Firefox managed storage properties other than adminSettings not applying

[theaquamarine]

Prerequisites

• I verified that this is not a filter issue (MUST be reported at filter issue tracker)
• This is not a support issue or a question
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue
• The issue is not present after wholly disabling uBlock Origin ("uBO") in the browser
• I checked the documentation to understand that the issue I report is not a normal behavior

I tried to reproduce the issue when...

• uBO is the only extension
• uBO with default lists/settings
• using a new, unmodified browser profile

Description

When configuring uBlock's managed storage properties for Firefox, properties other than adminSettings aren't being applied, but they're applied properly in Chrome and Edge. I'm using the Windows registry, but have tested quickly using a json and I think the same thing is happening.

I believe the issue is Firefox is escaping the properties and causing them to be read as strings rather than objects, as typeof (await vAPI.adminStorage.get(['toOverwrite'])).toOverwrite is string in Firefox but object in Chrome and Edge. adminSettings works as JSON.parse() is used on it, but not on the other properties, so the fix is probably more if ( typeof json === 'string' && json !== '' ) {data = JSON.parse(json);} like https://github.com/gorhill/uBlock/blob/ab6a59daf8bd183cbaf9f07d22f9d432d4adfc44/src/js/storage.js#L1392

The properties are also shown escaped on about:policies in Firefox even if they are not escaped in the registry (but not escaped on chrome://policy or edge://policy) suggesting Firefox is escaping them, but I've not been able to find anything saying this if this is expected.

A specific URL where the issue occurs

https://github.com

Steps to Reproduce

1. Configure an admin policy other than adminSettings, eg toOverwrite [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\Firefox\3rdparty\Extensions\[email protected]] "toOverwrite"="{\"trustedSiteDirectives\": [\"example.com\",\"example.org\"]}"

2. Start Firefox

Expected behavior

Settings are applied, in this example trusted sites are set to example.com and example.org

Actual behavior

Settings are applied, in this example trusted sites are not set

uBlock Origin version

1.41.8

Browser name and version

Firefox 98.0.2

Operating System and version

Windows Server 2019 17763.737

[theaquamarine]

Same using browser.storage.managed.get() - string in Firefox but object in Chrome & Edge.

browser.storage.managed.get(['toOverwrite'], function(result) {
  console.log(typeof result.toOverwrite)})

[gorhill]

Configure an admin policy other than adminSettings, eg toOverwrite [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\Firefox\3rdparty\Extensions\[email protected]] "toOverwrite"="{\"trustedSiteDirectives\": [\"example.com\",\"example.org\"]}"

I don't have Windows but what you are doing does not match the MDN documentation.

[theaquamarine]

I think that's just a case of the docs being outdated - there's a couple of examples of this approach being used by other extensions, and currently works with uBlock for configuring adminSettings, or for all settings with the PR applied.

• Extension Workshop showing a starter group policy template for extension policy, using key="Software\Policies\Mozilla\Firefox\3rdparty\Extensions\YOUR_EXTENSION_ID" https://extensionworkshop.com/documentation/enterprise/adding-policy-support-to-your-extension/#distributing-your-policy
• Legacy Browser Support providing group policy templates to configure the settings directly https://github.com/mozilla/legacy-browser-support/blob/master/policy_templates/admx/LegacyBrowserSupportFirefox.admx
• and since opening this, I've found someone asking about how to do this with uBlock on the Mozilla Enterprise mailing list https://www.mail-archive.com/[email protected]/msg04235.html

[gorhill]

The other thing I observe is that you set toOverwrite to a string "{\"trustedSiteDirectives\": [\"example.com\",\"example.org\"]}".

It's supposed to be an object, so should it not be {"trustedSiteDirectives": ["example.com","example.org"]} instead?

[theaquamarine]

Ah sorry, I should've flagged that- no, that's just the export tool, it's not escaped in the registry.

So the registry ends up looking like this

which is shown on Firefox's about:policies like this

and then that's presented to the extension as a string, rather than an array

vs the same setting in Chrome, on chrome://policy, and inspecting the extension in Chrome

[theaquamarine]

Mozilla say this is expected, and I've now got configuring Firefox via the registry working properly by changing the settings to REG_MULTI_SZ instead of REG_SZ as those are treated as json instead https://bugzilla.mozilla.org/show_bug.cgi?id=1762253