CM.EDITAR+ — Context Menu / ShellNew Manager

© 2026 SirSHAmun5on12 (SHAmun.fyi) Licensed under the Apache License 2.0 Maintainer: SirSHAmun5on12 — dev@eth-munson.com

CM.EDITAR+ is a Windows desktop utility that gives users full, safe, auditable control over the Windows Explorer New submenu and provides an optional per-user New+ submenu for curated templated file types. Every change is HKCU-scoped, snapshotted before write, verified after, and reversible from a built-in undo stack.

It ships a comprehensive 400+ extension catalog across 11 wired categories (AI/Automation, Archives, CAD/3D, Cloud Docs, Legacy, Media, Office/Docs, Omega Database, Power User, System, Text/Data) sourced from a single C# file (ExtensionCatalog.cs) and surfaced in both Category and A–Z views. High-risk executable extensions (.exe, .bat, .ps1, .crx, .msi, .scr, …) are classified risk: high and ship disabled by default — enforced by build-time invariants in both the C# tests and the catalog generator.

Status: v1.3.0 — public preview. All projects compile on Windows; the engine layers (Core / Registry / Apply / Templates / FileCreator) are substantively implemented. The Avalonia UI is wired to the engine via a single MainViewModel. Windows-specific calls (registry, DPAPI, SHChangeNotify) are isolated behind interfaces so the solution remains cross-compilable on Linux/macOS for CI authoring; runtime registry I/O only executes on Windows.

A built-in starter pack (29 templates) is seeded into %AppData%\CM.EDITAR+\Templates\ on first run so the Template Manager is immediately useful out-of-the-box.

If you find CM.EDITAR+ useful, tips welcome: https://SHAmun.fyi/tips.

Quick start (Windows)

You'll need Windows 10 or 11 and the .NET 8 SDK or any newer SDK (.NET 9, .NET 10 …) — the global.json accepts any SDK ≥ 8.0.100, so a single up-to-date SDK install is enough. Grab one from https://dotnet.microsoft.com/download if you don't have it.

# 1. Clone
git clone https://github.com/RealHaywoodJ/CM.EDITAR-Plus.git
cd CM.EDITAR-Plus

# 2. Build & test
dotnet build CM.EDITAR.sln -c Release
dotnet test  CM.EDITAR.sln -c Release

# 3. Run the desktop app
dotnet run --project src/CM.EDITAR.UI -c Release

On first launch the app seeds 29 ready-to-use templates (Markdown, JSON, YAML, Python, PowerShell, HTML, CSV, Dockerfile and more) into %AppData%\CM.EDITAR+\Templates\. Open the Manager, toggle the file types you want in your Windows New submenu, hit Apply Changes (green button) — your registry is snapshotted first, then only your personal HKCU keys are written, and Explorer is refreshed automatically. If anything looks wrong, Undo Last restores the snapshot.

Architecture

┌──────────────────────────────────────────────────────────────────┐
│  CM.EDITAR.UI  (Avalonia MVVM, .NET 8)                            │
│  MainViewModel · TemplateManagerViewModel · PreflightViewModel    │
└──────────────────────────────────────────────────────────────────┘
            │                    │                    │
            ▼                    ▼                    ▼
┌─────────────────┐  ┌──────────────────┐  ┌────────────────────┐
│ ApplyService    │  │ TemplateService  │  │ FileCreator (CLI)  │
│  snapshot →     │  │  CRUD · render · │  │  --create/--preview│
│  apply →        │  │  placeholders ·  │  │  --serve (named    │
│  SHChangeNotify │  │  Cmd sanitizer   │  │  pipe + DPAPI auth)│
│  → verify →     │  └──────────────────┘  └────────────────────┘
│  rollback       │            │                     │
└─────────────────┘            │                     │
            │                  ▼                     ▼
            ▼          ┌──────────────────────────────────┐
┌─────────────────┐    │ CM.EDITAR.Core (interfaces +     │
│ RegistryService │◄───┤ models · enums · DTOs)           │
│  ProgID resolve │    └──────────────────────────────────┘
│  HKCU writes    │
│  P/Invoke       │
└─────────────────┘
            │
            ▼
   Windows Registry (HKCU only at runtime)

Project layout

Project	Purpose
`CM.EDITAR.Core`	Models, enums, DTOs, service interfaces, on-disk path helpers
`CM.EDITAR.Registry`	Discovery, ProgID + UserChoice resolution, snapshots, P/Invoke
`CM.EDITAR.ApplyService`	Snapshot → apply → verify → rollback pipeline + signed audit
`CM.EDITAR.Templates`	Template CRUD, placeholder engine, Command sanitizer
`CM.EDITAR.FileCreator`	Atomic-write CLI + named-pipe server with DPAPI auth
`CM.EDITAR.UI`	Avalonia MVVM desktop app
`CM.EDITAR.Installer`	WiX 4 MSI (per-user) + installer snapshot/uninstall restore
`tests/*.Tests`	xUnit + FluentAssertions for Registry, Templates, FileCreator

