Hi There,

We are using some Android phone in a closed network (no Internet access)
and we want these phone to be able to solve DNS query.

But the thing is, they try to query 8.8.8.8 google DNS not our internal DNS server.
Althrough it is distributed via DHCP, the android phone still try to query the Google DNS.

After some research it seemd that there is no way to specify DNS manually without rooting the device.

So here is my question:
How do I root my device in a safe way? (That mean, without using KingRoot or any other untrusted software. As we don't really know what these softwares do)

and how do I secure my device after I rooted it? (as "I might be wrong here" there will be no password to prevent users to run a program as root)


Best regards,
Angel.

you dont mention the which device (every manufacturer/model/firmware version require a different root exploit).

the only devices that are securely root-able would be nexuses since google orders them to be able to be rooted. all other manufactures make it difficult to r00t requiring l33t h4x0rz to provide a solution.

Hi Schneidz,

Thanks for your reply.
These phone will be use in a workshop as internal telephony system.
Therefore we cannot afford to use expensive phone as there is a big chances that the phone we will use will be not handeled with care.

Anyway here are the phone spec:
Device-info:
OS Version: 3.4.5-1588582-user(S7390GXXUAOB1)
Android: 4.1.2
Device: kylevess
Model (and Product): GT-S7390G (kylevessxw)
Manufacture: samsung
Display: JZO54K.S7390GXXUAOB1
Brand: samsung
NetWorkType: Wifi


Angel.

Soooo ...
You want to rely on the largesse of people that go out of their way to provide a custom ROM (in their own time, unpaid), but you don't trust them.
Interesting attitude.

Rooting relies on finding an exploit - that means (smart) hackers are involved. To me, that means you have to be prepared to go all-in, or not at all.
It also relies on some-one bothering to do the leg-work - and generally that means only for popular models. I just looked at my notes for trying to root a Samsung GT-S6010. Several days of frustration and none of the root kits I tried was successful. I also bricked the device and had to use KIES to reload the initial firmware (twice, as the first had no effect).

if it was a closed network 8.8.8.8 would be unreachable. From the other hand dhcp will give dns address, I do not really understand why those devices want to use google. For example it works at home, in my home/local network. Probably I misunderstood something but that should not be an issue.

1 members found this post helpful.

Thanks for your reply

@syg00
Please don't get me wrong, I know what it takes to code at our own expense. (I did contribute to Nagios, PNP4Nagios and now I took over the LETS-Software project, all of these program are open source, so if anyone don't trust these program they can dig into them and check what it does)

I'm just saying that, this program is not open source, so, we can't be sure what it does exactly. That's all.

Now if you tell me it is safe, I would gladly trust you.
But how can you be sure?

I'm ready, but the thing is that I never touch an android device before few weeks back.
Which mean I know nothing about it(At least nothing compare to what you probably know about these devices)
But one thing is sure, is that I'm exited about it


@pan64
We want to setup our mail server on it and we need to resolve some internal address.
But to keep this post clean (with only one issue), we will forget about that DNS issue and keep only the rooting issue.

Best regards,
Angel.

Hm, I bought rooted devices too, and I rooted some others. At first you need to have some practice, need to understand how can you safely make a brick. Probably it costs a few phones. The safest way is to know exactly what are you trying to do (and obviously it depends on the device you have - not only on the brand, but on the real hardware and os).

Thanks schneidz,

Can you point me to some ressources (Doc, soft or methodology) so I can start to teach myself?

http://forum.xda-developers.com is a good resource, but you still need to look for the thread(s) discussing about your needs.

1 members found this post helpful.

Thanks, I'll dig from there.

It appears I did indeed mis-interpret your initial post.

Being able to read the code is no protection against possible exposures. Heartbleed recently proved that.
You may convince yourself that there is no obvious deliberate "back door", but even that is very questionable.
Has the inability to examine all the code stopped you buying phones and/or computers ?. What about smart TVs ... ?

As for resources, get searching - in my case a couple of days searching and a couple of further days reading was sufficient to dive in. Likely you'll find yourself spending quite a bit of time reading forum.xda-developers.com

too slow again ...

Thanks syg00,

Although I get your point (wich is correct, no dought about it), I hope that you get mine as well.

Best regards,
Angel.

meetoo. mine would default to my carriers dns and i actually needed to root in order to use googles dns ?:
http://forum.xda-developers.com/show....php?t=1974711qbking77 on youtube is pretty good.

also:
https://lmddgtfy.net/?q=GT-S7390G+root



you mite probably want to start installing android-tools which contains the adb and fastboot executables.

Shouldn't need to root the phone to change dns on your wireless network. DHCP will deliver whatever dns you have configured it to deliver..not googles or the service providers.

For example: I have a router that serves out 8.8.8.8 for wireless connections. When I look at my phone it says my dns for the home wireless connection is 8.8.8.8, if I change my dhcp server to send 8.8.4.4 to my wireless clients guess what? Yep..you guessed it my dns is now 8.8.4.4


I also have my own dns server (yah, yah I know...it's a home network..but MY dns NEVER goes down,...not so for my ISP's or even google..well, google doesn't go down but it does get slow..mine does not get slow...I am digressing..yet again...sigh...)


So, I can manually edit the home wireless connection directly from my phone, and I do, and change it o my internal dns server, which is authoritative.

So, even if you are running your own LTE/4G service out to clients/employee's or whatever...the phone should pickup whatever DNS you DHCP server sends to it right?

I'm not a programmer, only a lowly technician so what do I know:-)

oh.... and towelroot (search in google) SHOULD work on any phone below 5.0 (lollipop), which includes yours.

I supposed you could save the default firmware and configs using ADB or whatever, then root it using towelroot and compare the difference afterwards? I don't know how hard that would be but for a programmer it should be easy, peasy.

Cheers

first you should make sure your phone is suitable for rooting. before rooting, backing up Android phone is necessary. lastly, use a good toll to help root your phone can be helpful.