Extension signature verification relies on code that is not open source

[DemiMarie]

Does this issue occur when all extensions are disabled?: N/A (licensing problem)

• VS Code Version: N/A (licensing problem)
• OS Version: N/A (licensing problem)

Steps to Reproduce:

1. Build a version of VSCode with all proprietary dependencies removed.
2. Find that installing extensions (from any source) fails.

This is because verifying extension signatures depends on code that is not open source.

[isidorn]

Thanks for opening this issue. We are in the process of open-sourcing the signing module, and I expect it to happen in the next couple of milestones.