This is kind of annoying (even new state is needed to keep the layering
right). As part of aligning the read paths of the TLS 1.2 and TLS 1.3
state machine, we'll want to move to states calling
ssl_hash_current_message when the process the message, rather than when
the message is read. Right now the TLS 1.2 optional message story
(reuse_message) depends on all messages preceded by an optional message
using ssl_hash_message. For instance, if TLS 1.2 decided to place
CertificateStatus before ServerKeyExchange, we would not be able to
handle it.
However, V2ClientHello, by being handled in the message layer, relies on
ssl_get_message-driven hashing to replace the usual ClientHello hash
with a hash of something custom. This switches things so rather than
ClientHellos being always pre-hashed by the message layer, simulated
ClientHellos no-op ssl_hash_current_message.
This just replaces one hack with another (V2ClientHello is inherently
nasty), but this hack should be more compatible with future plans.
BUG=128
Change-Id: If807ea749d91e306a37bb2362ecc69b84bf224c9
Reviewed-on: https://boringssl-review.googlesource.com/13265
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
1a444daca6