/****** * name: thunderbird user.js * date: 24 August 2022 * version: v102.0-beta1 * url: https://github.com/HorlogeSkynet/thunderbird-user.js * license: MIT (https://github.com/HorlogeSkynet/thunderbird-user.js/blob/master/LICENSE) * README: 1. Consider using Tor if it meets your needs or fits your threat model * https://2019.www.torproject.org/about/torusers.html 2. Read the entire wiki * https://github.com/HorlogeSkynet/thunderbird-user.js/wiki 3. If you skipped step 2, return to step 2 4. Make changes * There are often trade-offs and conflicts between security vs privacy vs anti-tracking and these need to be balanced against functionality & convenience & breakage * Some site breakage and unintended consequences will happen. Everyone's experience will differ e.g. some user data is erased on exit (section 2800), change this to suit your needs * While not 100% definitive, search for "[SETUP" tags e.g. wanna re-enable account auto configuration? check 9101 & 9102 5. Some tag info [SETUP-INSTALL] if you experience any issue during Thunderbird setting up, read it [SETUP-FEATURE] if you miss some (expected) Thunderbird features, read it [SETUP-SECURITY] it's one item, read it [SETUP-WEB] can cause some websites to break [SETUP-CHROME] changes how Thunderbird itself behaves (i.e. not directly website related) * RELEASES: https://github.com/HorlogeSkynet/thunderbird-user.js/releases * It is best to use the release that is optimized for and matches your Thunderbird version * ESR91 users - If you are not using thunderbird-user.js v91... (not a definitive list) - 9999: switch the appropriate deprecated section(s) back on * INDEX: 0100: STARTUP 0200: GEOLOCATION / LANGUAGE / LOCALE 0300: QUIETER BIRD 0400: SAFE BROWSING 0600: BLOCK IMPLICIT OUTBOUND 0700: DNS / DoH / PROXY / SOCKS / IPv6 0800: LOCATION BAR / SEARCH BAR / SUGGESTIONS / HISTORY / FORMS 0900: PASSWORDS 1000: DISK AVOIDANCE 1200: HTTPS (SSL/TLS / OCSP / CERTS / HPKP) 1400: FONTS 1600: HEADERS / REFERERS 1700: CONTAINERS 2000: PLUGINS / MEDIA / WEBRTC 2400: DOM (DOCUMENT OBJECT MODEL) 2600: MISCELLANEOUS 2800: SHUTDOWN & SANITIZING 4500: RFP (RESIST FINGERPRINTING) 5000: OPTIONAL OPSEC 5500: OPTIONAL HARDENING 6000: DON'T TOUCH 7000: DON'T BOTHER 8000: DON'T BOTHER: FINGERPRINTING 9000: PERSONAL 9100: THUNDERBIRD (AUTO CONFIG / UI / HEADERS / ADDRESS BOOK) 9200: EMAIL COMPOSITION (ENCODING / FORMAT / VIEW) 9300: OTHER THUNDERBIRD COMPONENTS (CHAT / CALENDAR / RSS) 9400: THUNDERBIRD ENCRYPTION (OPENGPG / GNUPG) 9999: DEPRECATED / REMOVED / LEGACY / RENAMED ******/ /* START: internal custom pref to test for syntax errors * [NOTE] Not all syntax errors cause parsing to abort i.e. reaching the last debug pref * no longer necessarily means that all prefs have been applied. Check the console right * after startup for any warnings/error messages related to non-applied prefs * [1] https://blog.mozilla.org/nnethercote/2018/03/09/a-new-preferences-parser-for-firefox/ ***/ user_pref("_user.js.parrot", "START: Oh yes, the Norwegian Blue... what's wrong with it?"); /* 0000: disable about:config warning ***/ user_pref("browser.aboutConfig.showWarning", false); /*** [SECTION 0100]: STARTUP ***/ user_pref("_user.js.parrot", "0100 syntax error: the parrot's dead!"); /* 0101: disable default browser check * [SETTING] General > System Integration > Always check to see if Thunderbird is the default... ***/ user_pref("mail.shell.checkDefaultClient", false); /* 0102: set START page [SETUP-CHROME] * [SETTING] General > Thunderbird Start Page ***/ user_pref("mailnews.start_page.enabled", false); /* 0104: set NEWTAB page * true=Activity Stream (default), false=blank page ***/ user_pref("browser.newtabpage.enabled", false); /*** [SECTION 0200]: GEOLOCATION / LANGUAGE / LOCALE ***/ user_pref("_user.js.parrot", "0200 syntax error: the parrot's definitely deceased!"); /* 0201: use Mozilla geolocation service instead of Google if permission is granted [FF74+] * Optionally enable logging to the console (defaults to false) ***/ user_pref("geo.provider.network.url", "https://location.services.mozilla.com/v1/geolocate?key=%MOZILLA_API_KEY%"); // user_pref("geo.provider.network.logging.enabled", true); // [HIDDEN PREF] /* 0202: disable using the OS's geolocation service ***/ user_pref("geo.provider.ms-windows-location", false); // [WINDOWS] user_pref("geo.provider.use_corelocation", false); // [MAC] user_pref("geo.provider.use_gpsd", false); // [LINUX] /* 0203: disable region updates * [1] https://firefox-source-docs.mozilla.org/toolkit/modules/toolkit_modules/Region.html ***/ user_pref("browser.region.network.url", ""); // [FF78+] user_pref("browser.region.update.enabled", false); // [FF79+] /* 0204: set search region * [NOTE] May not be hidden if Thunderbird has changed your settings due to your region (0203) ***/ // user_pref("browser.search.region", "US"); // [HIDDEN PREF] /* 0210: set preferred language for displaying pages * [SETTING] General > Language & Appearance > Language > Choose the language used to display... * [TEST] https://addons.mozilla.org/about ***/ user_pref("intl.accept_languages", "en-US, en"); /* 0210b: Set dictionary to US ***/ user_pref("spellchecker.dictionary", "en-US"); /* 0211: use en-US locale regardless of the system or region locale * [SETUP-WEB] May break some input methods e.g xim/ibus for CJK languages [1] * [TEST] https://arkenfox.github.io/TZP/tests/formatting.html * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=867501,1629630 ***/ user_pref("javascript.use_us_english_locale", true); // [HIDDEN PREF] /*** [SECTION 0300]: QUIETER BIRD Starting in user.js v68, we only disable the auto-INSTALL of Thunderbird. You still get prompts to update, in one click. We have NEVER disabled auto-CHECKING, and highly discourage that. There are many legitimate reasons to turn off auto-INSTALLS, including hijacked or monetized extensions, time constraints, legacy issues, dev/testing, and fear of breakage/bugs. It is still important to do updates for security reasons, please do so manually if you make changes. ***/ user_pref("_user.js.parrot", "0300 syntax error: the parrot's not pinin' for the fjords!"); /** RECOMMENDATIONS ***/ /* 0320: disable recommendation pane in about:addons (uses Google Analytics) ***/ user_pref("extensions.getAddons.showPane", false); // [HIDDEN PREF] /* 0321: disable recommendations in about:addons' Extensions and Themes panes [FF68+] ***/ user_pref("extensions.htmlaboutaddons.recommendations.enabled", false); /** TELEMETRY ***/ /* 0330: disable new data submission [FF41+] * If disabled, no policy is shown or upload takes place, ever * [1] https://bugzilla.mozilla.org/1195552 ***/ user_pref("datareporting.policy.dataSubmissionEnabled", false); /* 0331: disable Health Reports * [SETTING] Privacy & Security > Thunderbird Data Collection and Use > Allow Thunderbird to send technical... ***/ user_pref("datareporting.healthreport.uploadEnabled", false); /* 0332: disable telemetry * The "unified" pref affects the behavior of the "enabled" pref * - If "unified" is false then "enabled" controls the telemetry module * - If "unified" is true then "enabled" only controls whether to record extended data * [NOTE] "toolkit.telemetry.enabled" is now LOCKED to reflect prerelease (true) or release builds (false) [2] * [1] https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/internals/preferences.html * [2] https://medium.com/georg-fritzsche/data-preference-changes-in-firefox-58-2d5df9c428b5 ***/ user_pref("toolkit.telemetry.unified", false); user_pref("toolkit.telemetry.enabled", false); // see [NOTE] user_pref("toolkit.telemetry.server", "data:,"); user_pref("toolkit.telemetry.archive.enabled", false); user_pref("toolkit.telemetry.newProfilePing.enabled", false); // [FF55+] user_pref("toolkit.telemetry.shutdownPingSender.enabled", false); // [FF55+] user_pref("toolkit.telemetry.updatePing.enabled", false); // [FF56+] user_pref("toolkit.telemetry.bhrPing.enabled", false); // [FF57+] Background Hang Reporter user_pref("toolkit.telemetry.firstShutdownPing.enabled", false); // [FF57+] /* 0333: disable Telemetry Coverage * [1] https://blog.mozilla.org/data/2018/08/20/effectively-measuring-search-in-firefox/ ***/ user_pref("toolkit.telemetry.coverage.opt-out", true); // [HIDDEN PREF] user_pref("toolkit.coverage.opt-out", true); // [FF64+] [HIDDEN PREF] user_pref("toolkit.coverage.endpoint.base", ""); /* 0334: disable PingCentre telemetry (used in several System Add-ons) [FF57+] * Defense-in-depth: currently covered by 0331 ***/ user_pref("browser.ping-centre.telemetry", false); /** STUDIES ***/ /* 0340: disable Studies * [NOTE] This option is missing from Thunderbird's preferences panel (hidden?) ***/ user_pref("app.shield.optoutstudies.enabled", false); /* 0341: disable Normandy/Shield [FF60+] * Shield is a telemetry system that can push and test "recipes" * [1] https://mozilla.github.io/normandy/ ***/ user_pref("app.normandy.enabled", false); user_pref("app.normandy.api_url", ""); /** CRASH REPORTS ***/ /* 0350: disable Crash Reports ***/ user_pref("breakpad.reportURL", ""); user_pref("browser.tabs.crashReporting.sendReport", false); // [FF44+] // user_pref("browser.crashReports.unsubmittedCheck.enabled", false); // [FF51+] [DEFAULT: false] /* 0351: enforce no submission of backlogged Crash Reports [FF58+] * [SETTING] Privacy & Security > Thunderbird Data Collection and Use > Allow Thunderbird to send backlogged crash reports... ***/ user_pref("browser.crashReports.unsubmittedCheck.autoSubmit2", false); // [DEFAULT: false] /** OTHER ***/ /* 0360: disable Captive Portal detection * [1] https://www.eff.org/deeplinks/2017/08/how-captive-portals-interfere-wireless-security-and-privacy ***/ user_pref("captivedetect.canonicalURL", ""); user_pref("network.captive-portal-service.enabled", false); // [FF52+] /* 0361: disable Network Connectivity checks [FF65+] * [1] https://bugzilla.mozilla.org/1460537 ***/ user_pref("network.connectivity-service.enabled", false); /* 0370: disable UI instrumentation ***/ user_pref("mail.instrumentation.postUrl", ""); user_pref("mail.instrumentation.askUser", false); user_pref("mail.instrumentation.userOptedIn", false); /* 0371: disable about:rights notification on fresh profiles * When a profile is loaded for the first time, a bottom notification appears with a button * showing "Know your rights...". If clicked, the _special_ page about:rights appears. * When `mail.rights.override` is unset (default), Thunderbird falls-back on `mail.rights.version` * value. If it's unset (default too) or lower than the current version, notification is displayed. * false=always show the notification * true=never show the notification * [1] https://searchfox.org/comm-esr102/source/mail/base/content/specialTabs.js#1266 ***/ user_pref("mail.rights.override", true); // [DEFAULT: unset] // user_pref("mail.rights.version", 1) // [DEFAULT: unset] /* 0372: allow Thunderbird usage without any configured email account [SETUP-INSTALL] ***/ user_pref("app.use_without_mail_account", true); /* 0380: disable the new/unread message count badge on taskbar icon * [1] https://www.thunderbird.net/en-US/thunderbird/91.0.2/releasenotes/#whatsnew */ // user_pref("mail.biff.show_badge", false); // [WINDOWS] /* 0381: show the number of "new" messages on taskbar icon (not the number of unread ones) ***/ // user_pref("mail.biff.use_new_count_in_badge", true); /*** [SECTION 0400]: SAFE BROWSING (SB) SB has taken many steps to preserve privacy. If required, a full url is never sent to Google, only a part-hash of the prefix, hidden with noise of other real part-hashes. Thunderbird takes measures such as stripping out identifying parameters and since SBv4 (FF57+) doesn't even use cookies. (#Turn on browser.safebrowsing.debug to monitor this