iTunes streaming unleashed

An enterprising developer has found a way to emulate Apple's AirPlay protocol and extend its functionality to allow streaming of audio to any computer without the need for special equipment, says PCWorld.

According to his Web site, Australian James Laird managed this feat by taking apart his girlfriend's malfunctioning AirPort Express and examining the contents of its ROM, where the device stores its firmware.

This, in turn, yielded the cryptographic keys that the company uses to protect the content streamed via AirPlay.

Compatible devices need those keys both in order to identify themselves to any copy of iTunes running on a network and to decrypt the audio that is streamed to them; as a result, the keys are closely guarded by Apple, which normally only hands them over to licensed accessory manufacturers.

Wired says, Laird calls his open source Perl script Shairport, which lets hardware and software receive AirTunes music from iTunes.

Apple uses a public-key encryption scheme for AirTunes streaming. This lets anyone encrypt and stream audio to the AirPort Express (or other compatible device), but iTunes would only stream to Apple devices. Now, with Shairport, iTunes can be tricked into streaming audio to anything at all.

Laird did this by cracking open the AirPort Express (literally), dumping the ROM and then searching around for the private key.