secureToken in rtmp streams

[thefallenghost]

Hi I'm new to rtmpdump and I was wondering if there's any way to decrypt the secureToken on some rtmp streams so I can use the -T? For example:

rtmpdump -r rtmp://198.144.158.138.:80/pub/aJNMYafWLD4qr7xhmutf -s http://www.castto.me/_.swf -p http://static.castto.me

I get :
secureToken..Hd85f18039955f2d48b59627eb51b054a2ec6 d244e6d2c0d559a96f119122fbbb21056ab0
secureTokenResponse............$ca8db014-36d2-46c1-af61-de9d2976b183C

For this stream in particular, it redirects (I think) to rtmp://cdn.castto.me:1935/pub/_definst_/aJNMYafWLD4qr7xhmutf. This doesn't work in rtmpdump (I'd be gratuful if someone explained how to make it work ) but it works in ffmpeg without any token!
edit: just realized it only gets you the current frame in ffmpeg and gets stuck there . I haven't been able to make this kind of stream work (2nd one) in rtmpdump while they did play in ffmpeg in the past, so I'd still like to know how!