Rcrypt1.1 [FINAL].c

#include <stdio.h>
#include <string.h>
#include <time.h>
#define MAX_L 104857

const char c_seq[96] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890+-*/.,\\<>?;':\"[]{}|_=`~!@#$%^&() ";
const short int seq[95][8]={
{5, 8, 1, 7, 2, 4, 3, 6},
{7, 2, 1, 6, 3, 8, 4, 5},
{3, 6, 2, 4, 7, 5, 1, 8},
{1, 8, 3, 6, 5, 7, 4, 2},
{2, 7, 8, 5, 4, 1, 3, 6},
{3, 4, 6, 8, 1, 2, 5, 7},
{2, 7, 4, 8, 3, 5, 6, 1},
{8, 6, 1, 5, 4, 2, 7, 3},
{4, 8, 1, 6, 3, 2, 5, 7},
{1, 7, 8, 2, 3, 4, 6, 5},
{1, 8, 3, 6, 2, 4, 7, 5},
{1, 4, 2, 8, 5, 3, 6, 7},
{5, 4, 7, 8, 3, 2, 1, 6},
{8, 2, 1, 4, 5, 6, 3, 7},
{6, 5, 4, 7, 1, 8, 3, 2},
{5, 8, 7, 1, 4, 2, 6, 3},
{2, 6, 4, 8, 1, 7, 3, 5},
{6, 3, 7, 5, 4, 1, 2, 8},
{4, 5, 7, 2, 6, 1, 3, 8},
{7, 3, 6, 5, 2, 1, 8, 4},
{3, 6, 4, 5, 1, 8, 2, 7},
{5, 1, 2, 8, 4, 7, 6, 3},
{6, 4, 2, 1, 7, 3, 5, 8},
{5, 7, 4, 2, 6, 3, 1, 8},
{7, 1, 2, 5, 6, 3, 8, 4},
{4, 8, 2, 1, 5, 7, 3, 6},
{3, 5, 8, 7, 1, 2, 6, 4},
{7, 5, 6, 8, 4, 2, 3, 1},
{7, 2, 1, 6, 5, 3, 8, 4},
{6, 3, 1, 8, 7, 5, 4, 2},
{3, 1, 5, 8, 7, 6, 4, 2},
{8, 3, 1, 5, 7, 4, 2, 6},
{7, 5, 8, 1, 3, 6, 2, 4},
{7, 5, 1, 8, 4, 3, 6, 2},
{7, 2, 3, 1, 6, 5, 4, 8},
{1, 2, 6, 4, 8, 7, 3, 5},
{7, 6, 2, 5, 4, 3, 8, 1},
{2, 8, 5, 3, 7, 6, 1, 4},
{4, 3, 5, 6, 2, 8, 7, 1},
{8, 1, 6, 2, 7, 5, 3, 4},
{4, 8, 3, 6, 1, 5, 2, 7},
{3, 4, 7, 6, 2, 8, 5, 1},
{4, 5, 8, 3, 6, 1, 2, 7},
{5, 4, 6, 2, 3, 7, 8, 1},
{7, 4, 3, 5, 1, 6, 8, 2},
{7, 4, 1, 5, 3, 8, 2, 6},
{5, 2, 8, 3, 7, 1, 4, 6},
{8, 2, 5, 6, 1, 7, 4, 3},
{7, 5, 1, 4, 3, 6, 8, 2},
{8, 5, 4, 6, 1, 3, 2, 7},
{6, 5, 7, 4, 8, 2, 1, 3},
{8, 3, 1, 7, 5, 4, 6, 2},
{2, 6, 7, 8, 4, 3, 1, 5},
{5, 2, 7, 8, 4, 3, 6, 1},
{4, 6, 8, 3, 1, 5, 7, 2},
{5, 1, 6, 3, 8, 7, 4, 2},
{7, 6, 3, 5, 1, 4, 2, 8},
{6, 8, 2, 7, 3, 4, 5, 1},
{7, 3, 5, 4, 6, 8, 1, 2},
{5, 8, 3, 7, 2, 4, 1, 6},
{7, 8, 6, 2, 1, 4, 5, 3},
{4, 8, 1, 3, 5, 2, 6, 7},
{8, 6, 7, 2, 5, 4, 3, 1},
{5, 8, 4, 2, 6, 3, 7, 1},
{4, 8, 7, 5, 2, 1, 3, 6},
{7, 1, 4, 2, 5, 8, 3, 6},
{2, 5, 1, 3, 7, 4, 6, 8},
{3, 7, 1, 4, 8, 2, 6, 5},
{7, 5, 6, 4, 8, 2, 3, 1},
{3, 8, 4, 7, 6, 2, 5, 1},
{4, 6, 3, 5, 8, 1, 2, 7},
{7, 2, 8, 4, 1, 3, 5, 6},
{4, 6, 7, 2, 1, 3, 8, 5},
{8, 2, 1, 5, 6, 4, 7, 3},
{6, 8, 5, 2, 4, 7, 3, 1},
{3, 7, 6, 8, 1, 5, 4, 2},
{3, 8, 1, 7, 5, 2, 6, 4},
{7, 2, 5, 6, 4, 3, 1, 8},
{3, 4, 1, 8, 2, 7, 5, 6},
{4, 7, 6, 2, 5, 1, 3, 8},
{6, 1, 3, 2, 5, 4, 7, 8},
{8, 4, 3, 5, 7, 2, 6, 1},
{3, 5, 6, 7, 1, 2, 8, 4},
{1, 3, 8, 6, 2, 7, 5, 4},
{5, 4, 1, 7, 6, 3, 8, 2},
{6, 3, 2, 1, 4, 5, 7, 8},
{3, 4, 5, 8, 7, 1, 2, 6},
{5, 6, 3, 8, 4, 2, 7, 1},
{7, 3, 4, 2, 5, 6, 8, 1},
{4, 6, 1, 3, 7, 2, 8, 5},
{1, 3, 6, 2, 8, 5, 7, 4},
{7, 1, 8, 5, 6, 4, 3, 2},
{3, 1, 5, 2, 8, 4, 6, 7},
{8, 5, 2, 4, 3, 1, 6, 7},
{2, 8, 7, 1, 4, 5, 3, 6}
};


