How bypass Tenda configuration import check

Post new topic   Reply to topic    DD-WRT Forum Index -> General Questions
Goto page 1, 2, 3  Next
Author Message
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Sun Jun 12, 2022 0:18    Post subject: How bypass Tenda configuration import check Reply with quote
I have a Tenda F3, and the available settings is very limited, absolutely ridiculous, but this router export the configurations in plain text with a lot of nice available settings, so you can thing I just set this file as I want and import the modified file to router, but NOOOOOO! NOOOOOO! The manufacturerers don't want to see you happy, they hate fun and love to see you frustrated and your sad face. So if you try to do it the router reject the modified configuration file with a "Failed to import" message. The two first lines of configuration file is:

#Please don't change this file by hand
@1245339

This "@1245339" seem a "hash" if you modify the file the hash don't match. So, please, anyone here know what algorithm is used in this number? I need know how to get the right number to make the magic.

My configuration is like this one:

https://github.com/irondsd/system/blob/master/RouterCfm.cfg

Thank you!
Sponsor
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Sun Jun 12, 2022 7:20    Post subject: Reply with quote
Welcome to the forums.

So this isnt even DD-WRT related.

DD-WRT has a nice way around exporting nvram to readable text file, but cannot be used for restoring, only the unreadable bin file can. I do this by opening a terminal connection to router and running nvram show > /tmp/somebackupidentifier.txt and then grab that file to desktop for reference should I need to reset the router to defaults.

As for your question, who knows, maybe someone, maybe no one, but since this isnt DD-WRT related, good luck with your query.

You could try doing different types of hashes to compare like md5 for instance, there are many different types, though modern hashes wont be as short as your reference and they dont use @ prefixes. This assuming its some sort of hash at all, and if it is, dont be surprised its some custom manufacturer/ISP type thing.

If it was a ISP router then likely a reference to their CPE/ACS system to identify the configuration version for instance. Else its anyone's guess.

Good luck.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Sun Jun 12, 2022 16:23    Post subject: Reply with quote
Hi Joker, thanks your attention, I know this is not DD-WRT related, I'm sorry about it, I don't like do it, but Tenda hasn't any forum, and I know here has people with a "special" knowledge about routers. I tried the most common hashs, without success, I also tried the number of lines and characters, also don't work, maybe this is really hard to understand algorithm but maybe can be very simple, who knows, maybe someone here know this "secret". I'm here, if someone know, please post here.
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Sun Jun 12, 2022 17:16    Post subject: Reply with quote
To be perfectly honest with you, if a device doesnt support DD-WRT I dont buy it.

Anything really, if I cant install 3rd party anything even phones I dont buy them.

Stock firmware is awful and the worst crime against any kind of security. So for me your already put yourself in a nice little box with a bullseye painted on it.

Good luck though.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Sun Jun 12, 2022 17:38    Post subject: Reply with quote
I agree with you, like iPhone you can't install external apps, is ridiculous, if you give me one iPhone I sell and buy an Android, but in my country is almost impossible to find a router compatible with custom firmwares and if you find one the price is an assault! Away from my reality. But ideal is to avoid when you have the choice really. Thanks Joker by keep my post here!
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Sun Jun 12, 2022 18:10    Post subject: Reply with quote
That iphone business is about to change Europe side, didn't you read the news? Not that would ever buy Apple anything, even if I was gifter all their crap I would put it in a pile and smash it to bits in a most eco manner possible. I wouldn't even sell it to my worst enemy.

They could pay me in fact, I rather starve.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Thu Jun 23, 2022 20:44    Post subject: Reply with quote
this "hash" seem a big secret... :D
dale_gribble39
DD-WRT Guru


Joined: 11 Jun 2022
Posts: 1899

PostPosted: Thu Jun 23, 2022 21:25    Post subject: Reply with quote
I've noticed two versions of this device listed on WikiDevi; The F3 (Broadcom BCM5357C0 MIPSR2) and the F3-16 (Realtek RTL8196E)

I would venture to say if it's the original F3, which is 2MB flash, and would require a Linux 2.6 kernel, it would be fun trying to make a firmware image suitable to replace the stock firmware.

Given the downloads page for stock firmware, there seems to be a v1, v3, and v4 listed. The label on your device would have the version number and hopefully an FCCID. That's the only way to ascertain any details on hardware if it's neither of the two listed in WikiDevi.

Does the PCB have a serial UART header? The "hash" could be some kind of checksum. Happy hunting.

_________________
"The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost

"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio

<fact>code knows no gender</fact>

This is me, knowing I've ruffled your feathers, and not giving a ****
Some people are still hard-headed.

