des.cpp

使用的是BCB5开发的一个简单的3DES的DEMO

//////////////////////////////////////////////////////////////////////////
/*
    Provided by 尹文才
    Email: [e-mail]
	This product is free for use.
*/
//////////////////////////////////////////////////////////////////////////

#include "memory.h"
#include "Des.h"
#include "stdio.h"
#include <stdlib.h>
#include "Unit1.h"
//////////////////////////////////////////////////////////////////////////

static void F_func(bool In[32], const bool Ki[48]);// f 函数
static void S_func(bool Out[32], bool In[48]);// S 盒代替
static void Transform(bool *Out, bool *In, const char *Table, int len);// 变换
static void Xor(bool *InA, const bool *InB, int len);// 异或
static void RotateL(bool *In, int len, int loop);// 循环左移
static void ByteToBit(bool *Out, const char *In, int bits);// 字节组转换成位组
static void BitToByte(char *Out, const bool *In, int bits);// 位组转换成字节组

//////////////////////////////////////////////////////////////////////////

// initial permutation IP
const static char IP_Table[64] = {
	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
};
// final permutation IP^-1 
const static char IPR_Table[64] = {
	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
};
// expansion operation matrix
static const char E_Table[48] = {
	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
};
// 32-bit permutation function P used on the output of the S-boxes 
const static char P_Table[32] = {
	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
};
// permuted choice table (key) 
const static char PC1_Table[56] = {
	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
};
// permuted choice key (table) 
const static char PC2_Table[48] = {
	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
};
// number left rotations of pc1 
const static char LOOP_Table[16] = {
	1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
};
// The (in)famous S-boxes 
const static char S_Box[8][4][16] = {
	// S1 
	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,
	// S2 
    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,
	// S3 
    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,
	// S4 
     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,
	// S5 
     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,
	// S6 
    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,
	// S7 
     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,
	// S8 
    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
};

//////////////////////////////////////////////////////////////////////////

static bool SubKey[16][48];// 16圈子密钥
int blocks=0;
int shortblocks=0;
bool firstTime = true;
extern char * FileIn;
extern char* FileOut;
//////////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////////////
// Code starts from Line 121
//////////////////////////////////////////////////////////////////////////
void DESencrypt(char Out[8], char In[8], EncryptionKind Type)
{
    static bool M[64], Tmp[32], *Li = &M[0], *Ri = &M[32];
    ByteToBit(M, In, 64);
    Transform(M, M, IP_Table, 64);
    if( Type == ENCRYPT ){
        for(int i=0; i<16; i++) {
            memcpy(Tmp, Ri, 32);
            F_func(Ri, SubKey[i]);
            Xor(Ri, Li, 32);
            memcpy(Li, Tmp, 32);
        }
    }else{
        for(int i=15; i>=0; i--) {
            memcpy(Tmp, Li, 32);
            F_func(Li, SubKey[i]);
            Xor(Li, Ri, 32);
            memcpy(Ri, Tmp, 32);
        }
	}
    Transform(M, M, IPR_Table, 64);
    BitToByte(Out, M, 64);
}
void Des_SetKey(const char Key[8])
{
    static bool K[64], *KL = &K[0], *KR = &K[28];
    ByteToBit(K, Key, 64);
    Transform(K, K, PC1_Table, 56);
    for(int i=0; i<16; i++) {
        RotateL(KL, 28, LOOP_Table[i]);
        RotateL(KR, 28, LOOP_Table[i]);
        Transform(SubKey[i], K, PC2_Table, 48);
    }
}
void F_func(bool In[32], const bool Ki[48])
{
    static bool MR[48];
    Transform(MR, In, E_Table, 48);
    Xor(MR, Ki, 48);
    S_func(In, MR);
    Transform(In, In, P_Table, 32);
}
void S_func(bool Out[32], bool In[48])
{
    for(char i=0,j,k; i<8; i++,In+=6,Out+=4) {
        j = (In[0]<<1) + In[5];
        k = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4];
		ByteToBit(Out, &S_Box[i][j][k], 4);
    }
}
void Transform(bool *Out, bool *In, const char *Table, int len)
{
    static bool Tmp[256];
    for(int i=0; i<len; i++)
        Tmp[i] = In[ Table[i]-1 ];
    memcpy(Out, Tmp, len);
}
void Xor(bool *InA, const bool *InB, int len)
{
    for(int i=0; i<len; i++)
        InA[i] ^= InB[i];
}
void RotateL(bool *In, int len, int loop)
{
    static bool Tmp[256];
    memcpy(Tmp, In, loop);
    memcpy(In, In+loop, len-loop);
    memcpy(In+len-loop, Tmp, loop);
}
void ByteToBit(bool *Out, const char *In, int bits)
{
    for(int i=0; i<bits; i++)
        Out[i] = (In[i/8]>>(i%8)) & 1;
}
void BitToByte(char *Out, const bool *In, int bits)
{
    memset(Out, 0, (bits+7)/8);
    for(int i=0; i<bits; i++)
        Out[i/8] |= In[i]<<(i%8);
}
	//字节型整数串部分复制
void arraycopy(char* source,int sourcePos,char* destination,int destinationPos,int length)
{
  for(int i=0;i<length;i++)
  destination[destinationPos+i]=source[sourcePos+i];
}

char* Triple_DES(char Out[8], char In[8], EncryptionKind Type)
{

	  char key1[8]={1,9,8,0,9,1,7};
      char key2[8]={2,9,9,0,9,1,8};
	  char key3[8]={3,7,8,0,9,5,7};

	  if (Type == ENCRYPT)
	  {
		Des_SetKey(key1);
        DESencrypt(Out, In, ENCRYPT);
        Des_SetKey(key2);
        DESencrypt(Out, Out, DECRYPT);
        Des_SetKey(key3);
        DESencrypt(Out, Out, ENCRYPT);
		char * tmp = &Out[0];
	    return tmp;
	  } 
	  else
	  {
        Des_SetKey(key3);
		DESencrypt(Out, In, DECRYPT);
        Des_SetKey(key2);
        DESencrypt(Out, Out, ENCRYPT);
        Des_SetKey(key1);
        DESencrypt(Out, Out, DECRYPT);
		char * tmp = &Out[0];
	    return tmp;
	  }

