Slashdot Mirror
New "Secure" Xbox Cracked In Under A Week
ilsie writes "Numbnut says it all in his post at xboxhacker.net. To quote his post, 'On behalf of the Xbox Linux Team, I am proud to announce that at 10:45BST the 'v1.1' secure version of the Xbox was proven to be running arbitrary BIOS code in a normal 256KByte modchip - with no additional hardware required. In short, in under a week we were able to normalize the new box to enable it to interoperate with Linux properly.'"
It brings me to this following tought: You can't protect anything that user has physical access to. Same situation is observable amongst CD 'copy (mis)protection' . Smart lads crack it in one week session. Maybe people should stop wasting money on copy proections and focus instead on actual product?
Lone Gunmen crew.
AMD didn't reverse engineer Intel's CPUs. They used to work together on processors.
Here's a thread you need to study.
it's in my head
Disclaimer: I am numbnut.
The 1.1 version of the Xbox is certainly designed to be Palladium Lite. The concept is that no code is executed unless it matches a one way hash signature. The only exception is the boot ROM (512 bytes) which lives in the nVidia-designed MCPX chip; this is used to validate the next code to execute, which validates the next code to execute and so on.
Unfortunately for MS (and perhaps nVidia), they chose a hashing algorithm which already had a known flaw. The hash, which works on QWORDS (64-bit quantities) is completely insensitive to b31 and b63 of a QWORD both being inverted.
Doubly unfortunately for MS, the VERY FIRST DWORD of the hashed region is the entry point, and contains a long relative jump. The effect of flipping b31 and b63 on this QWORD is to retarget the jump to RAM.
Triply unfortunately for MS, they have a small interpreter built into their ROM code, whose instruction set is capabel to to IO amd memory r/w before the bootrom is validated and executed. It was trivial to add some memory writes to the interpreted code stream to prep the memory targetted by the modified jump with a jump back into the flash.
The end result is perversion of the hashed region in a way invisible to the hashing algorithm, and execution flow jumping to arbitrary code in the flash.
I urge anyone interested in both the technical detail and the larger issues raised by this to read the threads on http://www.xboxhacker.net as this is a much larger issue than simply another Xbox crack.
I would recommend you read up on the legal issue of reverse engineering because it is under attack and it is not at all obvious that it will survive. I believe the latest issue of ACM Communications has an excellent article on the topic. Recent US Government laws are very disconcerting.
AMD had some fantastic processes for -- at the time -- incredibly fine micron CMOS fabrication. Intel had dink to show in the fab department. In order to build a 386 faster than 16 MHz, that wouldn't require raised-floor equipment to keep cool, they needed a license on AMD's fabrication technology.
AMD exchanged this license, in exchange for a license on 286 and future technologies. The grounds for what these future technologies were comprised of were the grounds for the Intel/AMD legal battles of the '90's. The courts agreed this was inclusive of the i386 microcode, and the rest... is history
"Flyin' in just a sweet place,
Never been known to fail..."
While there is actually some logic to that position, there is some history that shows this is a bad approach for MS to take. Way back when, in 1997 Ian Goldberg presented a talk on (amoung other things) how in Europe incremental changes to the security of GSM networks lead to a whole "generation" of well trained hackers. I don't think MS is really looking to do that for the community.
That was the BASIC, which was based on a listing of Dartmouth BASIC which they found in the trash. All MS did was port it to a different processor. They bought MSDOS from another company.
That's right, MS's original flagship products weren't written by MS. They started as they meant to continue.
It is in the latest issue. It says 'reverse engineering under siege,' It doesn't attempt to predict who will win the legal matters, but explains what the threat is and how it will cause extreme harm to the tech industry if reverse engineering is taken away. Most slashdotters probably know most of that, but it is an interesting read.
"Never, never suspect the dreams within the dreams of dreaming children." ~The Amazon Quartet