6 ms·

The last paragraph is both funny and so so in phase with a lot of security by obscurity found everywhere: "The V700 consults both “/proc/cpuinfo” to learn the

by Sytten 3y ago

The last paragraph is both funny and so so in phase with a lot of security by obscurity found everywhere: "The V700 consults both “/proc/cpuinfo” to learn the CPU serial number of the device it is on, and a binary file associated with the device file system structure as part of its method for determining its AES (Advanced Encryption Standard) key. It then ignores all of these device-specific items, and reverts back to a static key “87654321” stored in the binary."

LegitShady 3y ago
Not the first time something like this has happened. I believe it was the PS3 that was hacked to get Sony's private key because the ECDSA algorithms random factor 'k' always picked 4.
- ljouhet 3y ago
  https://xkcd.com/221/ https://xkcd.com/221/
csense 3y ago
That's the stupidest encryption key I ever heard in my life! That's the kind of thing an idiot would have on his luggage! [1] https://www.youtube.com/watch?v=B-NhD15ocwA https://www.youtube.com/watch?v=B-NhD15ocwA
- mangamadaiyan 3y ago
  Somewhere, hypothetically deep inside NK, someone is probably thinking "That's amazing, I've got the same combination on my luggage!"
  - netsharc 3y ago
    Do NKers have suitcases? It's not like (at least in my head) many of them travel for leisure. What percentage can even leave the country? For the rest, it seems like the country is such a police state that no one would try to open your bags, making a combination lock unnecessary. A quick google just now does tell me there are NKers who travel overseas for work or studies..
    - boomboomsubban 3y ago
      North Korea has both a middle/upper class and criminals. Foreign tourism may be rare, but domestic travel is a thing.
      - EliRivers 3y ago
        Oh boy, it sure does have an upper class! They are super hardcore about it.
        deleted 3y ago
        [deleted]
    - waste_monk 3y ago
      >A quick google just now does tell me there are NKers who travel overseas for work or studies.. I recall reading something along the lines of their being tens of thousands of North Koreans working in Russia, more or less in slavery, doing things like construction where the work is so dangerous that even the locals won't pick it up.
    - billpg 3y ago
      The nobility get to travel. The serfs have to stay and work for their lord.
      - Gordonjcp 3y ago
        Kind of like the US, then?
        DontchaKnowit 3y ago
        Not really gues like the cost of a few bags of cheetos will get you on a train halfway across the country
        School-Cotton 3y ago
        North Korea is nothing like the US. What a ridiculous comment.
selectodude 3y ago
<Patrician|Away> what does your robot do, sam <bovril> it collects data about the surrounding environment, then discards it and drives into walls http://bash.org/?240849 http://bash.org/?240849
mjg59 3y ago
The problem with tying encryption to the serial number is that it becomes harder to distribute the material in the first place - either you need to know the serial number of the device you're going to put a drive into so you can pre-encrypt the data, or you need to have extra code to encrypt the data on first boot (and then make very sure that first boot happens in the factory). Moving to a static key makes it much easier to handle all of this. Anyone who's able to reverse engineer the system well enough to obtain a static key would probably be able to figure out the dynamic algorithm anyway, so the practical outcome isn't terribly different.
- robertlagrant 3y ago
  This is the problem. Even if it used the real key, they could just change it. It's slightly harder, but not much.
captainmuon 3y ago
When I read this, it sounded very familiar. This is also how some Allwinner tablets derive their MAC address. And wow, it turns out it is an Allwinner based device! I found it out because we sold Allwinner devices and customers complained that after an update the MAC address changed. The MAC address is set at boot time, but the algorithm used was different in the binaries we got from Allwinner, and the source we used for compiling the update. They do have a reputation for not taking GPL too seriously. I could imagine in this case, the source-code version of libcdx_stream was supposed to give the proper machine ID that Allwinner uses in other places, but somebody sloppily patched it out for their encryption scheme.
- psychphysic 3y ago
  Makes sense to me, who could be bothered to clone drives and then have to wait for them to be re-encrypted per device. Instead of just modifying the firmware once? Especially considering the devices would be sold to strangers and it's quite unlikely the harddrive would make it into the hands of someone without access to the paired system. I suppose the re-encrypting could just be a second key, but still would require processing that is not worth anyone's time.
nottorp 3y ago
I'm betting they started with per device encryption and then someone in management figured out they'd need to generate one image per device and that would cost too much, so they left the code already written in and just added the hard coded key at the end.

