Most Secure OS

[Dat Guy]

Just now, LinusSecurityTips said:

I can use any OS I want with Qubes (and hence any kernel).

So Qubes OS is not the most secure OS because it's not an OS. Do you even read your own postings?

[LinusSecurityTips]

7 minutes ago, Dat Guy said:

So Qubes OS is not the most secure OS because it's not an OS. Do you even read your own postings?

Qubes is an OS that operates other OSs inside it.

[Dat Guy]

Qubes is a hypervisor, not an operating system. It might be the most secure hypervisor indeed, but it still needs an operating system.

You're new to tech, right?

[LinusSecurityTips]

Just now, Dat Guy said:

Qubes is a hypervisor, not an operating system. It might be the most secure hypervisor indeed, but it still needs an operating system.

No, Qubes is an OS that uses Xen as a hypervisor (Xen is the hypervisor, not Qubes). It isn't itself a hypervisor and in the future they're working on making it support other different hypervisors from Xen.

[Dat Guy]

Hmm: https://www.qubes-os.org/doc/supported-versions/

 

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The table below shows the OS used for dom0 in each Qubes OS release.

Qubes OS Version	Dom0 OS
Release 1	Fedora 13
Release 2	Fedora 18
Release 3.0	Fedora 20
Release 3.1	Fedora 20
Release 3.2	Fedora 23

 

Qubes OS is Linux-based. Told you, more or less.

[LinusSecurityTips]

16 minutes ago, Dat Guy said:

Hmm: https://www.qubes-os.org/doc/supported-versions/

 

 

Qubes OS is Linux-based. Told you, more or less.

Did you at least read it? "The table below shows the OS used for dom0 in each Qubes OS release."

 

Also read their FAQ: https://www.qubes-os.org/doc/user-faq/#is-qubes-just-another-linux-distribution

[Dat Guy]

Do you even know what a dom0 is?

 

Qubes OS runs on Linux. Always. Without any exception. Says the FAQ, says the Documentation.

How exactly do you plan to run Qubes OS without Linux?

 

All guest systems run on DomU.

Did you at least read it?

[LinusSecurityTips]

5 minutes ago, Dat Guy said:

Do you even know what a dom0 is?

Yes.

5 minutes ago, Dat Guy said:

Qubes OS runs on Linux. Always. Without any exception. Says the FAQ, says the Documentation.

How exactly do you plan to run Qubes OS without Linux?

 

All guest systems run on DomU.

Did you at least read it?

I did not find anything that suggests that OS "run on dom0", dom0 is only the administrative interface that lets you control other domains, it doesn't have access to the network, and it is isolated from other domains thanks to Xen. OSs such as Windows that you install inside Qubes run on Xen (and not on Linux)

 

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The administrative domain, also referred to as Dom0 (a term inherited from Xen), has direct access to all the hardware by default. Dom0 hosts the GUI domain and controls the graphics device, as well as input devices, such as the keyboard and mouse. The GUI domain runs the X server, which displays the user desktop, and the window manager, which allows the user to start and stop the applications and manipulate their windows.

 

Because Dom0 is security-sensitive, it is isolated from the network. It tends to have as little interface and communication with other domains as possible in order to minimize the possibility of an attack originating from an infected virtual machine.

 

The Dom0 domain manages the virtual disks of the other VMs, which are actually stored as files on the dom0 filesystem(s). Disk space is saved by virtue of various virtual machines (VM) sharing the same root file system in a read-only mode. Separate disk storage is only used for userʼs directory and per-VM settings. This allows software installation and updates to be centralized. It is also possible to install software only on a specific VM, by installing it as the non-root user, or by installing it in the non-standard, Qubes-specific /rw hierarchy.

 

[Dat Guy]

5 minutes ago, LinusSecurityTips said:

dom0 is only the administrative interface that lets you control other domains,

 

So, basically, Qubes OS is Linux with a VM. Which is pretty much what I said on page 1, right?

