Hello!
I wrote the following email to Sony Developer World, but they asked me to post it here.I don't know why I should do this because this page is not meintained by Sony. But hoping that Sony will give me a definitive answer I do as they asked me for:
[start of email]
I haven’t understood your risk explanation on your „Unlock your boot loader“ page because to my mind it is a little bit unprecise:
You wrote there:
“Risks
Please be aware that Sony cannot guarantee the full functionality, and will not be responsible, for any unsigned custom ROM being flashed to your device after the boot loader is unlocked. An unsigned custom ROM may not have gone through the thorough tests that we run for each device and software version that we release.
Also, a custom ROM might not work properly on your device, and certain functions and offerings may cease to work. The performance of the device might also be affected, and you may damage your device permanently. In worst case, unlocking the boot loader will cause physical injuries or material damage, for example, due to the device overheating.
Certain pre-loaded content on your device may also be inaccessible due to the removal of DRM security keys. For high-end devices running recent software versions, for instance Xperia Z3, the removal of DRM security keys may affect advanced camera functionality. For example, noise reduction algorithms might be removed, and performance when taking photos in low-light conditions might be affected. The secure user data partition may also become inaccessible, and you will not be able to get any more official software upgrades if you unlock the boot loader.
After unlocking your device, you should not enable My Xperia (found in the settings menu under security on some devices running Android 5.0) as this might cause the device to malfunction.”
I don’t understand the red marked sentence. So my question concerns the removal of the DRM security keys because I haven’t found out who and when they are removed:
WHO removes the DRM security keys? Is it done by SONY when unlocking the bootloader (and why do you do that?) or is it a risk caused by installing custom ROM’s or recovery images?
And what will happen if I’ll unlock the bootloader of my Sony Xperia Z5 compact via the integrated function “OEM unlock”? Will the DRM security keys deleted any way using this or will they be preserved? And will I be able to lock the bootloader again?
Regards
Ansgar
[end of email]
klausstoertebeker said:
WHO removes the DRM security keys? Is it done by SONY when unlocking the bootloader (and why do you do that?) or is it a risk caused by installing custom ROM’s or recovery images?
Click to expand...
Click to collapse
It's done automatically if you unlock the bootloader, i.e. "by Sony".
klausstoertebeker said:
And what will happen if I’ll unlock the bootloader of my Sony Xperia Z5 compact via the integrated function “OEM unlock”? Will the DRM security keys deleted any way using this or will they be preserved?
Click to expand...
Click to collapse
The DRM keys will be erased.
klausstoertebeker said:
And will I be able to lock the bootloader again?
Click to expand...
Click to collapse
Most likely, but the DRM keys cannot be restored. They are forever lost.
sorry, that's bull****.
remove the bootloader lock in developer settings and you will see, that Marlin, Widevine and CKB are still active and reported as "key ok"
and no, Sony does not remove them, you do it while flashing.
BTW. there are already early attempts in flashing, and yes they have deleted their DRMs. and no, there is no way to bring them back.
however, for the time being: keep the bootloader closed, as you've no benefits from unlocking it, yet.
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basthet said:
sorry, that's bull****.
remove the bootloader lock in developer settings and you will see, that Marlin, Widevine and CKB are still active and reported as "key ok"
and no, Sony does not remove them, you do it while flashing.
BTW. there are already early attempts in flashing, and yes they have deleted their DRMs. and no, there is no way to bring them back.
however, for the time being: keep the bootloader closed, as you've no benefits from unlocking it, yet.
Gesendet von meinem E5823 mit Tapatalk
Click to expand...
Click to collapse
Dude, you should relax. There's no manure in my post.
You have misunderstood the toggle in the developer settings menu. It does NOT unlock the bootloader.
The toggle only disables some software features that would cause trouble if you actually choose to unlock the bootloader.
Bootloader in unlocked using fastboot oem unlock, as always.
