On 5/13/2020 9:41 AM, Anthony Scarpino wrote:
On 4/30/20 10:19 AM, Xuelei Fan wrote:
Hi,
Could I get the following update reviewed:
http://cr.openjdk.java.net/~xuelei/8240871/webrev.00/
For TLS 1.3 full handshake, if the last handshake flight wraps the
Finished together with other handshake message, for example client
certificate, the flight could be wrapped and encrypted in one record
and delegated tasks would be used. There is no chance to return
FINISHED handshake status with SSLEngine.(un)wrap(). However, per the
HandshakeStatus.FINISHED specification, this handshake status is only
generated by a call to SSLEngine.wrap()/unwrap() and it is never
generated by SSLEngine.getHandshakeStatus().
In order to workaround this case for TLS 1.3, the FINISHED status
could present with SSLEngine.wrap() while delivering of the
NewSessionTicket post-handshake message. If this post-handshake
message is not needed, a follow-on SSLEngine.wrap() should be called
to indicate the FINISHED handshake status. Although this special
SSLEngine.wrap() should not consume or produce any application or
network data.
I also clean up some debug log, names and code style a little bit.
The update could be confirmed with Tomcat and Firefox in private mode,
as described in the bug description. As this case happens only when
psk_key_exchange_modes does not present, which is not a behavior
supported by JDK, I did not find a workaround for a new regression
test yet. I added the labels, noreg-external and noreg-hard.
Thanks,
Xuelei
I do not fully understand the situation, mostly because of SSLEngine
semantics. In normal operation, does is HandshakeStatus.FINISHED
returned when Finished is received or after the NewSessionTicket
message?
Not exactly. For TLS 1.2, FINISHED will be returned with unwrap() of
the finished handshake message. However, for TLS 1.3, FINISHED will be
returned any longer, because the finished handshake message is wrapped
with certificate message in one record.
For TLS 1.3:
1. client send certificate, certificate verify and finished handshake
message in one record.
2. server call unwrap(), and return NEED_TASK to handle the certificate
and certificate verify.
So, no more FINISHED for the unwrap() return.
It is fine if there is a after NewSessionTicket message. The wrap() for
the post-handshake message will return FINISHED.
The bug reported is a special one that the Firefox is run in private
mode, which does not request NewSessionTicket. So there is no
post-handshake generated and sent in server side. Then, there is no
FINISHED can be used if applications depends on it.
To workaround the case, a dummy wrap() or unwrap() could be used to get
the FINISHED. The wrap() or unwrap() actually do nothing but return the
FINISHED status.
My understanding would have been after Finished because NST is
suppose to be a post handshake message. So in this case there is no
problem, correct?
Correct.
I'm trying to figure out why you need an empty NST. Is the problem when
a number of messages are bundled together. For example, the Finished
message with a partial NST, then Finished isn't processed and both sides
are waiting? Or do both sides continue normal traffic, it's jut the
HandshakeStatus.FINISHED is one operation behind?
It should be fine as empty NST is just a signal to indicate the next
call to wrap(). The next call to wrap() just use the signal for the
return of FINISHED status, not network data produced, delivered or consumed.
One code comment so far:
433: The debug message purpose was to say the NST is a stateless ticket
and not a preshared key. Can we keep "stateless" in the message?
NewSessionTicket.java? Sure, I may just want to shrink to one line. It
was not intended.
Xuelei
