On 04.03.2013 15:51, Alan Bateman wrote:
On 04/03/2013 09:31, Alexey Utkin wrote:
Alan,
Do you agree with
/**
* Check the access right against the securityInfo in the
current thread.
*/
static boolean checkAccessMask(long securityInfo, int accessMask,
int genericRead, int genericWrite, int genericExecute, int
genericAll)
throws WindowsException
{
int privilegies = TOKEN_QUERY;
long hToken = OpenThreadToken(GetCurrentThread(),
privilegies, false);
if (hToken == 0L && processTokenWithDuplicateAccess != 0L)
hToken = DuplicateTokenEx(processTokenWithDuplicateAccess,
privilegies);
We can have the situation with:
1) OpenThreadToken return 0 without exception - that is ok for thread
without impersonation.
2) processTokenWithDuplicateAccess is 0 for some reason (weak precess
privileges)
For that case we have no access to process token without exception
(hToken :=: 0).
boolean hasRight = false;
if (hToken != 0L) {
So, in upper line we need to check token for non-empty value.
! Do you concern about the [false] return value for that case?
try {
hasRight = AccessCheck(hToken, securityInfo,
accessMask,
genericRead, genericWrite, genericExecute,
genericAll);
Here is the actual work, that can make an exception (for example it
happens for invalid SID)
} finally {
CloseHandle(hToken);
If token was open it have to be closed without excuses.
}
}
return hasRight;
}
implementation approach?
Can the handle to the token (hToken) be 0? In my comment I was
suggesting:
long hToken = OpenThreadToken(...);
try {
...
} finally {
CloseHandle(hToken);
}
but that doesn't work if OpenThreadToken succeeds with a handle of 0.
If 0 is not possible then there are a few other clean-ups that we
could do at a later time.
Ah, I remember now, we handle ERROR_NO_TOKEN so this means that
hToken can be 0. So this means that the CloseHandle does need to
check for 0 in the finally block.
-Alan.
-Alan