Starter pack

On first launch CM.EDITAR+ automatically seeds 29 ready-to-use templates into the user's %AppData%\CM.EDITAR+\Templates\ folder (no templates are overwritten if any already exist):

Template	Extension(s)	Type	Placeholders used
Markdown Notebook	`.md`	FileName	`%TITLE%`, `%USERNAME%`, `%DATE%`
Blank Text File	`.txt`	FileName	`%DATE%`, `%USERNAME%`
JSON Skeleton	`.json`	FileName	`%TITLE%`, `%DATE%`, `%USERNAME%`
YAML Config	`.yaml`, `.yml`	FileName	`%PROJECT%`, `%USERNAME%`, `%DATE%`
HTML Page	`.html`, `.htm`	FileName	`%TITLE%`, `%USERNAME%`, `%DATE%`
CSV with Headers	`.csv`	FileName	`%DATE%`
Blank File	(none)	NullFile	—
PowerShell Script	`.ps1`	FileName	`%DATE%`, `%USERNAME%`
Python Script	`.py`	FileName	`%DATE%`, `%USERNAME%`
Environment Vars	`.env`	FileName	`%DATE%`, `%USERNAME%`
Dockerfile	`.dockerfile`	FileName	`%DATE%`, `%USERNAME%`
TOML Config	`.toml`	FileName	`%PROJECT%`, `%USERNAME%`, `%DATE%`
README	`.readme`	FileName	`%TITLE%`, `%DATE%`, `%USERNAME%`
Config File	`.cfg`	FileName	`%DATE%`, `%USERNAME%`
Batch Script	`.bat`	FileName	`%DATE%`, `%USERNAME%`
Internet Shortcut	`.url`	FileName	`%URL%`
Lua Script	`.lua`	FileName	`%DATE%`, `%USERNAME%`
Shell Script	`.sh`	FileName	`%DATE%`, `%USERNAME%`
Gitignore	`.gitignore`	FileName	`%DATE%`, `%USERNAME%`
Gitattributes	`.gitattributes`	FileName	`%DATE%`, `%USERNAME%`
Rich Text Document	`.rtf`	FileName	`%DATE%`, `%USERNAME%`
INI Config	`.ini`	FileName	`%DATE%`, `%USERNAME%`
Log File	`.log`	FileName	`%DATE%`, `%TIME%`, `%USERNAME%`
Java Properties	`.properties`	FileName	`%DATE%`, `%USERNAME%`
PDF Document	`.pdf`	NullFile	—
Binary File	`.bin`	NullFile	—
Shortcut	`.lnk`	NullFile	—
Command Script	`.cmd`	FileName	`%DATE%`, `%USERNAME%`
Cron Schedule	`.cron`	FileName	`%DATE%`, `%USERNAME%`

NullFile templates create an empty file with the registered extension — used for binary formats (.pdf, .bin, .lnk) where a templated body wouldn't be a valid file, and for the generic blank-file entry.

The source files live in templates/starter-pack/<id>/ and are copied to the output directory at build time. The importer (StarterPackImporter) is wired into App.axaml.cs and runs asynchronously on a background thread at startup so it never delays the UI; the Template Manager awaits the import on first launch so the list is always populated when it opens.

Storage paths

Purpose	Path
Templates	`%AppData%\CM.EDITAR+\Templates\<id>\`
Snapshots	`%LocalAppData%\CM.EDITAR+\Backups\<stamp>.reg` (+ `.json` sidecar)
Audit log	`%LocalAppData%\CM.EDITAR+\Audit\changes.log`
Diagnostic logs	`%LocalAppData%\CM.EDITAR+\Logs\<timestamp>.log`
IPC secret	`%LocalAppData%\CM.EDITAR+\Secrets\filecreator.secret` (DPAPI-encrypted on Windows)

Building

Requires the .NET 8 SDK or any newer SDK (.NET 9, .NET 10 …). The global.json uses rollForward: latestMajor, so any SDK ≥ 8.0.100 will pick up the build — you do not need to downgrade or install an extra SDK if you already have a newer one. On Windows, also install the WiX Toolset 4 SDK NuGet (restored automatically).

WiX <Files Include=…> works on WiX 4.0.5. The auto-harvest element the installer uses (<Files Include="$(var.UIPublishDir)\**" />) is available across WiX v4 and v5 — there is no need to upgrade. The NuGet WixToolset.Sdk/4.0.5 pin is intentional for reproducible builds.

