des.cpp

位输入的DES 加密解密算法实现 单一CPP实现,其中1.txt用于明文输入,key2.txt用于密钥输入,out2.txt为加密后的密文 与解密后的明文输出

#include<iostream>
#include<bitset>
#include<fstream>
using namespace std;

int i,j;

bitset<56> key_swich_1(bitset<64> key)
{
	int swichtable[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};
	bitset<56> change;
	for (j = 0; j < 56; j ++)
		change.set(j,key.at(swichtable[j]-1));
	return change;
}

bitset<48> key_swich_2(bitset<56> key)
{
	int swichtable[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};
	bitset<48> change;
	for (j = 0; j < 48; j ++)
		change.set(j,key.at(swichtable[j]-1));
	return change;
}


void ip(bitset<64> & a){
	int iptable[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
	};
	bitset<64> change;
	for (j = 0; j < 64; j++)
		change.set(j,a.at(iptable[j]-1));
	for (j = 0; j < 64; j++)
		a.set(j,change.at(j));
}

bitset<48> extend_swich(bitset<32> a){
	int swichtable[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};
		bitset<48> change;
		for (j = 0; j < 48; j ++)
			change.set(j,a.at(swichtable[j]-1));
		return change;
}

bool boolreturn(int a){
	if (a == 0)
		return false;
	else if (a == 1)
		return true;
	else
	{
		cout<<"wrong!"<<endl;
		return true;
	}
}

bitset<4> int_bit(int a){
	bitset<4> s;
	s[3] = boolreturn(a%2);
	s[2] = boolreturn((a/2)%2);
	s[1] = boolreturn((a/4)%2);
	s[0] = boolreturn((a/8)%2);
	return s;
}

int bit_int(bitset<4> a){
	if (a[0] == false){
		if (a[1] == false){
			if (a[2] == false){
				if (a[3] == false)
					return 0;
				else
					return 1;
			}
			else{
				if (a[3] == false)
					return 2;
				else
					return 3;
			}
		}
		else{
			if (a[2] == false){
				if (a[3] == false)
					return 4;
				else
					return 5;
			}
			else{
				if (a[3] == false)
					return 6;
				else
					return 7;
			}
		}
	}
	else{
		if (a[1] == false){
			if (a[2] == false){
				if (a[3] == false)
					return 8;
				else
					return 9;
			}
			else{
				if (a[3] == false)
					return 10;
				else
					return 11;
			}
		}
		else{
			if (a[2] == false){
				if (a[3] == false)
					return 12;
				else
					return 13;
			}
			else{
				if (a[3] == false)
					return 14;
				else
					return 15;
			}
		}
	}
}


bitset<32> s_swich(bitset<48> a){
	bitset<4> temp[8];
	int s_box[8][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,
		 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,
		 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,
		 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,
		 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,
		 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,
		 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,
		 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};
	for(j = 0; j < 8; j ++)
	{
		int x = j * 6;
		temp[j][0] = a[x+1],temp[j][1] = a[x+2],temp[j][2] = a[x+3],temp[j][3] = a[x+4];
		if (a[x] == false){
			if (a[x + 5] == false)
				temp[j] = int_bit(s_box[j][0][bit_int(temp[j])]);
			else
				temp[j] = int_bit(s_box[j][1][bit_int(temp[j])]);
		}
		else{
			if (a[x + 5] == false)
				temp[j] = int_bit(s_box[j][2][bit_int(temp[j])]);
			else
				temp[j] = int_bit(s_box[j][3][bit_int(temp[j])]);
		}
	}
	bitset<32> rvalue;
	for (j = 0; j < 32; j ++)
	{
		int x = j/4;
		rvalue.set(j,temp[x].at(j-x*4));
	}
	return rvalue;
}

bitset<32> p_swich(bitset<32> a){
	int swichtable[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};
	bitset<32> change;
	for(j = 0; j < 32; j ++)
		change.set(j,a.at(swichtable[j]-1));
	return change;
}

void ip_swich_inverse(bitset<64> & a){
	int swichtable[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};
	bitset<64> change;
	for (j = 0; j < 64; j ++)
		change.set(j,a.at(swichtable[j] - 1));
	for (j = 0; j < 64; j++)
		a.set(j,change.at(j));
}

