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Review 000-tor-browser.js and 001-base-profile.js for 102

browser/app/profile/000-tor-browser.js may contain some old stuff that we could/should remove.

Also do any work outlined in #32759

001-base-profile.js

Convention: bold = we need to follow up.

  • intl.locale.requested
  • browser.search.update
  • browser.rights.3.shown
    • Remove! 😈️ (see comments)
  • startup.homepage_welcome_url, startup.homepage_welcome_url.additional
    • S131 might be interested
  • browser.aboutwelcome.enabled
  • startup.homepage_override_url
  • app.update.promptWaitTime
  • app.update.staging.enabled
  • browser.slowStartup.{notificationDisabled,maxSamples,samples}
    • Remove! 😈️ (see comments)
  • browser.disableResetPrompt
  • browser.privatebrowsing.autostart
  • browser.cache.disk.enable
  • permissions.memory_only
  • network.cookie.lifetimePolicy
  • security.nocertdb
  • dom.storage.next_gen
    • Remove! 😈️
  • browser.download.useDownloadDir
    • Remove the related checkbox? --> #40656
  • browser.download.manager.addToRecentDocs
  • signon.rememberSignons
    • Remove the related checkbox? --> #40656
  • browser.formfill.enable
    • Remove the related checkbox? --> #40656
  • signon.autofillForms
    • Remove the related checkbox? --> #40656
  • browser.sessionstore.privacy_level
  • browser.privatebrowsing.forceMediaMemoryCache
  • media.memory_cache_max_size
  • dom.security.https_only_mode
    • Add reference to the issue
  • dom.security.https_only_mode.upgrade_onion
    • Move to 000-tor-browser.js
    • Add reference to the issue
  • security.ssl.require_safe_negotiation
  • security.ssl3.dhe_rsa_aes_128_sha, security.ssl3.dhe_rsa_aes_256_sha, security.ssl3.ecdhe_ecdsa_aes_256_sha, security.ssl3.ecdhe_ecdsa_aes_128_sha, security.ssl3.ecdhe_rsa_aes_128_sha, security.ssl3.ecdhe_rsa_aes_256_sha, security.ssl3.rsa_aes_128_sha, security.ssl3.rsa_aes_256_sha
  • browser.send_pings
  • geo.enabled
    • Completely disable geolocation
    • Even part of legal terms!
    • Usage is through static prefs
  • geo.provider.network.url
    • Still used, but not sure we have a good reason to reassign it, since we are disabling geolocation in general (defense in depth?)
    • Keep it, or delete it?
      • My resolution: be coherent with the rest and keep it
  • browser.search.suggest.enabled
    • Still used, and synchronized with about:preferences#search (remove it from there?) --> #40656
  • browser.safebrowsing.*
    • All of them are still used
    • There are also additional preferences browser.safebrowsing.provider.* with URLs, see modules/libpref/init/all.js
      • Like geo.provider.network.url confuses me a little bit
  • extensions.ui.lastCategory
    • Still used, but I don't have a clue on why we use it, especially since when you go to about:addons you override it.
    • To be checked again
  • datareporting.healthreport.uploadEnabled and datareporting.policy.dataSubmissionEnabled
    • Used also in DisableTelemetry in browser/components/enterprisepolicies/Policies.jsm!
    • that function also sets toolkit.telemetry.archive.enabled, should we add it, too?
      • "This can only be enabled if unified is on."
      • My resolution: add it
  • toolkit.telemetry.unified, toolkit.telemetry.enabled, toolkit.telemetry.updatePing.enabled
  • default-browser-agent.enabled (Windows only)
    • Seems to be still used, and it's telemetry for engagement/marketing purposes: it checks users' default choices, even though they aren't Firefox.
    • It is also disk leak, since it schedules as a Windows task, and it needs to copy data to the registry!
  • identity.fxaccounts.enabled
    • Disables Firefox account/sync. Still many occurrences in the code.
  • services.sync.engine.*
    • Still used, but there are a few new preferences:
      • services.sync.engine.bookmarks
      • services.sync.engine.history
      • services.sync.engine.passwords
      • services.sync.engine.addresses
      • services.sync.engine.creditcards
    • They are synchronized with a sync.inc.xhtml panel, which we should be sure it is disabled
    • Should we keep them, and add the new ones, even though we find it's possible to completely opt out the synchronization with a more generic pref (like identity.fxaccounts.enabled)?
