[asterisk-dev] [Code Review] Fix SRTP for changing SSRC and multiple a=crypto SDP lines

[Terry Wilson]

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This is an automatically generated e-mail. To reply, visit:
https://reviewboard.asterisk.org/r/878/
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Review request for Asterisk Developers.


Summary
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Adding code to Asterisk that changed the SSRC during bridges and masquerades broke SRTP functionality. Also broken was handling the situation where an incoming INVITE had more than one crypto offer. This patch caches the SRTP policies the we use so that we can change the ssrc and inform libsrtp of the new streams. It also uses the first acceptable a=crypto line from the incoming INVITE.


This addresses bug 17563.
    https://issues.asterisk.org/view.php?id=17563


Diffs
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  /branches/1.8/channels/chan_sip.c 283320 
  /branches/1.8/include/asterisk/res_srtp.h 283320 
  /branches/1.8/main/rtp_engine.c 283320 
  /branches/1.8/res/res_rtp_asterisk.c 283320 
  /branches/1.8/res/res_srtp.c 283320 

Diff: https://reviewboard.asterisk.org/r/878/diff


Testing
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I tested by 1) Setting up Polycom phones to send two a=crypto lines 2) Changing SIP hold/unhold to call the rtp change_source callback to verify that changing source worked 3) Doing transfers that would cause a masquerade and therefore a source change 4) astobj2 show stats to verify that there were no object leaks with the above tests.


Thanks,

Terry