Rather than switching the order of the ServerHello and HelloVerifyRequest
states and processing each twice, have the states follow the protocol order.
HelloVerifyRequest reading is optional and ServerHello is strict. Use the
send_cookie bit to determine whether we're expecting a cookie or not.
Fix the dtls1_stop_timer call in these states to consistently hit the end of a
server flight; the previous flight should not be cleared from the retransmit
buffer until the entire next flight is received. That said, OpenSSL doesn't
appear to implement the part where, on receipt of the previous peer flight, the
buffered flight is retransmitted. (With the exception of a SSL3_MT_FINISHED
special-case in dtls1_read_bytes.) So if the peer is also OpenSSL, this doesn't
do anything.
Also fix the DTLS test which wasn't actually asserting that the ClientHello
matched.
Change-Id: Ia542190972dbffabb837d32c9d453a243caa90b2
Reviewed-on: https://boringssl-review.googlesource.com/1551
Reviewed-by: Adam Langley <agl@google.com>
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