--------------------------------------
Mac Pro (Mid 2012) - Two 2.4GHz 6-Core Intel Xeon E5645 processors 64GB 1333MHz DDR3 ECC SDRAM OpenSUSE Leap 15.5
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Thu Jun 23, 2022 21:40    Post subject: Reply with quote
My router is a F3 v2 rebranded, thanks dale_gribble39 the attention. I just want to load some settings to the router. The settings is already present on software why don't allow you set as you want? This manufacturers is incredible. I don't have any knowledge about flashing routers, or with router PCBs. Maybe someone here know the "hash" :D
dale_gribble39
DD-WRT Guru


Joined: 11 Jun 2022
Posts: 1899

PostPosted: Thu Jun 23, 2022 22:56    Post subject: Reply with quote
Without and FCCID or hi-res pictures or any further information, I can't help you without binwalking the stock firmware to see if there are any clues and/or acquiring an identical device.
Quote:
The label on your device would have the version number and hopefully an FCCID. That's the only way to ascertain any details on hardware if it's neither of the two listed in WikiDevi.

Does the PCB have a serial UART header? The "hash" could be some kind of checksum. Happy hunting.

_________________
"The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost

"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio

<fact>code knows no gender</fact>

This is me, knowing I've ruffled your feathers, and not giving a ****
Some people are still hard-headed.

--------------------------------------
Mac Pro (Mid 2012) - Two 2.4GHz 6-Core Intel Xeon E5645 processors 64GB 1333MHz DDR3 ECC SDRAM OpenSUSE Leap 15.5
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Fri Jun 24, 2022 1:38    Post subject: Reply with quote
My router don't has the FCCID on sticker you believe? :D Maybe is because it is rebranded. Really externally both versions is identical, I can't try to flash this router, because is the only router I have in the moment and I can't risk, but if I disassemble the router has some information which I can post here which can help you find this "hash", because I think that with this "hash" I can edit the exported config and after re-import it.
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Fri Jun 24, 2022 9:55    Post subject: Reply with quote
You are assuming this is some sort of hash, to me its just some internal reference to the configuration version which is generated elsewhere on firmware and this file you pasted is just the generated resulting portion, so editing this file is not going to work.

You would need to disassemble your firmware and look for the part which is responsible for generating this file you pasted, and then you may have your answer to where this hash as you call it is coming from or a way to modify the config directly.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
dale_gribble39
DD-WRT Guru


Joined: 11 Jun 2022
Posts: 1899

PostPosted: Fri Jun 24, 2022 14:12    Post subject: Reply with quote
The only other option being to examine the functions of the webUI; I had already alluded to reverse engineering the firmware. Without specific hardware details, especially a full dump of the flash chip, no suitable replacement firmware can be crafted. Of course, is this "@1245339" the same random number generated every time a configuration backup is made?
_________________
"The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost

"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio

<fact>code knows no gender</fact>

This is me, knowing I've ruffled your feathers, and not giving a ****
Some people are still hard-headed.

--------------------------------------
Mac Pro (Mid 2012) - Two 2.4GHz 6-Core Intel Xeon E5645 processors 64GB 1333MHz DDR3 ECC SDRAM OpenSUSE Leap 15.5
mrocha2
DD-WRT Novice


Joined: 11 Jun 2022
Posts: 19

PostPosted: Fri Jun 24, 2022 14:39    Post subject: Reply with quote
I did some tests and this number only change when you change anything on router configs using the web ui, if you do not change anything on config, the exported number is the same, if you change a little the number change a little, and if you change a lot the configs, the number change a lot.
the-joker
DD-WRT Developer/Maintainer


Joined: 31 Jul 2021
Posts: 2146
Location: All over YOUR webs

PostPosted: Fri Jun 24, 2022 14:54    Post subject: Reply with quote
So there you have it, mystery solved. But you cant edit this file itself and import it clearly this number is stored elsewhere for verification.

Surely you can export the configs and restore them without changing them?

The protection is there and verification kicks in to prevent you from restoring something that will likely have wrong parameter values (since manufacturer cant tell otherwise what is valid/invalid), this is done to stop non savvy tech users from bricking the device.

You still need to find out where this number is stored for verification, likely wont be human readable format, only by reverse engineering the FW you'll be able to tell.

_________________
Saving your retinas from the burn!🔥
DD-WRT Inspired themes for routers
DD-WRT Inspired themes for the phpBB Forum
DD-WRT Inspired themes for the SVN Trac & FTP site
Join in for a chat @ #style_it_themes_public:matrix.org or #style_it_themes:discord

DD-WRT UI Themes Bug Reporting and Discussion thread

Router: ANus RT-AC68U E1 (recognized as C1)
Goto page 1, 2, 3  Next Display posts from previous:    Page 1 of 3
Post new topic   Reply to topic    DD-WRT Forum Index -> General Questions All times are GMT

Navigation

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum