key.cpp

用c++实现des算法 整体思路 用key.cpp 文件来产生秘钥

//////////////////////////////////////////
//
// FileName: key.cpp 
// Creator: Du Feilong
// Date: 2007-10-11
// Comment: Create key
//
////////////////////////////////////////// 
#include<iostream>
#include<fstream>
#include<string>
using namespace std;


int StartKey[64];
int key0[56],key1[56],key2[56],key3[56],key4[56];
		
int LS[4]={1,1,2,2};
int C0[28],D0[28],C1[28],D1[28],C2[28],D2[28],C3[28],D3[28],C4[28],D4[28];
int KeyIPC[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};

int KeyPC[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};
	             
void StartKeyget()		
{

	for(int i=0;i<64;i++)
		StartKey[i]=0;
	cout<<"enter your key(8 characters)"<<endl;
	char n[8];
	getchar();
	for(int i=0;i<8;i++)
		n[i]=getchar();
	int k=0;
	while(k<8){								
		for(int i=7;i>=0;i--){
			StartKey[k*8+i]=n[k]&1;
			n[k]=n[k]>>1;
		}
		k++;
	}

}


void keyconversion1()
{
	int i;
	for(i=0;i<56;i++)
		key0[i]=StartKey[KeyIPC[i]];
}



void keydivide()
{
	int i;
	for(i=0;i<28;i++)
		C0[i]=key0[i];
	for(i=28;i<56;i++)
		D0[i-28]=key0[i];
}

void shift(int *cp,int *dp,int *c,int *d,int m)
{
	int i;
	for(i=0;i<28;i++){
		c[i]=cp[(i+m)%28];
		d[i]=dp[(i+m)%28];
	}
}


void keyconversion2(int *k,int *K)
{
	int i;
	for(i=0;i<56;i++)
		K[i]=k[KeyPC[i]];
}


void connect(int *c,int *d,int *k,int *K)
{
	int i;
	for(i=0;i<28;i++)
		k[i]=c[i];
	for(i=28;i<56;i++)
		k[i]=d[i-28];
	keyconversion2(k,K);
}





void displaykey(int *k)
{
	int i;
	for(i=0;i<56;i++){
		if(i%28==0&&i!=0)
			cout<<endl;
		cout<<k[i]<<" ";
	}
	cout<<endl;
}

void displayKey(int *K)
{
	int i;
	for(i=0;i<48;i++){
		if(i%16==0&&i!=0)
			cout<<endl;
		cout<<K[i]<<" ";
	}
	cout<<endl;
}
	
void createkey(int *Key1,int *Key2,int *Key3,int *Key4)
{
	StartKeyget();
	keyconversion1();
	keydivide();
	
	
	shift(C0,D0,C1,D1,LS[0]);
	connect(C1,D1,key1,Key1);
	
	shift(C1,D1,C2,D2,LS[1]);
	connect(C2,D2,key2,Key2);
	
	shift(C2,D2,C3,D3,LS[2]);
	connect(C3,D3,key3,Key3);
	
	shift(C3,D3,C4,D4,LS[3]);
	connect(C4,D4,key4,Key4);
}