Tor Browser 4.5 is released

The Tor Browser Team is proud to announce the first stable release in the 4.5 series. This release is available from the Tor Browser Project page and also from our distribution directory.

The 4.5 series provides significant usability, security, and privacy enhancements over the 4.0 series. Because these changes are significant, we will be delaying the automatic update of 4.0 users to the 4.5 series for one week.

Usability Improvements


On the usability front, we've improved the application launch experience for both Windows and Linux users. During install, Windows users are now given the choice to add Tor Browser to the Start Menu/Applications view, which should make it easier to find and launch. This choice is on by default, but can be disabled, and only affects the creation of shortcuts - the actual Tor Browser is still self-contained as a portable app folder. On the Linux side, users now start Tor Browser through a new wrapper that enables launching from the File Manager, the Desktop, or the Applications menu. The same wrapper can also be used from the command line.

We've also simplified the Tor menu (the green onion) and the associated configuration windows. The menu now provides information about the current Tor Circuit in use for a page, and also provides an option to request a new Tor Circuit for a site. Tor Browser is also much better at handling Tor Circuits in general: while a site remains in active use, all associated requests will continue to be performed over the same Tor Circuit. This means that sites should no longer suddenly change languages, behaviors, or log you out while you are using them.


Figure 1: The new Tor Onion Menu


Security Improvements


On the security front, the most exciting news is the new Security Slider. The Security Slider provides user-friendly vulnerability surface reduction - as the security level is increased, browser features that were shown to have a high historical vulnerability count in the iSec Partners hardening study are progressively disabled. This feature is available from the Tor onion menu's "Privacy and Security Settings" choice.


Figure 2: The new Security Slider

Our Windows packages are now signed with a hardware signing token graciously donated by DigiCert. This means that Windows users should no longer be prompted about Tor Browser coming from an unknown source. Additionally, our automatic updates are now individually signed with an offline signing key. In both cases, these signatures can be reproducibly removed, so that builders can continue to verify that the packages they produce match the official build binaries.

The 4.5 series also features a rewrite of the obfs2, obfs3, and ScrambleSuit transports in GoLang, as well as the introduction of the new obfs4 transport. The obfs4 transport provides additional DPI and probing resistance features which prevent automated scanning for Tor bridges. As long as they are not discovered via other mechanisms, fresh obfs4 bridge addresses will work in China today. Additionally, barring new attacks, private obfs4 addresses should continue to work indefinitely.


Privacy Improvements


On the privacy front, the 4.5 series improves on our pre-existing first party isolation implementation to prevent third party tracking. First party isolation provides the property that third party advertisements, like buttons, and "mashup" content that is included on one site will only know about your activity on that site, and will not be able to match it to your activity while you are on any other site. In other words, with first party isolation, Facebook, Twitter, and Google+ can't track you around the entire web using their infamous like buttons.

Specifically, in the 4.5 release, we now ensure that blob: URIs are scoped to the URL bar domain that created them, and the SharedWorker API has been disabled to prevent cross-site and third party communication. We also now make full use of Tor's circuit isolation to ensure that all requests for any third party content included by a site travel down the same Tor Circuit. This isolation also ensures that requests to the same third party site actually use separate Tor Circuits when the URL bar domain is different. This request isolation is enforced even when long-lived "HTTP Keep-Alive" connections are used.

We have also improved our resolution and locale fingerprinting defenses, and we now disable the device sensor and video statistics APIs.

New Search Provider


Our default search provider has also been changed to Disconnect. Disconnect provides private Google search results to Tor users without Captchas or bans.

Full Changelogs


Here is the complete list of changes in the 4.5 series since 4.0:

