But with respect, I read both of these references, as well as the Google Fonts reference, before posing my question, and none of them have to do with my case as far as I can tell.
This was unclear. Thanks for clarifying.
I’m using a default theme (twenty-thirteen) and very widely used plugins (e.g., Contact Form 7), so it is surprising to me that none of the js or css files have hashes attached to them.
The Twenty Thirteen Theme is, of course, from 2013, which is considered very old. Regardless, its resources such as stylesheets and such should be served from your same site, meaning that the integrity
attributes are not added, intentionally. Likewise, Contact Form 7 and many other well-written plugins bundle their resources with the plugin itself, which also means that those resources will not include integrity
attributes, either.
It may simply be the case that your page does not actually meet the criteria for SRI to be useful, in which case the plugin does not modify your output, by design.
If you can point at a specific resource you’re confused about, and if you can verify that it is in fact added to WordPress via the WordPress Plugin API hooks, I’ll happily take a closer look. But I haven’t the available resources to hunt for such an example on your site.
Good luck!