Please read up:
http://forum.xda-developers.com/showpost.php?p=63216335&postcount=23
http://forum.xda-developers.com/showpost.php?p=63216352&postcount=24
http://forum.xda-developers.com/showpost.php?p=63343765&postcount=33 (quoting you)
http://forum.xda-developers.com/showpost.php?p=63299154&postcount=17
Well, I'm relaxed, but you help no-one in posting wrong stuff.
Lets make it simple:
Compare it with a simple door and a door guard.
The door guard has order only to let you in, having a specific key.
In order to get this key, e.g. for the z3 family:
Go to Sonys webpage, register, download the key.
procedure for the z5c:
go into developer settings, enable: OEM unlock.
This corresponds to: Tell the guard, no key is required anymore.
Setting the flag of making something accessible is called "unlock" - so: in fact you can call it "unlock the boot loader" by enable the "OEM unlock" in Developer Settings*.
fastboot oem unlock does much more.
In my example:
go to the door,
ask the guard: is door open / already unlocked?
[z3c: handover the key to the guard]
[z3c: Wait to get the "Ok" to pass - guard: unlock the door] -> correspond to: setting flag: accessible = unlock
pushing the door open,
hanging a fat note in the entrance hall telling "Door is open";
So: you did not miss understood what the toggle does, but the whole procedure.
And no: the toggle does not disable some software feature, it just removes the OEM specific key requirement by accessing the boot loader
*Note: I know, that was quite rough simplification, and to be absolute correct: the OEM unlock toggle in Dev. Setting does in fact not physically "unlock" the boot loader. It just removes the requirement for a key in the unlocking process. However, that correspond to an open boot loader, as all attempt to enter it, will not be denied.
basthet said:
Well, I'm relaxed, but you help no-one in posting wrong stuff.
Lets make it simple:
Compare it with a simple door and a door guard.
The door guard has order only to let you in, having a specific key.
In order to get this key, e.g. for the z3 family:
Go to Sonys webpage, register, download the key.
procedure for the z5c:
go into developer settings, enable: OEM unlock.
This corresponds to: Tell the guard, no key is required anymore.
Setting the flag of making something accessible is called "unlock" - so: in fact you can call it "unlock the boot loader" by enable the "OEM unlock" in Developer Settings*.
fastboot oem unlock does much more.
In my example:
go to the door,
ask the guard: is door open / already unlocked?
[z3c: handover the key to the guard]
[z3c: Wait to get the "Ok" to pass - guard: unlock the door] -> correspond to: setting flag: accessible = unlock
pushing the door open,
hanging a fat note in the entrance hall telling "Door is open";
So: you did not miss understood what the toggle does, but the whole procedure.
And no: the toggle does not disable some software feature, it just removes the OEM specific key requirement by accessing the boot loader
*Note: I know, that was quite rough simplification, and to be absolute correct: the OEM unlock toggle in Dev. Setting does in fact not physically "unlock" the boot loader. It just removes the requirement for a key in the unlocking process. However, that correspond to an open boot loader, as all attempt to enter it, will not be denied.
Click to expand...
Click to collapse
I can't argue with you. I'm not even sure where we agree and disagree.
For the sake of other users, here's the clarification:
Under Developer settings, there is a setting called "OEM Unlocking - Allow the bootloader to be unlocked".
This setting does not unlock the bootloader, it just enables the possibility to unlock. That's why it's called "Allow the bootloader to be unlocked".
No DRM keys will be deleted by toggling this setting.
After setting "Allow the bootloader to be unlocked", you can unlock the bootloader using fastboot.
When doing so, the DRM keys will be deleted and the bootloader will be unlocked.
Until you issue the fastboot command, you can't flash any unsigned code - as usual.
nilezon said:
I can't argue with you. I'm not even sure where we agree and disagree.
For the sake of other users, here's the clarification:
Under Developer settings, there is a setting called "OEM Unlocking - Allow the bootloader to be unlocked".
This setting does not unlock the bootloader, it just enables the possibility to unlock. That's why it's called "Allow the bootloader to be unlocked".