      • As usual, is it to be seen as a defense in depth?
      • My resolution: add them for now, and remove them in the future, if we decide we don't actually need them
  • browser.region.network.scan
    • "Include wifi data in region request."
    • Already disabled by default, but being explicit here seems a good idea
  • browser.region.network.url, browser.region.update.enabled
    • Still used, but unlike the previous ones, have other defaults
    • toolkit/modules/Region.jsm also contains browser.region.local-geocoding (already false), should we add it explicitly?
      • My resolution: yes add it
  • browser.tabs.remote.separatedMozillaDomains
  • browser.urlbar.dnsResolveSingleWordsAfterSearch
  • messaging-system.rsexperimentloader.enabled
    • Still used in toolkit/components/nimbus/lib/RemoteSettingsExperimentLoader.jsm
    • The same file also has app.shield.optoutstudies.enabled, should we add it?
      • They are used in the same if in init
      • My resolution: added, to be coherent with other prefs
      • Notice that you don't enable opting out, if you want to opt out you have to set it false 😐️
      • Anyway, it's already false currently, so yet another defense in depth
  • trailhead.firstrun.branches
    • Remove! 😈️ (see comments)
  • browser.newtabpage.activity-stream.asrouter.userprefs.cfr.{addons,features}
    • See above, too
  • network.trr.resolvers
    • Seems an old preference, and new network.trr.* exist, including one to set https://mozilla.cloudflare-dns.com/dns-query as the default TRR provider (see StaticPrefLiast.yaml`)
    • Compare with Firefox 78 and #40048 (closed).
    • My resolution: changed to network.trr.default_provider_uri
  • network.trr.exclude-etc-hosts
    • Still used, but we should explain why false actually is the right value for us
  • security.pki.crlite_mode
    • Might be interesting, though. The problem is telemetry/downloads from Mozilla (see #40048 (closed))
  • signon.management.page.breach-alerts.enabled
    • "Firefox displays critical alerts in the Lockwise password manager when a website is breached." (#40048 (closed))
    • Still used, disabled to prevent sending telemetry/data to Mozilla
  • extensions.fxmonitor.enabled
  • signon.management.page.mobileAndroidURL and signon.management.page.mobileAppleURL
    • Part of lockwise ⚰, removed with b67b6138
    • Remove! 😈️
  • signon.recipes.remoteRecipes.enabled
    • Still used
  • dom.serviceWorkers.enabled and dom.push.enabled
    • Still used
  • webgl.disable-fail-if-major-performance-caveat, webgl.enable-webgl2
    • Still used
    • How do they help against fingerprinting?
  • gfx.downloadable_fonts.fallback_delay
  • browser.startup.homepage_override.buildID
    • How does it help against fingerprinting? I guess it was added to the user-agent back then, but now Firefox always show the spoofed date. Or is it used also for telemetry?
    • We have a patch to browser/components/BrowserContentHandler.jsm realted to this pref (the updater). Shall we review it?
    • modules/libpref/Preferences.cpp contains a list of preferences that are fingerprintable, and therefore removed from child processes, should we have a look at them, too (especially extensions.lastAppBuildId).
  • browser.link.open_newwindow.restriction
  • media.benchmark.vp9.threshold
    • "Set video VP9 to 0 for everyone (bug #22548 (closed))"
      • Is this still a valid reason?
    • Used as a static pref
  • dom.enable_resource_timing
    • "Bug #13024 (closed): To hell with this API"
      • Luckily enough timings are much more limited as a default, and 8 years ago was before spectre/meltdown. Check again the status of this, and add more reasons for which we should keep this?
    • Used as a static pref
  • privacy.resistFingerprinting
    • Lol. We should move this as the first one of the category?
    • My resolution: done it
  • privacy.resistFingerprinting.block_mozAddonManager
    • Thanks Mozilla 🙂 .
  • dom.webaudio.enabled
    • #13017 (closed)
    • Still used, also as a static pref
    • S131: what are the relations between this and WebRTC?
  • dom.webmidi.enabled