int **reverser(char *dat){
	// reverse the string and put the value back to dat
	int i,j=0;
	int len = strlen(dat);
	i=len-1;
	char RevStr[MAX_L]={};
		while(i >= 0)
		{
			RevStr[j] = dat[i];
			j++;
			i--;
		}
		RevStr[j] = '\0';
		strcpy(dat, RevStr);
		//printf("%s\n",data);
	return 0;
}


char *add_space(char *data){
	// ADD SPACE AT THE END OF MESSAGE TO MAKE SURE THE MESSAGE LENGTH IS DIVISIBLE BY 8
	
	//printf("%s",data);
	unsigned int dat_len=strlen(data);
	//printf("%u", dat_len);
	if(dat_len%8!=0){
	while (dat_len%8!=0){
		data[dat_len]=' ';
		dat_len++;
	}
	}data[dat_len]='\0';
	//printf("%s",data);
	return data;
}

char *front2back_en(char *data, int to_move, int dat_len){
	// ON ENCRYPT, BEFORE REARRANGING WITH KEY SEQUENCE, SENDS 2 CHARECTER FROM FRONT TO BACK
	// to_move: number of charecters to move
	
	//int a=0;
	//printf("%s",data);
	char front[8]={};
	//while(a<8){printf("f%cf",front[a]);a++;}
	int j=0,i=0;
	//printf(sizeof(front));
	while(i<to_move){
		front[i]=data[i];
		i++;}
	//printf("%d\n",strlen(front));
	while(i<dat_len){
		data[i-to_move]=data[i];
		i++;
	}
	while(j<to_move){
		data[(i+j)-to_move]=front[j];
		j++;
	}
	return data;
}

char *_encrypt(char *data, char c){
	// REARRANGE DATA (Splitted by LIST OF 8 CHARECTERS) BASED ON SEQUENCE BY THE KEY CHARECTER
	// c: the current key charecter
	
	char back[9]={}; // backup of data to look at when rearranging
	int i=0,j,x,n,loop;
	int serial[8];
	
	// getting serial
	for(loop = 0; loop < 8; loop++) {
		int ind;
		// e = strchr(c_seq, c);
		ind =(int)(strchr(c_seq, c) - c_seq);
		serial[loop] = seq[ind][loop];
	}
	int len=(int)strlen(data);
	
	
	while (i<len){
		x=0;
		n=i;
		// making 8 charecter list backuo
		while(n<i+8){
			back[x]=data[n];
			n++;
			x++;
		}
		x=0;
		// the rearrange
		for (j = 0; j < 8; j++){
			data[i+x]=back[serial[j]-1];
			x=(x+1)%8;

		}

		i+=8;
		// moving to next 8 charecter

	}
	return data;
}
char *encrypt(char *data, char *key){
	// WHY FRONT2BACK 1ST, THEN ENCRYPT?
	// => because if the key is 1 charecter long, theres no meaning of front2back, also doing at the end has no special meaning to this encryption. So move them 1st, then do encryption to tighten the flow.
	data = add_space(data);
	unsigned int key_i=0;
	unsigned int dat_len= strlen(data);
	unsigned int key_len= strlen(key);
	while(key_i<key_len){
		
 		front2back_en(data, 2, (int)dat_len);
		_encrypt(data,key[key_i]);
	 key_i++;
	}
 return data;
}

