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Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

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The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Sensitive Information

Removing any sensitive information from a repository is important. Sensitive information includes PII, PHI, customer/user information, server names, etc.

Removing PII and PHI

Git is a version control system that stores the history of all changes in a repository. If PII/PHI is checked in to a repository, it cannot simply be deleted since a record of the changes will still reside in the .git folder for every time that the file was changed. To fix this we will use a 3rd party open source tool called git filter-repo. Git has an inbuilt facility to fix these, filter-branch, but it is not performant and has some undesired side effects so to the point that the git maintainers suggest that it not be used.

Prerequisites

  • Install git filter-repo
  • Determine if the file(s) are tracked by Git LFS
    • cat .gitattributes
    • If the file or file extension is in .gitattributes then it is tracked by Git LFS
    • Gather a list of the Git object id’s for each file you are removing
      • git ls-files -s path/to/file
      • This will return “[6 Digit permission] [41 Digit OID] [size of the file] [file name]” you only need the 41 digit OID

Removing PII and PHI

  • git clone --mirror <repo> temp_name
  • cd temp_name
  • git filter-repo --path path/to/pii
  • git push --mirror https://url/to/repo
  • Contact GitHub Support or GitHub Premium Support, asking them to remove cached views and references to the sensitive data in pull requests on GitHub.
    • If the file(s) are tracked in LFS provide the OID’s to customer support and ask them to remove them as well
  • Finally make sure all users of the repository rebase branches instead of merging them. If they do not do this the old tainted history will get re-added See the official docs for more details

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