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Code signing policy

Status: releases are not signed yet. This policy takes effect with the first signed release, and the release notes will say so.

Signing service

Free code signing provided by SignPath.io, certificate by SignPath Foundation.

What is signed

Each release signs these files with Authenticode:

  • the two MSI installers
  • RevitModelMcp.dll and RevitModelMcp.Core.dll
  • RevitModelMcp.Updater.exe
  • RevitModelMcp.BatchSupervisor.exe

The signed files are the same ones inside the MSIs, the per-year add-in ZIP files and the managed Revit bundle.

Third-party libraries that ship in the packages are not signed by this project. Autodesk Revit assemblies are never included in any release asset. The Python package, the MCPB bundle and SHA256SUMS.txt are not Authenticode-signed; use the checks in verify downloads.

Team roles

Role Who Responsibility
Author Dinar Sharafutdinov Writes and commits the source code.
Reviewer Dinar Sharafutdinov Reviews every pull request from other contributors before it is merged.
Approver Dinar Sharafutdinov Approves each signing request.

The maintainer uses multi-factor authentication for GitHub and for SignPath. Contributors without commit rights open pull requests, and the reviewer merges them only after review and passing checks. Dependency updates and release pull requests from automation run the same checks.

How a release is signed

  1. The maintainer pushes a release tag.
  2. The release workflow builds the add-in, the installers and the bundle on GitHub-hosted runners.
  3. The workflow uploads the unsigned installers and archives as a workflow artifact and submits them to SignPath. SignPath checks that the build ran in this repository on GitHub.
  4. The approver reviews the signing request and approves it. Every release needs manual approval.
  5. SignPath signs the files listed above. The artifact configuration is kept in .signpath/artifact-configuration.xml. It restricts the product name to Model MCP and the product version to the release build.
  6. The workflow downloads the signed files, checks every signature, computes SHA256SUMS.txt, attests the assets and publishes the release.

Privacy policy

See the privacy policy. Signing adds no software behavior: the add-in sends no information to other networked systems beyond the update checks described there, and you can turn those off.

Verify downloads

Every release publishes SHA256SUMS.txt and a build provenance attestation for its assets. See Verify downloads for the commands. install.ps1 and the add-in updater check SHA256SUMS.txt before they install anything.

Build provenance

Build provenance is not code signing. A GitHub attestation binds a file digest to the release workflow and its source revision. Authenticode identifies a Windows publisher and applies to the files listed in What is signed.

The release workflow attests every staged release asset after signing and checksum generation. This includes installers, add-in and bundle archives, MCP manifests, Python distributions, SBOMs, and SHA256SUMS.txt.

GitHub CLI verifies each downloaded file with:

gh attestation verify <file> --repo sharafutdinovdi/revit-model-mcp

Verification requires a matching attestation from this repository. A checksum comparison alone does not verify build provenance.

Each release also carries revit-model-mcp-<version>.intoto.jsonl as a release asset. It holds the attestation bundles produced by the workflow, one bundle per line, so tools that only inspect release assets (such as OpenSSF Scorecard) can find the provenance. The file is not itself attested; verify the other assets with gh attestation verify as above.

Revit's unsigned add-in prompt

Revit asks whether to load an unsigned add-in the first time it loads the DLL, and again whenever the DLL content or its path changes. Choose Always Load and close Revit normally; Revit keeps the decision only after a graceful exit. Each automatic update therefore causes one prompt at the next Revit start until releases are signed.

Organizations that deploy their own code-signing certificate can sign the installed DLLs with install.ps1 -SignThumbprint <thumbprint>; see transport.

Reporting a problem

If you think a signed file violates this policy, report it through the process in SECURITY.md.