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Microsoft sends GitHub DMCA shutdown for Skype open source project

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Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#71

Post by danbmil99 »

Iv wrote: post #13
Xuzz wrote: post #5

Please note: this is not an attempt to clean-room reverse engineer Skype, or even to reverse engineer and create an open-source replacement. As shown with things like WINE, Microsoft does not (and probably cannot) take them down. No, that's not what "Skype Open Source" project is. This is a confusingly misnamed attempt to attach code to patched copies of copyrighted official Skype clients. Microsoft is not overreachi…

How exactly is one supposed to make a clean-room reverse engineering in the absence of any documentation and sophisticated obfuscation on Skype's part ?

Seems like you could do it in theory by observing the protocol in action. Set up two machines a-skyping, sniff all the packets, think real hard, write code that interoperates with Skype clients.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#72

Post by ajasmin »

Can someone explain why Microsoft would go to such length obfuscating the Skype code and taking down derivative work?

Is their IP worth the trouble? Do they see interoperability as a threat? Are they afraid of misbehaving clients?

Surely it's not just a case of a lawyer having too much time on his hands.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#73

Post by danbmil99 »

snarkinatree wrote: post #51

How about "Skype: The Missing Technical Manual"? MS will contribute nothing to the state of the art of free voice and video calls over the internet. As is so often the case, what they purchased with the Skype deal was a user base. One that they could never obtain with the own products. There is a way to do this without violating copyright. Do not waste time duplicating the P2P element of Skype (the P2P protocol). P2P…

If you don't want to be compatible with Skype, you don't need their codecs. There are plenty of good voice codecs around, freely licensable.

The issue is how to tap into the existing Skype userbase -- receive and make calls to Skype clients -- from an open-source client.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#74

Post by grimboy »

skypeopensource wrote: post #39
uxp wrote: post #22

Earlier quoted context omitted.

"Skype: patched and recompiled to do other stuff" is a better title. Decompiling a proprietary product, changing a few lines of code, and then releasing that code doesn't make it "open source", it makes it stolen code (semantics of "piracy is not theft" aside, it's still not his code to be releasing in it's entirety.).

You are wrong. Decompiling is just allowing research deeper in skype-black-box. Project itself is here https://github.com/skypeopensource/epycs

If you want to stay within the law my understanding is that you need to distribute patches against decompiled Skype rather than decompiled Skype with patches applied, otherwise you're distributing a derivative work. This may still be a legal grey area though. IANAL, you ANAL, we all ANAL and that.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#75

Post by yukyukyuk »

skypeopensource wrote: post #40
Xuzz wrote: post #5

Please note: this is not an attempt to clean-room reverse engineer Skype, or even to reverse engineer and create an open-source replacement. As shown with things like WINE, Microsoft does not (and probably cannot) take them down. No, that's not what "Skype Open Source" project is. This is a confusingly misnamed attempt to attach code to patched copies of copyrighted official Skype clients. Microsoft is not overreachi…

You are wrong. You eyes are blind by hating. Stop. Listen the Nature. Skype-open-source code here: https://github.com/skypeopensource/epycs repo was closed because i host in download section deobfuscated skype5.5 binary, my fault.

I think "Stop. Listen the nature." is quite possibly the best adaptation of the "my hair is a bird, your argument is invalid" meme to tech arguments.

Seriously, this is a gem.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#76

Post by fffggg »

gtirloni wrote: post #67
caf wrote: post #66

Earlier quoted context omitted.

I wonder if that's a small enough component to count as de minimus copying.

Is there the notion of minimum copyright infringement?

Yes and no. There is no such notion in copyright law. Case law is unclear, however: http://en.wikipedia.org/wiki/De_minimis#Copyright

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#77

Post by nl »

Iv wrote: post #49
aGHz wrote: post #27

Earlier quoted context omitted.

The term "clean room" has a well established meaning you probably aren't aware of, I refer you to [1], it might clear up what the original reply was referring to. [1] http://en.wikipedia.org/wiki/Clean_room_design

I am well aware of the joke that is the clean-room process. Note that it supposes that the first team has access to the specification, source code, or any IP-encumbered indication about how the software in question works. In the case of Skype, the only public information we have is the binary.

Note that it supposes that the first team has access to the specification, source code, or any IP-encumbered indication about how the software in question works

No it doesn't.

The Wikipeda link[1] mentions the original IBM PC clean room implementation by Columbia Data Products.

It doesn't have the complete story of that, but from memory the way it worked was CDP had one team documenting how the BIOS responded to inputs, and then a totally independent team reimplementing that behaviour.

Most clean room implementation don't have access to a specification, let alone source code.

[1] http://en.wikipedia.org/wiki/Clean_room_design

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#78

Post by nl »

Tloewald wrote: post #69
recoiledsnake wrote: post #34

Earlier quoted context omitted.

Maybe then you're not "supposed" to do it? For example, there is no reverse engineered libraries for Facetime and iOS API. If you use Apple's libraries, they can come after you for copyright infringement.

Cappuccino is exactly such a reverse engineered library, as is gnu step. For that matter Linux is a reverse engineered drop in replacement for the unix kernel.

I'm not familiar enough with Cappuccino to comment, but GNU Step was an independent implementation of the published OpenStep interfaces. That isn't reverse engineering.

Linux is an independent implementation of the Posix interfaces.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#79

Post by snarkinatree »

danbmil99 wrote: post #73
snarkinatree wrote: post #51

How about "Skype: The Missing Technical Manual"? MS will contribute nothing to the state of the art of free voice and video calls over the internet. As is so often the case, what they purchased with the Skype deal was a user base. One that they could never obtain with the own products. There is a way to do this without violating copyright. Do not waste time duplicating the P2P element of Skype (the P2P protocol). P2P…

If you don't want to be compatible with Skype, you don't need their codecs. There are plenty of good voice codecs around, freely licensable. The issue is how to tap into the existing Skype userbase -- receive and make calls to Skype clients -- from an open-source client.

I agree tapping into the existing userbase is enticing. And that's no doubt what some people are trying to do (e.g. the Russians).

But all VOIP codecs are not created equal. Skype's success is not due to NAT piercing. Even though Skype easy to use, maybe easier than previous SIP alternatives, if calls sounded terrible, people would not use it. Skype's success is due to being usable and having decent sound quality. They did not use the decades old codecs other softphones used. They wrote new ones. And anyone can use them.

Using the same codec as Skype uses should not in any way bind you to their network. It has nothing to do with compatibility. It has to due with getting Skype-level sound quality. Quality that the older codecs have failed to deliver.

It's easy to get people to sign up for free voice and video calls. The key word is "free". You do not have to find inroads into the "Skype user base". Skype spread by word of mouth. If people learn about another client that works as well or better (same sound quality), and it's easy to use, they will almost certainly try it.

Forgive me if I have misunderstood what you were trying to say in your comment. But I do not understand your reasoning.

Re: Microsoft sends GitHub DMCA shutdown for Skype open source project

#80

Post by caf »

Xuzz wrote: post #70
caf wrote: post #66

Earlier quoted context omitted.

I wonder if that's a small enough component to count as de minimus copying.

At least 3/4 of those 4000 lines is directly copied from Skype, and that's just one file. I don't think that's small enough to not matter; anyway, if it really was so small, it should easily have been rewritten with original code.

It's the size compared to the size of the relevant copyrighted work that matters, not compared to the size of the work it's copied into.
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