Package details page URLs use '?' rather than '%3F', and VCIO disregards the portion of the PURL starting with '?'

[johnmhoran]

While working on #1287, I noticed that when the results of a UI Package search query for a PURL with a qualifier include a PURL with a qualifier, the PURL displayed in the Package search results list uses '?' as the separator indicating that a qualifier follows, but the actual URL uses the ASCII-encoded '%3F'. Clicking such a link takes the user to the intended Package details page for the PURL with a qualifier.

However, the URLs displayed on the Package details page for any PURL with a qualifier use '?' rather than '%3F'. As a result, clicking such a link does not take the user to the page for the PURL with the qualifier. Instead, VCIO disregards that portion of the URL that starts with '?' -- if the PURL string up to the '?' identifies a Package in the database, clicking that link takes the user to that PURL without a qualifier, but if there is no such PURL in the database, a page-not-found/404 is returned instead.

A quick check of the API suggests there is no similar issue with the URL or PURL data there but this needs a more thorough check to be certain.

Related issues:

• VCIO-next: Do not mix unrelated affected and fixed packages #1508
• Consolidate 'Fixed by packages' tab and 'Affected packages' tab in Vulnerability details page #1287

[johnmhoran]

An example: pkg:nginx/nginx@0.8.9?os=windows

Several related questions come to mind:

• When identifying whether a PURL with a qualifier that is affected by a vulnerability is fixed by a subsequent PURL, must that subsequent PURL include the same qualifier in order to be treated as a fixed-by PURL for that affected PURL?
• What about a PURL wth a subpath?

[johnmhoran]

Regarding the API, a query for 'pkg:nginx/nginx@0.8.9?os=windows' returns fixed_packages data that includes a matching qualifier and a 'resource_url' with a properly encoded qualifier, but the entries for 'next_non_vulnerable_version' and 'latest_non_vulnerable_version' display only the version. See https://public.vulnerablecode.io/api/packages/bulk_search?format=api

The Package details page URL displays are similarly limited to the version.

Perhaps we should modify that API and UI data to include a full PURL rather than just the version to clarify exactly what data is being identified.

[johnmhoran]

For the time being I've replaced '?' with '%3F' while working on #1287 since the correct PURL and URL are important in matching affected with fixed-by Packages. The initial solution uses a custom filter to convert the incoming PackageURL object to a string, replaces '?' with '%3F' and returns the modified string. Seems to provide the results we want. There may be a more Pythonic solution (e.g., in models.py or views.py) but that has eluded me so far.

We still have open questions ^ re whether for our purposes a fixed-by PURL must match both qualifiers and subpath of the affected PURL. I think the answer is Yes but could be mistaken. Feedback is welcome and encouraged. ;-)