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From "Esmond Pitt" <esmond.p...@bigpond.com>
Subject RE: Tomcat 7 SSL Session ID
Date Wed, 05 Dec 2012 22:59:00 GMT
Vincent
 
RST always terminates a TCP connection. The question is really why was it
*sent.* The usual reason is writing to a connection that has already been
closed by the peer. Is there an incoming close_notify higher up in the SSL
log? I suppose not otherwise an SSLException would have been thrown.
 
Re loss of the SSL session, I suppose it is plausible that SSL discards it
on security grounds because of the broken connection.
 
EJP

  _____  

From: Vincent Goelen [mailto:goelenv@gmail.com] 
Sent: Wednesday, 5 December 2012 9:19 PM
To: Esmond Pitt
Subject: Re: Tomcat 7 SSL Session ID



http-bio-8443-exec-21, READ: TLSv1 Application Data, length = 32
http-bio-8443-exec-21, READ: TLSv1 Application Data, length = 432
http-bio-8443-exec-20, WRITE: TLSv1 Application Data, length = 32
http-bio-8443-exec-20, WRITE: TLSv1 Application Data, length = 976
http-bio-8443-exec-20, handling exception: java.net.SocketException: Broken
pipe
%% Invalidated:  [Session-1, TLS_RSA_WITH_AES_256_CBC_SHA]
http-bio-8443-exec-20, SEND TLSv1 ALERT:  fatal, description =
unexpected_message
http-bio-8443-exec-20, WRITE: TLSv1 Alert, length = 32
http-bio-8443-exec-20, Exception sending alert: java.net.SocketException:
Broken pipe
http-bio-8443-exec-20, called closeSocket()
http-bio-8443-exec-20, called close()
http-bio-8443-exec-20, called closeInternal(true)


This is what I get in the SSL debug logs.. It seems to happen when the tcp
connection is closed while the application data is being sent.. I think this
is a security thing to prevent SSL truncation attacks which sounds quite
normal to me. 

The issue is, why does my tcp connection close there:
http://users.telenet.be/goelenv/Schermafbeelding%202012-12-04%20om%2015.09.5
6.png

The screenshot above is one from where things go wrong when I analyse the
traffic, the tcp rst is one from the connection that was used by the
previous request.. But why can that rst packet terminate the current active
tcp connection?


2012/12/5 Esmond Pitt <esmond.pitt@bigpond.com>


Yes but he *already has* an SSL session which he states is being
invalidated. To the limited extent to which I could make sense of your
incomprehensible post, it appears to be 100% irrelevant.


-----Original Message-----
From: Martin Gainty [mailto:mgainty@hotmail.com]
Sent: Wednesday, 5 December 2012 11:27 AM
To: Tomcat Users List; goelenv@gmail.com
Subject: RE: Tomcat 7 SSL Session ID



yes but he needs to achieve a reliable connection between himself and the
SSLServer (at least until key negotiation has completed) broken pipe(s) are
a bear to debug but you have a few tools available to you:

netstat  SSLServerIP
-- if you see ANY intervening nodes hanging more than 4 sec drop from arp
cache generally by arp -d ServerIP
assuming your ServerIP is is 157.55.85.212 and the physical address of the
network you want to connect to is 00-aa-00-62-c6-09  (check with net-admin
for the physical-address or eth-addr to use) > arp -s 157.55.85.212
00-aa-00-62-c6-09  .... Adds a static entry.
 > arp -a                                    .... Displays the arp table.
route print will display the routes between you and the SSLServer if you
dont see a route referencing the server you may want to add in your own
route with
route add DESTINATION MASK Mask  METRIC NoOfHops Interface