  • dom.w3c_touch_events.enabled
  • dom.vr.enabled
    • Still valid; false by default also in Firefox (see StaticPrefList.yaml), but we disabled it explicitly in case Mozilla enabled it without us noticing.
      • Not reviewed, too, probably
    • #21607
  • security.webauth.webauthn
    • Reference: #26614, but if I understand correctly, this has never been audited! Disabled because we didn't audit, but then now followed up
      • Possible problem: we don't want this for Android because it depends on a proprietary dependency (that however might be replaced with a GPLv3 one)
    • In any case, the preference is still valid
  • dom.postMessage.sharedArrayBuffer.withCOOP_COEP
    • Still valid (used as a static pref)
    • Can we open #40016 again? I'm not satisfied by the way it was closed.
  • security.remote_settings.intermediates.enabled
    • Still used. Interestingly enough, this is true by default only on Android
    • Disabled in #30682 (closed), but gk opened #40099 to follow up
  • dom.use_components_shim
  • privacy.resistFingerprinting.letterboxing 🙂
  • dom.netinfo.enabled
    • Change the comment as Thorin suggested 🙂
    • The default is also false
  • network.http.referer.defaultPolicy
    • It sets the value that is already the default, but it does it only for non-PBM sessions (it takes for granted that PBM also has the same value). The reason was that it hasn't always been the default, see (#32948 (closed)).
    • Should we explicitly tell to do so in all modes? Or at least, should we update the description to tell it's a defense in depth?
      • My resolution: yes
  • network.http.referer.XOriginTrimmingPolicy
  • media.videocontrols.picture-in-picture.enabled
  • network.http.referer.hideOnionSource
  • network.http.windows-sso.enabled
  • dom.enable_event_timing
    • #40383 (closed)
    • Minimum is 16ms and rounded by 8ms; if we decided that we lost the war against time measurements we could even re-enable this.
  • dom.textMetrics.actualBoundingBox.enabled, dom.textMetrics.baselines.enabled, dom.textMetrics.emHeight.enabled, dom.textMetrics.fontBoundingBox.enabled
    • Not sure of the original issue, but it seems it arrived with 91.2 ESR update. In any case, it's enough obvious why we need them 😉
  • pdfjs.enableScripting
    • Added recently (#40424 (closed)), we should add the reference also to the file
  • javascript.options.large_arraybuffers
  • browser.display.use_system_colors
    • Added recently, but might need more work in the future, see #40057
  • privacy.firstparty.isolate
  • privacy.partition.network_state
  • network.cookie.cookieBehavior and network.cookie.cookieBehavior.pbmode
  • network.predictor.enabled
  • privacy.purge_trackers.enabled
    • Update the issue number to the correct one (#40220 (closed))
    • Check what GeckoView does (see the issue)
    • Not sure on why we don't want this...
  • network.dns.disablePrefetch
    • Do we need also network.dns.disablePrefetchFromHTTPS?
      • My resolution: yes, even policies disable both
  • network.protocol-handler.*
  • network.proxy.allow_bypass
  • network.http.tailing.enabled
  • network.http.http2.*
  • network.gio.supported-protocols
  • media.peerconnection.enabled
    • S131: This is for WebRTC, should we move it to Tor Browser?
  • media.gmp-provider.enabled, media.gmp-manager.url.override and media.gmp-manager.updateEnabled
    • They are okay, but we might use them for S131 stuff, so we should add them to our notes somewhere
    • There's also a related ticket: #15910 (add it to the pref file - added)
  • browser.eme.ui.enabled, media.gmp-widevinecdm.visible, media.gmp-widevinecdm.enabled, media.eme.enabled, media.mediadrm-widevinecdm.visible
    • All still used, but to track for S131, too
    • However, I wouldn't remove them and add them back to Tor Browser, I would keep them and then remove in S131's branch, so that base-browser remains unencumbered
  • devtools.webide.autoinstallADBExtension, devtools.webide.enabled
    • Remove! 😈️ (see comments, basically webide isn't a thing anymore)
  • devtools.debugger.chrome-debugging-host
  • network.file.disable_unc_paths
  • network.file.path_blacklist
