punktfunk/clients/windows/packaging

punktfunk Windows client — MSIX packaging

The Windows client ships as signed MSIX packages so Windows boxes get a real package (Start tile, clean install/uninstall) instead of a loose exe. CI builds + publishes them from .gitea/workflows/windows-client.yml to Gitea's generic package registry (https://git.unom.io/unom/-/packages), on every main push that touches the client (canary) and on vX.Y.Z release tags (stable) — see Release Channels.

Two architectures, one x64 runner. Both x64 and arm64 packages are produced off the single x64 Windows runner — x86_64-pc-windows-msvc builds natively, aarch64-pc-windows-msvc is cross-compiled (the x64 MSVC toolset ships the ARM64 cross compiler; since M10 nothing in the package links FFmpeg, so neither arch needs a per-arch FFMPEG_DIR tree staged on the runner — one less thing the ARM64 leg can be missing). Artifacts are arch-suffixed (..._x64.msix / ..._arm64.msix, each with its matching .cer); pack-msix.ps1 -Arch x64|arm64 stamps the manifest ProcessorArchitecture and names the output. See windows-client.yml for the cross-build rationale.

What's in the package

pack-msix.ps1 assembles a layout from a cargo build --release and runs makeappx + signtool:

File	Source
punktfunk-client.exe	the release build (the WinUI shell)
punktfunk-session.exe	the release build — the Vulkan session client the shell spawns for every stream (sibling resolution, src/spawn.rs). Skia links statically; vulkan-1.dll is a GPU-driver component, never bundled. ARM64 builds it --no-default-features (no Skia console UI) until rust-skia ships aarch64-pc-windows-msvc prebuilts
Microsoft.WindowsAppRuntime.Bootstrap.dll, resources.pri	staged by the client's build.rs via windows-reactor-setup::as_framework_dependent()
SDL3.dll	auto-staged by the sdl3 crate
licenses\*	the project's MIT/Apache texts + the generated THIRD-PARTY-NOTICES.txt (MSIX has no installer EULA page, so attribution ships as files)
Assets\*.png	checked-in tile/store logos (rasterized from packaging/flatpak/io.unom.Punktfunk.svg)
AppxManifest.xml	the template here, with {VERSION}/{PUBLISHER} substituted

No FFmpeg DLLs. The client decodes natively since M10 (pf-vkdecode / pf-dxvadec / OpenH264+rav1d — punktfunk-planning design/client-native-decode.md §6), so nothing here link-imports libav* and the wildcard avcodec/avformat/avutil/swscale/swresample-*.dll copy is gone, along with the FFmpeg LGPL notice that accompanied it — shipping that notice now would claim a dependency the package doesn't have. The host installer is unchanged: packaging/windows/pack-host-installer.ps1 still ships those DLLs for its AMF/QSV encode path.

Why an "unpackaged" WinUI app packages cleanly

main calls windows_reactor::bootstrap(), which runs MddBootstrapInitialize2 with OnPackageIdentity_NOOP (crates/libs/reactor/src/bootstrap.rs), so under MSIX package identity the App SDK bootstrapper is a no-op and the runtime is resolved from the manifest's <PackageDependency> on Microsoft.WindowsAppRuntime.2 instead (reactor pins WINDOWSAPPSDK_RELEASE_MAJORMINOR = 0x20000 = 2.0). It's a full-trust Win32 app (EntryPoint="Windows.FullTrustApplication" + runFullTrust) because it owns raw D3D11, Win32 low-level input hooks, WASAPI and SDL3.

Versioning

MSIX requires a strictly 4-part numeric version. The workflow computes:

• vX.Y.Z tag → X.Y.Z.0 (THE release; any -rc/+meta suffix is dropped for MSIX). Published to the stable latest/ alias and attached to the unified Gitea Release.
• main push / workflow_dispatch → 0.3.<run_number>.0 (canary, climbs by run number; canary/ alias).

Signing & install

CI signs every build with Azure Artifact Signing (formerly Trusted Signing) — account unomsigning, certificate profile unom-io, endpoint https://neu.codesigning.azure.net/. That chain is publicly trusted, so there is nothing to import:

# install the package for your CPU (and re-run for each upgrade)
Add-AppxPackage -Path .\punktfunk-client-windows_<ver>_x64.msix     # Intel/AMD
Add-AppxPackage -Path .\punktfunk-client-windows_<ver>_arm64.msix   # ARM64 (Snapdragon, etc.)

The MSIX declares a dependency on the Windows App SDK 2.x runtime; install the App SDK runtime if Add-AppxPackage reports a missing Microsoft.WindowsAppRuntime.2 framework.

How signing resolves

pack-msix.ps1 picks a backend in this order:

1. Azure Artifact Signing when AZURE_CODESIGNING_ENDPOINT / _ACCOUNT / _PROFILE are all set (the workflow sets them; they aren't secret). Credentials come from AZURE_TENANT_ID / AZURE_CLIENT_ID / AZURE_CLIENT_SECRET — the punktfunk-ci-signing service principal, which holds only the Artifact Signing Certificate Profile Signer role scoped to the unom-io profile. Keys are HSM-backed and never leave Azure, so there is no .pfx and no .cer is emitted.
2. MSIX_CERT_PFX_B64 / MSIX_CERT_PASSWORD — the older stable self-signed cert (CN=unom, public half checked in as punktfunk-codesign.cer), kept as a fallback.
3. An ephemeral self-signed cert (forks / local builds with no secrets at all).

Modes 2 and 3 still export a .cer to import into Cert:\LocalMachine\TrustedPeople first. On a v* tag, a build with no real signing backend fails closed rather than shipping a throwaway.

Two things about Azure mode that are easy to get wrong:

• Timestamping is mandatory, not best-effort. Azure mints a leaf cert per request that expires in about three days. An untimestamped signature therefore stops verifying within days of release, so the script refuses to retry without one (modes 2 and 3 keep the old best-effort retry).
• The manifest Publisher must equal the signer's subject exactly, because MSIX package identity is Name + Publisher. The default -Publisher is the unom-io profile's verified subject; after signing, the script reads the signature back off the .msix and fails the build on any drift. Changing it makes a different package — existing installs must be uninstalled, not upgraded.

Building locally

On the Windows runner / dev VM (MSVC + Windows SDK present), after a release build:

# x64
cargo build --release -p punktfunk-client-windows --target x86_64-pc-windows-msvc
pwsh -File clients/windows/packaging/pack-msix.ps1 `
  -Version 0.2.0.0 -TargetDir C:\t\x86_64-pc-windows-msvc\release -OutDir C:\t\msix

# arm64 (cross-compiled; no extra environment — the client links no FFmpeg)
cargo build --release -p punktfunk-client-windows --target aarch64-pc-windows-msvc
pwsh -File clients/windows/packaging/pack-msix.ps1 `
  -Version 0.2.0.0 -Arch arm64 -TargetDir C:\t\aarch64-pc-windows-msvc\release -OutDir C:\t\msix

Validated end-to-end on the build VM (pack → sign → Add-AppxPackage → framework-dependency resolution). The only step that needs a real display is launching the WinUI window (same on-glass constraint as the rest of the client).