No DRM keys will be deleted by toggling this setting.
After setting "Allow the bootloader to be unlocked", you can unlock the bootloader using fastboot.
When doing so, the DRM keys will be deleted and the bootloader will be unlocked.
Until you issue the fastboot command, you can't flash any unsigned code - as usual.
Click to expand...
Click to collapse
We are not arguing here
I asked you to be more specific as unlocking a door does not mean opening it.
However - there is one important thing missing and quite profound error in your summary (beside the "unlock" wording stuff...).
Enabling the "OEM Unlocking" switch bears a high security risk. Unsigned software now can enter the TA.
In fact: you do not have to run the fastboot unlock by yourself. Any piracy software can now make irreparable damages to the phone!
basthet said:
We are not arguing here
I asked you to be more specific as unlocking a door does not mean opening it.
However - there is one important thing missing and quite profound error in your summary (beside the "unlock" wording stuff...).
Enabling the "OEM Unlocking" switch bears a high security risk. Unsigned software now can enter the TA.
In fact: you do not have to run the fastboot unlock by yourself. Any piracy software can now make irreparable damages to the phone!
Click to expand...
Click to collapse
You are saying that toggling the "OEM Unlocking" switch would make TA partition writeable (by any other user than root)?
Why would you assume that?
nilezon said:
You are saying that toggling the "OEM Unlocking" switch would make TA partition writeable (by any other user than root)?
Why would you assume that?
Click to expand...
Click to collapse
No, I'm not saying this.
But the reason for the OEM Lock is to ensure, only OEM signed software is able to be installed.
Enabling "OEM Unlocking" removes this check.
This implies:
- Nice people can now provide software to be installed -> custom roms.
- Bad people can now also install software, but to their needs.
To keep it simple: Let some evil person post any rom called "official Sony z5c Android 6.0".
Let this bad person make the appearance of this rom as any official Sony Update.
Users with the OEM lock in place will not be able to install it, as the OEM key from Sony is missing.
Users with the OEM lock removed will install it w/o any burden.
Do not forget:
Original OEM Software still is signed as original software.
To install the original software, you do not have to toggle the "OEM unlock" in the Developers Settings, as this ROM carries the original OEM key.
to install original software, you do not have to fastboot oem unlock
Removing the OEM-key check with the "OEM unlock" switch, makes the OEM-key obsolete. Hence bears a security risk.
basthet said:
No, I'm not saying this.
But the reason for the OEM Lock is to ensure, only OEM signed software is able to be installed.
Enabling "OEM Unlocking" removes this check.
This implies:
- Nice people can now provide software to be installed -> custom roms.
- Bad people can now also install software, but to their needs.
To keep it simple: Let some evil person post any rom called "official Sony z5c Android 6.0".
Let this bad person make the appearance of this rom as any official Sony Update.
Users with the OEM lock in place will not be able to install it, as the OEM key from Sony is missing.
Users with the OEM lock removed will install it w/o any burden.
Do not forget:
Original OEM Software still is signed as original software.
To install the original software, you do not have to toggle the "OEM unlock" in the Developers Settings, as this ROM carries the original OEM key.
to install original software, you do not have to fastboot oem unlock
Removing the OEM-key check with the "OEM unlock" switch, makes the OEM-key obsolete. Hence bears a security risk.
Click to expand...
Click to collapse
OMG dude. Where are you getting this?
You toggle that switch and install an unsigned ROM and I'll eat my shorts.
nilezon said:
OMG dude. Where are you getting this?
You toggle that switch and install an unsigned ROM and I'll eat my shorts.
Click to expand...
Click to collapse
You either learn this in school, or should find it s.w. in the Android docs.
And instead of flaming you should start reading and learn IT.
So be brave and toggle the switch, which by your interpretation has no meaning.
The rest of the user i can only advice to keep it locked and only enable in order to flash customs Roms.
