[HOME] [DOWNLOAD] [DOCS] [NEWS] [SUPPORT] [TIPS] [ISSUES] [DONATE]

Whonix live mode / amnesia / amnesic / non-persistent / anti-forensics

After else you’re using only <click> but not <txtclick>? Is this on purpose? Because for the other conditions you’re using both.

Just now added. Seems so logical. Let me know if this was wrong.

Do you know how to add the shared folder path as one of Thunar’s fav destinations (along with home, desktop and so on)?

@Patrick

In persistent mode there is no text to click so it won’t do much but it won’t hurt either.

@HulaHoop

Either drag and drop it to “places”. Or right click on the folder and send it to the side pane.

2 Likes
1 Like

Please critically review: https://www.whonix.org/wiki/Grub-live#Forensics_Comparison

Could you test please for anti-forensics as per https://www.whonix.org/wiki/FAQ#Anti-forensic_Claims?

Tails documentation comments that swap may be the biggest threat to anti-forensics on Linux when running in a VM:

https://tails.boum.org/doc/advanced_topics/virtualization/index.en.html#security


Choices for dealing with swap:

Linux does use swapping despite having apparent “free” memory. The kernel tends to swap out long-inactive and memory -consuming processes. This frees up RAM for caches, thus improves responsiveness.

vm.swappiness = 0 does not completely prevent swapping.

Turning off for the whole system is not recommended because hitting the hard limit might cause a system crash. However it may be worth it for some usecases. It can be done by running sudo swapoff -a and rebooting.

An alternative libvirt only solution is to set guest memory pages to being locked:

https://libvirt.org/formatdomain.html#elementsMemoryBacking

<memoryBacking><locked/></memoryBacking>

When set and supported by the hypervisor, memory pages belonging to the domain will be locked in host’s memory and the host will not be allowed to swap them out, which might be required for some workloads such as real-time. For QEMU/KVM guests, the memory used by the QEMU process itself will be locked too: unlike guest memory, this is an amount libvirt has no way of figuring out in advance, so it has to remove the limit on locked memory altogether. Thus, enabling this option opens up to a potential security risk: the host will be unable to reclaim the locked memory back from the guest when it’s running out of memory, which means a malicious guest allocating large amounts of locked memory could cause a denial-of-service attack on the host. Because of this, using this option is discouraged unless your workload demands it; even then, it’s highly recommended to set a hard_limit (see memory tuning) on memory allocation suitable for the specific environment at the same time to mitigate the risks described above.

Which of these techniques should be recommended on the wiki?


Offtopic:

Should we recommend users run the live package on the GW too? I imagine there shouldn’t be any practical dangers after a guard node is set. However things like cached DNS requests or whatever else should be gone safely.

1 Like

Where does ^ researched info go on the wiki? Let’s decide on that after you agree on what the best solution is.

1 Like

Quote https://tails.boum.org/contribute/design/

Host system disks and partitions

Tails takes care not to use any filesystem that might exist on the host machine hard drive, unless explicitly told to do so by the user. The Debian Live persistence feature is disabled by passing nopersistence over the kernel command line to live-boot.

Added to https://www.whonix.org/wiki/Grub-live#Comparison

Should we also set kernel parameter nopersistence? It’s a live-boot feature, not a linux kernel or grub feature. grub-live depends on liveboot too but I don’t know if it makes a different for grub-live.

I think that setting is non-persistent, i.e. lost after reboot. Affects current session only.

Disabling swap permanently may involve changing some config file, perhaps /etc/fstab, might require a systemd unit file drop-in.

In case of grub-live on the host: Host operating system specific.

Also sudo apt-get purge swap-file-creator (if someone installed it or still having it installed after [multiple] release upgrade).

Don’t know yet.

grub-live on host: When we use grub-live currently - is swap even in use or not?

Whonix with grub-live: Is there even a swap partition or swap file by default in Non-Qubes-Whonix 15?

Possible internet service provider fingerprinting risk for such users:
Depends on how Tor guard changing process works. Tor might connect with old entry guard (supposed to be changed) since its previous change was not stored on the disk. Depends how that is implemented and if there are any bugs.

  • Tor starts -> notices any entry guard change is due -> changes entry guard -> connects: great
  • Tor starts -> connects with old entry guard (bug) -> notices any entry guard change is due -> changes entry guard -> connects: fingerprintable

Internet service provider fingerprinting for such users:
Tor consensus (since non-persistent) gets downloaded different (more often on reboot) compared to users who use persistence.

