tree b87ae57e395662dd0fe1004f6e55e52064e00ae1
parent 83ea777db54769c8bb95ddd62bf11c3946e6d3bf
author David Benjamin <davidben@google.com> 1581456441 -0500
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1581700817 +0000

Fix client handling of 0-RTT rejects with cipher mismatch.

Servers can only accept 0-RTT if the ciphers match. If they reject
0-RTT, however, they may change the cipher suite and even the PRF hash.
This is tricky, however, because the 0-RTT accept or reject signal comes
in EncryptedExtensions, which is *after* the new cipher suite is
installed. (Although a client could infer 0-RTT is rejected based on the
cipher suite if it wanted.)

While we correctly handled the PRF hash switch, we get the cipher suite
mixed up due to dependency on SSL_get_session and incorrectly decrypt
EncryptedExtensions. Fix this and add some tests.

Change-Id: Ia20f2ed665cf601d30a38f0c8d4786c4c111019f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/40005
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>