[NETID] Disable the 'Network ID' and 'Change' buttons and show the admin note when the current user is not an administrator

dll/win32/netid/netid.c

@@ -159,6 +159,68 @@ GetComputerNames(
     return TRUE;
 }
 
+static BOOL
+IsUserAdmin(VOID)
+{
+    SID_IDENTIFIER_AUTHORITY Authority = {SECURITY_NT_AUTHORITY};
+    PSID pAdminsSid = NULL;
+    HANDLE hToken = NULL;
+    PTOKEN_GROUPS pGroups = NULL;
+    BOOL bIsAdmin = FALSE;
+    DWORD dwSize, i;
+
+    if (!AllocateAndInitializeSid(&Authority, 2, SECURITY_BUILTIN_DOMAIN_RID,
+                                  DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0, 0,
+                                  &pAdminsSid))
+        return FALSE;
+
+    if (!OpenProcessToken(GetCurrentProcess(),
+                          TOKEN_QUERY,
+                          &hToken))
+        goto done;
+
+    dwSize = 0;
+    GetTokenInformation(hToken,
+                        TokenGroups,
+                        NULL,
+                        0,
+                        &dwSize);
+    if (dwSize == 0)
+        goto done;
+
+    pGroups = HeapAlloc(GetProcessHeap(), 0, dwSize);
+    if (pGroups == NULL)
+        goto done;
+
+    if (!GetTokenInformation(hToken,
+                             TokenGroups,
+                             pGroups,
+                             dwSize,
+                             &dwSize))
+        goto done;
+
+    for (i = 0; i < pGroups->GroupCount; i++)
+    {
+        if (EqualSid(pGroups->Groups[i].Sid, pAdminsSid))
+        {
+            bIsAdmin = TRUE;
+            break;
+        }
+    }
+
+done:
+    if (pGroups != NULL)
+        HeapFree(GetProcessHeap(), 0, pGroups);
+
+    if (hToken != NULL)
+        CloseHandle(hToken);
+
+    if (pAdminsSid != NULL)
+        FreeSid(pAdminsSid);
+
+    return bIsAdmin;
+}
+
 static
 BOOL
 IsValidDomainName(
@@ -611,6 +673,16 @@ NetIDPage_OnInitDialog(
     LoadStringW(hDllInstance, (pNetIdData->JoinStatus == NetSetupDomainName)? 6 : 5, szBuffer, ARRAYSIZE(szBuffer));
     SetDlgItemText(hwndDlg, IDC_WORKGROUPDOMAIN, szBuffer);
     SetDlgItemText(hwndDlg, IDC_WORKGROUPDOMAIN_NAME, pNetIdData->JoinName);
+
+    /* Show the administrator note and disable controls when the user is not an administator */
+    if (!IsUserAdmin())
+    {
+        LoadStringW(hDllInstance, 1021, szBuffer, ARRAYSIZE(szBuffer));
+        SetDlgItemText(hwndDlg, IDC_MESSAGETEXT, szBuffer);
+
+        EnableWindow(GetDlgItem(hwndDlg, IDC_NETWORK_ID), FALSE);
+        EnableWindow(GetDlgItem(hwndDlg, IDC_NETWORK_PROPERTY), FALSE);
+    }
 }
 
 static