}
void DES_Start(EncryptionKind Type, char * filename)
{
	//file handle
        FILE * fIn;
	FILE * fOut;
	FILE * decryptfile;
	long len_In, len_Out; //length of in and out files
	char Ci[8];
        char M[8];

	if (firstTime)
	{
	//open In and Out files for encryption
          if((fIn = fopen(filename, "rb")) == NULL)
            printf("open file %s failed!",filename);
          if((fOut = fopen("D:\\encrypted.des", "wb+")) == NULL)
            printf("open file encrypted.des failed!\n");



	//get length
    fseek(fIn, 0L, SEEK_END); 
    len_In = ftell(fIn);
    fseek(fIn, 0L, SEEK_SET);
    printf("the length is %d\n", len_In);
	fseek(fOut, 0L, SEEK_END); 
    len_Out = ftell(fOut); 
    fseek(fOut, 0L, SEEK_SET);
    printf("the length is %d\n", len_Out);
	
	//calculate num of blocks and short blocks
	blocks = (int)len_In/8;
	printf("the num of block is %d\n",blocks);
	shortblocks = (int)len_In%8;
	firstTime = false;
	}
	if(Type == ENCRYPT)  //ENCRYPT
	{
	  for(int i=0;i<blocks;i++)
	  {
	    
	    fread( M, sizeof( char ), 8,  fIn);
		Triple_DES(Ci,M,ENCRYPT);
		fwrite(Ci,sizeof(char),8,fOut);
	  }
	  if (shortblocks == 0)
	  {
         fclose(fIn);
		 fclose(fOut);
	  }
      if (shortblocks > 0)	//short blocks
	  {
	    char * buffer = NULL; //buffer for short blocks
	    char * buffertmp = NULL;
	    char  Out[8];
	    buffer = (char *)malloc(shortblocks); 
	    buffertmp = (char *)malloc(8-shortblocks);
	    fread(buffer,sizeof(char),shortblocks,fIn);
            fclose(fIn);
	    arraycopy(Ci,shortblocks,buffertmp,0,8-shortblocks);  //C(n-1)右8-k位->b
	    char temp[8];
	    arraycopy(buffertmp,0,temp,0,8-shortblocks);
	    arraycopy(buffer,0,temp,8-shortblocks,shortblocks);  //b和M(n)拼接，存入temp
	    fseek(fOut,-(8-shortblocks),SEEK_CUR);  //temp写入指针退(8-k)字节，使C(n-1)成为短块
		char * tmp = NULL;
		tmp = Triple_DES(Out,temp,ENCRYPT);
	    fwrite(tmp,sizeof(char),8,fOut); 
		fclose(fOut);
	  }
      
	}
	else		//DECRYPT
	{
	  int i=0;
	  if((fOut = fopen("D:\\encrypted.des", "rb+")) == NULL)
        printf("open file encrypted.des failed!\n");
	  if((decryptfile = fopen(filename, "wb+")) == NULL)
        printf("open file %s failed!\n",filename);
	  fseek(fOut,0L,SEEK_SET);
	  for(int i=0;i<blocks-1;i++)
	  {
	    fread( Ci, sizeof( char ), 8,  fOut);
	    Triple_DES(M,Ci,DECRYPT);
	    fwrite(M,sizeof(char),8,decryptfile);
	  }
	  if (shortblocks > 0)
	  {
	        fseek(fOut,shortblocks,SEEK_CUR);//文件指针移至C(n)
		char Cn[8];
		char * tmp;
		fread(Cn,sizeof(char),8,fOut);
		tmp=Triple_DES(Cn,Cn,DECRYPT);
		memcpy(Cn,tmp,8);
		fseek(fOut,-(shortblocks+8),SEEK_CUR);//文件指针退至C(n-1)
		char Cnprior[8];
		fread(Cnprior,sizeof(char),8,fOut);
		char* buffertmp = NULL;
		buffertmp = (char *)malloc(8-shortblocks);
		arraycopy(Cn,0,buffertmp,0,8-shortblocks);
		arraycopy(buffertmp,0,Cnprior,shortblocks,8-shortblocks);//Mn左(8-k)字节挪到C(n-1)
		char buffer[8];
		Triple_DES(buffer,Cnprior,DECRYPT);
	        fwrite(buffer,sizeof(char),8,decryptfile);
	        char * buffertmp2 = NULL;
		buffertmp2 = (char *)malloc(shortblocks);
		arraycopy(Cn,8-shortblocks,buffertmp2,0,shortblocks);
		fwrite(buffertmp2,sizeof(char),shortblocks,decryptfile);//Mn右k字节作为明文最后一块写入
	  }
	        fclose(fOut);
		fclose(decryptfile);
	}
}