tree b10b17036aacc666fbe41061f063521df1798ac8
parent 2d691ca60ddb535a7a54fb07fd2252bd6017bee7
author David Benjamin <davidben@google.com> 1611180632 -0500
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1611183452 +0000

Define TLSEXT_TYPE_quic_transport_parameters to the old code point for now.

QUICHE currently does not know to call
SSL_set_quic_use_legacy_codepoint, picking up the current default of the
legacy code point. It then assumes that the
TLSEXT_TYPE_quic_transport_parameters constant may be used to extract
transport parameters, so after
https://boringssl-review.googlesource.com/c/boringssl/+/44704, it
breaks.

To smooth over the transition, we now define three constants:
TLSEXT_TYPE_quic_transport_parameters_legacy,
TLSEXT_TYPE_quic_transport_parameters_standard, and the old constant.
The old constant will match whatever the default is (for now, legacy) so
the default is self-consistent. Then plan is then:

1. BoringSSL switches to the state in this CL: the default code point
   and constant are the legacy one, but there are APIs to specify the
   code point. This will not affect QUICHE, which only uses the
   defaults.

2. QUICHE calls SSL_set_quic_use_legacy_codepoint and uses the
   corresponding _legacy or _standard constant. It should *not* use the
   unsuffixed constant at this point.

3. BoringSSL switches the default setting and the constant to the
   standard code point. This will not affect QUICHE, which explicitly
   configures the code point it wants.

4. Optional: BoringSSL won't switch the default back to legacy, so
   QUICHE can switch _standard to unsuffixed and BoringSSL
   can remove the _standard alias (but not the function) early.

5. When QUICHE no longer needs both code points, it unwinds the
   SSL_set_quic_use_legacy_codepoint code and switches back to the
   unsuffixed constant.

6. BoringSSL removes all this scaffolding now that it's no longer
   needed.

Update-Note: This this fixes a compatibility issue with
https://boringssl-review.googlesource.com/c/boringssl/+/44704.

Change-Id: I9f75845aba58ba93e9665cd6f05bcd080eb5f139
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45124
Reviewed-by: David Schinazi <dschinazi@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>