Related:
https://tails.boum.org/blueprint/persistent_Tor_state/

^ in our case it wouldn’t be “completely non-persistent” but still different (caching an old version and then redownloading each time booted in live mode).

Related:
https://www.whonix.org/wiki/Comparison_with_Others#Fingerprint

Tails disables removable drives auto-mounting.

Quote https://tails.boum.org/contribute/design/

Removable drives auto-mounting is disabled in Tails 0.7 and newer.

https://git-tails.immerda.ch/tails/plain/config/chroot_local-includes/etc/dconf/db/local.d/00_Tails_defaults

https://git-tails.immerda.ch/tails/plain/config/chroot_local-includes/etc/dconf/db/local.d/00_Tails_defaults contains config for GNOME only, which is OK in context of Tails since Tails’ default desktop is GNOME and others are unsupported.

Added to https://www.whonix.org/wiki/Grub-live#Comparison

I wonder if grub-live should implement disables removable drives auto-mounting too? Either:

  • By default, if grub-live is installed: might be easy to implement, though XFCE only. Supporting this for all kinds of host desktop environments and package selections might be difficult.
  • Same as above, but only when using live boot option in grub boot menu: might be more difficult to implement. (Some code, if live boot, drop disable auto mount config snippet; if persistent boot, delete auto mount config snippet.)

I am looking at Tails design document and trying to figure out what Tails does in order to implement amnesia / non-persistence / anti-forensics so these features can be implemented in grub-live (or where appropriate) too.

This is what I found:


  1. Debian live based

  1. Host system disks and partitions

Tails takes care not to use any filesystem that might exist on the host machine hard drive, unless explicitly told to do so by the user. The Debian Live persistence feature is disabled by passing nopersistence over the kernel command line to live-boot.


  1. Filesystems stored on removable devices

Removable drives auto-mounting is disabled in Tails 0.7 and newer.


4): wiperam

Host system RAM

In order to protect against memory recovery such as cold boot attack, most of the system RAM is overwritten when Tails is being shutdown or when the boot medium is physically removed. Also, memory allocated to processes is erased upon process termination.

(related: Is RAM Wipe possible inside Whonix?)


  1. swap

Host system swap

Tails takes care not to use any swap filesystem that might exist on the host machine hard drive. Most of this is done at build time: the /sbin/swapon binary is replaced by a fake no-op script, and live-boot’s swapon option is not set.


Did I miss any Tails amnesia features?

Could anyone please double check https://tails.boum.org/contribute/design/ and/or research further on how Tails implements non-persistence?

More likely than not cannot hurt until we have a good reason to remove it.

Indeed. My solution was to include it in rc.local instead of messing with the fstab, but that’s just a simple hackish workaround not something suitable for a Whonix Host. Though for someone wanting to run a Whonix live VM it is doable and necessary to be certain no traces are left.

Haven’t tried it, does it disable swap when running?

What concerns me at the moment is running on a default Linux host that is non-live to be as safe as possible for a Whonix-live VM.

Nothing turns up under cat /proc/swaps

You’re right such risks exist. It is already the case for people following the 1Guard/App advice anyhow or those who use snapshots to avoid storing state between different WS VM trust levels. However I think the good still exceeds the fingerprinting disadvantages. Int that case - leaking destinations/DNS caced info about visited locations which could be just as bad as storing the state of the site/webpages itself on the disk in the WS.

1 Like

Seems necessary to prevent accidental use of host file systems when booted from a stick.


Done for security against malicious device rather than for anti-forensics

2.7.3 Mounting of filesystems stored on removable devices

Some attacks recently put under the spotlights exploit vulnerabilities in the desktop software stack that triggers automatic mounting, display and files preview of filesystems stored on removable devices.

Looks like you got them all.

Two features unrelated to live system that seem interesting and worth looking into:

2.6.3.7 “Virtual” input system

2.7.2 (Disabling) HTTP keepalive

1 Like

New section added using yesterday’s info:

1 Like

I don’t think it’s a good solution at all. First during boot swap file get used and then at a non-guaranteed time, swap will be disabled. By that time, encryption keys could have already leaked into it.

Yet to be checked.

Then we need to point out these fingerprinting disadvantages and let users decide.

Perhaps the perfect use (accepting fingerprinting disadvantages) would be: shut down all Whonix-Workstations, boot Whonix-Gateway into persistent mode (let Tor do its thing, update Tor state files (entry guards, Tor consensus) and then reboot Whonix-Gateway into live mode. Only then start Whonix-Workstations. To be repeated how often?

New section added using yesterday’s info:

Partially doesn’t belong there.