DM-Verity Explanation

[mrbigdrawsz]

Alright y'all,

I'm confused as hell about this whole DM-Verity thing and I haven't found a clear explanation, so please help a brotha out.

And please feel free to add anything you'd like that I might be missing, but the questions below are what I'm confused on.

1. Da'fuq is DM-Verity?

2. So I get the notification when I boot up and I'm not overly worried about that annoyance, but still not sure if that notification is stating that I do have encryption turned on or if I do not have it turned on.

3. Flashing the "no-verity-opt-encrypt-5.1.zip...does that decrypt my data "permanently"?

4. Why is it that even after I flash that, when I go and do a backup with TWRP, then attempt to flash another ROM (after full wipe) I'm prompted for a password?

5. And obviously, like a lot of people, it won't accept the password that I set when I first setup the phone.

PLEASE help me to understand this so I don't have to keep wiping my phone completely, flashing stock rom and recovery, locking, unlocking, flashing recovery, rooting, etc....every time.

 

[Jo_Jo_2000]

Alright y'all,

I'm confused as hell about this whole DM-Verity thing and I haven't found a clear explanation, so please help a brotha out.

And please feel free to add anything you'd like that I might be missing, but the questions below are what I'm confused on.

1. Da'fuq is DM-Verity?

2. So I get the notification when I boot up and I'm not overly worried about that annoyance, but still not sure if that notification is stating that I do have encryption turned on or if I do not have it turned on.

3. Flashing the "no-verity-opt-encrypt-5.1.zip...does that decrypt my data "permanently"?

4. Why is it that even after I flash that, when I go and do a backup with TWRP, then attempt to flash another ROM (after full wipe) I'm prompted for a password?

5. And obviously, like a lot of people, it won't accept the password that I set when I first setup the phone.

PLEASE help me to understand this so I don't have to keep wiping my phone completely, flashing stock rom and recovery, locking, unlocking, flashing recovery, rooting, etc....every time.

1) A service verifying that the system partition has not been tampered with, aka you cannot write to it, which is why there are "systemless" everything now.
2) That 5 seconds screen appears when your device is unlocked no matter what is on the system partition. Even if you are running full stock. Unlocked means your kernel partition will not be verified to be stock, allowing you to add root or patch out dm-verity.
3) I don't think so, as it is "opt"ional encrypt. It just makes sure that there will be no automatic reencryption of your partition.
Actually you cannot decrypt your partition, it might erase it instead.
4) yes you will be prompted for a pw even in twrp, so you can access the zip file from your encrypted partition. If you now were to wipe the entire /data partition including /data/media (aka /sdcard), and create a new ext4 fs on it and apply no-verity-opt-encrypt to your new custom rom (if it is not included), you will not be prompted for a password, but loose all your data.
5) ??? huh?? when you first set up the phone there is no password, you choose it afterwards.

 

[mrbigdrawsz]

1) A service verifying that the system partition has not been tampered with, aka you cannot write to it, which is why there are "systemless" everything now.
2) That 5 seconds screen appears when your device is unlocked no matter what is on the system partition. Even if you are running full stock. Unlocked means your kernel partition will not be verified to be stock, allowing you to add root or patch out dm-verity.
3) I don't think so, as it is "opt"ional encrypt. It just makes sure that there will be no automatic reencryption of your partition.
Actually you cannot decrypt your partition, it might erase it instead.
4) yes you will be prompted for a pw even in twrp, so you can access the zip file from your encrypted partition. If you now were to wipe the entire /data partition including /data/media (aka /sdcard), and create a new ext4 fs on it and apply no-verity-opt-encrypt to your new custom rom (if it is not included), you will not be prompted for a password, but loose all your data.
5) ??? huh?? when you first set up the phone there is no password, you choose it afterwards.

First...THANK YOU FOR 1-4!

As for 5, when I'm initially setting up the Rom it asks for the fingerprint and if I say yes then I'm asking how I want to verify, because it forces me to do fingerprint + PIN or password. So when I set that and I'm asked for it in TWRP or if it comes up after flashing another ROM, it never accepts it. Keeps telling me it's wrong. This happens even if I set it up after I'm actually booted into the rom for the first time and then set it up through the settings menu.

 

[Jo_Jo_2000]

First...THANK YOU FOR 1-4!

As for 5, when I'm initially setting up the Rom it asks for the fingerprint and if I say yes then I'm asking how I want to verify, because it forces me to do fingerprint + PIN or password. So when I set that and I'm asked for it in TWRP or if it comes up after flashing another ROM, it never accepts it. Keeps telling me it's wrong. This happens even if I set it up after I'm actually booted into the rom for the first time and then set it up through the settings menu.

soemone on xda may has already found a fix for this, look in your rom thread or open a new one if you have to deal with such problems again.

 

[Discoreggae]

First...THANK YOU FOR 1-4!

As for 5, when I'm initially setting up the Rom it asks for the fingerprint and if I say yes then I'm asking how I want to verify, because it forces me to do fingerprint + PIN or password. So when I set that and I'm asked for it in TWRP or if it comes up after flashing another ROM, it never accepts it. Keeps telling me it's wrong. This happens even if I set it up after I'm actually booted into the rom for the first time and then set it up through the settings menu.

Have you found the answer to question 5 ? It cost me to wipe my phone and I need to root it again but afraid of that password issue.

 

[mrbigdrawsz]

Have you found the answer to question 5 ? It cost me to wipe my phone and I need to root it again but afraid of that password issue.

In my experience, it's only happened with certain ROM's. I've gone from Stock to Dirty U. and back to Stock with no issue. But I'll go from anything to Ressurection Remix and I run into this issue if I try and flash something else after flashing R.R. That's the only ROM that I've had the issue with and that's using multiple versions of TWRP. So I'm not sure exactly what's causing it, but I certainly haven't flashed R.R. since (granted it's a great ROM) because it's just a headache going through all the nonsense to get back to where I want to be.

Sorry I don't have a more definitive answer, but that's been my experience.

 

[easyrider77]

Quick question (at least I hope) on this no verity thing

I'm seeing a lot of no verity zip flashing these days. I've actually rooted an lg k20 doing it.

So to make it a simple root procedure, if I just flashed the normal rom+gapps and twrp of corse, but also flashed no verity zip file, will that give any issues, say if the phone really didn't need to have the no verity zip flashed......like would adding the no verity zip step in the rooting process as a norm, would there be any ill affects or bricking the phone and such?

I hope that all made sense.

 

[redpoint73]

So to make it a simple root procedure, if I just flashed the normal rom+gapps and twrp of corse, but also flashed no verity zip file, will that give any issues, say if the phone really didn't need to have the no verity zip flashed......like would adding the no verity zip step in the rooting process as a norm, would there be any ill affects or bricking the phone and such?

I'd say "no". The "no verity" zip is just a patched boot.img, which is one of the files that gets modified with root, or flashing custom ROMs, and is easily fixed or turned back to stock.

On the other hand, if you are that concerned, flashing "no verity" just IMO is not a big benefit. All it does, is remove the verity warning screen when you reboot the phone, which goes away in 5 seconds, of if you press the power button (same as the unlocked bootloader warning screen). I've never bothered with the "no verity" as this little thing (the warning screen) doesn't bother me. But obviously, it bothers some folks. So the choice is yours.