5.6.5 Jailbreak (closed-kindle) -- released!

[knc1]

FW 5.6.5 - KT2 (a.k.a. 7g, Kindle Basic)
Update directions:
http://www.amazon.com/gp/help/custom...deId=201605570

Update package:
https://s3.amazonaws.com/G7G_Firmwar...ndle_5.6.5.bin

@eschwartz - go ahead and merge this information with the list in O.P. FAQ if you would like.

[eschwartz]

Forgot that one.

[grant2]

Originally Posted by Branch Delay

If we still have any active developers, searching for a new anti-update mechanism that doesn't require root would be handy.

I'm sorry if this is a dumb question, but is it difficult or impossible to gain root on a kindle that is jailbroken?

Is there any good reason not to get root, if that's needed to safely use wi-fi?

[drgonzalez94]

Originally Posted by grant2

I'm sorry if this is a dumb question, but is it difficult or impossible to gain root on a kindle that is jailbroken?

Is there any good reason not to get root, if that's needed to safely use wi-fi?

No such thing as a dumb question. I support anyone who takes it upon themselves to try to learn. At the moment, because of the limitations with the firmware, the only way to obtain root access is via the serial debug interface (I'm not sure there is any other way to do it, honestly, based on the jailbreak history I've seen).

You'd need a 1.8v serial adapter and to read one of the numerous threads here. There is absolutely no reason to not obtain root access. You always have more freedom that way and would be able to jailbreak regardless of current firmware installed. You should be able to connect to wifi and preserve the jailbreak after it has been applied, but there is no telling what applications will stop working with each subsequent OTA update of the firmware.

Frankly I sideload all my content, even what I buy off amazon and see no need to connect to wifi at all. It is a power drain and Goodreads is just a gimmick I never paid much attention to.

[eschwartz]

Jailbreaking is the process of gaining root.
EDIT: Yes, notwithstanding knc1 below, this is the practical result.

That's what a serial jailbreak does, and that's what this jailbreak will do.

[knc1]

Originally Posted by grant2

I'm sorry if this is a dumb question, but is it difficult or impossible to gain root on a kindle that is jailbroken?

Is there any good reason not to get root, if that's needed to safely use wi-fi?

First reply of the day, so I am drawing on a big, fresh, stack of words that I haven't typed yet.

When you write 'safely use WiFi' I am guessing you mean being safe from a forced, OTA update.
That guess is based on the context of this thread, not in general.

The two are related by a chain of dependencies.
A few bits of background first though...

"gaining root" -
A common phrase (in *nix based systems, Kindle Linux is one such) for accessing the device as the (all powerful) system administrative user. (Android is also a *nix based system.)
In those systems, the default "super user", user's name, is: 'root'.

Although the privledge tests are based on the user's identification number (0) and any name might be assigned UID of 0.

In another O.S. it could be called "gaining admin".
Because in those systems, the default "super user", user's name, is: 'admin'.

"user visible, mass storage" -
The part of the file system tree visible to the user over the USB cable.
Which on the Kindles, is actually only a tiny twig of the entire file system tree.

"jail" -
One use of "jail" refers to the prohibitation on accessing any part of the file system tree, **other than** that tiny twig.

Another use of the term refers to the fact that a Kindle (using the built-in update machinery) will only install cyrptographically signed packages.
That is because those packages have access to the file system outside of the visible, user's mass storage, twig.

Note: the built-in updater does run as UID 0, a.k.a: 'root'.

"jail break" - as used at this site in reference to the Kindles -
Also, somethings refered to (incorrectly) as: "gaining root".

"jail break" is the installing a signature certificate in the Kindle's certificate store that will verify the cyrptographically signed packages created here.
(In the interest of full disclosure, of packages created anywhere, that where created with our "KindleTool" - which is OpenSource, stored in a public repository.)

The Kindle's certificate store is a directory of the file system **outside** of that small twig which can be seen over the USB cable.