void des_encrypt(bitset<64> & m,const bitset<64> key)
{
	bitset<56> s1key = key_swich_1(key);
	int figure[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
	bitset<28> c,d;
	for (i = 0; i < 56; i ++){
		if (i < 28)
			c.set(i,s1key.at(i));
		else
			d.set(i-28,s1key.at(i));
	}
	bitset<48> K[16];
	for(i = 0; i < 16; i ++)
	{
		c = c << figure[i];
		d = d << figure[i];
		bitset<56> mK;
		for (j = 0; j < 56; j++)
		{
			if(j < 28)
				mK.set(j,c.at(j));
			else
				mK.set(j,d.at(j - 28));
		}
		K[i] = key_swich_2(mK);									//生成16个key
	}
	ip(m);
	bitset<32> L,R;
	for(i = 0; i < 32; i ++)
	{
		L.set(i,m.at(i));
		R.set(i,m.at(i+32));
	}
	for(i = 0; i < 16; i ++)
	{
		bitset<48> e_R = extend_swich(R);
		e_R = e_R ^ K[i];
		bitset<32> after_s;
		after_s = s_swich(e_R);
		after_s = p_swich(after_s);
		bitset<32> R_temp = R;
		R = L ^ after_s;
		L = R_temp;
	}
	for(i = 0; i < 64; i ++){
		if(i < 32)
			m.set(i,R.at(i));
		else
			m.set(i,L.at(i-32));
	}
	ip_swich_inverse(m);
}


void des_decrypt(bitset<64> & m,const bitset<64> key)
{
	bitset<56> s1key = key_swich_1(key);
	int figure[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
	bitset<28> c,d;
	for (i = 0; i < 56; i ++){
		if (i < 28)
			c.set(i,s1key.at(i));
		else
			d.set(i-28,s1key.at(i));
	}
	bitset<48> K[16];
	for(i = 0; i < 16; i ++)
	{
		c = c << figure[i];
		d = d << figure[i];
		bitset<56> mK;
		for (j = 0; j < 56; j++)
		{
			if(j < 28)
				mK.set(j,c.at(j));
			else
				mK.set(j,d.at(j - 28));
		}
		K[i] = key_swich_2(mK);									//生成16个key
	}
	ip(m);
	bitset<32> L,R;
	for(i = 0; i < 32; i ++)
	{
		L.set(i,m.at(i));
		R.set(i,m.at(i+32));
	}
	for(i = 0; i < 16; i ++)
	{
		bitset<48> e_R = extend_swich(R);
		e_R = e_R ^ K[15 - i];
		bitset<32> after_s;
		after_s = s_swich(e_R);
		after_s = p_swich(after_s);
		bitset<32> R_temp = R;
		R = L ^ after_s;
		L = R_temp;
	}
	for(i = 0; i < 64; i ++){
		if(i < 32)
			m.set(i,R.at(i));
		else
			m.set(i,L.at(i-32));
	}
	ip_swich_inverse(m);
}


void main(){
	ifstream fin("1.txt");
	ifstream fin_key("key2.txt");
	ofstream fout("out2.txt");
	bitset<64> a[100];
	i = 0;
	while(!fin.eof()){
		for (j = 0; j < 64; j++)
		{
			bool temp;
			fin>>temp;
			a[i].set(j,temp);
		}
		i++;
	}
	bitset<64> key;
	for( j = 0; j < 64; j ++){
		bool temp1;
		fin_key>>temp1;
		key.set(j,temp1);
	}
	cout<<a[0]<<endl;
	cout<<key<<endl;
	des_encrypt(a[0],key);
	for (i = 0; i < 64; i++)
		fout<<a[0][i]<<" ";
	fout<<endl;
	fout<<endl;
	des_decrypt(a[0],key);
	for (i = 0; i < 64; i++)
		fout<<a[0][i]<<" ";
//	bitset<4> c = '0','1','1','0';
//	cout<<c<<endl;
/*	for(i = 0; i < 16; i++)
		cout<<int_bit(i)<<endl;
	bitset<4> x;
	x[0] = 0,x[1] = 1,x[2] = 0,x[3] = 1;
	cout<<bit_int(x)<<endl;*/

}