mimemagic VS noseyparker

If you're curious, here's how I solved it for ruby back in the day. Still used magic bytes, but added an overlay on top of the freedesktop.org DB: https://github.com/mimemagicrb/mimemagic/pull/20

Get it directly from github commit.

[AO3-6152] - Due to a licensing incident with a Rails dependency known as mimemagic, we had to update Rails to 5.2.5 and mimemagic to 0.3.6.

I don't think mimemagic works on Windows after the drama. I opened a PR for that a month ago but no one seems to care: https://github.com/mimemagicrb/mimemagic/pull/141

"License, motherfucker"

I know the vulgarity of the statements is tongue in cheek, but this one has been reinforced lately by the "MIME Magic" debacle[1], mama mia.

[1] https://github.com/mimemagicrb/mimemagic/issues/98

it has a licensing issue

https://github.com/mimemagicrb/mimemagic/commit/749a7e59de480b7c0373acc4f8ceb4444352ba46#diff-2ea7e2364883967953ab518a8316b639e612b8a6f20eadb7b97939d91c8e2612

On the other hand mimemagic provides by_magic https://github.com/mimemagicrb/mimemagic#usage which does detection by heuristic. It's a radically different method for a radically different use case.

Anyway, I created a PR addressing new Mimemagic not working on Windows https://github.com/mimemagicrb/mimemagic/pull/141

Someone broke the internet for rails https://github.com/mimemagicrb/mimemagic/issues/98

Yes!

Sometimes a file has no extension. Other times the extension is a lie. Still other times, you may be dealing with an unnamed bytestring and wish to know what kind of content it is.

This last case happens quite a lot in Nosey Parker [1], a detector of secrets in textual data. There, it is possible to come across unnamed files in Git history, and it would be useful to the user to still indicate what type of file it seems to be.

I added file type detection based on libmagic to Nosey Parker a while back, but it's not compiled in by default because libmagic is slow and complicates the build process. Also, libmagic is implemented as a large C library whose primary job is parsing, which makes the security side of me jittery.

I will likely add enabled-by-default filetype detection to Nosey Parker using Magika's ONNX model.

[1] https://github.com/praetorian-inc/noseyparker

Yes and no.

On the one hand, Nosey Parker is effectively a special-purpose `grep` with a bunch of security-relevant patterns built-in, including one for PEM-encoded keys: <https://github.com/praetorian-inc/noseyparker/blob/main/data...>

On the other hand, to naively run the check you describe, you would need access to a copy of all of GitHub, which isn't feasible.

What you can do with Nosey Parker is use its GitHub enumeration features to specify your GitHub organization and a list of GitHub usernames you are interested in, and scan against just those. This will implicitly list all the relevant public repositories, clone them, and scan their entire history.

For your use case, another thing you could do is use the new GitHub code search (<https://cs.github.com>) to regex search for particular keys or tokens. That new search seems to cover lots of the public content available on GitHub.

Also, to put some color on this use case: in offensive security engagements (aka "red team" engagements) at Praetorian, we frequently find leaked credentials or tokens on GitHub or elsewhere, which allow us deeper access into the client's systems. It's a significant problem.

A tool just got open-sourced called Nosey Parker that scans commits and git history for secrets. You could look at Nosey Parker's source code to see how they scan commits and design your tool based on that.