Fails to parse go stdlib version when experiments are set about grype

[willmurphyscode]

Hi @jonjohnsonjr, thanks for offering to help with this!

The code changes to make are really in Syft. Essentially, Syft should make 2 changes:

1. The metadata Syft emits about Go packages should include what experiments are enabled, so that this information isn't lost
2. Syft should trim the stdlib / go version to a valid semver version (remove the space and everything after.)

The definition of the Go package metadata is here: https://github.com/anchore/syft/blob/6107e5e2ad6e60f3f74ff4d3b2ca2ccffbed26ed/syft/pkg/golang.go#L4 - this definition likely needs new fields to hold information about the experiments, and then they need to be populated.

The function that scans the go binary for build info and other information is here: https://github.com/anchore/syft/blob/3023a5a7bc870f70a3dd24213d795516288ca0df/syft/pkg/cataloger/golang/scan_binary.go#L22 - I'm not certain exactly the right factoring for where we should trim the version info and capture the metadata, but this function is in the neighborhood.

Happy to discuss further! Please let me know if you have any questions.

[tgerla]

Hi @jonjohnsonjr, thanks for the report! It looks like today we take that field as-is but we need to probably parse out the flags after the X:. We might need to find a place to record those flags somewhere. We'll put this in the backlog for a fix. Let us know if you're interested in working on it and we can help get you started.

[luhring]

Just adding an explicit note that this causes false negatives, too. The Go stdlib usually accounts for a large surface area in vuln-matching a Go binary, so situations where Grype doesn't take the stdlib into account would mean missing any number of vulns if Go experiments are used. Also IIUC there are worlds where using Go experiments is much more common, such as to support FIPS.

[jonjohnsonjr]

Let us know if you're interested in working on it and we can help get you started.

I can take a stab at it if you can point me in the approximate direction 🙏