How to Configure Windows Sandbox Local Traefik TLS Cipher Suites via XML in Windows 11

Restricting edge reverse proxy cipher suites to forward-secret AEAD ciphers (such as ECDHE-ECDSA-AES256-GCM-SHA384 and CHACHA20-POLY1305) is a vital security requirement for financial and healthcare compliance. Traefik supports native TLS option configuration for cipher suite whitelisting. Windows Sandbox on Windows 11 provides an isolated container for validating cipher enforcement safely without altering host machine network configurations.

Why Test TLS Cipher Suites in Windows Sandbox

Testing cipher suite restrictions directly on host workstations can break local services or conflict with Windows Schannel policy settings. Launching Traefik inside an isolated Windows Sandbox enables engineers to test cipher negotiation order, legacy client rejection, and PFS (Perfect Forward Secrecy) enforcement safely.

Authoring the Windows Sandbox WSB XML

Save the following XML document as TraefikCipherSandbox.wsb on your Windows 11 machine:

<Configuration>
  <VGpu>Default</VGpu>
  <Networking>Default</Networking>
  <MappedFolders>
    <MappedFolder>
      <HostFolder>C:\TraefikCipherLab</HostFolder>
      <SandboxFolder>C:\TraefikCipherLab</SandboxFolder>
      <ReadOnly>true</ReadOnly>
    </MappedFolder>
  </MappedFolders>
  <LogonCommand>
    <Command>powershell.exe -ExecutionPolicy Bypass -NoExit -File C:\TraefikCipherLab\setup-ciphers.ps1</Command>
  </LogonCommand>
</Configuration>

PowerShell Deployment Bootstrapper

Save the bootstrapping script as C:TraefikCipherLabsetup-ciphers.ps1:

Write-Host "Setting up Traefik TLS Cipher Suite Lab..." -ForegroundColor Cyan

$Dir = "C:Traefik"
New-Item -ItemType Directory -Force -Path $Dir | Out-Null

$ZipUrl = "https://github.com/traefik/traefik/releases/download/v3.0.0/traefik_v3.0.0_windows_amd64.zip"
Invoke-WebRequest -Uri $ZipUrl -OutFile "$Dir	raefik.zip"
Expand-Archive -Path "$Dir	raefik.zip" -DestinationPath $Dir -Force

$Config = @"
entryPoints:
  websecure:
    address: ":443"
tls:
  options:
    strict-ciphers:
      minVersion: "VersionTLS12"
      cipherSuites:
        - "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384"
        - "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384"
        - "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305"
        - "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305"
"@

Set-Content -Path "$Dirdynamic_conf.yml" -Value $Config
Write-Host "Traefik TLS Options Configured for Strict AEAD Ciphers." -ForegroundColor Green

Testing Cipher Negotiation

Launch the sandbox configuration and run OpenSSL s_client tests against port 443 with -cipher ECDHE-RSA-AES256-GCM-SHA384. Confirm that the handshake succeeds, while testing with deprecated CBC ciphers fails cleanly. Closing the sandbox leaves no residual configuration files.