AW: md5 / randomness (Re: audio support for application interfacewith nanoBTS) - OpenBSC

4 Oct 2009

On Sunday 04 October 2009 13:51:29 Harald Welte wrote:
...
  one further note on the missing md5 file:

 As it seems it is only used to generate a pseudo-random 32bit value 
 for use in the SSRC:  I'd rather not introduce a copy of MD5 for that.

 There are two options to take:

 1) simply use the same [not very random] method as we use for the TMSI

 2) introduce a dependency to openssl and use that.  Given that nanoBTS
    also support OML/RSL over SSL/TLS, I think sooner or later we will
    have to add that dependency anyway. 
hi,

i think that very good random is not required. in our case we don't have
large scale RTP conferences with thousands of sources. we have to choose
a random number that just differs from the one selected by nanoBTS. (the
RTP session will fail afer some seconds when using same SSRC.)

andreas