By Seth Michael Larson
The Open Source Security Foundation (OpenSSF) Securing Software Repositories Working Group (WG) has just released a new guide for maintainers of open source software repositories. The guide details a new security capability named “Trusted Publishers” which utilizes the OpenID Connect standard (OIDC) to authenticate with a package repository without the use of long-lived secrets thus avoiding many related security and operational challenges.
Trusted Publishers: Enhancing Security for Open Source Repositories
The guide details the implementation and design considerations gathered from implementing Trusted Publishers in multiple open source software repositories like the Python Package Index (PyPI) and Rubygems.org.
Implementation and Design Considerations
Trusted Publishers pair well with other security technologies like SLSA build provenance as they are built on the same underlying technology in OIDC. For some identity providers, Trusted Publishers also allow binding verifiable metadata like the source repository URL to a published artifact to avoid social confusion attacks like “Star-Jacking”.
User Adoption and Impact
In addition to added security benefits, Trusted Publishers are popular with users when they’re available. For example, PyPI added support for Trusted Publishers in April of 2023 and has since seen over 14,000 projects voluntarily adopt Trusted Publishers.
Accessing and Contributing to the Guide
You can find the guide hosted on openssf.org and submit contributions on GitHub. Thanks to everyone in the working group who contributed their expertise and reviews during the writing of this guide.
About the OpenSSF Securing Software Repositories Working Group
The OpenSSF Securing Software Repositories Working Group focuses on the maintainers of software repositories, software registries, and tools which rely on them. The working group provides a forum to share experiences and to discuss shared problems, risks, and threats. For more information on the OpenSSF Securing Software Repositories Working Group, see our GitHub Repo.
About the Author
Seth Larson is the Security Developer-in-Residence at the Python Software Foundation, Python Software Foundation Fellow, maintainer of popular Python open source packages like urllib3 and Requests, and an advocate for open source sustainability and security.