  • All Platforms
    • Update Tor to 0.2.6.7 with additional patches:
      • Bug 15482: Reset timestamp_dirty each time a SOCKSAuth circuit is used
    • Update NoScript to 2.6.9.22
    • Update HTTPS-Everywhere to 5.0.3
      • Bug 15689: Resume building HTTPS-Everywhere from git tags
    • Update meek to 0.17
    • Include obfs4proxy 0.0.5
      • Use obfs4proxy for obfs2, obfs3, obfs4, and ScrambleSuit bridges
    • Pluggable Transport Dependency Updates:
      • Bug 15265: Switch go.net repo to golang.org/x/net
      • Bug 15448: Use golang 1.4.2 for meek and obs4proxy
    • Update Tor Launcher to 0.2.7.4. Changes since 0.2.7.0.2 in 4.0.8:
      • Bug 11879: Stop bootstrap if Cancel or Open Settings is clicked
      • Bug 13271: Display Bridge Configuration wizard pane before Proxy pane
      • Bug 13576: Don't strip "bridge" from the middle of bridge lines
      • Bug 13983: Directory search path fix for Tor Messanger+TorBirdy
      • Bug 14122: Hide logo if TOR_HIDE_BROWSER_LOGO set
      • Bug 14336: Fix navigation button display issues on some wizard panes
      • Bug 15657: Display the host:port of any connection faiures in bootstrap
      • Bug 15704: Do not enable network if wizard is opened
    • Update Torbutton to 1.9.2.2. Changes since 1.7.0.2 in 4.0.8:
      • Bug 3455: Use SOCKS user+pass to isolate all requests from the same url domain
      • Bug 5698: Use "Tor Browser" branding in "About Tor Browser" dialog
      • Bug 7255: Warn users about maximizing windows
      • Bug 8400: Prompt for restart if disk records are enabled/disabled.
      • Bug 8641: Create browser UI to indicate current tab's Tor circuit IPs
        • (Many Circuit UI issues were fixed during 4.5; see release changelogs for those).
        • Bug 13651: Prevent circuit-status related UI hang.
        • Bug 13666: Various circuit status UI fixes
        • Bug 13671: Make bridges visible on circuit display
        • Bug 13672: Make circuit display optional
        • Bug 13881: Localize strings for tor circuit display
        • Bug 13882: Fix display of bridges after bridge settings have been changed
        • Bugs 13891+15207: Fix exceptions/errors in circuit display with bridges
        • Bug 14324: Show HS circuit in Tor circuit display
        • Bug 14866: Show correct circuit when more than one exists for a given domain
        • Bug 14937: Show meek and flashproxy bridges in tor circuit display
        • Bug 15086: Handle RTL text in Tor circuit display
        • Bug 15472: Make node text black in circuit status UI
        • Bug 15510: Close Tor Circuit UI control port connections on New Identity

        -->

    • Bug 9387: Security Slider 1.0
      • Include descriptions and tooltip hints for security levels
      • Notify users that the security slider exists
      • Make use of new SVG, jar, and MathML prefs
    • Bug 9442: Add New Circuit button to Torbutton menu
    • Bug 9906: Warn users before closing all windows and performing new identity.
    • Bug 10216: Add a pref to disable the local tor control port test
    • Bug 10280: Strings and pref for preventing plugin initialization.
    • Bug 11175: Remove "About Torbutton" from onion menu.
    • Bug 11236: Don't set omnibox order in Torbutton (to prevent translation)
    • Bug 11449: Fix new identity error if NoScript is not enabled
    • Bug 13019: Change locale spoofing pref to boolean
    • Bug 13079: Option to skip control port verification
    • Bug 13406: Stop directing users to download-easy.html.en on update
    • Bug 13650: Clip initial window height to 1000px
    • Bugs 13751+13900: Remove SafeCache cache isolation code in favor of C++ patch
    • Bug 13766: Set a 10 minute circuit lifespan for non-content requests
    • Bug 13835: Option to change default Tor Browser homepage
    • Bug 13998: Handle changes in NoScript 2.6.9.8+
    • Bug 14100: Option to hide NetworkSettings menuitem
    • Bug 14392: Don't steal input focus in about:tor search box
    • Bug 14429: Provide automatic window resizing, but disable for now
    • Bug 14448: Restore Torbutton menu operation on non-English localizations
    • Bug 14490: Use Disconnect search in about:tor search box
    • Bug 14630: Hide Torbutton's proxy settings tab.
    • Bug 14631: Improve profile access error msgs (strings for translation).
    • Bugs 14632+15334: Display Cookie Protections only if disk records are enabled
    • Bug 15085: Fix about:tor RTL text alignment problems
    • Bug 15460: Ensure FTP urls use content-window circuit isolation
    • Bug 15502: Wipe blob: URIs on New Identity
    • Bug 15533: Restore default security level when restoring defaults
    • Bug 15562: Bind SharedWorkers to thirdparty pref
  • Bug 3455: Patch Firefox SOCKS and proxy filters to allow user+pass isolation
  • Bug 4100: Raise HTTP Keep-Alive back to 115 second default
  • Bug 5698: Fix branding in "About Torbrowser" window
  • Bug 10280: Don't load any plugins into the address space by default
  • Bug 11236: Fix omnibox order for non-English builds
    • Also remove Amazon, eBay and bing; add Youtube and Twitter
  • Bug 11955: Backport HTTPS Certificate Pinning patches from Firefox 32
  • Bug 12430: Provide a preference to disable remote jar: urls
  • Bugs 12827+15794: Create preference to disable SVG images (for security slider)
  • Bug 13019: Prevent Javascript from leaking system locale
  • Bug 13379: Sign our MAR update files
  • Bug 13439: No canvas prompt for content callers
  • Bug 13548: Create preference to disable MathML (for security slider)
  • Bug 13586: Make meek use TLS session tickets (to look like stock Firefox).
  • Bug 13684: Backport Mozilla bug #1066190 (pinning issue fixed in Firefox 33)
  • Bug 13788: Fix broken meek in 4.5-alpha series
  • Bug 13875: Spoof window.devicePixelRatio to avoid DPI fingerprinting
  • Bug 13900: Remove 3rd party HTTP auth tokens via Firefox patch
  • Bug 14392: Make about:tor hide itself from the URL bar
  • Bug 14490: Make Disconnect the default omnibox search engine
  • Bug 14631: Improve startup error messages for filesystem permissions issues
  • Bugs 14716+13254: Fix issues with HTTP Auth usage and TLS connection info display
  • Bug 14937: Hard-code meek and flashproxy node fingerprints
  • Bug 15029: Don't prompt to include missing plugins
  • Bug 15406: Only include addons in incremental updates if they actually update
  • Bug 15411: Remove old (and unused) cacheDomain cache isolation mechanism
  • Bug 15502: Isolate blob: URI scope to URL domain; block WebWorker access
  • Bug 15562: Disable Javascript SharedWorkers due to third party tracking
  • Bug 15757: Disable Mozilla video statistics API extensions
  • Bug 15758: Disable Device Sensor APIs