activity) [1] https://feeding.cloud.geek.nz/posts/how-safe-browsing-works-in-firefox/ [2] https://wiki.mozilla.org/Security/Safe_Browsing [3] https://support.mozilla.org/kb/how-does-phishing-and-malware-protection-work ***/ user_pref("_user.js.parrot", "0400 syntax error: the parrot's passed on!"); /* 0401: disable SB (Safe Browsing) * [WARNING] Do this at your own risk! These are the master switches ***/ // user_pref("browser.safebrowsing.malware.enabled", false); // user_pref("browser.safebrowsing.phishing.enabled", false); /* 0402: disable SB checks for downloads (both local lookups + remote) * This is the master switch for the safebrowsing.downloads* prefs (0403, 0404) ***/ // user_pref("browser.safebrowsing.downloads.enabled", false); /* 0403: disable SB checks for downloads (remote) * To verify the safety of certain executable files, Thunderbird may submit some information about the * file, including the name, origin, size and a cryptographic hash of the contents, to the Google * Safe Browsing service which helps Thunderbird determine whether or not the file should be blocked * [SETUP-SECURITY] If you do not understand this, or you want this protection, then override this ***/ user_pref("browser.safebrowsing.downloads.remote.enabled", false); // user_pref("browser.safebrowsing.downloads.remote.url", ""); // Defense-in-depth /* 0404: disable SB checks for unwanted software ***/ // user_pref("browser.safebrowsing.downloads.remote.block_potentially_unwanted", false); // user_pref("browser.safebrowsing.downloads.remote.block_uncommon", false); /* 0405: disable "ignore this warning" on SB warnings [FF45+] * If clicked, it bypasses the block for that session. This is a means for admins to enforce SB * [TEST] see https://github.com/arkenfox/user.js/wiki/Appendix-A-Test-Sites#-mozilla * [1] https://bugzilla.mozilla.org/1226490 ***/ // user_pref("browser.safebrowsing.allowOverride", false); /*** [SECTION 0600]: BLOCK IMPLICIT OUTBOUND [not explicitly asked for - e.g. clicked on] ***/ user_pref("_user.js.parrot", "0600 syntax error: the parrot's no more!"); /* 0601: disable link prefetching * [1] https://developer.mozilla.org/docs/Web/HTTP/Link_prefetching_FAQ ***/ user_pref("network.prefetch-next", false); /* 0602: disable DNS prefetching * [1] https://developer.mozilla.org/docs/Web/HTTP/Headers/X-DNS-Prefetch-Control ***/ user_pref("network.dns.disablePrefetch", true); // user_pref("network.dns.disablePrefetchFromHTTPS", true); // [DEFAULT: true] /* 0603: disable predictor / prefetching ***/ user_pref("network.predictor.enabled", false); user_pref("network.predictor.enable-prefetch", false); // [FF48+] [DEFAULT: false] /* 0604: disable link-mouseover opening connection to linked server * [1] https://news.slashdot.org/story/15/08/14/2321202/how-to-quash-firefoxs-silent-requests ***/ user_pref("network.http.speculative-parallel-limit", 0); /* 0610: enforce no "Hyperlink Auditing" (click tracking) * [1] https://www.bleepingcomputer.com/news/software/major-browsers-to-prevent-disabling-of-click-tracking-privacy-risk/ ***/ // user_pref("browser.send_pings", false); // [DEFAULT: false] /* 0610: don't refresh nor reload pages when tab/window is not active or in idle state * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=518805 ***/ user_pref("browser.meta_refresh_when_inactive.disabled", true); /*** [SECTION 0700]: DNS / DoH / PROXY / SOCKS / IPv6 ***/ user_pref("_user.js.parrot", "0700 syntax error: the parrot's given up the ghost!"); /* 0701: disable IPv6 * IPv6 can be abused, especially with MAC addresses, and can leak with VPNs: assuming * your ISP and/or router and/or website is IPv6 capable. Most sites will fall back to IPv4 * [STATS] Firefox telemetry (July 2021) shows ~10% of all connections are IPv6 * [NOTE] This is an application level fallback. Disabling IPv6 is best done at an * OS/network level, and/or configured properly in VPN setups. If you are not masking your IP, * then this won't make much difference. If you are masking your IP, then it can only help. * [NOTE] PHP defaults to IPv6 with "localhost". Use "php -S 127.0.0.1:PORT" * [TEST] https://ipleak.org/ * [1] https://www.internetsociety.org/tag/ipv6-security/ (Myths 2,4,5,6) ***/ user_pref("network.dns.disableIPv6", true); user_pref("network.notify.IPv6", false); /* 0702: set the proxy server to do any DNS lookups when using SOCKS * e.g. in Tor, this stops your local DNS server from knowing your Tor destination * as a remote Tor node will handle the DNS request * [1] https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/WebBrowsers ***/ user_pref("network.proxy.socks_remote_dns", true); /* 0703: disable using UNC (Uniform Naming Convention) paths [FF61+] * [SETUP-CHROME] Can break extensions for profiles on network shares * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/26424 ***/ user_pref("network.file.disable_unc_paths", true); // [HIDDEN PREF] /* 0704: disable GIO as a potential proxy bypass vector [FF60+] * Gvfs/GIO has a set of supported protocols like obex, network, archive, computer, * dav, cdda, gphoto2, trash, etc. By default only sftp is accepted (FF87+) * [1] https://bugzilla.mozilla.org/1433507 * [2] https://en.wikipedia.org/wiki/GVfs * [3] https://en.wikipedia.org/wiki/GIO_(software) ***/ user_pref("network.gio.supported-protocols", ""); // [HIDDEN PREF] /* 0705: disable proxy direct failover for system requests [FF91+] * [WARNING] Default true is a security feature against malicious extensions [1] * [SETUP-CHROME] If you use a proxy and you trust your extensions * [1] https://blog.mozilla.org/security/2021/10/25/securing-the-proxy-api-for-firefox-add-ons/ ***/ // user_pref("network.proxy.failover_direct", false); /* 0706: disable proxy bypass for system request failures [FF95+] * RemoteSettings, UpdateService, Telemetry [1] * [WARNING] If false, this will break the fallback for some security features * [SETUP-CHROME] If you use a proxy and you understand the security impact * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1732792,1733994,1733481 ***/ // user_pref("network.proxy.allow_bypass", false); // [HIDDEN PREF FF95-96] /* 0710: disable DNS-over-HTTPS (DoH) rollout [FF60+] * 0=off by default, 2=TRR (Trusted Recursive Resolver) first, 3=TRR only, 5=explicitly off * see "doh-rollout.home-region": USA 2019, Canada 2021, Russia/Ukraine 2022 [3] * [1] https://hacks.mozilla.org/2018/05/a-cartoon-intro-to-dns-over-https/ * [2] https://wiki.mozilla.org/Security/DOH-resolver-policy // * [3] https://support.mozilla.org/en-US/kb/firefox-dns-over-https * [4] https://www.eff.org/deeplinks/2020/12/dns-doh-and-odoh-oh-my-year-review-2020 ***/ // user_pref("network.trr.mode", 5); /* 0706: disable proxy direct failover for system requests [FF91+] * [WARNING] Default true is a security feature against malicious extensions [1] * [SETUP-CHROME] If you use a proxy and you trust your extensions * [1] https://blog.mozilla.org/security/2021/10/25/securing-the-proxy-api-for-firefox-add-ons/ ***/ // user_pref("network.proxy.failover_direct", false); /*** [SECTION 0800]: LOCATION BAR / SEARCH BAR / SUGGESTIONS / HISTORY / FORMS ***/ user_pref("_user.js.parrot", "0800 syntax error: the parrot's ceased to be!"); /* 0801: disable location bar using search * Don't leak URL typos to a search engine, give an error message instead * Examples: "secretplace,com", "secretplace/com", "secretplace com", "secret place.com" * [NOTE] This does not affect explicit user action such as using search buttons in the * dropdown, or using keyword search shortcuts you configure in options (e.g. "d" for DuckDuckGo) * [SETUP-CHROME] If you don't, or rarely, type URLs, or you use a default search * engine that respects privacy, then you probably don't need this ***/ user_pref("keyword.enabled", false); // [DEFAULT: false] /* 0802: disable location bar domain guessing * domain guessing intercepts DNS "hostname not found errors" and resends a * request (e.g. by adding www or .com). This is inconsistent use (e.g. FQDNs), does not work * via Proxy Servers (different error), is a flawed use of DNS (TLDs: why treat .com * as the 411 for DNS errors?), privacy issues (why connect to sites you didn't * intend to), can leak sensitive data (e.g. query strings: e.g. Princeton attack), * and is a security risk (e.g. common typos & malicious sites set up to exploit this) ***/ user_pref("browser.fixup.alternate.enabled", false); /* 0804: disable live search suggestions * [NOTE] Both must be true for the location bar to work * [SETUP-CHROME] Override this if you trust and use a privacy respecting search engine ***/ user_pref("browser.search.suggest.enabled", false); /* 0810: disable search and form history * [SETUP-WEB] Be aware that autocomplete form data can be read by third parties [1][2] * [NOTE] We also clear formdata on exit (2811) * [1] https://blog.mindedsecurity.com/2011/10/autocompleteagain.html * [2] https://bugzilla.mozilla.org/381681 ***/ user_pref("browser.formfill.enable", false); /* 0811: disable Form Autofill * [NOTE] Stored data is NOT secure (uses a JSON file) * [NOTE] Heuristics controls Form Autofill on forms without @autocomplete attributes * [1] https://wiki.mozilla.org/Firefox/Features/Form_Autofill ***/ user_pref("extensions.formautofill.addresses.enabled", false); // [FF55+] user_pref("extensions.formautofill.available", "off"); // [FF56+] user_pref("extensions.formautofill.creditCards.available", false); // [FF57+] user_pref("extensions.formautofill.creditCards.enabled", false); // [FF56+] user_pref("extensions.formautofill.heuristics.enabled", false); // [FF55+] /* 0820: disable coloring of visited links * Bulk rapid history sniffing was mitigated in 2010 [1][2]. Slower and more expensive * redraw timing attacks were largely mitigated in FF77+ [3]. Using RFP (4501) further hampers timing * attacks. Don't forget clearing history on exit (2811). However, social engineering [2#limits][4][5] * and advanced targeted timing attacks could still produce usable results * [1] https://developer.mozilla.org/docs/Web/CSS/Privacy_and_the_:visited_selector * [2] https://dbaron.org/mozilla/visited-privacy * [3] https://bugzilla.mozilla.org/1632765 * [4] https://earthlng.github.io/testpages/visited_links.html (see github wiki APPENDIX A on how to use) * [5] https://lcamtuf.blogspot.com/2016/08/css-mix-blend-mode-is-bad-for-keeping.html ***/ user_pref("layout.css.visited_links_enabled", false); /*** [SECTION 0900]: PASSWORDS [1] https://support.mozilla.org/kb/use-primary-password-protect-stored-logins-and-pas ***/ user_pref("_user.js.parrot", "0900 syntax error: the parrot's expired!"); /* 0903: disable auto-filling username & password form fields * can leak in cross-site forms *and* be spoofed * [NOTE] Username & password is still available when you enter the field * [1] https://freedom-to-tinker.com/2017/12/27/no-boundaries-for-user-identities-web-trackers-exploit-browser-login-managers/ * [2] https://homes.esat.kuleuven.be/~asenol/leaky-forms/ ***/ user_pref("signon.autofillForms", false); /* 0904: disable formless login capture for Password Manager [FF51+] ***/ user_pref("signon.formlessCapture.enabled", false); /* 0905: limit (or disable) HTTP authentication credentials dialogs triggered by sub-resources [FF41+] * hardens against potential credentials phishing * 0 = don't allow sub-resources to open HTTP authentication credentials dialogs * 1 = don't allow cross-origin sub-resources to open HTTP authentication credentials dialogs * 2 = allow sub-resources to open HTTP authentication credentials dialogs (default) ***/ user_pref("network.auth.subresource-http-auth-allow", 1); /* 0906: enforce no automatic authentication on Microsoft sites [FF91+] [WINDOWS 10+] * [1] https://support.mozilla.org/kb/windows-sso ***/ user_pref("network.http.windows-sso.enabled", false); // [DEFAULT: false] /* 0910: prevent