Skype 5-way Calling Limit Cracked 427
BobPaul writes "It turns out when Skype limited 10 way calling to Intel Processors only it really was arbitrary! Maxxus has a patched version of Skype that allows 10-way calling regardless of the processor installed. There's also info about the patch: "The patch is the result of two phases: code analysis and design of the patch. The code analysis, or reverse engineering, reveals the relevant code block, which overrides Skype's limitation for Intel's dual-core CPUs. The patch design isolates the minimal set of instructions that need to be modified to cancel this limitation." Windows only so far."
"Arbitrary"? (Score:5, Interesting)
And now that it's in the open, (like that was going to take very long?) I wonder if they'll remove the block?
Optimization is where? (Score:5, Interesting)
I'm having trouble understanding what this optimization that used the special features of Intel chips (presumably their high power) was. It looks from the patch that they just check who the manufacturer is, and if it is not AMD, they pretend your computer doesn't have the power to host 10 participants.
What's also interesting is that folks likely signed up for SkypeOut and other paid products not realizing that they would be treated differently depending on what chipsets they happen to use, especially as that choice matters almost no where else. They should give more warning about this to paid users.
This focus on locking software into specific vendor chips seems a dangerous one. No longer will it be the best chip that will win, but the focus goes to competing on locking up software applications. The proprietary unix'es went down that path, and it would be sad if Intel managed to get that to happen here.
Re:Optimization is where? (Score:4, Interesting)
My guess, like yours, is that this is blatant marketing crap. But it would be nice to see some tests of how many people can be usefully conferenced on different hardware. Skype is a CPU pig, and it's possible that they really have optimized it for some Intel-specific feature.
Limit (Score:5, Interesting)
Re:Poor programmer at Skype (Score:1, Interesting)
Skype are acting like utter jackasses, and this is a nice big point for OSS in the open-vs-closed software wars, but it's really just marketing bullshit - Skype can do what they want with their software and caveat emptor... if it was something serious like Ford removing your car's side impact guards if you own a Hitachi garage door opener then maaaybe there would be a lawsuit there...
Re:"Arbitrary"? (Score:5, Interesting)
Don't Believe the Skype (Score:4, Interesting)
Or, so as not to break other programs that use cpuid (to determine which instructions they can run, for example) perhaps this could be done in a user-space way.
I'm thinking of artsdp as a model, so you would just launch your Skype client with something like "cpufake --cpuid='Genuine Intel Dual Core We Like Skype' skype.bin" (or whatever it's called.)
I've got no idea how such a program would work, but the article did say the code was encrypted so I wonder if that would be an issue.
Re:Optimization is where? (Score:3, Interesting)
What I'd like to see is benchmarks, on Intel and Amd, with 10 clients attached. That way, we can see if the code is indeed optimized for Intel, or if it's just crap. I suspect it's crap.
If anything, I'd suspect we'd see Intel being, what, 10% or 15% less load. Which would be something, but not something which justifies a 50% crippling of AMD hardware. And it'd be funny if AMD actually performed better.
Yeah, someone should benchmark:
Origional Executable, 5 clients, Intel
Origional Executable, 5 clients, AMD
Origional Executable, 10 clients, Intel (for reference against modifications)
Modified Executable, 10 clients, Intel
Modified Executable, 10 clients, AMD
and let us know what the real beef is.
~Will
don't forget openwengo (Score:1, Interesting)
Comment removed (Score:3, Interesting)
10, or more? (Score:3, Interesting)
Of interest here is also the code marked with (*). It reveals that the string is somehow used if a certain memory location has the value 4. Theory is, this 4 means "4 additional conference members";
Is that possible that by modifying some variables...we can have unlimited number of user in the conference?
Intel compiler? (Score:3, Interesting)
Re:Indeed... (Score:5, Interesting)
I tried skype a couple times (mostly because some girl talked me into it), but she wasn't worth it. The lack on interoperability totally killed it. The last thing I need is yet another app running on my main console all the time. Asterisk runs happilly on my server in the corner and rings my normal home phones all over the house if someone is trying to reach me. I might even pay for a skype IAX2 or SIP access account. But being a closed system they are too much trouble to deal with.