  • Linux

    • Bug 12468: Only print/write log messages if launched with --debug
    • Bug 13375: Create a hybrid GUI/desktop/shell launcher wrapper
    • Bug 13717: Make sure we use the bash shell on Linux
    • Bug 15672: Provide desktop app registration+unregistration for Linux
    • Bug 15747: Improve start-tor-browser argument handling

  • Windows

    • Bug 3861: Begin signing Tor Browser for Windows the Windows way
    • Bug 10761: Fix instances of shutdown crashes
    • Bug 13169: Don't use /dev/random on Windows for SSP
    • Bug 14688: Create shortcuts to desktop and start menu by default (optional)
    • Bug 15201: Disable 'runas Administrator' codepaths in updater
    • Bug 15539: Make installer exe signatures reproducibly removable

  • Mac

    • Bug 10138: Switch to 64bit builds for MacOS

    Here is the list of changes since the last 4.5 alpha (4.5a5):

    • All Platforms
      • Update Tor to 0.2.6.7 with additional patches:
        • Bug 15482: Reset timestamp_dirty each time a SOCKSAuth circuit is used
      • Update NoScript to 2.6.9.22
      • Update HTTPS-Everywhere to 5.0.3
        • Bug 15689: Resume building HTTPS-Everywhere from git tags
      • Update meek to 0.17
      • Update obfs4proxy to 0.0.5
      • Update Tor Launcher to 0.2.7.4
        • Bug 15704: Do not enable network if wizard is opened
        • Bug 11879: Stop bootstrap if Cancel or Open Settings is clicked
        • Bug 13576: Don't strip "bridge" from the middle of bridge lines
        • Bug 15657: Display the host:port of any connection faiures in bootstrap
      • Update Torbutton to 1.9.2.2
        • Bug 15562: Bind SharedWorkers to thirdparty pref
        • Bug 15533: Restore default security level when restoring defaults
        • Bug 15510: Close Tor Circuit UI control port connections on New Identity
        • Bug 15472: Make node text black in circuit status UI
        • Bug 15502: Wipe blob URIs on New Identity
        • Bug 15795: Some security slider prefs do not trigger custom checkbox
        • Bug 14429: Disable automatic window resizing for now
      • Bug 4100: Raise HTTP Keep-Alive back to 115 second default
      • Bug 13875: Spoof window.devicePixelRatio to avoid DPI fingerprinting
      • Bug 15411: Remove old (and unused) cacheDomain cache isolation mechanism
      • Bugs 14716+13254: Fix issues with HTTP Auth usage and TLS connection info display
      • Bug 15502: Isolate blob URI scope to URL domain; block WebWorker access
      • Bug 15794: Crash on some pages with SVG images if SVG is disabled
      • Bug 15562: Disable Javascript SharedWorkers due to third party tracking
      • Bug 15757: Disable Mozilla video statistics API extensions
      • Bug 15758: Disable Device Sensor APIs
    • Linux
      • Bug 15747: Improve start-tor-browser argument handling
      • Bug 15672: Provide desktop app registration+unregistration for Linux
    • Windows
      • Bug 15539: Make installer exe signatures reproducibly removable
      • Bug 10761: Fix instances of shutdown crashes

    Post update 4/28/2015: Provide screenshots of the Tor Onion menu and Security Slider.
    Post update 4/28/2015: Add section headers.