access to emails until the master password is entered * If a master password has been set, Thunderbird will prevent access to locally available emails * until the secret is provided. * This preference MAY mitigate risk due to intimate relationship threat in some cases (see [2])... * [WARNING] This DOES NOT encrypt locally cached emails anyhow (poor man's application security) * [WARNING] This preference is very buggy, you might not manage to start Thunderbird when it's switched on * [1] https://support.mozilla.org/en-US/kb/protect-your-thunderbird-passwords-master-password * [2] https://www.schneier.com/wp-content/uploads/2020/06/Privacy_Threats_in_Intimate_Relationships-1.pdf ***/ // user_pref("mail.password_protect_local_cache", true); // [HIDDEN PREF] /*** [SECTION 1000]: DISK AVOIDANCE ***/ user_pref("_user.js.parrot", "1000 syntax error: the parrot's gone to meet 'is maker!"); /* 1001: disable disk cache * [SETUP-CHROME] If you think disk cache helps perf, then feel free to override this * [NOTE] We also clear cache on exit (2811) ***/ user_pref("browser.cache.disk.enable", false); /* 1002: disable media cache from writing to disk in Private Browsing * [NOTE] MSE (Media Source Extensions) are already stored in-memory in PB ***/ user_pref("browser.privatebrowsing.forceMediaMemoryCache", true); // [FF75+] user_pref("media.memory_cache_max_size", 65536); /* 1003: disable storing extra session data [SETUP-CHROME] * define on which sites to save extra session data such as form content, cookies and POST data * 0=everywhere, 1=unencrypted sites, 2=nowhere ***/ user_pref("browser.sessionstore.privacy_level", 2); /* 1004: set the minimum interval between session save operations * Increasing this can help on older machines and some websites, as well as reducing writes [1] * [1] https://bugzilla.mozilla.org/1304389 ***/ user_pref("browser.sessionstore.interval", 30000); // [DEFAULT: 15000] /*** [SECTION 1200]: HTTPS (SSL/TLS / OCSP / CERTS / HPKP) Your cipher and other settings can be used in server side fingerprinting [TEST] https://www.ssllabs.com/ssltest/viewMyClient.html [TEST] https://browserleaks.com/ssl [TEST] https://ja3er.com/ [1] https://www.securityartwork.es/2017/02/02/tls-client-fingerprinting-with-bro/ ***/ user_pref("_user.js.parrot", "1200 syntax error: the parrot's a stiff!"); /** SSL (Secure Sockets Layer) / TLS (Transport Layer Security) ***/ /* 1201: require safe negotiation * Blocks connections to servers that don't support RFC 5746 [2] as they're potentially vulnerable to a * MiTM attack [3]. A server without RFC 5746 can be safe from the attack if it disables renegotiations * but the problem is that the browser can't know that. Setting this pref to true is the only way for the * browser to ensure there will be no unsafe renegotiations on the channel between the browser and the server * [SETUP-WEB] SSL_ERROR_UNSAFE_NEGOTIATION: is it worth overriding this for that one site? * [STATS] SSL Labs (July 2021) reports over 99% of top sites have secure renegotiation [4] * [1] https://wiki.mozilla.org/Security:Renegotiation * [2] https://datatracker.ietf.org/doc/html/rfc5746 * [3] https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3555 * [4] https://www.ssllabs.com/ssl-pulse/ ***/ user_pref("security.ssl.require_safe_negotiation", true); /* 1206: disable TLS1.3 0-RTT (round-trip time) [FF51+] * This data is not forward secret, as it is encrypted solely under keys derived using * the offered PSK. There are no guarantees of non-replay between connections * [1] https://github.com/tlswg/tls13-spec/issues/1001 * [2] https://www.rfc-editor.org/rfc/rfc9001.html#name-replay-attacks-with-0-rtt * [3] https://blog.cloudflare.com/tls-1-3-overview-and-q-and-a/ ***/ user_pref("security.tls.enable_0rtt_data", false); /** OCSP (Online Certificate Status Protocol) [1] https://scotthelme.co.uk/revocation-is-broken/ [2] https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ ***/ /* 1211: enforce OCSP fetching to confirm current validity of certificates * 0=disabled, 1=enabled (default), 2=enabled for EV certificates only * OCSP (non-stapled) leaks information about the sites you visit to the CA (cert authority) * It's a trade-off between security (checking) and privacy (leaking info to the CA) * [NOTE] This pref only controls OCSP fetching and does not affect OCSP stapling * [SETTING] Privacy & Security > Security > Certificates > Query OCSP responder servers... * [1] https://en.wikipedia.org/wiki/Ocsp ***/ user_pref("security.OCSP.enabled", 1); // [DEFAULT: 1] /* 1212: set OCSP fetch failures (non-stapled, see 1211) to hard-fail [SETUP-WEB] * When a CA cannot be reached to validate a cert, Thunderbird's just continues the connection (=soft-fail) * Setting this pref to true tells Thunderbird's to instead terminate the connection (=hard-fail) * It is pointless to soft-fail when an OCSP fetch fails: you cannot confirm a cert is still valid (it * could have been revoked) and/or you could be under attack (e.g. malicious blocking of OCSP servers) * [1] https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ * [2] https://www.imperialviolet.org/2014/04/19/revchecking.html ***/ user_pref("security.OCSP.require", true); /** CERTS / HPKP (HTTP Public Key Pinning) ***/ /* 1221: disable Windows 8.1's Microsoft Family Safety cert [FF50+] [WINDOWS] * 0=disable detecting Family Safety mode and importing the root * 1=only attempt to detect Family Safety mode (don't import the root) * 2=detect Family Safety mode and import the root * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/21686 ***/ user_pref("security.family_safety.mode", 0); /* 1223: enable strict pinning * PKP (Public Key Pinning) 0=disabled, 1=allow user MiTM (such as your antivirus), 2=strict * [SETUP-WEB] If you rely on an AV (antivirus) to protect your web browsing * by inspecting ALL your web traffic, then leave at current default=1 * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/16206 ***/ user_pref("security.cert_pinning.enforcement_level", 2); /* 1224: enable CRLite [FF73+] * 0 = disabled * 1 = consult CRLite but only collect telemetry * 2 = consult CRLite and enforce both "Revoked" and "Not Revoked" results * 3 = consult CRLite and enforce "Not Revoked" results, but defer to OCSP for "Revoked" (FF99+, default FF100+) * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1429800,1670985,1753071 * [2] https://blog.mozilla.org/security/tag/crlite/ ***/ user_pref("security.remote_settings.crlite_filters.enabled", true); user_pref("security.pki.crlite_mode", 2); /* 1225: enable loading of client certificates stored in OS certificate storage * Bug: this does **NOT** work for S/MIME [1] * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1726442 ***/ // user_pref("security.osclientcerts.autoload", true); /** MIXED CONTENT ***/ /* 1241: disable insecure passive content (such as images) on https pages [SETUP-WEB] ***/ user_pref("security.mixed_content.block_display_content", true); /* 1244: enable HTTPS-Only mode in all windows [FF76+] * When the top-level is HTTPS, insecure subresources are also upgraded (silent fail) * [TEST] http://example.com [upgrade] * [TEST] http://httpforever.com/ [no upgrade] ***/ user_pref("dom.security.https_only_mode", true); // [FF76+] user_pref("dom.security.https_only_mode_pbm", true); // [FF80+] /* 1245: enable HTTPS-Only mode for local resources [FF77+] ***/ user_pref("dom.security.https_only_mode.upgrade_local", true); /* 1246: disable HTTP background requests [FF82+] * When attempting to upgrade, if the server doesn't respond within 3 seconds, Thunderbird sends * a top-level HTTP request without path in order to check if the server supports HTTPS or not * This is done to avoid waiting for a timeout which takes 90 seconds * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1642387,1660945 ***/ user_pref("dom.security.https_only_mode_send_http_background_request", false); /** UI (User Interface) ***/ /* 1270: display warning on the padlock for "broken security" (if 1201 is false) * Bug: warning padlock not indicated for subresources on a secure page! [2] * [1] https://wiki.mozilla.org/Security:Renegotiation * [2] https://bugzilla.mozilla.org/1353705 ***/ user_pref("security.ssl.treat_unsafe_negotiation_as_broken", true); /* 1271: control "Add Security Exception" dialog on SSL warnings * 0=do neither, 1=pre-populate url, 2=pre-populate url + pre-fetch cert (default) * [1] https://github.com/pyllyukko/user.js/issues/210 ***/ user_pref("browser.ssl_override_behavior", 1); /* 1272: display advanced information on Insecure Connection warning pages * only works when it's possible to add an exception * i.e. it doesn't work for HSTS discrepancies (https://subdomain.preloaded-hsts.badssl.com/) * [TEST] https://expired.badssl.com/ ***/ user_pref("browser.xul.error_pages.expert_bad_cert", true); /* 1280: display warnings when insecure HTTP connections are made ***/ user_pref("security.warn_entering_weak", true); user_pref("security.warn_leaving_secure", true); user_pref("security.warn_viewing_mixed", true); /*** [SECTION 1400]: FONTS ***/ user_pref("_user.js.parrot", "1400 syntax error: the parrot's bereft of life!"); /* 1401: disable rendering of SVG OpenType fonts ***/ user_pref("gfx.font_rendering.opentype_svg.enabled", false); /* 1402: limit font visibility (Windows, Mac, some Linux) [FF94+] * Uses hardcoded lists with two parts: kBaseFonts + kLangPackFonts [1], bundled fonts are auto-allowed * In normal windows: uses the first applicable: RFP (4506) over TP over Standard * In Private Browsing windows: uses the most restrictive between normal and private * 1=only base system fonts, 2=also fonts from optional language packs, 3=also user-installed fonts * [1] https://searchfox.org/mozilla-central/search?path=StandardFonts*.inc ***/ // user_pref("layout.css.font-visibility.private", 1); // user_pref("layout.css.font-visibility.standard", 1); // user_pref("layout.css.font-visibility.trackingprotection", 1); /*** [SECTION 1600]: HEADERS / REFERERS full URI: https://example.com:8888/foo/bar.html?id=1234 scheme+host+port+path: https://example.com:8888/foo/bar.html scheme+host+port: https://example.com:8888 [1] https://feeding.cloud.geek.nz/posts/tweaking-referrer-for-privacy-in-firefox/ ***/ user_pref("_user.js.parrot", "1600 syntax error: the parrot rests in peace!"); /* 1601: control when to send a cross-origin referer * 0=always (default), 1=only if base domains match, 2=only if hosts match * [SETUP-WEB] Breakage: older modems/routers and some sites e.g banks, vimeo, icloud, instagram * If "2" is too strict, then override to "0" and use Smart Referer extension (Strict mode + add exceptions) ***/ user_pref("network.http.referer.XOriginPolicy", 2); /* 1602: control the amount of cross-origin information to send [FF52+] * 0=send full URI (default), 1=scheme+host+port+path, 2=scheme+host+port ***/ user_pref("network.http.referer.XOriginTrimmingPolicy", 2); /*** [SECTION 1700]: CONTAINERS ***/ user_pref("_user.js.parrot", "1700 syntax error: the parrot's bit the dust!"); /* 1701: enable Container Tabs and its UI setting [FF50+] * https://wiki.mozilla.org/Security/Contextual_Identity_Project/Containers ***/ user_pref("privacy.userContext.enabled", true); user_pref("privacy.userContext.ui.enabled", true); /* 1702: set behavior on "+ Tab" button to display container menu on left click [FF74+] * [NOTE] The menu is always shown on long press and right click ***/ // user_pref("privacy.userContext.newTabContainerOnLeftClick.enabled", true); /*** [SECTION 2000]: PLUGINS / MEDIA / WEBRTC ***/ user_pref("_user.js.parrot", "2000 syntax error: the parrot's snuffed it!"); /* 2001: disable WebRTC (Web Real-Time Communication) * Thunderbird uses mDNS hostname obfuscation on desktop (except Windows7/8) and the * private IP is NEVER exposed, except