybit[i].e];
                tempTable = (BYTE(*)[16])getTable(i + 2);
                BYTE sum2 = tempTable[mybit[i + 1].a*2 + mybit[i + 1].f][mybit[i + 1].b*8 + mybit[i + 1].c*4 + mybit[i + 1].d*2 + mybit[i + 1].e];
                BYTE sum = sum1 << 4 | sum2;
                memcpy(Str + EIndex, &sum, 1);
                EIndex++;
            }
#ifdef CHANGE
            DisPlaceItem(Str, result, 4); //结果与左边置换
#endif
            for (int i = 0; i < 4; i++)
            {
                L0[i] ^= Str[i];
            }
#ifdef ENCRPT
            if (j != 15)
#else
            if (j != 0)  //将左边写到右边
#endif
                memcpy(fileOffset + 4, L0, 4);
            else
                memcpy(fileOffset, L0, 4);
        }
        
#ifdef CHANGE
        DisPlaceItem(fileOffset, DisPlaceRIPTable, 8);//IP逆置换
#endif
        //memcpy(CBC_IV, fileOffset, 8);
        //-----------------------------------------------
        
    }

    printf_s("got it");
    for (int i = 0; i < 16; i++)
    {
        free(SubKey[i]);
    }
    CloseHandle(hFile);
    CloseHandle(hFileMapping);
    UnmapViewOfFile(fileVa);
    
    
    system("pause");
    return 0;
}


void DisPlaceItem(PVOID fileVa,PBYTE KEY,int length) //fileva为需要置换的内容首地址 key为置换表,length为输出字节数
{
    PBYTE File = (PBYTE)fileVa;
    BYTE Result[8] ;
    memset(Result, 0xff, 8);
    int DisIndex = 1;
    for (int i = 0; i < length; i++)
    {    
        int bitofEach = 1;
        while (true)
        {
            BYTE temp1 = KEY[DisIndex-1];
            BYTE ByteIndex = temp1 / 8;
            ByteIndex = temp1 % 8 == 0 ? ByteIndex -1 : ByteIndex;
            BYTE BitIndex = temp1- ByteIndex*8;
            BYTE temptemp = *(File + ByteIndex);
            if (bitofEach < BitIndex)
            {
                temptemp = *(File + ByteIndex) << (BitIndex - bitofEach);
            }
            else if (bitofEach>BitIndex)
            {
                temptemp = *(File + ByteIndex) >> (bitofEach - BitIndex);
            }
            BYTE t = GET_BIT(temptemp, bitofEach);
            Result[i] = Result[i] & GET_BIT(temptemp, bitofEach);
            if (DisIndex % 8 == 0)
                break;
            DisIndex++;
            bitofEach++;
        }
        DisIndex++;
    }
    memcpy(fileVa, Result, length);
}
PBYTE SHL_Connect(PBYTE p1, PBYTE p2, int index) //循环移位并连接
{
    PBYTE pbyte = (PBYTE)malloc(7);
    DWORD d1 = FORM_DWORD(p1[0], p1[1], p1[2], p1[3]);
    DWORD d2 = FORM_DWORD(p2[0], p2[1], p2[2], p2[3]) <<4;
    d1 = data_rl(d1, MoveCount[index], 32);
    d2 = data_rl(d2, MoveCount[index], 32) >>4;
    for (int i = 0; i < 4; i++)
    {
        *(p1 + i) = FORM_BYTE(d1, i + 1);
        *(p2 + i) = FORM_BYTE(d2, i + 1);
    }
    memcpy(pbyte, p1, 3);
    BYTE temp = p1[3] | p2[0];
    *(pbyte + 3) = temp;
    memcpy(pbyte + 4, p2, 3);
    return pbyte;
}
DWORD data_rl(DWORD x, BYTE y, BYTE z)  //移位的实现
{
    DWORD temp;
    temp = x >> (y - z );
    temp = temp << 4;
    x = x << z;
    x = x | temp;
    return x;
}
LPVOID  getTable(int index)
{
    switch (index)
    {
    case 1:
        return S1;
        break;
    case 2:
        return S2;
        break;
    case 3:
        return S3;
        break;
    case 4:
        return S4;
        break;
    case 5:
        return S5;
        break;
    case 6:
        return S6;
        break;
    case 7:
        return S7;
        break;
    case 8:
        return S8;
        break;
    default:
        break;
    }
}