    • Cannot find our related issue, but found c6cbbca9. However, everything is explained in Bugzilla (and wow, I didn't know about file:///net).
  • svg.disabled
  • mathml.disabled
  • svg.context-properties.content.allowed-domains
  • security.ssl.enable_false_start
  • network.http.connection-retry-timeout
    • We set 0, which means "do not use a second connection"
    • Only Tor Browser, if still needed (see legacy/trac#7656 (closed))
      • Moved, and follow up in the performance issue (#32759)
  • network.manage-offline-status
    • To avoid phoning home? I found the related bug #18945 (closed), but not the exact reason.
  • network.captive-portal-service.enabled and network.connectivity-service.enabled
    • Still used, and okay both for Tor Browser and base-browser. S131 might want something different, and maybe customize network.connectivity-service.IPv{4,6}.url
  • dom.push.serverURL
  • extensions.autoDisableScopes
    • "If the add-on is a foreign install and is in a scope where add-ons that were dropped in should default to disabled then disable it"
    • We use scope 0, i.e., we don't disable any addon (why? Is this because of HTTPS-E ⚰ and NoScript?)
  • extensions.bootstrappedAddons
  • extensions.checkCompatibility.4.*
    • Remove! 😈️
  • extensions.databaseSchema
    • It's still recognized, for XPI stuff... But why are we using it? I'd like to remove it, if possible.
  • extensions.enabledScopes
    • We allow also SCOPE_APPLICATION, is it for NoScript? Default scope is profile, otherwise, but I am not sure on how the whole thing works, since Mozilla bundles addons, after all, like the screenshots
  • extensions.pendingOperations
    • This is used by Firefox to do things, why are we setting its default, that Firefox will change it anyway?
  • extensions.getAddons.showPane, extensions.htmlaboutaddons.recommendations.enabled
    • Still used, the former has even a policy
  • extensions.webextensions.restrictedDomains
    • I'd like a second audit on it, opened an issue to follow-up (#41445 (closed))
  • extensions.postDownloadThirdPartyPrompt
    • Show the prompt to install addons even though they are "recommended by Mozilla"
    • Recommended by Thorin in #40177 (closed)
  • intl.multilingual.downloadEnabled
  • browser.uiCustomization.state
  • security.cert_pinning.enforcement_level
  • security.osclientcerts.autoload
  • security.family_safety.mode
  • security.enterprise_roots.enabled
  • security.certerrors.mitm.priming.enabled
  • gfx.offscreencanvas.domain-enabled, gfx.offscreencanvas.domain-allowlist
  • browser.share_menu.allow
  • browser.urlbar.suggest.topsites
  • browser.urlbar.update1.{interventions,searchTips}
    • Remove! 😈️ (see comments)
  • corroborator.enabled
  • taskbar.grouping.useprofile
    • "If marked as such in prefs, use a hash of the profile path for the id instead of the install path hash setup by the installer."
    • S131 might want a different value (provided it's still useful, after we disable the items)
  • browser.taskbar.lists.enabled, browser.taskbar.lists.frequent.enabled, browser.taskbar.lists.tasks.enabled, browser.taskbar.lists.recent.enabled
    • Good, but for ESR115 we'll have to test the new things about private mode that arrived recently

000-tor-browser.js

  • app.update.notifyDuringDownload
  • app.update.url.manual
  • app.update.url.details
  • app.update.badgeWaitTime
  • app.releaseNotesURL
  • app.releaseNotesURL.aboutDialog
  • app.feedback.baseURL
  • browser.shell.checkDefaultBrowser
  • network.proxy.socks
  • network.proxy.socks_port
  • network.proxy.socks_remote_dns
  • network.proxy.no_proxies_on
  • network.proxy.allow_hijacking_localhost
  • network.proxy.type
  • network.proxy.failover_direct
    • Used as a static pref
  • network.security.ports.banned
  • network.dns.disabled
  • network.http.max-persistent-connections-per-proxy
  • browser.uiCustomization.state
    • Should we make sure it's only in one place? I.e., delete the one from 001-base-profile.js once we add the one in 000-tor-browser.js? (but I haven't compared them, yet)
  • browser.uiCustomization.state
  • network.http.http3.enabled
  • torbrowser.version
  • Review the old torbutton/torlauncher preferences (we have another issue for that)
Edited by Pier Angelo Vendrame