by Sytten 3y ago

LegitShady 3y ago

Not the first time something like this has happened. I believe it was the PS3 that was hacked to get Sony's private key because the ECDSA algorithms random factor 'k' always picked 4.

ljouhet 3y ago
https://xkcd.com/221/ https://xkcd.com/221/

csense 3y ago

That's the stupidest encryption key I ever heard in my life! That's the kind of thing an idiot would have on his luggage! [1] https://www.youtube.com/watch?v=B-NhD15ocwA https://www.youtube.com/watch?v=B-NhD15ocwA

mangamadaiyan 3y ago
Somewhere, hypothetically deep inside NK, someone is probably thinking "That's amazing, I've got the same combination on my luggage!"
- netsharc 3y ago
  Do NKers have suitcases? It's not like (at least in my head) many of them travel for leisure. What percentage can even leave the country? For the rest, it seems like the country is such a police state that no one would try to open your bags, making a combination lock unnecessary. A quick google just now does tell me there are NKers who travel overseas for work or studies..
  - boomboomsubban 3y ago
    North Korea has both a middle/upper class and criminals. Foreign tourism may be rare, but domestic travel is a thing.
    - EliRivers 3y ago
      Oh boy, it sure does have an upper class! They are super hardcore about it.
      - deleted 3y ago
        [deleted]
  - waste_monk 3y ago
    >A quick google just now does tell me there are NKers who travel overseas for work or studies.. I recall reading something along the lines of their being tens of thousands of North Koreans working in Russia, more or less in slavery, doing things like construction where the work is so dangerous that even the locals won't pick it up.
  - billpg 3y ago
    The nobility get to travel. The serfs have to stay and work for their lord.
    - Gordonjcp 3y ago
      Kind of like the US, then?
      - DontchaKnowit 3y ago
        Not really gues like the cost of a few bags of cheetos will get you on a train halfway across the country
      - School-Cotton 3y ago
        North Korea is nothing like the US. What a ridiculous comment.

selectodude 3y ago

<Patrician|Away> what does your robot do, sam <bovril> it collects data about the surrounding environment, then discards it and drives into walls http://bash.org/?240849 http://bash.org/?240849

mjg59 3y ago

The problem with tying encryption to the serial number is that it becomes harder to distribute the material in the first place - either you need to know the serial number of the device you're going to put a drive into so you can pre-encrypt the data, or you need to have extra code to encrypt the data on first boot (and then make very sure that first boot happens in the factory). Moving to a static key makes it much easier to handle all of this. Anyone who's able to reverse engineer the system well enough to obtain a static key would probably be able to figure out the dynamic algorithm anyway, so the practical outcome isn't terribly different.

robertlagrant 3y ago
This is the problem. Even if it used the real key, they could just change it. It's slightly harder, but not much.

captainmuon 3y ago

When I read this, it sounded very familiar. This is also how some Allwinner tablets derive their MAC address. And wow, it turns out it is an Allwinner based device! I found it out because we sold Allwinner devices and customers complained that after an update the MAC address changed. The MAC address is set at boot time, but the algorithm used was different in the binaries we got from Allwinner, and the source we used for compiling the update. They do have a reputation for not taking GPL too seriously. I could imagine in this case, the source-code version of libcdx_stream was supposed to give the proper machine ID that Allwinner uses in other places, but somebody sloppily patched it out for their encryption scheme.

psychphysic 3y ago
Makes sense to me, who could be bothered to clone drives and then have to wait for them to be re-encrypted per device. Instead of just modifying the firmware once? Especially considering the devices would be sold to strangers and it's quite unlikely the harddrive would make it into the hands of someone without access to the paired system. I suppose the re-encrypting could just be a second key, but still would require processing that is not worth anyone's time.

nottorp 3y ago

I'm betting they started with per device encryption and then someone in management figured out they'd need to generate one image per device and that would cost too much, so they left the code already written in and just added the hard coded key at the end.