# Restore + build + run unit tests
pwsh ./scripts/build.ps1

# Build the MSI installer
pwsh ./scripts/build-installer.ps1

# Build the portable ZIP
pwsh ./scripts/build-portable.ps1

Manual:

dotnet restore CM.EDITAR.sln
dotnet build   CM.EDITAR.sln -c Release
dotnet test    CM.EDITAR.sln -c Release

The solution also restores and builds on Linux/macOS for CI authoring; only the Windows-only services (registry I/O, DPAPI) become no-ops or throw.

How Apply works (and why it's safe)

Stage edits in the UI. Nothing is written.
Preflight generates an ApplyManifest containing every concrete RegistryOperation (Add / Modify / Delete) the batch will perform. The keypath is shown verbatim.
Snapshot — every key the manifest will touch is exported to a timestamped .reg file under %LocalAppData%\CM.EDITAR+\Backups\ along with a JSON sidecar containing the SHA-256, exported keys, user SID, and manifest ID. Snapshots are never overwritten.
Apply — every operation is funneled through RegistryService.ApplyOperation, which refuses any non-HKCU keypath at the entry point.
SHChangeNotify(SHCNE_ASSOCCHANGED) asks Explorer to refresh.
Verify — the manifest is re-read against the live registry. If any operation didn't take, rollback runs immediately by importing the snapshot.
Audit — a signed (HMAC-SHA256, per-install secret) JSON line is appended to changes.log for every Apply / Undo, success or failure.

Rollback / Undo

Undo Last restores the most recent snapshot.
Undo All restores every snapshot in reverse-chronological order.
Snapshots are also imported manually with regedit /s <snapshot>.reg.

Threat model summary

Asset	Threat	Mitigation
Windows registry integrity	Rogue HKLM / system-wide writes	All writes funneled through `RegistryService.ApplyOperation` which throws on non-HKCU paths
Snapshots	Tampering with rollback files	SHA-256 stored in JSON sidecar; restore verifies before importing
Audit log	After-the-fact forgery	Each line signed with HMAC-SHA256 keyed by per-install DPAPI secret
FileCreator IPC	Other users invoking the pipe	Named-pipe ACL restricted to the current user SID
FileCreator IPC	Replay / brute-force tokens	DPAPI-protected per-install secret + constant-time validation + 10 req/sec throttle
Command templates	Drive-by code execution	Two-gate sanitizer: `commandApproved=true` AND no disallowed tokens (network paths, `Invoke-Expression`, etc.)
Templates	Malicious payload	Static-by-default; only Command templates can execute and require explicit user approval
Snapshot files on disk	Local exfiltration	Stored under per-user `%LocalAppData%`; never uploaded automatically

Code signing

Unsigned binaries trigger Windows SmartScreen warnings on download and at install time. Both build-installer.ps1 and build-portable.ps1 include an optional signing step that runs signtool.exe (from the Windows 10/11 SDK) against every EXE and, for the MSI build, the installer itself.

Obtaining a certificate

For production releases use an Extended Validation (EV) code-signing certificate from a publicly trusted CA (e.g. DigiCert, Sectigo, GlobalSign). EV certificates establish SmartScreen reputation immediately. Standard OV certificates also work but may require download count to build reputation. Self-signed certificates are supported for internal/test builds only.

Export the certificate as a password-protected PFX (.pfx / .p12) file.

Local developer signing

# Sign the MSI (and the EXEs embedded in it)
pwsh ./scripts/build-installer.ps1 -SignWith "C:\certs\my-cert.pfx"

# Sign the EXEs in the portable ZIP
pwsh ./scripts/build-portable.ps1 -SignWith "C:\certs\my-cert.pfx"

If the PFX is password-protected, set the password via the environment variable before running:

$env:SIGN_PFX_PASSWORD = "your-pfx-password"
pwsh ./scripts/build-installer.ps1 -SignWith "C:\certs\my-cert.pfx"

CI / CD secrets contract

The build scripts read two environment variables when -SignWith is not passed. Configure these as secrets in your CI system (GitHub Actions, Azure Pipelines, etc.):

Secret name	Value
`SIGN_PFX_BASE64`	Base-64-encoded content of the PFX file (`base64 -w0 cert.pfx`)
`SIGN_PFX_PASSWORD`	Password that protects the PFX file

The scripts write the decoded PFX to a temp file, sign all targets, then immediately delete the temp file. When both variables are absent the signing step is skipped and the build completes with a warning — unsigned CI artifacts are still produced so the pipeline never breaks on a missing certificate.

Example GitHub Actions step:

- name: Build signed MSI
  shell: pwsh
  env:
    SIGN_PFX_BASE64:    ${{ secrets.SIGN_PFX_BASE64 }}
    SIGN_PFX_PASSWORD:  ${{ secrets.SIGN_PFX_PASSWORD }}
  run: pwsh ./scripts/build-installer.ps1

Timestamp authority

Both scripts use the DigiCert RFC 3161 timestamp server (http://timestamp.digicert.com, SHA-256). Timestamping ensures the signature remains valid after the certificate's validity period expires. To use a different TSA, edit the /tr argument in the Invoke-SignFile helper inside each script.

