Dont’ use XOR encryption only when you encrypt data. It’s weak. Combine it with other methods/algorithms. You can for ex. xor a string and then encrypt it with AES 256.
Definitions and Includes
#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
int XOR(WCHAR **dest, const WCHAR *src, int slen, const WCHAR *key, int klen);
XOR method
int XOR(WCHAR **dest, const WCHAR *src, int slen, const WCHAR *key, int klen){
int kIndex = 0;
*dest = (WCHAR*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, slen * sizeof(WCHAR));
if (*dest == NULL) return 0;
for (int i = 0; i < slen - 1; i++){
*(*dest + i) = src[i] ^ key[kIndex++];
if (kIndex == klen - 1) kIndex = 0;
}
*(*dest + (slen - 1)) = '\0';
return slen;
}
Usage
int main(void){
WCHAR *xored;
const WCHAR plain[] = L"maldevel\0";
const WCHAR xorkey[] = L"gt32fvbn678jkfdcvb34tgbn\0";
int xoredChars = 0;
wprintf(L"plain text: %s\n", plain);
xoredChars = XOR(&xored, plain, wcslen(plain) + 1, xorkey, wcslen(xorkey) + 1);
if (xoredChars > 0)
wprintf(L"xor result: %s\n", xored);
if (xored)HeapFree(GetProcessHeap(), 0, xored);
return EXIT_SUCCESS;
}
