We'll need to maintain two transcripts on the ECH client and then, once
we know which of ClientHelloOuter or ClientHelloInner is used, overwrite
the default transcript with the alternate one.
Rather than indirect through a pointer, move support is easy enough.
Then this can just be hs->transcript = std::move(hs->inner_transcript).
Bug: 275
Change-Id: Id4b0a0a48b956cd65ce8fc3dacfd16eebe2eb778
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/47993
Reviewed-by: Adam Langley <agl@google.com>
Our use-case for this does not require optimisation at the current time,
so a clean C implementation is fine.
Change-Id: I8f29572c33e8dbcc37961c099c71c14aafc8d0a3
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45164
Reviewed-by: David Benjamin <davidben@google.com>