if required in TRUSTED scenarios; i.e. after * you grant device (microphone or camera) access * [SETUP-HARDEN] Test first. Windows7/8 users only: behind a proxy who never use WebRTC * [TEST] https://browserleaks.com/webrtc * [1] https://groups.google.com/g/discuss-webrtc/c/6stQXi72BEU/m/2FwZd24UAQAJ * [2] https://datatracker.ietf.org/doc/html/draft-ietf-mmusic-mdns-ice-candidates#section-3.1.1 ***/ user_pref("media.peerconnection.enabled", false); /* 2002: force WebRTC inside the proxy [FF70+] ***/ user_pref("media.peerconnection.ice.proxy_only_if_behind_proxy", true); /* 2003: force a single network interface for ICE candidates generation [FF42+] * When using a system-wide proxy, it uses the proxy interface * [1] https://developer.mozilla.org/en-US/docs/Web/API/RTCIceCandidate * [2] https://wiki.mozilla.org/Media/WebRTC/Privacy ***/ user_pref("media.peerconnection.ice.default_address_only", true); /* 2004: force exclusion of private IPs from ICE candidates [FF51+] * [SETUP-HARDEN] This will protect your private IP even in TRUSTED scenarios after you * grant device access, but often results in breakage on video-conferencing platforms ***/ user_pref("media.peerconnection.ice.no_host", true); /* 2020: disable GMP (Gecko Media Plugins) * [1] https://wiki.mozilla.org/GeckoMediaPlugins ***/ user_pref("media.gmp-provider.enabled", false); /* 2021: disable widevine CDM (Content Decryption Module) * [NOTE] This is covered by the EME master switch (2022) ***/ user_pref("media.gmp-widevinecdm.enabled", false); /* 2022: disable all DRM content (EME: Encryption Media Extension) * Optionally hide the setting which also disables the DRM prompt * [SETUP-WEB] e.g. Netflix, Amazon Prime, Hulu, HBO, Disney+, Showtime, Starz, DirectTV * [TEST] https://bitmovin.com/demos/drm * [1] https://www.eff.org/deeplinks/2017/10/drms-dead-canary-how-we-just-lost-web-what-we-learned-it-and-what-we-need-do-next ***/ user_pref("media.eme.enabled", false); // user_pref("browser.eme.ui.enabled", false); /* 2030: disable autoplay of HTML5 media [FF63+] * 0=Allow all, 1=Block non-muted media (default), 5=Block all * [NOTE] You can set exceptions under site permissions ***/ user_pref("media.autoplay.default", 5); /* 2031: disable autoplay of HTML5 media if you interacted with the site [FF78+] * 0=sticky (default), 1=transient, 2=user * Thunderbird's Autoplay Policy Documentation (PDF) is linked below via SUMO * [NOTE] If you have trouble with some video sites, then add an exception (2030) * [1] https://support.mozilla.org/questions/1293231 ***/ user_pref("media.autoplay.blocking_policy", 2); /*** [SECTION 2400]: DOM (DOCUMENT OBJECT MODEL) ***/ user_pref("_user.js.parrot", "2400 syntax error: the parrot's kicked the bucket!"); /* 2401: disable "Confirm you want to leave" dialog on page close * Does not prevent JS leaks of the page close event * [1] https://developer.mozilla.org/docs/Web/Events/beforeunload ***/ user_pref("dom.disable_beforeunload", true); /* 2402: prevent scripts from moving and resizing open windows ***/ user_pref("dom.disable_window_move_resize", true); /* 2403: block popup windows ***/ user_pref("dom.disable_open_during_load", true); /* 2404: limit events that can cause a popup [SETUP-WEB] ***/ user_pref("dom.popup_allowed_events", "click dblclick mousedown pointerdown"); /*** [SECTION 2600]: MISCELLANEOUS ***/ user_pref("_user.js.parrot", "2600 syntax error: the parrot's run down the curtain!"); /* 2601: prevent accessibility services from accessing your browser [RESTART] * [1] https://support.mozilla.org/kb/accessibility-services ***/ user_pref("accessibility.force_disabled", 1); /* 2602: disable sending additional analytics to web servers * [1] https://developer.mozilla.org/docs/Web/API/Navigator/sendBeacon ***/ user_pref("beacon.enabled", false); /* 2603: remove temp files opened with an external application * [1] https://bugzilla.mozilla.org/302433 ***/ user_pref("browser.helperApps.deleteTempFileOnExit", true); /* 2604: disable page thumbnail collection ***/ user_pref("browser.pagethumbnails.capturing_disabled", true); // [HIDDEN PREF] /* 2606: disable UITour backend so there is no chance that a remote page can use it ***/ user_pref("browser.uitour.enabled", false); user_pref("browser.uitour.url", ""); /* 2607: disable various developer tools in browser context * [1] https://github.com/pyllyukko/user.js/issues/179#issuecomment-246468676 ***/ user_pref("devtools.chrome.enabled", false); /* 2608: reset remote debugging to disabled * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/16222 ***/ user_pref("devtools.debugger.remote-enabled", false); // [DEFAULT: false] /* 2611: disable middle mouse click opening links from clipboard * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/10089 ***/ user_pref("middlemouse.contentLoadURL", false); /* 2616: remove special permissions for certain mozilla domains [FF35+] * [1] resource://app/defaults/permissions ***/ user_pref("permissions.manager.defaultsUrl", ""); /* 2617: remove webchannel whitelist ***/ user_pref("webchannel.allowObject.urlWhitelist", ""); /* 2619: use Punycode in Internationalized Domain Names to eliminate possible spoofing * [SETUP-WEB] Might be undesirable for non-latin alphabet users since legitimate IDN's are also punycoded * [TEST] https://www.xn--80ak6aa92e.com/ (www.apple.com) * [1] https://wiki.mozilla.org/IDN_Display_Algorithm * [2] https://en.wikipedia.org/wiki/IDN_homograph_attack * [3] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=punycode+firefox * [4] https://www.xudongz.com/blog/2017/idn-phishing/ ***/ user_pref("network.IDN_show_punycode", true); /* 2620: enforce PDFJS, disable PDFJS scripting [SETUP-CHROME] * This setting controls if the option "Display in Thunderbird" is available in the setting below * and by effect controls whether PDFs are handled in-browser or externally ("Ask" or "Open With") * PROS: pdfjs is lightweight, open source, and more secure/vetted than most * Exploits are rare (one serious case in seven years), treated seriously and patched quickly. * It doesn't break "state separation" of browser content (by not sharing with OS, independent apps). * It maintains disk avoidance and application data isolation. It's convenient. You can still save to disk. * CONS: You may prefer a different pdf reader for security reasons * CAVEAT: JS can still force a pdf to open in-browser by bundling its own code ***/ user_pref("pdfjs.disabled", false); // [DEFAULT: false] user_pref("pdfjs.enableScripting", false); // [FF86+] /* 2621: disable links launching Windows Store on Windows 8/8.1/10 [WINDOWS] ***/ user_pref("network.protocol-handler.external.ms-windows-store", false); /* 2623: disable permissions delegation [FF73+] * Currently applies to cross-origin geolocation, camera, mic and screen-sharing * permissions, and fullscreen requests. Disabling delegation means any prompts * for these will show/use their correct 3rd party origin * [1] https://groups.google.com/forum/#!topic/mozilla.dev.platform/BdFOMAuCGW8/discussion ***/ user_pref("permissions.delegation.enabled", false); /** DOWNLOADS ***/ /* 2651: enable user interaction for security by always asking where to download * [SETUP-CHROME] On Android this blocks longtapping and saving images ***/ user_pref("browser.download.useDownloadDir", false); /* 2653: disable adding downloads to the system's "recent documents" list ***/ user_pref("browser.download.manager.addToRecentDocs", false); /* 2654: enable user interaction for security by always asking how to handle new mimetypes [FF101+] * [SETTING] General>Files and Applications>What should Thunderbird do with other files ***/ user_pref("browser.download.always_ask_before_handling_new_types", true); /** EXTENSIONS ***/ /* 2660: lock down allowed extension directories * [SETUP-CHROME] This will break extensions, language packs, themes and any other * XPI files which are installed outside of profile and application directories * [1] https://mike.kaply.com/2012/02/21/understanding-add-on-scopes/ * [1] https://archive.is/DYjAM (archived) ***/ user_pref("extensions.enabledScopes", 5); // [HIDDEN PREF] user_pref("extensions.autoDisableScopes", 15); // [DEFAULT: 15] /* 2662: disable webextension restrictions on certain mozilla domains (you also need 4503) [FF60+] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1384330,1406795,1415644,1453988 ***/ // user_pref("extensions.webextensions.restrictedDomains", ""); /*** [SECTION 2800]: SHUTDOWN & SANITIZING ***/ user_pref("_user.js.parrot", "2800 syntax error: the parrot's bleedin' demised!"); /** SANITIZE ON SHUTDOWN: ALLOWS COOKIES + SITE DATA EXCEPTIONS FF102+ ***/ /* 2810: enable Thunderbird to clear items on shutdown (2811) * [NOTE] Exceptions: A "cookie" block permission also controls "offlineApps" (see note in 2811). * serviceWorkers require an "Allow" permission. For cross-domain logins, add exceptions for * both sites e.g. https://www.youtube.com (site) + https://accounts.google.com (single sign on) * [WARNING] Be selective with what cookies you keep, as they also disable partitioning (1767271) * [SETTING] Privacy & Security>History>Custom Settings>Clear history when Thunderbird closes * [SETTING] to add site exceptions: Ctrl+I>Permissions>Cookies>Allow (when on the website in question) * [SETTING] to manage site exceptions: Options>Privacy & Security>Permissions>Settings ***/ user_pref("privacy.sanitize.sanitizeOnShutdown", true); /* 2811: set/enforce what items to clear on shutdown (if 2810 is true) [SETUP-CHROME] * [NOTE] If "history" is true, downloads will also be cleared * [NOTE] "sessions": Active Logins: refers to HTTP Basic Authentication [1], not logins via cookies * [NOTE] "offlineApps": Offline Website Data: localStorage, service worker cache, QuotaManager (IndexedDB, asm-cache) * [1] https://en.wikipedia.org/wiki/Basic_access_authentication ***/ user_pref("privacy.clearOnShutdown.cache", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.downloads", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.formdata", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.history", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.sessions", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.offlineApps", true); user_pref("privacy.clearOnShutdown.cookies", true); // user_pref("privacy.clearOnShutdown.siteSettings", false); // [DEFAULT: false] /* 2812: delete cache on exit [FF96+] * [NOTE] We already disable disk cache (1001) and clear on exit (2811) which is more robust * [1] https://bugzilla.mozilla.org/1671182 ***/ // user_pref("privacy.clearsitedata.cache.enabled", true); /** SANITIZE MANUAL: ALL OR NOTHING ***/ /* 2820: reset default items to clear with Ctrl-Shift-Del [SETUP-CHROME] * This dialog can also be accessed from the menu History>Clear Recent History * Thunderbird remembers your last choices. This will reset them when you start Thunderbird * [NOTE] Regardless of what you set "downloads" to, as soon as the dialog * for "Clear Recent History" is opened, it is synced to the same as "history" ***/ user_pref("privacy.cpd.cache", true); // [DEFAULT: true] user_pref("privacy.cpd.formdata", true); // [DEFAULT: true] user_pref("privacy.cpd.history", true); // [DEFAULT: true] user_pref("privacy.cpd.sessions", true); // [DEFAULT: true] user_pref("privacy.cpd.offlineApps", false); // [DEFAULT: false] user_pref("privacy.cpd.cookies", false); // user_pref("privacy.cpd.downloads", true); // not used, see note above // user_pref("privacy.cpd.passwords", false); // [DEFAULT: false] not listed // user_pref("privacy.cpd.siteSettings", false); // [DEFAULT: false] /* 2821: clear Session Restore data when sanitizing on shutdown or manually [FF34+] * [NOTE] Not needed if Session Restore is not used (0102) or it is already cleared with history (2811) * [NOTE] privacy.clearOnShutdown.openWindows