//XOR Encrypt 0.0.1
//by Sean Kane - http://celtickane.com

#include <stdio.h>
#include <conio.h>
#include <string.h>

char *crypt(char *bufData, char *bufKey, int strLength);

int main()
{
	char bufData[50], bufKey[50];
	char *ptrData, *ptrKey;
	char chrChoice;

	ptrData = bufData;
	ptrKey = bufKey;
	
	while ((chrChoice!='q') && (chrChoice!='Q'))
	{
	printf("Encrypt(E), Decrypt(D), Quit(Q): ");
	scanf("\n%c",&chrChoice);

	switch (chrChoice)
	{
	case 'e': case 'E':
		printf("Enter word to encrypt: ");
		chrChoice = scanf("%s",ptrData);
	
		printf("Enter encryption key: ");
		scanf("%s",ptrKey);
	
		ptrData = crypt(ptrData,ptrKey, strlen(bufKey));

		printf("Encrypted data: %s\n\n",bufData);
		break;
	case 'd': case 'D':
		printf("Enter word to decrypt: ");
		scanf("%s",ptrData);
	
		printf("Enter encryption key: "); 
		scanf("%s",ptrKey);
	
		ptrData = crypt(ptrData,ptrKey, strlen(bufKey));

		printf("Decrypted data: %s\n\n",bufData);
		break;
	case 'q': case'Q':
		break;
	default:
		printf("\nPlease type E, D, or Q\n");
		break;
	}
	
	}
	return 0;
}

char *crypt(char *bufData, char *bufKey, int strLength)
{
	int d, k;
	k = 0;
	for(d=0;d<strLength;d++)
	{
		bufData[d] = bufData[d] ^ bufKey[k];
		(k == strLength) ? k = 0 : k++;
	}
	return bufData;
}