It is that adding a signature certificate **outside** of the area the user is allowed to access that is the hard part of inventing a "jail break".

One more note:
Nearly all multi-user, computer systems ever built have had the concept of an "operator's console".
In Linux (and other *nix based systems) - this is the first serial port on the system.
Without it, they will not even start.
Although they don't test if anything is connected to the first serial port - the bits and bytes might be falling on the floor.
And this first serial port runs as the "super user" - a.k.a: UID 0 - a.k.a: 'root'.

If you gain physical access to that first serial port, you have gained 'root' on the computer system.
Kindles are no different than any other *nix system in that respect.

(Single user computer systems had lights and switches or plug-in cables and jacks.)

= = = =

So much for the background - Now for the answer to the question -

To block OTA updates, you must alter the OTA update system -

To alter the OTA update system, you must be able to access the file system outside of the user visible twig -

There are not (there isn't suppose to be) any programs installed that let the user access the file system from the USB storage.
So you have to add one -

But to add one, it has to be cryptographically signed by a signature certificate that the Kindle 'knows' about -

But to add a certificate to the file system outside of the USB storage, you need a signed update package.
Catch-22 (its the name of a movie, google it).
**or**
some sly programmer that has found a way around the bars of the jail.
Which brings us right back to the topic of this thread.

= = = =

There is another way to prevent the OTA forced updates -
Alter the resources it requires to run -
Which includes use of the USB storage system, the same one that the user does have access to.
(Note: A basic design error on the part of lab126, but don't anyone tell them that.)

One certain way is to use up all of the free space so that there isn't any place for the updater to store the update file.
I.E: Just create one file, the size of USB storage free space.
A truely ugly, time consuming, operation on FAT32.

Another (not so certain) way is to use up the name entries that the updater normally uses.
The reader can find threads here about the success (and non-success) of that method.

[eschwartz]

knc1 -- maybe storing updates in user-accessible storage is a design flaw, maybe not.
But I imagine it is also a design flaw to reserve an extra 200 MB of an already limited storage media for the sole purpose of saving update packages away from the user.

I'm not worried this will change.

[knc1]

Originally Posted by eschwartz

knc1 -- maybe storing updates in user-accessible storage is a design flaw, maybe not.
But I imagine it is also a design flaw to reserve an extra 200 MB of an already limited storage media for the sole purpose of saving update packages away from the user.

I'm not worried this will change.

One of the reasons I didn't hesitate to mention it.

They could have enlarged /var/local years ago if they wanted to and started using that instead.

But the user could still deny the Kindle access to the download server by keeping it in airplane mode.
Since that would still be so easy for the user to do -
I think your point outweighs mine.

[eschwartz]

Moderator Notice

This thread is a sticky which tracks the 5.6.5 jailbreak. As I said above, I will delete (at my discretion) any posts which I feel do not contribute to that goal.

People are subscribing to this thread in the interest of getting notified about new developments, primarily the public release of said jailbreak.
Getting notifications due to random schmoozing is NOT useful for that purpose.


If it isn't about the jailbreak in some way, shape or form, I am almost definitely going to delete it.
We have other forums to discuss books, or failing that, the Lounge.

[drgonzalez94]

Indeed. I should clarify my reply...based on the previous jailbreak history I've seen meaning recently (as in nothing for the 5.6.x.x.x series firmwares) not requiring serial access. But yes, you'll gain root access when you jailbreak. Then you could use one of the numerous techniques knc1 listed to circumvent the OTA update system. Guess that's what happens when you type replies half asleep.

[hackqiang]

Great Jobs

[makara]

So where jailbreak?

[eschwartz]

As per the first post, and the LARGE RED NOTICE, it is "coming soon".

[loco]

Originally Posted by eschwartz

As per the first post, and the LARGE RED NOTICE, it is "coming soon".

+1 on that esch

[Branch Delay]

Contacted Amazon trying to see if they have any sort of estimated date on if/when they are targeting a patch. Guessing they won't tell me anything, but I'll keep everyone up to date.