Implement osrtp rfc8643

[kd7hto]

Hello. Please review this code and consider it for the master branch. It includes some modifications to support the implementation of rfc 8643 (Optional SRTP or OSRTP). In addition to this code change, we also added the following xml change:

[signalwire-ci]

Unit-tests failed: https://public-artifacts.signalwire.cloud/drone/signalwire/freeswitch/328/artifacts.html

[andywolk]

@kd7hto

get_time
  test/test_aws.c(209):
    chk_eq_str: '20210106T184838Z' != '20210106T184839Z'

Here is the failing test:
https://github.com/signalwire/freeswitch/blob/master/src/mod/applications/mod_http_cache/test/test_aws.c#L209
and it is failing on:

fst_check_string_equals(time_stamp_test, time_stamp);

saying time_stamp_test does not match time_stamp.

I restarted Drone CI to see if that test fails again.
Purpose of the tests is to make sure that changes do not break anything.
So now we need to make sure that this PR does not break anything.

[kd7hto]

@andywolk so it looks like it passed the automation build and test. Is there something else I need to be doing to further this along? Do I need to get someone assigned to review the proposed changes?

[crienzo]

@andywolk switch_core_media changes will not affect mod_http_cache.

[crienzo]

Big problem with accepting changes to this part of FreeSWITCH is there is no evidence it is correct. Hard to validate by gut instinct.

[kd7hto]

@crienzo, @andywolk, thanks for taking a look at this. So if you've looked, the RFC is not a big one. We have several endpoints that have the ability to signal for OSRTP that I'm happy to schedule some time with you to do some testing if that helps.

The alternative as I see it is that we keep working with a one-off, however, we would very much like this to make it into the code base so that it is there for everyone in future releases.

Please let me know if I can help you with some testing with our endpoints.

Thank you.

Eugene Christensen

[kd7hto]

@andywolk @crienzo, please advise me on this. Is there no option for working forward to inclusion into the baseline product?

Thank you.

Eugene.

[crienzo]

There is. We have quite a backlog at the moment, but can work to move forward on this.

[kd7hto]

Thank you.