RegSetValueEx and CHAR - c++

Question

consider the following code
addHash("hash");
bool addHash(char* hash) {
HKEY hKey = 0;
int code = RegOpenKey(HKEY_CURRENT_USER, subkey, &hKey);
const int length = strlen(hash)+1;
WCHAR whash[100];
MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, hash, strlen(hash), whash, 100);
LONG setRes = RegSetValueEx(hKey, L"hash", 0, REG_SZ, (LPBYTE)whash, strlen(hash)+1);
return true;
}
After code is compiled and executed "ha" is puted into registry. Can somebody tell me where the problem is?
Thank you in advance!

Answer 1

The last argument is the number of bytes, not the number of characters, that the second last argument points to.
So the first five bytes (strlen(hash) + 1) of whash will be stored in the registry. Change to:
LONG setRes = RegSetValueEx(hKey,
L"hash",
0,
REG_SZ,
(LPBYTE)whash,
(wcslen(whash) + 1) * sizeof(WCHAR));
You may also need to initialise whash (I don't think MultiByteToWideChar() adds a null terminator for you):
WCHAR whash[100] = { 0 };

Answer 2

I think this is what you are trying to do:
#include <tchar.h>
#include <Windows.h>
using namespace std;
bool addHash(wstring hash) {
const wchar_t* wHash = hash.c_str();
LONG ret = RegSetKeyValue(HKEY_CURRENT_USER, _T("Software\\aa\\test"), _T("hash"), REG_SZ, wHash, hash.length() * sizeof(wchar_t));
return (ret == ERROR_SUCCESS);
}
int main()
{
addHash(_T("A42B2094EDC43"));
return 0;
}
Hope this helps ;)