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@basthet:
So, if I get you right, I just need a customized firmware (e. g. a pre-rooted one), toggle that "OEM unlock" switch and install it via recovery mode? And that without loosing DRM keys? If it is so easy rooting is no problem, isn't it?
klausstoertebeker said:
@basthet:
So, if I get you right, I just need a customized firmware (e. g. a pre-rooted one), toggle that "OEM unlock" switch and install it via recovery mode? And that without loosing DRM keys? If it is so easy rooting is no problem, isn't it?
Click to expand...
Click to collapse
No, "OEM Unlock" is just a option to allow OEM unlock, so you have to unlock bootloader after enabling it (and you'll loose DRM key)
Hi.
Before my question I'll write about my experience because I am sure it will help many many people.
As many of you, I always ROOT my smartphones.
Nowadays, the new phones, they come with this new technology to avoid root and other things called " OEM Lock " under the Developer's Options.
Following every step provided in the root guide for you phone, the new step to enable OEM Unlock under Developer Options
is a must!
The only thing that they don't say is that you MUST leave OEM Unlock ALWAYS ENABLED during and AFTER the root, and not only during the root
process.
Not knowing that, what did I do? Right After rooting my Samsung Note 5 I disabled the OEM Unlock. When I restarted the smartphone, it got into something called FAP Protection Black Screen where you are not able to leave not even if you try to root the phone again with the img file!
If you get in the FAP Protection Screen, like I did, despair will take over, I promise! And Google will not help you!
Is there a solution?
I found one, but not in any Google Page.
You need to download the firware img file for your phone, exactly same model,
in my case it was SM-N920G (Samsung Note 5), and for your specific country. Luckily for my phone it was not so hard to find, just hard to download (1,7GB with average 15 kB/s speed!). You will find different versions, some related to a Phone Company Operator that your country has, other related to no operator at all (sure I chose that).
After you get the firware file, just use Odin with that file to flash the phone, just like how you did to root the phone, but now, instead of using the root img file with Odin Software, you'll use the firmware file. That will not only solve the problem and give you access to your phone again, but in my case the Operator Flag disappeared and the data and apps installed miraculously were intact! I was pretty sure I was supposed to lose everything, but that didn't happen!
I'm sure what I wrote above will help many desperate people out there!
Now, my main question here:
You can never disable OEM Unlock in your life, with a rooted phone, period! So, it's really dangerous to leave the developer options enabled, allowing anyone that uses the phone to change it, even if by accident. In my case, as another example, besides rooting my phone, I rooted my father's phone too (because it was previously mine). I'd like to avoid by any means that by any chance me, or my father, disable to the OEM Unlock.
So, my question:
If I disable the Developer Option in order to "hide" it, will the changes that I did inside it remain working perfectly? I'm afraid that if I disable the developer options, somehow, it might take every option inside it back to the "default", just like it was before I enabled the developer Options, meaning in this case, OEM Unlock would get DISABLED again!
Is it safe to disable the Developer Options when OEM Unlock is Enable and MUST Remain like that?
Thank you.
Lost a night of sleep for the same problem with a Samsung S8.
This should be added to *every* mod guide.
In my case was worse too...if you root the phone and wipe data, when you open first time developer option you'll find "OEM Unlock" disabled (but I assume it's enabled at bootloader level). So when I check / uncheck it I doom my phone to lock on next restart...
how to get to boot menu on htc u12 plus, smallest width setting got adjusted wrong in developer options and power got cycled, all I can see on lock screen are 1,2 and 3 cant unlock, any ideas?
Hello, i hope this is the right place to post on.
So, from the last post i made, i rooted my phone, and bricked it again. So i flashed the stock firmware. Everything is just fine,
but is there a way to disable OEM Unlock without bricking the phone again? Or it can never be disabled?
Hi dushDJ, first you have to enable developer mode. This can be done by going to settings>info device>softwareinfo> and then click on the buildnumber until it says developer mode enabled.
Then go back to the main page of settings and click on developer options. Search for oem unlocking now click on it and type your password.
That should do it.