Issues reading from Windows Registry - c++

Question

I am attempting to read values from the Windows Registry. I am reading one value from HKLM\System and one value from HKLM\Software. I can easily read the value from System... but I cannot read the value from Software.
Snippit from Registry Editor:
Snippit from ReadReg():
int ReadReg(LPCTSTR subkey, LPCTSTR name, DWORD type)
{
HKEY key;
TCHAR value[255];
DWORD valuelen = 255;
LONG result = RegOpenKeyEx(HKEY_LOCAL_MACHINE, subkey, 0, KEY_READ, &key);
cout << "RegOpenKeyEx Req is: " << subkey << endl;
cout << "RegOpenKeyEx result is: " << PrintErrorCode(result) << endl;
result = RegQueryValueEx(key, name, NULL, &type, (LPBYTE)&value, &valuelen);
cout << "RegQueryValueEx Req is: " << name << endl;
cout << "RegQueryValueEx result is: " << PrintErrorCode(result) << "\n" << endl;
RegCloseKey(key);
return 0;
}
Snippit from Inject():
int Inject()
{
ReadReg("Software\\Microsoft\\Windows NT\\CurrentVersion\\Svchost", "demo", REG_MULTI_SZ);
ReadReg("System\\CurrentControlSet\\services\\SvcHostDemo\\Parameters", "ServiceDll", REG_EXPAND_SZ);
return 0;
}
Snippit from Standard Out:
The big question is... why can't I look at the value from "demo"?

Answer 1

You need to add the KEY_WOW64_64KEY flag when calling RegOpenKeyEx(). And you should change KEY_READ to KEY_QUERY_VALUE since you are just reading a value and don't need the other rights that KEY_READ grants.
Also, the last parameter of RegQueryValueEx() needs to be expressed in bytes, not in TCHARs.
#ifndef KEY_WOW64_64KEY
#define KEY_WOW64_64KEY 0x0100
#endif
int ReadReg(LPCTSTR subkey, LPCTSTR name, DWORD type)
{
HKEY key;
TCHAR value[255];
DWORD valuelen = sizeof(value);
LONG result = RegOpenKeyEx(HKEY_LOCAL_MACHINE, subkey, 0, KEY_QUERY_VALUE | KEY_WOW64_64KEY, &key);
cout << "RegOpenKeyEx Req is: " << subkey << endl;
cout << "RegOpenKeyEx result is: " << PrintErrorCode(result) << endl;
result = RegQueryValueEx(key, name, NULL, &type, (LPBYTE)&value, &valuelen);
cout << "RegQueryValueEx Req is: " << name << endl;
cout << "RegQueryValueEx result is: " << PrintErrorCode(result) << "\n" << endl;
RegCloseKey(key);
return 0;
}