[LinusSecurityTips]

2 minutes ago, Dat Guy said:

So, basically, Qubes OS is Linux with a VM. Which is pretty much what I said on page 1, right?

No, "Dom0 is only the administrative interface that lets you control other domains" does not mean that Qubes is "Linux with a VM". Please read their own FAQ on why Qubes is not a Linux distribution:

https://www.qubes-os.org/doc/user-faq/#is-qubes-just-another-linux-distribution

[Dat Guy]

OK, so here's the essential question for you who can obviously only read half of a website before posting here:

Which kernel does Qubes OS's hypervisor Xen run on?

 

Bonus points for a link to the kernel's source code, because it's, you know, Open Source and stuff.

[LinusSecurityTips]

2 minutes ago, Dat Guy said:

OK, so here's the essential question for you who can obviously only read half of a website before posting here:

Which kernel does Qubes OS's hypervisor Xen run on?

Xen itself uses a microkernel design (and not a monolithic kernel as other systems such as Linux). Read the wiki page on Xen: https://en.wikipedia.org/wiki/Xen

[Dat Guy]

Another website you stopped reading half-way down. Xen uses a microkernel design. Xen is not a microkernel. You can easily find that information on the very Wikipedia article page you have just linked.

 

Qubes OS has a kernel which consists of 3 files.

One of them is, according to Wikipedia, a statically linked executable file that contains the Linux kernel.

 

So, again, Qubes OS runs Xen on a Linux kernel.

Similarly to Android running a Java VM on a Linux kernel, if you understand it easier this way.

Most of the user stuff of Android runs on Java, most of the user stuff of Qubes OS runs on Xen.

It's still basically running on the Linux kernel.

 

That's why they have their own Linux kernel repository on GitHub by the way:

https://github.com/QubesOS/qubes-linux-kernel

 

The "Qubes Linux kernel".

edit: It happens to be a Fedora Linux kernel, by the way. Told you so...

 

I understand that you don't have much experience with tech, but could you please just stop arguing against the facts now?

[LinusSecurityTips]

20 minutes ago, Dat Guy said:

Another website you stopped reading half-way down. Xen uses a microkernel design. Xen is not a microkernel. You can easily find that information on the very Wikipedia article page you have just linked.

I think you're the one that only read half-way down

"Xen ... is a hypervisor using a microkernel design"
 

Quote

 

Qubes OS has a kernel which consists of 3 files.

One of them is, according to Wikipedia, a statically linked executable file that contains the Linux kernel.

As I said dom0 uses Linux (fedora), however the thing that runs virtual machines (Xen) does not run on dom0 (as you falsely suggest with your JavaVM on Android analogy).

 

Quote

That's why they have their own Linux kernel repository on GitHub by the way:

https://github.com/QubesOS/qubes-linux-kernel

That's the code for dom0 which uses Linux (fedora to be precise), what's your point?

Quote

I understand that you don't have much experience with tech, but could you please just stop arguing against the facts now?

How about I quote the person that founded Qubes OS?

 

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Second, all mainstream desktop OSes, such as Windows, Linux, BSD, even OSX, are all based on a monolithic kernels, which present a significant security problem. This is because a typical monolithic kernel of a contemporary desktop OS contains tens of millions of lines of code, and to make it worse, most of this code is reachable from (untrusted) applications via all sorts of APIs, making the attack surface on the kernel huge. And it requires just one successful kernel exploit to own the whole system, bypassing any security mechanisms that might have been built on top of it, such as SELinux, LXC, etc.

 

Additionally, all the various drivers, networking and USB stacks, are also hosted in the kernel, making attacks via buggy networking (e.g. via buggy 802.11 stacks or buggy firmware) or USB stacks a practical possibility. And there is essentially nothing one can do about it, when using an OS based on a monolithic kernel.

