gle.ovo.

RTMPE and DMCA

In case you don’t know, Adobe has issued a DMCA against open source software rtmpdump that was hosted on SourceForge.

Let’s make a short analysis on what’s going on :

The RTMP protocol is a binary exchange format that is implemented by the Flash Player and is mainly used for audio/video streaming, but also realtime data exchange.

There are several RTMP servers available. At first there was only the Flash Media Server (FMS) which is very expensive, and after some years RTMP has been reverse engineered and documented, so open source video streaming servers were built : this includes Red5 and my own haXeVideo

Early in January, Adobe announced that they would “open” the RTMP protocol. That didn’t change much since we already knew most of it, but it was a nice move since it would mean that an official documentation would be made available, and would be maintained with protocol changes and improvements.

IMHO opening a protocol is often a win-win situation. It enables people to build their own custom software based on your technology – making it much more a standard. Still, by having a standard, you can still get a lot of clients that want to buy your brand as long as your technology is not too bad, so it brings a sane competition based on software quality and not on any kind of vendor lock-in. It also allows open source software to develop the technology much further than what you could have been doing by yourself.

However, around the same time, Adobe added a new feature to FMS which is an encrypted stream that only the Flash Player can decode. This is called RTMPE and I guess it was build as a marketing argument for FMS clients which wanted their content protected by DRM .

Of course, most of you reading this know that the whole thing is just bullshit, because if the Flash Player can decrypt the stream, then once the encryption key is known any software can decrypt it as well. And since the Flash Player run on your computer inside your memory, finding the key is not something very hard…

So, the folks being the rtmpdump software found or someone give them the RTMPE encryption key used by Flash Player and they added it to the software, so it can work as well on encrypted streams, which can be useful if you want to debug your application for instance.

Sadly, in the US, there is something known as software patents and DMCA (read more about it on Wikipedia if you don’t know about it). That’s why SourceForge, which is US based, removed the rtmpdump software as soon as it received Adobe complain.

Trying to be “open” is definitely not compatible with using DRM which is just a particular example of security-through-obscurity

And finally here’s a small hexadecimal poem :

    47656E75696E6520 41646F626520466C
    61736820506C6179 657220303031F0EE
    C24A8068BEE82E00 D0D1029E7E576EEC
    5D2D29806FAB93B8 E636CFEB31AE

Can’t wait to receive my own DMCA now…

EDIT : here’s the complete RTMPE protocol documentation



Comments are closed.