Verification commands

dotnet build CM.EDITAR.sln
dotnet test  CM.EDITAR.sln

# Discovery (Windows only):
dotnet run --project src/CM.EDITAR.UI -- # then click Refresh

# FileCreator CLI:
.\src\CM.EDITAR.FileCreator\bin\Debug\net8.0\CM.EDITAR.FileCreator.exe --preview --template-id <guid>
.\src\CM.EDITAR.FileCreator\bin\Debug\net8.0\CM.EDITAR.FileCreator.exe --create  --template-id <guid> --target "C:\Temp\test.md"
.\src\CM.EDITAR.FileCreator\bin\Debug\net8.0\CM.EDITAR.FileCreator.exe --serve

# Installer:
msiexec /i .\dist\installer\CM.EDITAR.Setup.msi

# UI end-to-end smoke flows (Windows only; needs WinAppDriver running):
dotnet publish src/CM.EDITAR.UI -c Release -o publish/ui
$env:CM_EDITAR_UI_EXE = (Resolve-Path .\publish\ui\CM.EDITAR.UI.exe)
dotnet test tests/CM.EDITAR.UI.E2E -c Release

The UI E2E suite covers discovery, stage+apply round-trip, and undo. It builds on every platform but only executes when WinAppDriver is reachable and CM_EDITAR_UI_EXE is set; the dedicated ui-e2e.yml GitHub Actions lane runs it on windows-latest and uploads screenshots/logs on failure. See tests/CM.EDITAR.UI.E2E/README.md for local setup details.

License

CM.EDITAR+ is licensed under the Apache License, Version 2.0 — see LICENSE for the full text and NOTICE for attribution requirements. The Apache 2.0 license is permissive (you can use, modify and redistribute the code, including in commercial / closed-source projects) and includes an explicit patent grant.

Contributing & community

Bug reports and feature requests: open a GitHub Issue.
Pull requests: see CONTRIBUTING.md. All PRs must include tests and a short description of the change.
Code of conduct: CODE_OF_CONDUCT.md (Contributor Covenant v2.1).
Security disclosures: see SECURITY.md — please email dev@eth-munson.com rather than opening a public issue.
Maintainers: MAINTAINERS.md · contributors: AUTHORS.md.
Release history: CHANGELOG.md.

Support the project

Maintainer site: https://SHAmun.fyi
Tips: https://SHAmun.fyi/tips
Contact: dev@eth-munson.com

Navigation Menu

Repository files navigation

CM.EDITAR+ — Context Menu / ShellNew Manager

Quick start (Windows)

Architecture

Project layout

Starter pack

Storage paths

Building

How Apply works (and why it's safe)

Rollback / Undo

Threat model summary

Code signing

Obtaining a certificate

Local developer signing

CI / CD secrets contract

Timestamp authority

Verification commands

License

Contributing & community

Support the project

About

Releases

Packages

Contributors

Languages

Name		Name	Last commit message	Last commit date
Latest commit History 9 Commits
.github		.github
artifacts		artifacts
attached_assets		attached_assets
lib		lib
scripts		scripts
src		src
templates/starter-pack		templates/starter-pack
tests		tests
tools		tools
.editorconfig		.editorconfig
.gitignore		.gitignore
.npmrc		.npmrc
.replit		.replit
.replitignore		.replitignore
AUTHORS.md		AUTHORS.md
CHANGELOG.md		CHANGELOG.md
CM.EDITAR.sln		CM.EDITAR.sln
CODE_OF_CONDUCT.md		CODE_OF_CONDUCT.md
CONTRIBUTING.md		CONTRIBUTING.md
Directory.Build.props		Directory.Build.props
LICENSE		LICENSE
MAINTAINERS.md		MAINTAINERS.md
NOTICE		NOTICE
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
SECURITY.md		SECURITY.md
global.json		global.json
package.json		package.json
pnpm-lock.yaml		pnpm-lock.yaml
pnpm-workspace.yaml		pnpm-workspace.yaml
replit.md		replit.md
tsconfig.base.json		tsconfig.base.json
tsconfig.json		tsconfig.json

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CM.EDITAR+ — Context Menu / ShellNew Manager

Quick start (Windows)

Architecture

Project layout

Starter pack

Storage paths

Building

How Apply works (and why it's safe)

Rollback / Undo

Threat model summary

Code signing

Obtaining a certificate

Local developer signing

CI / CD secrets contract

Timestamp authority

Verification commands

License

Contributing & community

Support the project

About

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Code of conduct

Contributing

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