Parts of purls that should be percent-encoded are not correctly encoded

[malice00]

I've been working on some issues for cdxgen with generating Gradle purls for projects. My issue is that Gradle prefixes project names with a ':', which should imho not be an issue if the name would actually be percent-encoded. I noticed during testing however, that this is not the case.

Checking your code, you do actually use encodeURIComponent, but then explicitly turn '%3A' back into ':'. When I then feed the generated purl into your fromString-method to validate it, it fails, because of the ':' in the purl:

packageurl-js/src/package-url.js

Line 132 in 3e0e106

let [scheme, remainder] = purl.split(':', 2);

Now, for a top-level project in Gradle, I could remove the ':', but then the question becomes how to handle sub-projects. These have the ':' not just at the front, but inbetween the layered projects as well (eg. :a:b:c:d). Currently, cdxgen removes the initial ':' and changes the remaining ':' to a '/', which unfortunately with the way your code works, makes all parts before the last '/' part of the namespace! This could then generate a purl that identifies multiple projects, eg:

• Namespace 'a/b/c', name 'd' --> purl: 'a/b/c/d'
• Namespace 'a/b', name ':c:d' --> purl 'a/b/c/d'

I would expect when using a name like :a:b, to get a purl looking more or less like pkg:maven/namespace/%3Aa%3Ab@version.

In case the current behavior is not an error, but actually expected, I think there is need for a discussion about how to make purls for Gradle (in case there hasn't already been one).

Also, in case this is an error, there's more places in your code where specific characters are explicitly decoded -- maybe worth taking a look at those as well...

[steven-esser]

v1.2.1 released with fixes for #45 and #52. Is there still an issue on your side @malice00?

If so, would love to figure out what else is left to fix.