 

In Qubes, on the other hand, we use Xen hypervisor to provide security isolation between domains, and Xen is just a few hundred of thousands lines of code. It also doesn't need to provide all sorts of APIs to applications, because the Xen hypervisor is essentially only interested in CPU scheduling, memory management and power management, and very few things beyond that. Most notably, the Xen hypervisor knows nothing about networking, disk storage, filesystems, USB stacks, etc, as all those tasks are delegated to (often untrusted) service VMs.

 

https://theinvisiblethings.blogspot.com/2012/09/how-is-qubes-os-different-from.html

In short, Qubes is based on a microkernel (Xen) while other OSs are based on monolithic kernels (such as the Linux kernel).

[Dat Guy]

9 minutes ago, LinusSecurityTips said:

"Xen ... is a hypervisor using a microkernel design"

 

Yup.

 

It is a hypervisor running on a kernel.

The very kernel in their repository.

Which is a fucking Linux kernel.

 

Quote

however the thing that runs virtual machines (Xen) does not run on dom0

 

Xen is a hypervisor, not a kernel. There is exactly no way to start Xen without an underlying kernel.

Xen requires a kernel like Linux, XenServer's kernel or whatever to even do anything.

 

Reading only half the page, part 3. Could you finally stop that?

 

Quote

That's the code for dom0 which uses Linux (fedora to be precise), what's your point?

 

My point is that this code is the same code which runs Xen. Xen itself does not have any kernel code. (Go on and show me the particular source code to prove me wrong. I already pointed you to the general GitHub place. I'm already looking forward to your failing to do so.)

 

Quote

Qubes is based on a microkernel (Xen)

Xen is a hypervisor. Qubes is based on a hypervisor (Xen) running on an embedded Linux kernel.

 

Show me the Xen's "kernel" sources from the Qubes repository please. I'll happily agree that you're right if you can prove it. For now, all you do is repeatedly quoting the wrong parts of a page which proves you wrong.

 

I'm out here until you do. 

[LinusSecurityTips]

@datguy Interesting to note how you ignore these paragraphs from Qubes OS founder because they clearly disprove your assertion that Xen is not a microkernel

Quote

Second, all mainstream desktop OSes, such as Windows, Linux, BSD, even OSX, are all based on a monolithic kernels, which present a significant security problem. This is because a typical monolithic kernel of a contemporary desktop OS contains tens of millions of lines of code, and to make it worse, most of this code is reachable from (untrusted) applications via all sorts of APIs, making the attack surface on the kernel huge. And it requires just one successful kernel exploit to own the whole system, bypassing any security mechanisms that might have been built on top of it, such as SELinux, LXC, etc.

 

Additionally, all the various drivers, networking and USB stacks, are also hosted in the kernel, making attacks via buggy networking (e.g. via buggy 802.11 stacks or buggy firmware) or USB stacks a practical possibility. And there is essentially nothing one can do about it, when using an OS based on a monolithic kernel.

 

In Qubes, on the other hand, we use Xen hypervisor to provide security isolation between domains, and Xen is just a few hundred of thousands lines of code. It also doesn't need to provide all sorts of APIs to applications, because the Xen hypervisor is essentially only interested in CPU scheduling, memory management and power management, and very few things beyond that. Most notably, the Xen hypervisor knows nothing about networking, disk storage, filesystems, USB stacks, etc, as all those tasks are delegated to (often untrusted) service VMs.

 

https://theinvisiblethings.blogspot.com/2012/09/how-is-qubes-os-different-from.html

:

 

 

[LinusSecurityTips]

22 minutes ago, Dat Guy said:

 

Yup.

 

It is a hypervisor running on a kernel.

By your own logic the Linux kernel is a microkernel (as the Wikipedia page says "Xen ... is a hypervisor using a microkernel design") but it's not! Linux is a monolithic kernel, and not a microkernel. It's mind blowing that you can't understand this simple fact.

