TLS 1.3: simultaneous support for TLS 1.2 and 1.3

[daverodgman]

Enable support for building the library with support for both 1.2 and 1.3 available.

[yuhaoth]

current work task: hannestschofenig#297

• 3 PRs are in review ,
  • Add signature_algorithms field to mbedtls_ssl_config  hannestschofenig/mbedtls#322,
  • add handshake dispatch hannestschofenig/mbedtls#328 ,
  • Enable simultaneous support in mbedtls_ssl_setup hannestschofenig/mbedtls#337
• The status is compiler pass and test fail.

Other tasks in backlog

• Build and test fail with some options hannestschofenig/mbedtls#301, tasks for test options status.
  • Verify and fix different options: disable MBEDTLS_SSL_USE_MPS, enable MBEDTLS_PROTO_* and nbio=0 hannestschofenig/mbedtls#297
  • Verify and fix different options: disable MBEDTLS_SSL_USE_MPS, enable MBEDTLS_PROTO_* , disable TLS1_3 and nbio=0  hannestschofenig/mbedtls#298
  • Non MPS ssl-opt.sh test failed with nbio=2 hannestschofenig/mbedtls#238, own by FB guys.
  • Need to breakdown into more tasks later.
• Add state machine functions to improve maintainability hannestschofenig/mbedtls#338
• Add macro and function for choosing message layer hannestschofenig/mbedtls#339

Others:

• Some PR can be upstreamed to development branch.
• Add more different test in all.sh and ssl-opt.sh

[mpg]

From the above comment linking to PR in the prorotype's repo, and according to @yuhaoth's memories, this was about doing the work in the prototype, so it doesn't seem relevant for upstream, much less for the upstream MVP.

Hence, moving out of the MVP epic.

[ronald-cron-arm]

Work on prototype that we are not going to do as such. The simultaneous support of TLS 1.2 and TLS 1.3 in the prototype will result from the work of making the prototype and the upstream support converge through regular merge of development into the prototype.