prevents resuming from crashes (also see 5008) * [NOTE] privacy.cpd.openWindows has a bug that causes an additional window to open ***/ // user_pref("privacy.clearOnShutdown.openWindows", true); // user_pref("privacy.cpd.openWindows", true); /* 2822: reset default "Time range to clear" for "Clear Recent History" (2820) * Thunderbird remembers your last choice. This will reset the value when you start Thunderbird * 0=everything, 1=last hour, 2=last two hours, 3=last four hours, 4=today * [NOTE] Values 5 (last 5 minutes) and 6 (last 24 hours) are not listed in the dropdown, * which will display a blank value, and are not guaranteed to work ***/ user_pref("privacy.sanitize.timeSpan", 0); /*** [SECTION 4500]: RFP (RESIST FINGERPRINTING) RFP covers a wide range of ongoing fingerprinting solutions. It is an all-or-nothing buy in: you cannot pick and choose what parts you want [WARNING] DO NOT USE extensions to alter RFP protected metrics 418986 - limit window.screen & CSS media queries (FF41) [TEST] https://arkenfox.github.io/TZP/tzp.html#screen 1281949 - spoof screen orientation (FF50) 1281963 - hide the contents of navigator.plugins and navigator.mimeTypes (FF50-99) FF53: fixes GetSupportedNames in nsMimeTypeArray and nsPluginArray (1324044) 1330890 - spoof timezone as UTC0 (FF55) 1360039 - spoof navigator.hardwareConcurrency as 2 (FF55) 1217238 - reduce precision of time exposed by javascript (FF55) FF56 1369303 - spoof/disable performance API 1333651 - spoof User Agent & Navigator API version: spoofed as ESR (FF102+ this is limited to Android) OS: JS spoofed as Windows 10, OS 10.15, Android 10, or Linux | HTTP Headers spoofed as Windows or Android 1369319 - disable device sensor API 1369357 - disable site specific zoom 1337161 - hide gamepads from content 1372072 - spoof network information API as "unknown" when dom.netinfo.enabled = true 1333641 - reduce fingerprinting in WebSpeech API FF57 1369309 - spoof media statistics 1382499 - reduce screen co-ordinate fingerprinting in Touch API 1217290 & 1409677 - enable some fingerprinting resistance for WebGL 1382545 - reduce fingerprinting in Animation API 1354633 - limit MediaError.message to a whitelist FF58-90 967895 - spoof canvas and enable site permission prompt (FF58) 1372073 - spoof/block fingerprinting in MediaDevices API (FF59) Spoof: enumerate devices as one "Internal Camera" and one "Internal Microphone" Block: suppresses the ondevicechange event 1039069 - warn when language prefs are not set to "en*" (also see 0210, 0211) (FF59) 1222285 & 1433592 - spoof keyboard events and suppress keyboard modifier events (FF59) Spoofing mimics the content language of the document. Currently it only supports en-US. Modifier events suppressed are SHIFT and both ALT keys. Chrome is not affected. 1337157 - disable WebGL debug renderer info (FF60) 1459089 - disable OS locale in HTTP Accept-Language headers (ANDROID) (FF62) 1479239 - return "no-preference" with prefers-reduced-motion (FF63) 1363508 - spoof/suppress Pointer Events (FF64) 1492766 - spoof pointerEvent.pointerid (FF65) 1485266 - disable exposure of system colors to CSS or canvas (FF67) 1494034 - return "light" with prefers-color-scheme (FF67) 1564422 - spoof audioContext outputLatency (FF70) 1595823 - return audioContext sampleRate as 44100 (FF72) 1607316 - spoof pointer as coarse and hover as none (ANDROID) (FF74) 1621433 - randomize canvas (previously FF58+ returned an all-white canvas) (FF78) 1653987 - limit font visibility to bundled and "Base Fonts" (Windows, Mac, some Linux) (FF80) 1461454 - spoof smooth=true and powerEfficient=false for supported media in MediaCapabilities (FF82) FF91+ 531915 - use fdlibm's sin, cos and tan in jsmath (FF93, ESR91.1) 1756280 - enforce navigator.pdfViewerEnabled as true and plugins/mimeTypes as hard-coded values (FF100) 1692609 - reduce JS timing precision to 16.67ms (previously FF55+ was capped at 100ms) (FF102) ***/ user_pref("_user.js.parrot", "4500 syntax error: the parrot's popped 'is clogs"); /* 4501: enable privacy.resistFingerprinting [FF41+] * [SETUP-WEB] RFP can cause some website breakage: mainly canvas, use a site exception via the urlbar * RFP also has a few side effects: mainly timezone is UTC0, and websites will prefer light theme * [1] https://bugzilla.mozilla.org/418986 ***/ user_pref("privacy.resistFingerprinting", true); /* 4502: set new window size rounding max values [FF55+] * [SETUP-CHROME] sizes round down in hundreds: width to 200s and height to 100s, to fit your screen * [1] https://bugzilla.mozilla.org/1330882 ***/ user_pref("privacy.window.maxInnerWidth", 1600); user_pref("privacy.window.maxInnerHeight", 900); /* 4503: disable mozAddonManager Web API [FF57+] * [NOTE] To allow extensions to work on AMO, you also need 2662 * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1384330,1406795,1415644,1453988 ***/ user_pref("privacy.resistFingerprinting.block_mozAddonManager", true); // [HIDDEN PREF] /* 4504: enable RFP letterboxing [FF67+] * Dynamically resizes the inner window by applying margins in stepped ranges [2] * If you use the dimension pref, then it will only apply those resolutions. * The format is "width1xheight1, width2xheight2, ..." (e.g. "800x600, 1000x1000") * [SETUP-WEB] This is independent of RFP (4501). If you're not using RFP, or you are but * dislike the margins, then flip this pref, keeping in mind that it is effectively fingerprintable * [WARNING] DO NOT USE: the dimension pref is only meant for testing * [1] https://bugzilla.mozilla.org/1407366 * [2] https://hg.mozilla.org/mozilla-central/rev/6d2d7856e468#l2.32 ***/ user_pref("privacy.resistFingerprinting.letterboxing", true); // [HIDDEN PREF] // user_pref("privacy.resistFingerprinting.letterboxing.dimensions", ""); // [HIDDEN PREF] /* 4505: experimental RFP [FF91+] * [WARNING] DO NOT USE unless testing, see [1] comment 12 * [1] https://bugzilla.mozilla.org/1635603 ***/ // user_pref("privacy.resistFingerprinting.exemptedDomains", "*.example.invalid"); // user_pref("privacy.resistFingerprinting.testGranularityMask", 0); /* 4506: set RFP's font visibility level (1402) [FF94+] ***/ // user_pref("layout.css.font-visibility.resistFingerprinting", 1); // [DEFAULT: 1] /* 4510: disable using system colors * [SETTING] General > Language and Appearance > Fonts and Colors > Colors > Use system colors ***/ user_pref("browser.display.use_system_colors", false); // [DEFAULT false NON-WINDOWS] /* 4511: enforce non-native widget theme * Security: removes/reduces system API calls, e.g. win32k API [1] * Fingerprinting: provides a uniform look and feel across platforms [2] * [1] https://bugzilla.mozilla.org/1381938 * [2] https://bugzilla.mozilla.org/1411425 ***/ user_pref("widget.non-native-theme.enabled", true); // [DEFAULT: true] /* 4512: enforce links targeting new windows to open in a new tab instead * 1=most recent window or tab, 2=new window, 3=new tab * Stops malicious window sizes and some screen resolution leaks. * You can still right-click a link and open in a new window * [NOTE] Thunderbird only supports 3 (see [2]) * [TEST] https://arkenfox.github.io/TZP/tzp.html#screen * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/9881 * [2] https://searchfox.org/comm-esr102/source/mail/app/profile/all-thunderbird.js#721 ***/ user_pref("browser.link.open_newwindow", 3); // [DEFAULT: 3] /* 4513: set all open window methods to abide by "browser.link.open_newwindow" (4512) * [NOTE] Thunderbird only supports 0 (see [2]) * [1] https://searchfox.org/mozilla-central/source/dom/tests/browser/browser_test_new_window_from_content.js * [2] https://searchfox.org/comm-esr102/source/mail/app/profile/all-thunderbird.js#730 ***/ user_pref("browser.link.open_newwindow.restriction", 0); /* 4520: disable WebGL (Web Graphics Library) * [SETUP-WEB] If you need it then override it. RFP still randomizes canvas for naive scripts ***/ user_pref("webgl.disabled", true); /*** [SECTION 5000]: OPTIONAL OPSEC Disk avoidance, application data isolation, eyeballs... ***/ user_pref("_user.js.parrot", "5000 syntax error: the parrot's taken 'is last bow"); /* 5001: start Thunderbird in PB (Private Browsing) mode * [NOTE] In this mode all windows are "private windows" and the PB mode icon is not displayed * [NOTE] The P in PB mode can be misleading: it means no "persistent" disk state such as history, * caches, searches, cookies, localStorage, IndexedDB etc (which you can achieve in normal mode). * In fact, PB mode limits or removes the ability to control some of these, and you need to quit * Thunderbird to clear them. PB is best used as a one off window (Menu>New Private Window) to provide * a temporary self-contained new session. Close all Private Windows to clear the PB mode session. * [1] https://wiki.mozilla.org/Private_Browsing * [2] https://support.mozilla.org/kb/common-myths-about-private-browsing ***/ // user_pref("browser.privatebrowsing.autostart", true); /* 5002: disable memory cache * capacity: -1=determine dynamically (default), 0=none, n=memory capacity in kibibytes ***/ user_pref("browser.cache.memory.enable", false); user_pref("browser.cache.memory.capacity", 0); /* 5003: disable saving passwords * [NOTE] This does not clear any passwords already saved ***/ user_pref("signon.rememberSignons", false); /* 5004: disable permissions manager from reading or writing to disk [FF41+] [RESTART] * [SETUP-CHROME] This means any permission changes (cookie or mail remote content) are session only * [1] https://bugzilla.mozilla.org/967812 ***/ user_pref("permissions.memory_only", true); // [HIDDEN PREF] /* 5005: disable intermediate certificate caching [FF41+] [RESTART] * [NOTE] This affects login/cert/key dbs. The effect is all credentials are session-only. * Saved logins and passwords are not available. Reset the pref and restart to return them ***/ // user_pref("security.nocertdb", true); // [HIDDEN PREF in FF101 or lower] /* 5006: disable favicons in history and bookmarks * [NOTE] Stored as data blobs in favicons.sqlite, these don't reveal anything that your * actual history (and bookmarks) already do. Your history is more detailed, so * control that instead; e.g. disable history, clear history on exit, use PB mode * [NOTE] favicons.sqlite is sanitized on Thunderbird close ***/ user_pref("browser.chrome.site_icons", false); /* 5007: exclude "Undo Closed Tabs" in Session Restore ***/ user_pref("browser.sessionstore.max_tabs_undo", 0); /* 5008: disable resuming session from crash ***/ user_pref("browser.sessionstore.resume_from_crash", false); /* 5009: disable "open with" in download dialog [FF50+] * Application data isolation [1] * [1] https://bugzilla.mozilla.org/1281959 ***/ // user_pref("browser.download.forbid_open_with", true); /* 5013: disable browsing and download history * [NOTE] We also clear history and downloads on exit (2811) ***/ user_pref("places.history.enabled", false); /* 5016: discourage downloading to desktop * 0=desktop, 1=downloads (default), 2=last used ***/ // user_pref("browser.download.folderList", 2); /*** [SECTION 5500]: OPTIONAL HARDENING Thunderbird-User.JS maintainer here : Whereas not recommended by upstream arkenfox, we disable each one of those Web features as we focus on keeping Thunderbird an email client and not a browser. ***/ user_pref("_user.js.parrot", "5500 syntax error: this is an ex-parrot!"); /* 5501: disable MathML (Mathematical Markup Language) [FF51+] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=mathml ***/ user_pref("mathml.disabled", true); // 1173199 /* 5502: disable in-content SVG (Scalable Vector Graphics) [FF53+] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+svg ***/ user_pref("svg.disabled", true); // 1216893 /* 5503: disable graphite * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+graphite * [2] https://en.wikipedia.org/wiki/Graphite_(SIL) ***/ user_pref("gfx.font_rendering.graphite.enabled", false); /* 5504: disable asm.js [FF22+] * [1] http://asmjs.org/ * [2] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=asm.js * [3] https://rh0dev.github.io/blog/2017/the-return-of-the-jit/ ***/ user_pref("javascript.options.asmjs", false); /* 5505: disable Ion and baseline JIT to harden against JS exploits * [NOTE] When both Ion and JIT are disabled, and trustedprincipals * is enabled, then Ion can still be used by extensions (1599226) * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+jit * [2] https://microsoftedge.github.io/edgevr/posts/Super-Duper-Secure-Mode/ ***/ user_pref("javascript.options.ion", false); user_pref("javascript.options.baselinejit", false); user_pref("javascript.options.jit_trustedprincipals", true); // [FF75+] [HIDDEN PREF] /* 5506: disable WebAssembly [FF52+] * Vulnerabilities [1] have increasingly been found, including those known and fixed * in native programs years ago [2]. WASM has powerful low-level access, making * certain attacks (brute-force) and vulnerabilities more possible * [STATS] ~0.2% of websites, about half of which are for crytomining / malvertising [2][3] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=wasm * [2] https://spectrum.ieee.org/tech-talk/telecom/security/more-worries-over-the-security-of-web-assembly * [3] https://www.zdnet.com/article/half-of-the-websites-using-webassembly-use-it-for-malicious-purposes ***/ user_pref("javascript.options.wasm", false); /* 5590: show a prompt when opening a link in external applications ***/ user_pref("security.external_protocol_requires_permission", true); /*** [SECTION 6000]: DON'T TOUCH ***/ user_pref("_user.js.parrot", "6000 syntax error: the parrot's 'istory!"); /* 6001: enforce Mozilla's blocklist * [WHY] It includes updates for "revoked certificates" * [1] https://blog.mozilla.org/security/2015/03/03/revoking-intermediate-certificates-introducing-onecrl/ ***/ user_pref("extensions.blocklist.enabled", true); // [DEFAULT: true] /* 6002: enforce no referer spoofing * [WHY] Spoofing can affect CSRF (Cross-Site Request Forgery) protections ***/ user_pref("network.http.referer.spoofSource", false); // [DEFAULT: false] /* 6004: enforce a security delay on some confirmation dialogs such as install, open/save * [1] https://www.squarefree.com/2004/07/01/race-conditions-in-security-dialogs/ ***/ user_pref("security.dialog_enable_delay", 1000); // [DEFAULT: 1000] /* 6008: enforce no First Party Isolation [FF51+] * [WARNING] Replaced with network partitioning (FF85+) and TCP (2701), * and enabling FPI disables those. FPI is no longer maintained ***/ user_pref("privacy.firstparty.isolate", false); // [DEFAULT: false] /* 6009: enforce SmartBlock shims [FF81+] * In FF96+ these are listed in about:compat * [1] https://blog.mozilla.org/security/2021/03/23/introducing-smartblock/ ***/ user_pref("extensions.webcompat.enable_shims", true); // [DEFAULT: true] /* 6010: enforce/reset TLS 1.0/1.1 downgrades to session only * [NOTE] In FF97+ the TLS 1.0/1.1 downgrade UX was removed * [TEST] https://tls-v1-1.badssl.com:1010/ ***/ user_pref("security.tls.version.enable-deprecated", false); // [DEFAULT: false] /* 6011: enforce disabling of Web Compatibility Reporter [FF56+] * Web Compatibility Reporter adds a "Report Site Issue" button to send data to Mozilla * [WHY] To prevent wasting Mozilla's time with a custom setup ***/ user_pref("extensions.webcompat-reporter.enabled", false); // [DEFAULT: false] /* 6012: disable SHA-1 certificates ***/ user_pref("security.pki.sha1_enforcement_level", 1); // [DEFAULT: 1 FF102+] /* 6050: prefsCleaner: reset items removed from arkenfox FF92+ ***/ // user_pref("browser.urlbar.trimURLs", ""); // user_pref("dom.caches.enabled", ""); // user_pref("dom.storageManager.enabled", ""); // user_pref("dom.storage_access.enabled", ""); // user_pref("dom.targetBlankNoOpener.enabled", ""); // user_pref("network.cookie.thirdparty.sessionOnly", ""); // user_pref("network.cookie.thirdparty.nonsecureSessionOnly", ""); // user_pref("privacy.firstparty.isolate.block_post_message", ""); // user_pref("privacy.firstparty.isolate.restrict_opener_access", ""); // user_pref("privacy.firstparty.isolate.use_site", ""); // user_pref("privacy.window.name.update.enabled", ""); // user_pref("security.insecure_connection_text.enabled", ""); /*** [SECTION 7000]: DON'T BOTHER Thunderbird-User.JS maintainer here : Actually we do, TB is an e-mail client, not a (bloated) browser. Thus some of below preferences have been set, despite upstream (Arkenfox) warnings. ***/ user_pref("_user.js.parrot", "7000 syntax error: the parrot's pushing up daisies!"); /* 7001: disable APIs * Location-Aware Browsing, Full Screen, offline cache (appCache), Virtual Reality * [WHY] The API state is easily fingerprintable. Geo and VR are behind prompts (7002). * appCache storage capability was removed in FF90. Full screen requires user interaction ***/ user_pref("geo.enabled", false); user_pref("full-screen-api.enabled", false); user_pref("browser.cache.offline.enable", false); user_pref("dom.vr.enabled", false); // [DEFAULT: false FF97+] /* 7003: disable non-modern cipher suites [1] * [WHY] Passive fingerprinting. Minimal/non-existent threat of downgrade attacks * [1] https://browserleaks.com/ssl ***/ // user_pref("security.ssl3.ecdhe_ecdsa_aes_256_sha", false); // user_pref("security.ssl3.ecdhe_ecdsa_aes_128_sha", false); // user_pref("security.ssl3.ecdhe_rsa_aes_128_sha", false); // user_pref("security.ssl3.ecdhe_rsa_aes_256_sha", false); // user_pref("security.ssl3.rsa_aes_128_gcm_sha256", false); // no PFS // user_pref("security.ssl3.rsa_aes_256_gcm_sha384", false); // no PFS // user_pref("security.ssl3.rsa_aes_128_sha", false); // no PFS // user_pref("security.ssl3.rsa_aes_256_sha", false); // no PFS /* 7004: control TLS versions * [WHY] Passive fingerprinting and security ***/ // user_pref("security.tls.version.min", 3); // [DEFAULT: 3] // user_pref("security.tls.version.max", 4); /* 7005: disable SSL session IDs [FF36+] * [WHY] Passive fingerprinting and perf costs. These are session-only * and isolated with network partitioning (FF85+) and/or containers ***/ // user_pref("security.ssl.disable_session_identifiers", true); // [HIDDEN PREF in FF101 or lower] /* 7006: onions * [WHY] Thunderbird doesn't support hidden services. Use Tor Browser ***/ // user_pref("dom.securecontext.allowlist_onions", true); // [FF97+] 1382359/1744006 // user_pref("network.http.referer.hideOnionSource", true); // 1305144 /* 7007: referers * [WHY] Only cross-origin referers (1600s) need control ***/ user_pref("network.http.sendRefererHeader", 0); user_pref("network.http.referer.trimmingPolicy", 0); /* 7008: set the default Referrer Policy [FF59+] * 0=no-referer, 1=same-origin, 2=strict-origin-when-cross-origin, 3=no-referrer-when-downgrade * [WHY] Defaults are fine. They can be overridden by a site-controlled Referrer Policy ***/ user_pref("network.http.referer.defaultPolicy", 0); // [DEFAULT: 2] user_pref("network.http.referer.defaultPolicy.pbmode", 0); // [DEFAULT: 2] /* 7010: disable HTTP Alternative Services [FF37+] * [WHY] Already isolated with network partitioning (FF85+) ***/ user_pref("network.http.altsvc.enabled", false); // user_pref("network.http.altsvc.oe", false); // [DEFAULT: false FF94+] /* 7011: disable website control over browser right-click context menu * [WHY] Just use Shift-Right-Click ***/ user_pref("dom.event.contextmenu.enabled", false); /* 7012: disable icon fonts (glyphs) and local fallback rendering * [WHY] Breakage, font fallback is equivalency, also RFP * [1] https://bugzilla.mozilla.org/789788 * [2] https://gitlab.torproject.org/legacy/trac/-/issues/8455 ***/ user_pref("gfx.downloadable_fonts.enabled", false); // [FF41+] user_pref("gfx.downloadable_fonts.fallback_delay", -1); /* 7013: disable Clipboard API * [WHY] Fingerprintable. Breakage. Cut/copy/paste require user * interaction, and paste is limited to focused editable fields ***/ user_pref("dom.event.clipboardevents.enabled", false); /* 7014: disable System Add-on updates * [WHY] It can compromise security. System addons ship with prefs, use those ***/ // user_pref("extensions.systemAddon.update.enabled", false); // [FF62+] // user_pref("extensions.systemAddon.update.url", ""); // [FF44+] /* 7015: enable the DNT (Do Not Track) HTTP header * [WHY] DNT is enforced with Tracking Protection which is used in ETP Strict (2701) ***/ // user_pref("privacy.donottrackheader.enabled", true); /* 7016: customize ETP settings * [WHY] Arkenfox only supports strict (2701) which sets these at runtime ***/ // user_pref("network.cookie.cookieBehavior", 5); // user_pref("network.http.referer.disallowCrossSiteRelaxingDefault", true); // user_pref("network.http.referer.disallowCrossSiteRelaxingDefault.top_navigation", true); // [FF100+] // user_pref("privacy.partition.network_state.ocsp_cache", true); // user_pref("privacy.query_stripping.enabled", true); // [FF101+] [ETP FF102+] // user_pref("privacy.trackingprotection.enabled", true); // user_pref("privacy.trackingprotection.socialtracking.enabled", true); // user_pref("privacy.trackingprotection.cryptomining.enabled", true); // [DEFAULT: true] // user_pref("privacy.trackingprotection.fingerprinting.enabled", true); // [DEFAULT: true] /* 7017: disable service workers * [WHY] Already isolated (FF96+) with TCP (2701) behind a pref (2710) * or blocked with TCP in 3rd parties (FF95 or lower) ***/ // user_pref("dom.serviceWorkers.enabled", false); /* 7018: disable Web Notifications * [WHY] Web Notifications are behind a prompt (7002) * [1] https://blog.mozilla.org/en/products/firefox/block-notification-requests/ ***/ // user_pref("dom.webnotifications.enabled", false); // [FF22+] // user_pref("dom.webnotifications.serviceworker.enabled", false); // [FF44+] /* 7019: disable Push Notifications [FF44+] * [WHY] Push requires subscription * [NOTE] To remove all subscriptions, reset "dom.push.userAgentID" * [1] https://support.mozilla.org/kb/push-notifications-firefox ***/ // user_pref("dom.push.enabled", false); /*** [SECTION 8000]: DON'T BOTHER: FINGERPRINTING [WHY] They are insufficient to help anti-fingerprinting and do more harm than good [WARNING] DO NOT USE with RFP. RFP already covers these and they can interfere [NOTE] An empty User-Agent may break Microsoft Exchange OAuth2 login ***/ user_pref("_user.js.parrot", "8000 syntax error: the parrot's crossed the Jordan"); /* 8001: disable APIs ***/ // user_pref("device.sensors.enabled", false); // user_pref("dom.enable_performance", false); // user_pref("dom.enable_resource_timing", false); // user_pref("dom.gamepad.enabled", false); // user_pref("dom.netinfo.enabled", false); // [DEFAULT: false NON-ANDROID: false ANDROID FF99+] // user_pref("dom.webaudio.enabled", false); /* 8002: disable other ***/ // user_pref("browser.display.use_document_fonts", 0); // user_pref("dom.w3c_touch_events.enabled", 0); // user_pref("media.navigator.enabled", false); // user_pref("media.ondevicechange.enabled", false); // user_pref("media.video_stats.enabled", false); // user_pref("media.webspeech.synth.enabled", false); // user_pref("webgl.enable-debug-renderer-info", false); /* 8003: spoof ***/ // user_pref("dom.maxHardwareConcurrency", 2); // user_pref("font.system.whitelist", ""); // [HIDDEN PREF] // user_pref("general.appname.override", ""); // [HIDDEN PREF] // user_pref("general.appversion.override", ""); // [HIDDEN PREF] // user_pref("general.buildID.override", ""); // [HIDDEN PREF] // user_pref("general.oscpu.override", ""); // [HIDDEN PREF] // user_pref("general.platform.override", ""); // [HIDDEN PREF] // user_pref("general.useragent.override", ""); // [HIDDEN PREF] // user_pref("ui.use_standins_for_native_colors", true); /*** [SECTION 9000]: PERSONAL