Skype55 deobfuscated version released

http://skype-open-source.blogspot.com/2012/03/skype55-deobfuscated-released.html

by mariuz • 14 years ago

133 66 14 years ago

skype-open-source.blogspot.com

martey• 14 years ago

I don't understand this project. According to the creator, the purpose is "to make Skype open source" [1], but the project relies on binary files distributed by Skype. As a result, they have repeatedly faced DMCA notices [2] which regularly causes the source code is become unavailable.

An earlier blog post made it to Hacker News. I found the comment at http://news.ycombinator.com/item?id=2611728 insightful.

[1] http://skype-open-source.blogspot.com/2011/06/skype-protocol...

[2] https://github.com/skypeopensource/skypeopensource/issues/1

beza1e1• 14 years ago

For a clean room reverse engineering they could analyse the Skype binaries to document the protocol.

kogir• 14 years ago

Clean room requires that those creating the implementation don't have access to the original implementation. Having the same person(s) inspect the binaries and create an implementation fails this requirement.

See: http://en.wikipedia.org/wiki/Clean_room_design

rplnt• 14 years ago

Can't be the protocol itself patented?

Deinumite• 14 years ago

Yeah... I don't really understand what their issue is to be honest. It really is up to Skype if they want to release their protocol. You can't really force anyone into being open source. I actually disagree with their methods, its the same as a closed source company violating the GPL when they steal source code like this.

dchest• 14 years ago

It really is up to Skype if they want to release their protocol.

This isn't true. Nothing stops you from analyzing and implementing their protocol. This project, however, is only the first part.

nikcub2• 14 years ago

Reverse engineering has given us so many good things - Samba, OpenOffice, Wine, MAME (and other emulators) the bitkeeper debacle, which gave us git. Then there are all the Linux and UNIX drivers that were written by reverse engineering windows drivers because vendors weren't supporting those operating systems.

The guys who reverse engineered Exchange Server were acquired by Cisco.

I don't understand why the Skype case is 'evil'. distributing the binaries may violate terms of service, but it isn't illegal in large parts of the world.

tibbon• 14 years ago

Remember, open source doesn't mean free. It just means you can view the source.

_delirium• 14 years ago

That's not the usual use of the term in tech. Even Microsoft, after some initial confusion, has settled on using "shared source" rather than "open source" to describe situations where they share the source but not under an open-source-definition-compatible license.

simonw2• 14 years ago

The Open Source Definition provides a very clear explanation of when the term open source should be used: http://www.opensource.org/osd.html

dr_rezzy• 14 years ago

For spamming this is a gold mine.

stanley• 14 years ago

Mind elaborating?

helmut_hed• 14 years ago

I don't believe that this is (despite stated intent) making Skype "open source". It would be more accurate to say that this work makes it possible to create an open-source wrapper around a proprietary kernel. This wrapper could then be updated as times change to support different platforms, as long as the linkage to the kernel was compatible. This neatly steps around some legal problems because:

1) The wrapper itself is not encumbered (unless some patent issues applied)

2) Users with a legal copy of Skype on one platform can apply the wrapper themselves (though they cannot redistribute the result)

You can even imagine distributing (via, say, github) a kit consisting of the wrapper and a tool that applies that wrapper to a user-supplied Skype binary. All legal as far as I know (IANAL etc.)

gcb• 14 years ago

This already happens and is dismissed on the linked blog comments.

But i have no idea what it IS then

drivebyacct212• 14 years ago

Why? With that much work and grey legal areas, it's much easier to embrace WebRTC and just try to evangelize it or applications that use it. I think Skype will be a thing of the past soon enough. WebRTC is already quite impressive for a few lines of JavaScript (and optionally C++ if you want to do server side muxing and reduce the number of connections needed in a multiparty "call").

In a couple days I wrote a pretty simple, but functional multiparty video chat web-app. I'm just waiting for Chrome to support multiple PeerConnection objects.

I guess I don't understand the obsession with trying to interop with Skype.

ceejayoz• 14 years ago

> I guess I don't understand the obsession with trying to interop with Skype.

Massive existing user base?

Joeboy3• 14 years ago

>> I guess I don't understand the obsession with trying to >> interop with Skype.

> Massive existing user base?

Web browsers have even more massive user base though, and (insha'Allah) will include WebRTC as standard before too long.

forrestthewoods2• 14 years ago

No way. Skype is hands down the highest quality online voice chat system. I play online games with friends and we always use Skype for voice chat.

I don't know what sort of audio processing magic Skype is performing but whatever it is it's incredibly good. My group tried lots of alternatives (Ventrilo, Mumble, TeamSpeak, Steam, etc) and Skype is easily the best. All the others have issues with poor quality, speaker feedback, and/or keyboard sounds. Skype has none of that. Crystal clear voice chat even when the mic is directly beside a clickety clackety keyboard.

It'll take a hell of a lot more then a simple web client to dethrone Skype.

drivebyacct212• 14 years ago

It's not as if Mozilla and Google chose rinkydink codecs for WebRTC...

Anderkent• 14 years ago

Silly how it must vary between places, for me skype has always been terrible for conferences, with delay of a couple seconds, constant disconnections, using ridiculous amounts of bandwidth, attempting to modify volume of other programs (!?) etc., while Ventrilo/TeamSpeak never had any issues.

Skype55 deobfuscated version released

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