Update security.md with regards to MUL22-02 (and MUL22-04)

[pinkisemils]

Due to recent changes to the daemon to prevent early and late boot leaks, the security docs need to be updated to reflect the new behavior.

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This change is 

[faern]

Reviewable status: 0 of 1 files reviewed, 5 unresolved discussions (waiting on @pinkisemils)

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docs/security.md line 275 at r1 (raw file):
"it will maintain the blocking policy if the currently applied policy is blocking" tells me very little, or is very confusing.

I think we can rewrite this entire paragraph to be clearer. Let's start by swapping the order of the first sentence.

The service will transition to the [disconnected] state before exiting. To limit leaks during computer shutdown it will maintain the blocking firewall rules upon exit if auto-connect or "Always require VPN" is enabled, or if the service expect that it's being killed due to a computer shutdown.

Or something like that.

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docs/security.md line 276 at r1 (raw file):

[disconnected] state before exiting, but it will maintain the blocking policy if
the currently applied policy is blocking or if the daemon should auto-connect on
startup, unless it can detect that the shutdown was initiated by the user. If

I don't think we should use the word shutdown too much. It's too easy to confuse between daemon shutdown and computer shutdown. When we talk about the service being terminated I think we should avoid the term "shutdown" for this reason.

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docs/security.md line 289 at r1 (raw file):

enforce the blocking policy before being stopped.

### Linux

Nit. But empty line after header please 🙏

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docs/security.md line 290 at r1 (raw file):

### Linux
Due to the dependence on various other services, the system service is not

Maybe replace "the system service" with "mullvad-daemon" to make it clear what is what, since the paragraph talks about two different system services.

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docs/security.md line 291 at r1 (raw file):

### Linux
Due to the dependence on various other services, the system service is not
started early enough to prevent leaks. To aid this, another system unit is

"To aid this" is IMO unclear to me. But might be my English that is the problem. I would have written. "To prevent the leaks, we have another ..."

[pinkisemils]

Reviewable status: 0 of 1 files reviewed, 4 unresolved discussions (waiting on @faern and @pinkisemils)

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docs/security.md line 275 at r1 (raw file):

Previously, faern (Linus Färnstrand) wrote…

"it will maintain the blocking policy if the currently applied policy is blocking" tells me very little, or is very confusing.

I think we can rewrite this entire paragraph to be clearer. Let's start by swapping the order of the first sentence.

The service will transition to the [disconnected] state before exiting. To limit leaks during computer shutdown it will maintain the blocking firewall rules upon exit if auto-connect or "Always require VPN" is enabled, or if the service expect that it's being killed due to a computer shutdown.

Or something like that.

I've improved it to refer to the daemon directly,

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docs/security.md line 276 at r1 (raw file):

Previously, faern (Linus Färnstrand) wrote…

I don't think we should use the word shutdown too much. It's too easy to confuse between daemon shutdown and computer shutdown. When we talk about the service being terminated I think we should avoid the term "shutdown" for this reason.

I agree, I've switched to the daemon process stops.

[pinkisemils]

Reviewable status: 0 of 1 files reviewed, 4 unresolved discussions (waiting on @faern)

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docs/security.md line 290 at r1 (raw file):

Previously, faern (Linus Färnstrand) wrote…

Maybe replace "the system service" with "mullvad-daemon" to make it clear what is what, since the paragraph talks about two different system services.

Done.

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docs/security.md line 291 at r1 (raw file):

Previously, faern (Linus Färnstrand) wrote…

"To aid this" is IMO unclear to me. But might be my English that is the problem. I would have written. "To prevent the leaks, we have another ..."

Done.

[faern]

Great 👍 For reference: This updates the security document to describe the fixes implemented for MUL22-02. #3940, #3942 and #3943

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved