Post Syndicated from Lennart Poettering original https://0pointer.net/blog/projects/apple-sucks.html
So,
Apple now blocks third-party software from accessing iPods. But is behaviour like that
news? No, unfortunately not at all.
Let’s have a look on two technologies that are closely related to the iPod
and Apple-style media playback: DAAP (Digital
Audio Access Protocol) and RAOP
(Remote Audio Output Protocol). RAOP is the protocol that is spoken when
you want to output audio from iTunes over the network on your AirPort base
station. DAAP is the popular protocol which you can use to swap music
between multiple iTunes instances on a LAN. Both technologies use cryptographic hashes to block interoperable alternative implementations.
Now, the RAOP client crypto key has been extracted from iTunes, hence its
now possible to implement alternative software that takes the role of iTunes
and streams audio to an AirPort. However, noone managed to extract the RAOP
server key yet, hence noone is able to implement software that exposes itself
as AirPort-compatible audio sink on the network, so that iTunes could stream
data to it.
With DAAP it’s a similar situation: iTunes uses cryptographic hashes to make
sure that only real iTunes instances can swap audio with each other. This key
has been broken multiple times, hence there are now a couple of alternative
DAAP implementations, which can swap audio with iTunes (Rhythmbox being one
example). However, with iTunes 7 Apple changed the cryptographic key once
again, and until now nobody managed to break it.
So basically, Apple now dongles AirPorts to iTunes, iTunes to iTunes and
iTunes to iPods. The whole Apple eco-system of media devices and software is dongled
together. And none of the current iterations of the underlying technologies
have been fully broken yet.
While the audio files you can buy at the iTunes shop may now be DRM-free,
you’re still locked into the Apple eco-system if you do that. They replaced DRM with
vendor lock-in.
This lock-in behaviour is childish at best. DAAP once was the de-facto
standard for swapping media files in LANs. Swapping files in LANs is
perfectly legitimate and legal. Then, Microsoft/Intel started to include a
similar technology in UPnP, the UPnP
MediaServer. An open technology that has now been included in endless media
server devices. Several Free Software implementations exist (most notably gUPnP). These days, uPNP MediaServer is
ubiquitous, DAAP is no more. Apple had the much better starting position, but
they blew it, because of their childish locking-out of alternative
implementations.
I believe that DAAP is the superior protocol in comparison to UPnP
MediaServer. (Not really surprising, since I wrote most of Avahi, which is a free implementation of
mDNS/DNS-SD (“Zeroconf”), the (open) Apple technology that is the basis for
DAAP.) However, due to the closedness of DAAP I would recommend everyone to
favour UPnP MediaServer over DAAP. It’s a pity.
Both DAAP and UPnP MediaServer are transfer protocols, nothing that is ever
directly exposed to the user. Right now, Free Software media players support DAAP much better than UPnP MediaServer. Hopefully, they will start to
abstract the differences away, and allow swapping music the same way over DAAP
and over uPnP. And hopefully, DAAP will eventually die or Apple will open
it. They have shown that they are able to change for the good, they became much
more open with WebKit, and they changed the license of Bonjour to a real Free
Software license. Let’s hope they will eventually notice that locking users in
makes their own technology irrelevant in the long term.
Oh, and let’s hope that Jon finds the time to break all remaining Apple crypto keys! Jon, DAAP 7.0, and the RAOP server key is waiting for you! I’d love to make PulseAudio RAOP-compatible, both as client and as server.