Non-project related but useful. If any interest you, add them to your overrides ***/ user_pref("_user.js.parrot", "9000 syntax error: the parrot's cashed in 'is chips!"); /* WELCOME & WHAT'S NEW NOTICES ***/ user_pref("mailnews.start_page_override.mstone", "ignore"); // master switch /* WARNINGS ***/ // user_pref("browser.tabs.warnOnClose", false); // [DEFAULT false FF94+] // user_pref("browser.tabs.warnOnOpen", false); // user_pref("full-screen-api.warning.delay", 0); // user_pref("full-screen-api.warning.timeout", 0); /* UPDATES ***/ // user_pref("app.update.auto", false); // [NON-WINDOWS] disable auto app updates // [NOTE] You will still get prompts to update, and should do so in a timely manner // user_pref("browser.search.update", false); // disable search engine updates (e.g. OpenSearch) // [NOTE] This does not affect Mozilla's built-in or Web Extension search engines // user_pref("extensions.update.enabled", false); // disable extension and theme update checks // user_pref("extensions.update.autoUpdateDefault", false); // disable installing extension and theme updates // [SETTING] about:addons>Extensions>[cog-wheel-icon]>Update Add-ons Automatically (toggle) // user_pref("extensions.getAddons.cache.enabled", false); // disable extension metadata (extension detail tab) /* APPEARANCE ***/ // user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true); // [FF68+] allow userChrome/userContent // user_pref("ui.prefersReducedMotion", 1); // disable chrome animations [FF77+] [RESTART] [HIDDEN PREF] // 0=no-preference, 1=reduce: with RFP this only affects chrome // user_pref("ui.systemUsesDarkTheme", 1); // [FF67+] [HIDDEN PREF] // 0=light, 1=dark: with RFP this only affects chrome /* CONTENT BEHAVIOR ***/ // user_pref("accessibility.typeaheadfind", true); // enable "Find As You Type" // user_pref("clipboard.autocopy", false); // disable autocopy default [LINUX] /* UX BEHAVIOR ***/ // user_pref("general.autoScroll", false); // middle-click enabling auto-scrolling [DEFAULT: false on Linux] // user_pref("mail.tabs.autoHide", true); // hides the tab bar if there is only one tab // user_pref("ui.key.menuAccessKey", 0); // disable alt key toggling the menu bar [RESTART] /* UX FEATURES ***/ // user_pref("reader.parse-on-load.enabled", false); // Reader View /* OTHER ***/ // user_pref("browser.bookmarks.max_backups", 2); // user_pref("network.manage-offline-status", false); // see bugzilla 620472 // user_pref("xpinstall.signatures.required", false); // enforced extension signing (Nightly/ESR) /* RETURN RECEIPT BEHAVIOR ***/ // user_pref("mail.mdn.report.enabled", false); // disable return receipt sending unconditionally /* CUSTOM HEADERS ***/ // user_pref("mail.compose.other.header", "X-Custom-Header,X-Another-Custom-Header"); // corresponding values can be set in compose window ("double-arrow" drop-down) // user_pref("mail.identity.id1.headers", "References, InReplyTo"); // user_pref("mail.identity.id1.header.References", "References: <2ad46d80-c8ce-49a3-9896-16171788ac28@example.tld>\n <31ff00c2-b7cb-4063-beeb-a0bdd424c3a7@example1.tld>"); // user_pref("mail.identity.id1.header.InReplyTo", "In-Reply-To: <31ff00c2-b7cb-4063-beeb-a0bdd424c3a7@example1.tld>"); user_pref("mail.identity.id1.headers", ""); user_pref("mail.identity.id1.header.References", ""); user_pref("mail.identity.id1.header.InReplyTo", ""); /*** [SECTION 9100]: THUNDERBIRD (AUTO CONFIG / UI / HEADERS / ADDRESS BOOK) Options general to Thunderbird's mail configuration and user interface [1] https://searchfox.org/comm-esr91/source/ [2] http://kb.mozillazine.org/Mail_and_news_settings ***/ user_pref("_user.js.parrot", "9100 syntax error: this parrot is blind!"); /** AUTO CONFIG ***/ /* 9101: Disable auto-configuration [SETUP-INSTALL] * These options disable auto-configuration of mail servers in Thunderbird. * Such settings require a query to Mozilla which could have privacy implications * if the user wishes to keep the existence of the mail provider private. * [1] https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Autoconfiguration ***/ user_pref("mailnews.auto_config.guess.enabled", false); user_pref("mailnews.auto_config.fetchFromISP.enabled", false); user_pref("mailnews.auto_config.fetchFromISP.sendEmailAddress", false); user_pref("mailnews.auto_config.fetchFromExchange.enabled", false); user_pref("mailnews.auto_config_url", ""); user_pref("mailnews.auto_config.addons_url",""); /* 9102: Disable account provisioning [SETUP-INSTALL] * This option allows users to create a new email account through partner providers. * [1] https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Account_Provisioner ***/ user_pref("mail.provider.enabled", false); /** UI (User Interface) ***/ /* 9111: Show full email instead of just name from address book * true=Show just the display name for people in the address book (default) * false=Show both the email address and display name. ***/ user_pref("mail.showCondensedAddresses", false); /* 9112: Disable "Filelink for Large Attachments" feature * [1] https://support.thunderbird.net/kb/filelink-large-attachments ***/ user_pref("mail.cloud_files.enabled", false); /* 9113: Don't hide cookies and passwords related (advanced?) buttons ***/ user_pref("pref.privacy.disable_button.view_cookies", false); user_pref("pref.privacy.disable_button.cookie_exceptions", false); user_pref("pref.privacy.disable_button.view_passwords", false); /** HEADERS ***/ /* 9120: * true=Show Sender header in message pane. * false=Does nothing. (default) ***/ user_pref("mailnews.headers.showSender", true); /* 9121: * true=Show User Agent header in message pane * false=Does nothing. (default) ***/ user_pref("mailnews.headers.showUserAgent", false); /* 9122: Hello argument * Lets you replace your IP address with the specified string in Received: headers when your * IP address is not a "fully qualified domain name" (FQDN). Typically you only need to do this * when you have a NAT box to prevent it from using the NAT boxes IP address. * If you don't set it to something in your SMTP server's domain it may increase your spam * score. ***/ user_pref("mail.smtpserver.default.hello_argument", "[127.0.0.1]"); /* 9123: Displayed dates and times * [SETUP-INSTALL] When your e-mail program displays the e-mail's date and time, it normally * converts them to your time zone. If your computer's time zone settings are wrong, then you will * see the wrong time (and possibly the wrong date). * To turn this conversion off, you can use a preference setting. * It affects the headers that you see in e-mails that you open or preview, but it does not affect * the Date column in folders. * [1] http://kb.mozillazine.org/Time_and_time_zone_settings * [2] http://wiki.cacert.org/ThunderBirdAdvancedConfig * ***/ user_pref("mailnews.display.original_date", false); /* 9124: Display the sender's Timezone when set to true ***/ user_pref("mailnews.display.date_senders_timezone", false); /* 9125: Display Time Date based on Received Header * Thunderbird shows the time when the message was sent, according to the sender. It is possible * to make Thunderbird show the time when the message arrived on your mail server, based on the * "Received" header. Set the following preference. New messages will show the time the message * was received, rather than when it was sent. ***/ // user_pref("mailnews.use_received_date", true); /** ADDRESS BOOK ***/ /* 9130: Address book collection [SETUP-FEATURE] * Disable Thunderbird internal address book email collection * Consider using CardBook extension instead (https://addons.thunderbird.net/addon/cardbook/) * [SETTING] Preferences > Composition > Addressing > Automatically add outgoing e-mail addresses... * [SETTING][CARDBOOK] CardBook > Preferences > Email > Collect Outgoing Email ***/ // user_pref("mail.collect_addressbook", "jsaddrbook://history.sqlite"); user_pref("mail.collect_email_address_outgoing", false); /* 9131: Only use email addresses, without their Display Names [CARDBOOK] [SETUP-FEATURE] * By default, CardBook extension incorporates contacts display names in addresses fields. * This could leak sensitive information to all recipients. * [SETTING][CARDBOOK] CardBook > Preferences > Email > Sending Emails > Only use email addresses... ***/ user_pref("extensions.cardbook.useOnlyEmail", true); /*** [SECTION 9200]: EMAIL COMPOSITION (ENCODING / FORMAT / VIEW) Options that relate to composition, formatting and viewing email ***/ user_pref("_user.js.parrot", "9200 syntax error: this parrot has got no mail!"); /** ENCODING ***/ /* 9201: Prevent fallback encoding to windows-1252, prefer 7bit or 8bit UTF-8 * [1] http://forums.mozillazine.org/viewtopic.php?f=28&t=267341 * [2] https://bugzilla.mozilla.org/show_bug.cgi?id=214729 * [3] https://stackoverflow.com/a/28531705 ***/ user_pref("intl.fallbackCharsetList.ISO-8859-1", "UTF-8"); /* 9202: Set encoding of incoming mail ***/ user_pref("mailnews.view_default_charset", "UTF-8"); /* 9203: Set encoding of outgoing mail ***/ user_pref("mailnews.send_default_charset", "UTF-8"); /* 9204: Forces encoding in reply to be the default charset * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=234958#c2 ***/ user_pref("mailnews.reply_in_default_charset", true); /* 9205: Avoid information leakage in reply header * Reply header may contain sensitive information about system locale (date and/or language) * 0=no header * 1=" wrote:" (see `reply_header_authorwrotesingle` below) * 2="On wrote:" (see `reply_header_ondateauthorwrote` below [DEFAULT]) * 3=" wrote On :" (see `reply_header_authorwroteondate` below`) * 4=user specified (you may use below tokens to forge your own format [DISCOURAGED]) ***/ user_pref("mailnews.reply_header_type", 1); user_pref("mailnews.reply_header_authorwrotesingle", "#1 wrote:"); // user_pref("mailnews.reply_header_ondateauthorwrote", "On #2 #3, #1 wrote:"); // user_pref("mailnews.reply_header_authorwroteondate", "#1 wrote on #2 #3:"); /* 9206: Prevent spellchecking dictionary leakage through Content-Language header * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1370217 ***/ user_pref("mail.suppress_content_language", true); /* 9207: Sanitize Date header to convert date to UTC and round to closest minute * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1603359 ***/ user_pref("mail.sanitize_date_header", true); /** COMPOSITION ***/ /* 9210: Check spelling before sending [SETUP-FEATURE] * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=667133 ***/ user_pref("mail.SpellCheckBeforeSend", false); /* 9212: Compose email in plaintext unless expressly overridden * [SETUP-FEATURE] Sometimes HTML is useful especially when used with Markdown Here * [SETTING] Account Settings > Composition & Addressing > Composition > Compose messages in HTML format * [NOTE] Holding down shift when you click on "Write" will bypass * [1] http://kb.mozillazine.org/Plain_text_e-mail_%28Thunderbird%29 * [2] https://support.mozilla.org/en-US/questions/1004181 * [3] https://markdown-here.com ***/ user_pref("mail.html_compose", false); user_pref("mail.identity.default.compose_html", false); /* 9213: Send only plaintext email by default * [SETUP-FEATURE] Only use HTML email if you need it, see [1] * Email that is HTML should also have plaintext multipart for plain text users. * 0=auto (default, send only plain text if the message is free of any rich formatting or inserted elements. Otherwise send both a HTML part and plain text alternative part) * 1=plain text (only send a plain text part, losing any rich formatting or inserted elements) * 2=HTML (only send a HTML part) * 3=both (send both the HTML part and the plain text alternative part) * [1] https://drewdevault.com/2016/04/11/Please-use-text-plain-for-emails.html ***/ user_pref("mail.default_send_format", 1); /* 9214: What classes can process incoming