In broadcast environments like college radio stations, there's a constant tension between security and operational efficiency. We need to allow DJs to play media while preventing unauthorized copying or distribution. The standard Windows user account system presents some interesting possibilities for solving this.

Here's the core of our solution architecture:

# PowerShell script to create the necessary users
New-LocalUser -Name "ProgramUser" -NoPassword -Description "Standard DJ account"
New-LocalUser -Name "MediaUser" -Password (ConvertTo-SecureString "ComplexPassword123!" -AsPlainText -Force) -Description "Media access account"

# Set ACLs for media folder
$acl = Get-Acl "C:\Media"
$rule = New-Object System.Security.AccessControl.FileSystemAccessRule("MediaUser","ReadAndExecute","Allow")
$acl.SetAccessRule($rule)
Set-Acl "C:\Media" $acl

The key to our solution lies in Windows' RunAs functionality. We can use scheduled tasks to bridge the gap between security and usability:

# Create a scheduled task that runs as MediaUser but can be triggered by ProgramUser
$action = New-ScheduledTaskAction -Execute "C:\Program Files\Traktor\Traktor.exe"
$principal = New-ScheduledTaskPrincipal -UserId "MediaUser" -LogonType Password
$settings = New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -DontStopIfGoingOnBatteries
Register-ScheduledTask -Action $action -Principal $principal -Settings $settings -TaskName "TraktorMediaPlayback" -Description "Runs Traktor as MediaUser"

For crash recovery scenarios, we implemented a simple monitoring system:

# Monitoring script (runs as SYSTEM account)
while ($true) {
    $traktor = Get-Process -Name "Traktor" -ErrorAction SilentlyContinue
    if (-not $traktor) {
        Start-ScheduledTask -TaskName "TraktorMediaPlayback"
        # Log the restart event
        Write-EventLog -LogName Application -Source "MediaPlayer" -EventId 1001 -EntryType Information -Message "Traktor restarted automatically"
    }
    Start-Sleep -Seconds 30
}

For domain-joined systems, Group Policy Preferences offer another way to implement this:

# XML for Group Policy Preference (Scheduled Task)
<ScheduledTasks clsid="{CC63F200-7309-4ba0-B154-A71CD118DBCC}">
  <TaskV2 clsid="{D8896630-B814-4f1f-BDAD-5F31D441AFA7}" name="TraktorMediaPlayback" image="1" changed="2023-05-15 12:00:00" uid="{A8F9E0A1-3D5B-4A7C-9C2D-1E3F4B5C6D7E}">
    <Properties action="R" name="TraktorMediaPlayback" runAs="MediaUser" logonType="S4U">
      <Task version="1">
        <RegistrationInfo>
          <Description>Runs Traktor as MediaUser</Description>
        </RegistrationInfo>
        <Actions Context="Author">
          <Exec>
            <Command>C:\Program Files\Traktor\Traktor.exe</Command>
          </Exec>
        </Actions>
      </Task>
    </Properties>
  </TaskV2>
</ScheduledTasks>

While this approach solves our immediate problem, there are some important caveats:

• The MediaUser credentials are still stored on the system
• DJs could potentially access the media files through other applications
• File system auditing should be enabled to track access attempts

For enhanced security, consider implementing additional controls like AppLocker to restrict which applications can access the media folder.

When implementing restricted media playback systems in Windows environments, administrators often face this dilemma: how to allow users to launch applications under different credentials without disclosing those credentials. The scenario becomes particularly critical in broadcast environments where uptime is essential, yet media security must be maintained.

The Windows security model provides several mechanisms for controlled privilege elevation:

// Sample C# code demonstrating Windows impersonation
using System;
using System.Security.Principal;
using System.Runtime.InteropServices;

public class ImpersonationDemo {
    [DllImport("advapi32.dll", SetLastError=true)]
    public static extern bool LogonUser(
        string lpszUsername,
        string lpszDomain,
        string lpszPassword,
        int dwLogonType,
        int dwLogonProvider,
        out IntPtr phToken);
    
    public static void RunAsMediaUser() {
        IntPtr userToken = IntPtr.Zero;
        bool success = LogonUser(
            "MediaUser",
            "DOMAIN",
            "securePassword123",
            2, // LOGON32_LOGON_INTERACTIVE
            0, // LOGON32_PROVIDER_DEFAULT
            out userToken);
        
        if (success) {
            WindowsIdentity identity = new WindowsIdentity(userToken);
            WindowsImpersonationContext context = identity.Impersonate();
            
            // Run Traktor or other media application here
            Console.WriteLine("Running as MediaUser");
            
            context.Undo();
        }
    }
}

For our radio station scenario, we have several viable approaches:

1. Scheduled Task Method

Create a scheduled task configured to run as MediaUser with stored credentials:

schtasks /create /tn "TraktorPlayback" /tr "C:\Program Files\Traktor\Traktor.exe" 
/sc ONSTART /ru MediaUser /rp P@ssw0rd /rl HIGHEST

Then provide a shortcut to:

schtasks /run /tn "TraktorPlayback"

2. Secondary Logon Service

Create a service that manages application execution:

sc create "MediaPlayback" binPath= "C:\Service\MediaService.exe" 
obj= "DOMAIN\MediaUser" password= "securePassword123"

3. Group Policy Preferences

Configure item-level targeting in Group Policy to push credentials securely:

<Item>
  <Targeting>
    <Conditions>
      <User>ProgramUser</User>
    </Conditions>
  </Targeting>
  <Properties action="U" runAs="DOMAIN\MediaUser" 
   password="AQCAAANCMnd8BFdERjHoAwE/Cl+sBAAAA..." />
</Item>

When implementing these solutions:

• Always use the principle of least privilege
• Regularly rotate service account passwords
• Enable auditing to monitor credential usage
• Consider implementing Just Enough Administration (JEA)

For more robust solutions:

// PowerShell constrained endpoint example
$sessionConfig = New-PSSessionConfigurationFile -Path .\MediaEndpoint.pssc 
-RunAsCredential DOMAIN\MediaUser -SessionType RestrictedRemoteServer
-RoleDefinitions @{'DOMAIN\ProgramUsers'=@{RoleCapabilities='MediaPlayback'}}

This creates a PowerShell endpoint that automatically elevates privileges while restricting what commands can be run.