  • Excuse me, encryption is the only thing that Tor always have been doing really well.

    Encryption have for some time now been a well understood technology, and the thing easiest to get right and secure in an anonymity solution. Even today when Tor have improved a lot in other areas which they used to ignore during the pre-TBB time, I feel confident that encryption is still the hardest thing to break in Tor.

    Anonymous

    April 29, 2015

    Permalink

    Have been getting a Click jacking warning when trying to complete a captcha on a file host.

    Happens when trying to enter the text and again when trying to copy / paste the jumbled text from one box to another.

    Never got such a warning in previous versions

    For example: set highest security level or forbid Javascript globally in the NoScript settings, then load a Cloudflare-protected page like

    https://support.cloudflare.com/hc/en-us/articles/203306930-Does-CloudFl…

    When you start typing the captcha, you'll get a ClearClick alert from NoScript and have to unlock the input field to complete the captcha.

    BTW: If Javascript is allowed, Cloudflare generates a simpler captcha that doesn't trigger a ClearClick alert.

    Question is Why ?
    Is it a bug ?
    Is it just a false positive ?
    And what's changed in NoScript since previous version where I never saw any clear click warning on anything I clicked.

    Yes, it happens to me too. As you say, this didn't happen on any previous versions.

    Does gk have an idea why it is happening now, and how to solve this 'problem'.

    Thanks

    Yes, this happens to me too.

    It's a bit inconvenient.

    Does anyone know why it is happening now - 4.0.8 was fine.

    Any ideas how to solve the problem?

    Anonymous

    April 29, 2015

    Permalink

    "...menu now provides information about the current Tor Circuit in use for a page, and also..."

    Fantastic. First step in the right direction like Vidalia -with all features- was.

    And in TAILS this is a PROBLEM cause of integration in browser??

    I haven't seen the new 4.5.
    Is info about Crypto algorithm and Media Info
    reintegrated or is there something special not?

    Anonymous

    April 29, 2015

    Permalink

    Thanks for your efforts. In theory, Tor Browser 4.5 is a very great browser. But I have some issues plaguing me.

    All provided Bridges Functions didn't work after upgrading to 4.5.
    flashproxy, fte, fte-ipv6, meek-amazon, meek-azure, obfs3, obfs4, scramblesuit.....all died.

    I saw the Pluggable Transports working through my system monitor, but all shut down automatically within a few seconds.

    Now I have to enter my custom bridges manually.

    Another issue, the tor onion menu sometimes displayed but sometimes not displayed.

    I have tried it in both of my two computers (WinXP & Win7), but same outcome.

    I am not a new user to Tor Browser. But I don't know how to solve these issues. Anyone can help? Thanks!

    Oh, my god. People who are living in heaven will never understand hell. I'm living in the region occupied by an evil red regime. All universal values are invalid here. We don't have a normal internet but a very very fu*king big and powerful intranet. So, Tor and Bridges to Tor, and or meek are very important for me. Please optimize the Bridges Function. Thank you very much.

    ???

    I was commenting that obs4 isn't broken, which is what the original message seemed to suggest.

    How about you tone down the drama a bit?

    I'm so sorry. Perhaps, we have misunderstanding with each other's words.
    I meant that maybe the bridges function (especially meek) in new version 4.5 was being blocked by the GFW.
    I am very helpless. I need technical supports to solve this issue.
    Thanks!

    I assume you were referring to the sha256sum of torbrowser-install-4.5_en-US.exe?

    If you're using the Windows version of Tor Browser 4.5, may I suggest that you also use gpg4win to verify the signature of that software.

    This is what I did after reading your above post:

    Using gpg4win, I verified that Tor Browser 4.5 (Windows platform) had not been tampered with.

    However my computation of the sha256sum of torbrowser-install-4.5_en-US.exe is a3219f359bf3f04056a1c8796d103d1bc2e0bd24f181538f70564b3d19532c3a

    which is different from the one published in https://dist.torproject.org/torbrowser/4.5/sha256sums.txt

    Perhaps mikeperry, arma or erinn would like to explain the discrepancy?