InterfaceNumbercheck with net-admin DESTINATION is generally the
dotted.quad.of.SSLServercheck with net-admin generally Mask =255.255.255.0
will docheck with net admin about which Interface to use..avoid 127.0.0.1
(unless testing locally)check with net admin on NoOfHops param ..generally

the lower the better use curl (command line url) to check the validity of

the certificate, keys and passwordscurl -1 --cacert [file] --key

PrivateKey.jks --pass PrivateKeyPass --key-type PEM --pubkey PublicKey.jks-1

says use TLSv1check the type of key most keys start out as PEM PEM key ends

with .PEM extension ...DER key with .DER... ENG key ends with

.ENGhttp://curl.haxx.se/docs/sslcerts.html once you've been able to achieve

a Key Exchange you will have a valid SSL Connection..remember binaries have
lower CPU so test with a reliable binary first then start debugging your
code (i assume you added your CA cert into your local truststore) enough
pollution?
Martin
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 > From: esmond.pitt@bigpond.com
> To: goelenv@gmail.com; users@tomcat.apache.org
> Subject: RE: Tomcat 7 SSL Session ID
> Date: Wed, 5 Dec 2012 09:57:38 +1100
>
> Broken pipes don't invalidate the SSL session. They just break the TCP
> connection. The SSL session persists, across multiple TCP connections,
> until it is specifically invalidated by someone: for example, timed
> out by the SSLSessionContext.
>
> EJP
>
>   _____
>
> From: Vincent Goelen [mailto:goelenv@gmail.com]
> Sent: Wednesday, 5 December 2012 1:15 AM
> To: Tomcat Users List
> Subject: Re: Tomcat 7 SSL Session ID
>
>
> Hey,
>
> thanks for the help!
>
> To be clear, I do not want a 0ms timeout... I'm doing research about
> how "usable" the SSL session tracking option is for session management...
> With the standard settings it seems very unstable to me, when sending
> alot of parallel requests I get a broken socket error invalidating the
> ssl session and making the session with this id disappear. In this
> case it would seem to me that it's easy to create Denial of Service
> attacks by just sending alot of requests so the user loses his session.
>
> By playing with the timeouts I found out this problem doesn't occur
> when I set the timeout to 0, just by playing with the settings.
> Perhaps because this disables the possibility of too many parallel
> connections? I can't find the reason of this in the Tomcat or SSL specs...
>
> I've added a screenshot of a capture where things go wrong without
> setting a keepAlive.. So I send alot of requests to the server, the
> first clientHello (pck 38943) and the following packets everything
> goes ok, when the application data is being send I get a tcp rst from
> port 54195 (this is the connection that was used for the transactions
> before the current one) ... At this moment my session gets invalidates
> making the next SSL handshake a full one with new ID (pckt 40361, ...)
>
>
>
>
> 2012/11/29 Christopher Schultz <chris@christopherschultz.net>
>
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Vincent,
>
>
> On 11/28/12 3:14 AM, Vincent Goelen wrote:
> > When the keepAliveTimeout is not set to "0" I can see in the SSL
> > debug logs the SSL session get's invalidated after some requests
> > with a Broken Pipe exception. Is this because there are too many
> > open connections during the keepAliveTimeout?
>
>
> It's probably because of your pathological keepAliveTimeout. 0ms
> seems, er, low. Why did you choose 0ms?
>
> I haven't looked at the code, so I'm not sure if the elapsed timer
> starts when the last request is completed (which seems reasonable) or
> when the last request started. I suspect the latter. 0ms is awfully
> short. Are you sure that your client is capable of accepting the
> response to the previous request and turn-around and make another
> request across the same channel before 0ms passes?
>
>
> > It also only happens when processing the requests takes some time
> > (fe. storing items in database) or when I put the threat to sleep
> > for testing purpose.
>
>
> So if you have a trivial request (say, HEAD for a static resource),
> you can never get a failure?
>
>
> > When inspecting the traffic I see some tcp-rst packages (problem is
> > here?) from previous connections while the current one is being
> > processed.
>
>
> When you say "current one" what do you mean? If you are using a single
> connection with HTTP keepalive, then there is only one connection to
> talk about: you can't get RSTs from "previous connections". You may be
> getting TCP RST as the server closes the connection while the client
> is trying to write. Is that what you are experiencing?
>
>
> > My question is why these SSL Sessions get invalidated after alot of
> > quick requests to the server since this gives a problem with my SSL
> > Session tracking since the id changes then.
>
>
> Maybe if you can explain why you want a 0ms keepalive timeout it would
> be helpful. If you want to disable keep alives, set
> maxKeepAliveRequests="1". If you want to allow an infinite timeout,
> try using keepAliveTimeout="-1" as the documentation states.
>
> - -chris
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