Re:Lawsuit (Score:5, Interesting)
Re:Emulation would have worked too? (Score:3, Interesting)
Can't you get the OS to look through the code before it's executed and replace the offending instruction with a simulated version, like they do to workaround the pentium f00f bug?
Re:Aaaah Maxxuss (Score:5, Interesting)
Re:Optimization is where? (Score:3, Interesting)
I'd love to see some real comparative benchmarks betweent he chips using different instructions to achieve the same ends and see how they perform, but I'm not aware of any. At any rate, I can easily believe that the AMD chips aren't as good at executing the Intel instructions as the Intel chips are.
Re:Aaaah Maxxuss (Score:1, Interesting)
The purpouse of HDCP is to encrypt data to prevent real-time brute force attacks and ensure only licenced devices are communicating.
For Blu-ray Disc (and HD DVD if it survives) the copy protection that has to be cracked is in fact AACS.
Skype didn't break any laws. (Score:5, Interesting)
The reason this issue is important is that it seems likely Intel went to Skype, and in some way coerced/bribed them to do this. This could be extremely strong evidence in helping AMD with their current lawsuit against Intel. Hence AMD issuing a subpoena to Skype, to retrieve information that will show whether or not Intel is to blame for this limitation.
It's silly to hear people saying AMD should sue Skype. AMD doesn't care about skype, nor are they trying to run a huge campaign of lawsuits. They are only interested in forcing Intel to stop their current tactics which have arguably kept AMD from massive success in the OEM market.
Re:DMCA anyone? (Score:4, Interesting)
Re:Lawsuit (Score:2, Interesting)
One might argue that it does "force obsolescence" because Windows is so ubiquitous--you want to be able to run Vista, you gotta have an nVidia (sp?). But that isn't the case either, as you can turn off "aero" and use the "classic" look, which requires a less sophisticated graphics card.
Nice try giving a shot at Bill though...
Re:Lawsuit (Score:3, Interesting)
Re:should teach intel a lesson (Score:3, Interesting)
Exactly. So, why would skype want to make such a move if it obviously would lose sales from it also? If Intel has a hand in this, I don't see how it is legal for Intel and skype to make a deal that would make AMD and/or other CPUs look bad when they most likely can handle the conferences. Or if not, they can probably 'catch up' with Intel really quick. I don't know how the law works in the USA exactly and IANAL, but this sort of defamation is illegal in Europe (I don't know how much this [wikipedia.org] is relevant to this situation). It's one thing to add value to skype when you buy Intel (optimize it for intel CPUs) and another thing to remove value when you buy AMD (remove features it probably is capable of handling), ultimately making AMD look bad unfairly.
I could be sort of ok with this if it was a QoS thing, but if it was, it shouldn't have been implemented by checking for the chips manufacturer and th user should be given the opportunity to "use at his own risk". At least skype should have announced the feature Intel's CPUs have AMD lacks. I think this is a dangerous road to go down. Imagine a future where you would choose the programs you run based on the manufacturer of the CPU you use. Even worse, imagine the deadlocks where you need to run 2 programs that favor different manufacturers. The worst part being that the 'obsticales' are completely artificial. And the competition wouldn't be on each cpu's merits, but on the manufacturer's connections.
Re:Maxxuss (Score:1, Interesting)
I'd rather such cracks were made public and explained clearly by someone with good command of the English language than wrapped up in some lame warez-style
I am more impressed by his clear explanation of the technique than the crack itself (which is pretty standard stuff, not special or anything)
It -is- AMD theyre locking out. (Score:2, Interesting)
Re:Aaaah Maxxuss (Score:1, Interesting)
The chip takes the raw data from the GPU's framebuffer and tranceives it to DVI or HDMI outputs. You will only get uncrypted transfers when the resolution is below or equal to 960x540.
For all resolutions above 960x540 the chip will enforce HDCP. This enforcement is part of the licence and can not be controlled by software.
That's why the newst nVidia and ATI gfx cards that supposedly were HDCP compatible turned out to be incompatible. They thought they could add HDCP into the firmware of their cards later, but they soon found out this would have violated the licence for playing HD-DVD.
So all new cards will have to be mounted with licenced HDCP hardware chips.
x86 Apples? (Score:2, Interesting)
Re:Law suit bullshit... (Score:2, Interesting)