data. * (0=All classes (default), 1=Don't display HTML, 2=Don't display HTML and inline images, * 3=Don't display HTML, inline images and some other uncommon types, 100=Use a hard coded list) * In the past this has mitigated a vulnerability CVE-2008-0304 (rare) * [1] https://www.mozilla.org/en-US/security/advisories/mfsa2008-12/ * [2] https://bugzilla.mozilla.org/show_bug.cgi?id=677905 ***/ user_pref("mailnews.display.disallow_mime_handlers", 3); /* 9215: How to display HTML parts of a message body * (0=Display the HTML normally (default), 1=Convert it to text and then back again * 2=Display the HTML source, 3=Sanitize the HTML, 4=Display all body parts) * (in trunk builds later than 2011-07-23) * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=602718 * [2] https://hg.mozilla.org/comm-central/rev/c1ef44a22eb2 * [3] https://www.bucksch.org/1/projects/mozilla/108153/ ***/ user_pref("mailnews.display.html_as", 3); /* 9216: Prefer to view as plaintext or HTML [SETUP-FEATURE] * true=Display a message as plain text when there is both a HTML and a plain * text version of a message body * false=Display a message as HTML when there is both a HTML and a plain text * version of a message body. (default) ***/ user_pref("mailnews.display.prefer_plaintext", false); /* 9217: Inline attachments [SETUP-FEATURE] * true=Show inlinable attachments (text, images, messages) after the message. * false=Do not display any attachments with the message ***/ user_pref("mail.inline_attachments", false); /* 9218: Big attachment warning * [1] https://support.mozilla.org/en-US/questions/1081046 * [2] http://forums.mozillazine.org/viewtopic.php?f=39&t=2949521 */ user_pref("mail.compose.big_attachments.notify", true); // [DEFAULT: true] /* 9219: Set big attachment size to warn at */ user_pref("mail.compose.big_attachments.threshold_kb", 9220); // [DEFAULT: 5120] // user_pref("mailnews.message_warning_size", 20971520); // [DEFAULT: 20971520] /* 9220: Set public recipients number from which BCC is advised ***/ // user_pref("mail.compose.warn_public_recipients.threshold", 15); // [DEFAULT: 15] /* 9221: Show an alert if the warning above has not been addressed ***/ user_pref("mail.compose.warn_public_recipients.aggressive", true); /** VIEW ***/ /* 9230: Disable JavaScript * [NOTE] JavaScript is already disabled in message content. * [1] https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Releases/3 * [2] https://stackoverflow.com/questions/3054315/is-javascript-supported-in-an-email-message * ***/ user_pref("javascript.enabled", false); /* 9231: Disable media source extensions * [1] https://www.ghacks.net/2014/05/10/enable-media-source-extensions-firefox ***/ user_pref("media.mediasource.enabled", false); /* 9232: Disable hardware decoding support ***/ user_pref("media.hardware-video-decoding.enabled", false); /* 9233: Default image permissions * 1=Allow all images to load, regardless of origin. (Default), * 2=Block all images from loading. * 3=Prevent third-party images from loading * [1] http://kb.mozillazine.org/Permissions.default.image ***/ user_pref("permissions.default.image", 2); /* 9240: Builtin phishing/scamming detection * [NOTE] These preferences are enabled by default and should not usually be touched. * [1] https://searchfox.org/comm-central/source/mail/modules/PhishingDetector.jsm ***/ user_pref("mail.phishing.detection.enabled", true); user_pref("mail.phishing.detection.disallow_form_actions", true); user_pref("mail.phishing.detection.ipaddresses", true); user_pref("mail.phishing.detection.mismatched_hosts", true); /*** [SECTION 9300]: OTHER THUNDERBIRD COMPONENTS (CHAT / CALENDAR / RSS) Options that relate to other Thunderbird components such as the chat client, calendar and RSS) ***/ user_pref("_user.js.parrot", "9300 syntax error: this parrot is not tweeting!"); /** CHAT ***/ /* 9301: Disable chat functionality [SETUP-FEATURE] ***/ user_pref("mail.chat.enabled", false); /* 9302: Disable logging of group chats ***/ user_pref("purple.logging.log_chats", false); /* 9303: Disable logging of 1 to 1 conversations ***/ user_pref("purple.logging.log_ims", false); /* 9304: Disable logging of system messages ***/ user_pref("purple.logging.log_system", false); /* 9305: Disable typing notifications ***/ user_pref("purple.conversations.im.send_typing", false); /* 9306: When chat is enabled, do not connect to accounts automatically * 0=Do not connect / show the account manager, * 1=Connect automatically. (Default) ***/ // user_pref("messenger.startup.action", 0); /* 9307: When chat is enabled, do not report idle status ***/ // user_pref("messenger.status.reportIdle", false); /* 9308: Disable chat desktop notifications ***/ // user_pref("mail.chat.show_desktop_notifications", false); /* 9309: Decide how much information will be shown in chat notifications * 0=Show all info (sender, chat message message preview), * 1=Show sender's info only (not message preview), * 2=No info (fill dummy values). ***/ user_pref("mail.chat.notification_info", 2); /** CALENDAR ***/ /* 9312: Set calendar timezone to avoid system detection [SETUP-INSTALL] * By default, extensive system detection would be performed to find user's current timezone. * Setting this preference to "UTC" should disable it. * You may also directly set it to your timezone, i.e. "Pacific/Fakaofo" * [SETTING] Calendar > Calendar > Timezone ***/ user_pref("calendar.timezone.local", "UTC"); // [DEFAULT: ""] /** RSS ***/ /** These features don't actually do anything as they aren't implemented * [1] https://searchfox.org/comm-esr102/source/mail/base/content/mailWindowOverlay.js#1082 * [2] https://bugzilla.mozilla.org/show_bug.cgi?id=458606#c9 /* 9320: What classes can process incoming data. * (0=All classes (default), 1=Don't display HTML, 2=Don't display HTML and inline images, * 3=Don't display HTML, inline images and some other uncommon types, 100=Use a hard coded list) * [1] https://www.privacy-handbuch.de/handbuch_31j.htm user_pref("rss.display.disallow_mime_handlers", 3); /* 9321: How to display HTML parts of a message body * (0=Display the HTML normally (default), 1=Convert it to text and then back again * 2=Display the HTML source, 3=Sanitize the HTML, 4=Display all body parts) * (in trunk builds later than 2011-07-23) * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=602718 * [2] https://hg.mozilla.org/comm-central/rev/c1ef44a22eb2 * [3] https://www.bucksch.org/1/projects/mozilla/108153/ user_pref("rss.display.html_as", 1); /* 9322: Prefer to view as plaintext or HTML * true=Display a message as plain text when there is both a HTML and a plain * text version of a message body * false=Display a message as HTML when there is both a HTML and a plain text * version of a message body. (default) user_pref("rss.display.prefer_plaintext", true); **/ /* 9323: Feed message display (summary or web page), on open. * Action on double click or enter in threadpane for a feed message. * 0=open content-base url in new window, 1=open summary in new window, * 2=toggle load summary and content-base url in message pane, * 3=load content-base url in browser * [1] http://forums.mozillazine.org/viewtopic.php?f=39&t=2502335 ***/ user_pref("rss.show.content-base", 3); /* 9324: Feed message display (summary or web page), on select. * 0=global override, load web page, 1=global override, load summary, * 2=use default feed folder setting from Subscribe dialog; if no setting default to 1 ***/ user_pref("rss.show.summary", 1); /* 9325: Feed message additional web page display. * 0=no action, 1=load web page in default browser, on select ***/ user_pref("rss.message.loadWebPageOnSelect", 0); /*** [SECTION 9400]: THUNDERBIRD ENCRYPTION (OPENGPG / GNUPG) Options that relate to e-mail encryption in Thunderbird. [1] https://wiki.mozilla.org/Thunderbird:OpenPGP [2] https://support.mozilla.org/kb/openpgp-thunderbird-howto-and-faq ***/ user_pref("_user.js.parrot", "9400 syntax error: this parrot is talking in codes!"); /** GNUPG ***/ /* 9409: Allow the use of external GnuPG * Whenever RNP fails to decrypt a message, Thunderbird will tray against system GnuPG * [1] https://wiki.mozilla.org/Thunderbird:OpenPGP:Smartcards#Allow_the_use_of_external_GnuPG ***/ user_pref("mail.openpgp.allow_external_gnupg", true); // [HIDDEN PREF] /*** [SECTION 9999]: DEPRECATED / REMOVED / LEGACY / RENAMED Documentation denoted as [-]. Items deprecated prior to FF91 have been archived at [1] [1] https://github.com/arkenfox/user.js/issues/123 ***/ user_pref("_user.js.parrot", "9999 syntax error: the parrot's shuffled off 'is mortal coil!"); /* ESR91.x still uses all the following prefs // [NOTE] replace the * with a slash in the line above to re-enable them // FF93 // 7003: disable non-modern cipher suites // [-] https://bugzilla.mozilla.org/1724072 // user_pref("security.ssl3.rsa_des_ede3_sha", false); // 3DES // FF94 // 1402: limit font visibility (Windows, Mac, some Linux) [FF79+] - replaced by new 1402 // [-] https://bugzilla.mozilla.org/1715507 // user_pref("layout.css.font-visibility.level", 1); // FF96 // 0302: disable auto-INSTALLING Thunderbird updates via a background service + hide the setting [FF90+] [WINDOWS] // [1] https://support.mozilla.org/kb/enable-background-updates-firefox-windows // [-] https://bugzilla.mozilla.org/1738983 user_pref("app.update.background.scheduling.enabled", false); // FF97 // 7006: onions - replaced by new 7006 "allowlist" // [-] https://bugzilla.mozilla.org/1744006 // user_pref("dom.securecontext.whitelist_onions", true); // 1382359 // FF99 // 6003: enforce CSP (Content Security Policy) // [1] https://developer.mozilla.org/docs/Web/HTTP/CSP // [-] https://bugzilla.mozilla.org/1754301 user_pref("security.csp.enable", true); // [DEFAULT: true] // FF100 // 7009: disable HTTP2 - replaced by network.http.http2* prefs // [WHY] Passive fingerprinting. ~50% of sites use HTTP2 [1] // [1] https://w3techs.com/technologies/details/ce-http2/all/all // [-] https://bugzilla.mozilla.org/1752621 // user_pref("network.http.spdy.enabled", false); // user_pref("network.http.spdy.enabled.deps", false); // user_pref("network.http.spdy.enabled.http2", false); // user_pref("network.http.spdy.websockets", false); // [FF65+] // FF101 // 9211: Behavior when sending HTML message // (0=Ask, 1=Send as plain text, 2=Send as HTML anyway, // 3=Include both plain text and HTML message bodies in message) // Email that is HTML should also have plaintext multipart for plain text users. // [1] https://drewdevault.com/2016/04/11/Please-use-text-plain-for-emails.html // [-] https://bugzilla.mozilla.org/1727493 user_pref("mail.default_html_action", 1); // 9213: Downgrade email to plaintext by default // [-] https://bugzilla.mozilla.org/1727493 user_pref("mailnews.sendformat.auto_downgrade", true); // FF102 // 0901: set when Thunderbird should prompt for the primary password // 0=once per session (default), 1=every time it's needed, 2=after n minutes (0902) // [-] https://bugzilla.mozilla.org/1767099 user_pref("security.ask_for_password", 2); // 0902: set how long in minutes Thunderbird should remember the primary password (0901) // [-] https://bugzilla.mozilla.org/1767099 user_pref("security.password_lifetime", 5); // [DEFAULT: 30] // 2801: delete cookies and site data on exit - replaced by sanitizeOnShutdown* (2810) // 0=keep until they expire (default), 2=keep until you close Thunderbird // [-] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1681493,1681495,1681498,1759665 user_pref("network.cookie.lifetimePolicy", 2); // 6007: enforce Local Storage Next Generation (LSNG) [FF65+] // [-] https://bugzilla.mozilla.org/1764696 user_pref("dom.storage.next_gen", true); // [DEFAULT: true FF92+] // ***/ /* END: internal custom pref to test for syntax errors ***/ user_pref("_user.js.parrot", "SUCCESS: No no he's not dead, he's, he's restin'!");