char *b2f_de(char *data, int to_move){
	// ON DECRYPT, AFTER REARRANGING WITH KEY SEQUENCE, SENDS 2 CHARECTER FROM BACK TO FRONT
	// to_move: number of charecters to move
	char front[MAX_L]={};

	int len= strlen(data), i=0;
	while (i<len-to_move){
		front[i]=data[i];
		i++;
	}
	//strncpy(front,data,(size_t)len-x);
	i=0;
	while(i<to_move){
		data[i]=data[len+i-to_move];
		i++;
	}
	i=0;
	while(i<len-to_move){
		data[i+to_move]=front[i];
		i++;
	}
	//int a=0;
	//printf("%s",data);
	//char rev_back[8]={};
	//while(a<8){printf("f%cf",front[a]);a++;}
	//int b_step=0;
	//printf(sizeof(front));
	//while(b_step<x){
	//	rev_back[x-b_step-1]=data[len-b_step-1];
	//	b_step++;
	//}

	//reverser(rev_back);
	//strcat(front,rev_back);
	//printf("\n%s	%s\n",data,front);
	//strcpy(data,front);
	return data;
	}


char *_decrypt(char *data, char c){
	// REVERT BACK TO ORIGINAL STATE FROM REARRANGED CHARECTERS
	
	// things are same as _encrypt
	
	char back[9]={};
	
	
	int i=0,j,x,n,loop;
	int serial[8];
	for(loop = 0; loop < 8; loop++) {
		int ind;
		// e = strchr(c_seq, c);
		ind =(int)(strchr(c_seq, c) - c_seq);
		serial[loop] = seq[ind][loop];
	 }
	unsigned int len=strlen(data);

	while (i<(int)len){
		x=0;
		n=i;
		while(n<i+8){
			back[x]=data[n];
			n++;
			x++;
		}
		x=0;
		
		// the revertion
		for (j = 0; j < 8; j++){
			// printf("%d",serial[j]);
			data[i+serial[j]-1]=back[x];
			x++;

		}
		// printf("==");
		i+=8;

	}
	return data;
}
char *decrypt(char *data, char *key){
	// int dat_i;
	data = add_space(data);
	// printf("\n1	%s",data);
	unsigned int key_i=0;
	// unsigned int dat_len= strlen(data);
	unsigned int key_len= strlen(key);
	// printf("\n2	%s\t%s",data,key);
	reverser(key);
	// printf("\n3	%s\t%s",data,key);
	while(key_i<key_len){
		// Decrypt 1st, then back2front
 		_decrypt(data,key[key_i]);
		// printf("\n5	%s\t%s",data,key);
		b2f_de(data);
	 		key_i++;
	}
 return data;
}
//lmlo wrR  dfro etoaul hl

int main() {
	char input[MAX_L] = {};
	char key[MAX_L] = {};
	char input2[MAX_L];
	
	
	printf("Enter message: ");
	
	
	fgets(input, MAX_L, stdin);
	char *pos;
	if ((pos=strchr(input, '\n')) != NULL)
	*pos = '\0';
	// I REALLY DONT REMEMBER THE USE OF POS (POSITION MAYBE?)
	
	strcpy(input2, input);
	
	
	printf("Enter key: ");
	
	
	fgets(key, MAX_L, stdin);
	//char *pos;
	if ((pos=strchr(key, '\n')) != NULL)
	*pos = '\0';
	//char *inp = encrypt0(input);
	//char seq{100}{8};
	// printf("%s",input);
	double msg_len= strlen(input);
	double key_len= strlen(key);
	
	clock_t en_begin = clock();
	
	
	// LIGHT IS THE ENCRYPTED VERSION OF DATA
	char *light=encrypt(input, key); 
	
	
	
	clock_t en_end = clock();
	double en_time_spent = (double)(en_end - en_begin) / CLOCKS_PER_SEC;
	printf("encrypted\n=========\n\n%s\n\nEncrypted in %fs",light,en_time_spent);
	//char aaa[]="qwert";
	//reverser(&aaa);
	//printf("%s",aaa);
	clock_t de_begin = clock();
	
	
	// DARK IS THE DECRYPTED VERSION OF INPUT
	char *dark=decrypt(input2,key);
	
	
	
	// THESE TIMING STUFFS ARE JUST FOR OPTIMISATION CHECK
	
	clock_t de_end = clock();
	double de_time_spent = (double)(de_end - de_begin) / CLOCKS_PER_SEC;
	printf("\ndecrypted\n=========\n\n%s\n\nDecrypted in %fs\n",dark,de_time_spent);
	printf("Msg len= %d\nKey len= %d\n\nEncrypted in %lfs\nDecrypted in %lfs\n  time per key (en): %lfs\n  time per key (de): %lfs",(int)msg_len,(int)key_len,en_time_spent,de_time_spent,(double)(en_time_spent/key_len),(double)(de_time_spent/key_len));
	return 0;
	}