    Windows bundles are signed now using the authenticode method to avoid scary warnings if you try to run the installer after downloading it (or in some cases to be able to run the installer at all). This signing happens after the build and thus changes the SHA256 sum. In order to use the advanced verification method outlined on https://www.torproject.org/docs/verifying-signatures.html.en you have to strip that signature off first. One tool mentioned there doing this is osslsigncode. There might be other tools which are easier to use for Windows users though.

    Anonymous

    April 29, 2015

    Permalink

    "Update Tor to 0.2.6.7 with additional patches: "

    Does this mean Tor 0.2.6.7 is now stable and can be compiled from source and used?

    Another thing.. Don't you think that the default search engine for Tor Browser should be DuckDuckGo over its Hidden service? This makes more sense than Startpage.

    In terms of search results, Disconnect is far better than DuckDuckGo, as it uses Google, while DuckDuckGo does not. I for one am really happy with Disconnect, so much so I made it the default search engine for my non-Tor Browsers like Chrome and Firefox.

    It makes no sense (to me) to use a search engine simply because it has a hidden service, if the search results are poor.

    DDG search results are quite good, often better than those from Startpage. What surprised me is that a direct search at Google sometimes gave me results than I did not get by searching over Startpage.

    Anonymous

    April 29, 2015

    Permalink

    On Windows, the privacy and security settings screen doesn't show any description for the current security level unless I change it

    I guess what happens is that you don't use the security slider to disable JavaScript (i.e. set its mode to "high"). In this case you are using the slider's custom mode (the "Custom Values" checkbox should be checked now) which results in no descriptions.

    Tor Browser > Edit > Preferences > Advanced > Network > No proxy

    1. extensions.torbutton.saved.transparentTor true<br />
    2. extensions.torbutton.settings_method transparent<br />
    3. network.proxy.socks_remote_dns false

    (export TOR_SKIP_LAUNCH=1; <i>path-to-tor-browser-dir</i>/Browser/start-tor-browser --verbose)

    Anonymous

    April 29, 2015

    Permalink

    On April 21st, 2015 Anonymous said:

    When I drag text from Kwrite, if the character is Chinese, to the text field of Tbb 4.5a5, the copy one is going to be an unrecognized symbol.

    Plus, dragging Chinese text from Knotes to both Tbb 4.5a and 4.08 is also effected.

    reply

    Anonymous

    April 29, 2015

    Permalink

    I am currently using TBB 4.0.8; and usually, i have been noticed about a new update.
    However, TBB has not shown an notification about the 4.5 update. Is this normal?

    Anonymous

    April 29, 2015

    Permalink

    re attack surface area
    why not have a means to disable frames? 90% of the time they merely exist to let me know how many likes (and let facebook know that i've been there and elsewhere)

    Anonymous

    April 29, 2015

    Permalink

    Fedora 20, downloaded using 'torbrowser-launcher', it fails with "SIGNATURE VERIFICATION FAILED!", and on the command line:
    gpg: Signature made Tue 31 Mar 2015 10:35:12 AM EDT using RSA key ID D40814E0
    gpg: Can't check signature: public key not found

    I have no idea why it is downloading the 4.5a5 version today when you say above in the blog post that you are not releasing 4.5 to public consumption in this week. I try to get and verify the file myself (after importing the correct key manually to my keyring using your instructions at www.torproject.org/docs/verifying-signatures.html.en):

    gpg --verify sha256sums.txt.asc tor-browser-linux64-4.5a5_en-US.tar.xz
    gpg: Signature made Tue 31 Mar 2015 10:35:12 AM EDT using RSA key ID D40814E0
    gpg: BAD signature from "Tor Browser Developers (signing key) "

    "BAD signature"? I got this all three times I tried cleaning and re-downloading, even with another user on the system.

    Anonymous

    April 29, 2015

    Permalink

    Minor bug on the resizing feature, on Windows, right after starting Tor Browser or clicking new identity and before it is fully loaded and resized if I minimize the window by clicking the tray bar icon, the window disappears and doesn't come back again

    Anonymous

    April 29, 2015

    Permalink

    I notice that while using tor 4.5 and opening a normal browser the normal browser sometimes lost internet connection.

    Anonymous

    April 30, 2015

    Permalink

    Great Update. But i have an issue. The download window doesn't get updated anymore. Downloads appear but the download rate and the transferred amount isn't updated every few msec. Only pressing F5 updates the window.

    When i move the button for the download window to the toolbar it doesn't work in this version.

    I am on Windows 7.