This is part of a very deep dependency chain. I'm sniffing at making all
the add_clienthello callbacks const. Between HelloVerifyRequest,
HelloRetryRequest, and soon ECH, we're creating lots of ClientHellos per
connection. That's probably easiest to manage if constructing a
ClientHello had no side effects.
Update-Note: The change to the return type isn't quite compatible, but I
only found one caller of this function, which has since been fixed. (If
we need to return a non-const value for compatibility, we can do that
and document that the caller should not mutate the output.)
Change-Id: I21f18f7438920a5b03d874fa548f054af3a42c4a
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/47664
Reviewed-by: Adam Langley <agl@google.com>
David Benjamin
Adam Langley