[Dat Guy]

Still no link to Xen's kernel code, only a lot of phrases.

Nobody said Xen was a microkernel. It's a hypervisor, just like "the founder" said.

 

If you would just read what he said.

 

 

A hypervisor - even one "with a microkernel design" for its virtual domains - needs a kernel to run on.

Still waiting for the boot code Xen would need if it wouldn't run on a different kernel (like Linux). Where is the link?

 

Please no more quotes answering an entirely different question.

I never doubted Xen was a hypervisor. You can stop bringing quotes which say it is.

 

Bring me a link to the kernel code instead. Or admit that you don't have a clue.

[Dat Guy]

6 minutes ago, LinusSecurityTips said:

(as the Wikipedia page says "Xen ... is a hypervisor using a microkernel design")

 

Yup.

 

Qubes OS runs in an isolated "sandbox" on top of a Xen "microkernel"-like virtual domain.

Which runs on top of... a kernel. Now which one?

 

1) Linux.

2) Not Linux. In this case: Bring me the code.

 

Still waiting.

[LinusSecurityTips]

1 minute ago, Dat Guy said:

Still no link to Xen's kernel code, only a lot of phrases.

https://github.com/QubesOS/qubes-builder-github

https://github.com/search?utf8=✓&q=org%3AQubesOS+xen&type=

1 minute ago, Dat Guy said:

Nobody said Xen was a microkernel. It's a hypervisor.

But you said that Xen runs on a microkernel, and that for Qubes it runs on Linux, which is nonsense since Linux is a monolithic kernel and not a microkernel.

 

[Dat Guy]

24 minutes ago, LinusSecurityTips said:

Interesting to note how you ignore these paragraphs from Qubes OS founder because they clearly disprove your assertion that Xen is not a microkernel

You are the one who ignores "these holy paragraphs".

 

Xen virtualizes (and isolates) the userland. Just like the Java VM does on Android.

Still running Linux.

[Dat Guy]

1 minute ago, LinusSecurityTips said:

https://github.com/QubesOS/qubes-builder-github

Oh, dear...

 

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This is Qubes builder plugin which reports to github issues when package containing a fix is uploaded to the repository. 

 

Have you even tried? 

Still waiting for the "Xen kernel code" which is "not Linux".

[LinusSecurityTips]

2 minutes ago, Dat Guy said:

 

Yup.

 

Qubes OS runs in an isolated "sandbox" on top of a Xen "microkernel"-like virtual domain.

Which runs on top of... a kernel. Now which one?

 

1) Linux.

2) Not Linux. In this case: Bring me the code.

 

Still waiting.

No, you claimed that Xen runs on top of a Linus microkernel (Here's what you said: "Qubes OS runs Xen on a Linux kernel.") You already agreed that Xen is based on a microkernel design, are you now going to claim that Linux is a microkernel?

[LinusSecurityTips]

2 minutes ago, Dat Guy said:

Oh, dear...

 

 

Have you even tried? 

Still waiting for the "Xen kernel code" which is "not Linux".

My error, wanted to mention the qubes-builder that compiles and creates the Qubes ISO

https://github.com/QubesOS/qubes-builder

[Dat Guy]

Just now, LinusSecurityTips said:

No, you claimed that Xen runs on top of a Linus microkernel

 

There is no Linux microkernel.

 

Just now, LinusSecurityTips said:

(Here's what you said: "Qubes OS runs Xen on a Linux kernel.")

 

Which is true.

 

Just now, LinusSecurityTips said:

You already agreed that Xen is based on a microkernel design, are you now going to claim that Linux is a microkernel?

 

I never did that.

 

Still waiting for your proof which kernel that Xen runs on. Xen is not a kernel.

Show me the Xen "kernel" source please. There is only a Xen hypervisor code available.

 

Which DOES NOT RUN without an underlying kernel.

 

Which is Linux, on Qubes OS.