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Windows: Fix qt_ntfs_permission_lookup

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Specifying qt_ntfs_permission_lookup++ in application code didn't
make qfilesystemengine_win.cpp respect Windows ACL as it was supposed
to. This was because GetTokenInformation for TokenUser failed always in
resolveLibs() function, because the TOKEN_USER struct that was given to
it wasn't large enough to contain both TOKEN_USER and SID structs that
GetTokenInformation wants to return in this case.

Fixed by calling GetTokenInformation twice, first to determine the
required size, and then another time to get the actual token info.
Additionally, the SID returned as part of the token info needs to be
stored for the lifetime of the application, as the TRUSTEE_W struct
has a pointer to it (currentUserTrusteeW).

The worldTrusteeW initialization also required a change to properly
store the SID.

Note: The dynamic resolution of FreeSid and other SID manipulating
functions doesn't appear to be necessary, as they are found on the
same ifdef level (in winbase.h) as the GetTokenInformation, which
already isn't dynamically resolved.

Task-number: QTBUG-247
Change-Id: I0294c85ea903c86d03c2fcd3d801502b378dc0e5
Reviewed-by: Joerg Bornemann <joerg.bornemann@nokia.com>
This commit is contained in:
Miikka Heikkinen 2012-01-12 15:43:07 +02:00 committed by Qt by Nokia
parent 2fab348c81
commit 49c5c3e5c5
1 changed files with 46 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
src/corelib/io/qfilesystemengine_win.cpp
View File

@ -160,6 +160,31 @@ typedef DWORD (WINAPI *PtrGetEffectiveRightsFromAclW)(PACL, PTRUSTEE_W, OUT PACC
static PtrGetEffectiveRightsFromAclW ptrGetEffectiveRightsFromAclW = 0;
static TRUSTEE_W currentUserTrusteeW;
static TRUSTEE_W worldTrusteeW;
static PSID currentUserSID = 0;
static PSID worldSID = 0;
/*
Deletes the allocated SIDs during global static cleanup
*/
class SidCleanup
{
public:
~SidCleanup();
};
SidCleanup::~SidCleanup()
{
qFree(currentUserSID);
currentUserSID = 0;
// worldSID was allocated with AllocateAndInitializeSid so it needs to be freed with FreeSid
if (worldSID) {
::FreeSid(worldSID);
worldSID = 0;
}
}
Q_GLOBAL_STATIC(SidCleanup, initSidCleanup)
typedef BOOL (WINAPI *PtrGetUserProfileDirectoryW)(HANDLE, LPWSTR, LPDWORD);
static PtrGetUserProfileDirectoryW ptrGetUserProfileDirectoryW = 0;
@ -199,25 +224,35 @@ static void resolveLibs()
// Create TRUSTEE for current user
HANDLE hnd = ::GetCurrentProcess();
HANDLE token = 0;
initSidCleanup();
if (::OpenProcessToken(hnd, TOKEN_QUERY, &token)) {
TOKEN_USER tu;
DWORD retsize;
if (::GetTokenInformation(token, TokenUser, &tu, sizeof(tu), &retsize))
ptrBuildTrusteeWithSidW(&currentUserTrusteeW, tu.User.Sid);
DWORD retsize = 0;
// GetTokenInformation requires a buffer big enough for the TOKEN_USER struct and
// the SID struct. Since the SID struct can have variable number of subauthorities
// tacked at the end, its size is variable. Obtain the required size by first
// doing a dummy GetTokenInformation call.
::GetTokenInformation(token, TokenUser, 0, 0, &retsize);
if (retsize) {
void *tokenBuffer = qMalloc(retsize);
if (::GetTokenInformation(token, TokenUser, tokenBuffer, retsize, &retsize)) {
PSID tokenSid = reinterpret_cast<PTOKEN_USER>(tokenBuffer)->User.Sid;
DWORD sidLen = ::GetLengthSid(tokenSid);
currentUserSID = reinterpret_cast<PSID>(qMalloc(sidLen));
if (::CopySid(sidLen, currentUserSID, tokenSid))
ptrBuildTrusteeWithSidW(&currentUserTrusteeW, currentUserSID);
}
qFree(tokenBuffer);
}
::CloseHandle(token);
}
typedef BOOL (WINAPI *PtrAllocateAndInitializeSid)(PSID_IDENTIFIER_AUTHORITY, BYTE, DWORD, DWORD, DWORD, DWORD, DWORD, DWORD, DWORD, DWORD, PSID*);
PtrAllocateAndInitializeSid ptrAllocateAndInitializeSid = (PtrAllocateAndInitializeSid)GetProcAddress(advapiHnd, "AllocateAndInitializeSid");
typedef PVOID (WINAPI *PtrFreeSid)(PSID);
PtrFreeSid ptrFreeSid = (PtrFreeSid)GetProcAddress(advapiHnd, "FreeSid");
if (ptrAllocateAndInitializeSid && ptrFreeSid) {
if (ptrAllocateAndInitializeSid) {
// Create TRUSTEE for Everyone (World)
SID_IDENTIFIER_AUTHORITY worldAuth = { SECURITY_WORLD_SID_AUTHORITY };
PSID pWorld = 0;
if (ptrAllocateAndInitializeSid(&worldAuth, 1, SECURITY_WORLD_RID, 0, 0, 0, 0, 0, 0, 0, &pWorld))
ptrBuildTrusteeWithSidW(&worldTrusteeW, pWorld);
ptrFreeSid(pWorld);
if (ptrAllocateAndInitializeSid(&worldAuth, 1, SECURITY_WORLD_RID, 0, 0, 0, 0, 0, 0, 0, &worldSID))
ptrBuildTrusteeWithSidW(&worldTrusteeW, worldSID);
}
}
HINSTANCE userenvHnd = QSystemLibrary::load(L"userenv");