[Qemu-devel] [PATCH 1/1] qga-win: fix 1357789 - installation on localized windows - acquire user and group names by well-known SIDs

[Daniel Rempel]

Replace hardcoded user and group names ("Administrators", "SYSTEM") with the 
ones acquired from system. Windows uses localized strings for these names and 
it may cause the installation to fail.
Windows has Well-known SIDs for "Administrators" group and "SYSTEM" user so 
they were used to identify required users and groups.
Well-known SIDs: 
https://support.microsoft.com/en-us/help/243330/well-known-security-identifiers-in-windows-operating-systems

Signed-off-by: Daniel Rempel <address@hidden>
---

 qga/vss-win32/install.cpp | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/qga/vss-win32/install.cpp b/qga/vss-win32/install.cpp
index f4160a3..19220b7 100644
--- a/qga/vss-win32/install.cpp
+++ b/qga/vss-win32/install.cpp
@@ -18,6 +18,9 @@
 #include <wbemidl.h>
 #include <comdef.h>
 #include <comutil.h>
+#include <sddl.h>
+
+#define BUFFER_SIZE 1024
 
 extern HINSTANCE g_hinstDll;
 
@@ -135,6 +138,30 @@ out:
     return hr;
 }
 
+/* Acquire group or user name by SID */
+static HRESULT getNameByStringSID(
+    const wchar_t *sid, LPWSTR buffer, LPDWORD bufferLen)
+{
+    HRESULT hr = S_OK;
+    PSID psid = NULL;
+    SID_NAME_USE groupType;
+    DWORD domainNameLen = BUFFER_SIZE, retval;
+    wchar_t domainName[BUFFER_SIZE];
+
+    chk(ConvertStringSidToSidW(sid, &psid));
+    retval = LookupAccountSidW(NULL, psid, buffer, bufferLen,
+                domainName, &domainNameLen, &groupType);
+
+    LocalFree(psid);
+
+    if (0 == retval) {
+        hr = HRESULT_FROM_WIN32(GetLastError());
+    }
+
+out:
+    return hr;
+}
+
 /* Find and iterate QGA VSS provider in COM+ Application Catalog */
 static HRESULT QGAProviderFind(
     HRESULT (*found)(ICatalogCollection *, int, void *), void *arg)
@@ -216,6 +243,10 @@ STDAPI COMRegister(void)
     CHAR dllPath[MAX_PATH], tlbPath[MAX_PATH];
     bool unregisterOnFailure = false;
     int count = 0;
+    DWORD bufferLen = BUFFER_SIZE;
+    wchar_t buffer[BUFFER_SIZE];
+    const wchar_t *administratorsGroupSID = L"S-1-5-32-544";
+    const wchar_t *systemUserSID = L"S-1-5-18";
 
     if (!g_hinstDll) {
         errmsg(E_FAIL, "Failed to initialize DLL");
@@ -284,11 +315,12 @@ STDAPI COMRegister(void)
 
     /* Setup roles of the applicaion */
 
+    chk(getNameByStringSID(administratorsGroupSID, buffer, &bufferLen));
     chk(pApps->GetCollection(_bstr_t(L"Roles"), key,
                              (IDispatch **)pRoles.replace()));
     chk(pRoles->Populate());
     chk(pRoles->Add((IDispatch **)pObj.replace()));
-    chk(put_Value(pObj, L"Name",        L"Administrators"));
+    chk(put_Value(pObj, L"Name", buffer));
     chk(put_Value(pObj, L"Description", L"Administrators group"));
     chk(pRoles->SaveChanges(&n));
     chk(pObj->get_Key(&key));
@@ -303,8 +335,10 @@ STDAPI COMRegister(void)
     chk(GetAdminName(&name));
     chk(put_Value(pObj, L"User", _bstr_t(".\\") + name));
 
+    bufferLen = BUFFER_SIZE;
+    chk(getNameByStringSID(systemUserSID, buffer, &bufferLen));
     chk(pUsersInRole->Add((IDispatch **)pObj.replace()));
-    chk(put_Value(pObj, L"User", L"SYSTEM"));
+    chk(put_Value(pObj, L"User", buffer));
     chk(pUsersInRole->SaveChanges(&n));
 
 out:
-- 
2.9.3