tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Vincent Goelen <goel...@gmail.com>
Subject Re: Tomcat 7 SSL Session ID
Date Thu, 06 Dec 2012 10:12:26 GMT
Hey,
I'm completely aware that a RST always terminates a TCP connections..
But in my case, there's an TCP rst from a connection thats already finished
it's job causing problems for the active connection! At least that's what I
think is going on here..
As you can see in the screenshot of my wireshark capture, the TCP rst there
is not from the connection that's writing application data..

The session get's invalidates here because of an unexpected close of the
connection which is completely normal regarding the SSL specs.

grts,
Vincent

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

> 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<http://users.telenet.be/goelenv/Schermafbeelding%202012-12-04%20om%2015.09.56.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
> ______________________________________________
> Verzicht und Vertraulichkeitanmerkung
> Diese Nachricht ist vertraulich. Sollten Sie nicht der vorgesehene
> Empfaenger sein, so bitten wir hoeflich um eine Mitteilung. Jede unbefugte
> Weiterleitung oder Fertigung einer Kopie ist unzulaessig. Diese Nachricht
> dient lediglich dem Austausch von Informationen und entfaltet keine
> rechtliche Bindungswirkung. Aufgrund der leichten Manipulierbarkeit von
> E-Mails koennen wir keine Haftung fuer den Inhalt uebernehmen.
>
>
>  > 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
> > -----BEGIN PGP SIGNATURE-----
> > Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
> > Comment: GPGTools - http://gpgtools.org
> > Comment: Using GnuPG with undefined - http://www.enigmail.net/
> >
> > iEYEARECAAYFAlC3w6YACgkQ9CaO5/Lv0PDX/QCfcPmdRD/FSyDB51QdOqgqwGbI
> > tLwAmweVvlGCGqU2eAdYtrzezwkEPhZF
> > =J7dz
> > -----END PGP SIGNATURE-----
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
> > For additional commands, e-mail: users-help@tomcat.apache.org
> >
> >
> >
> >
>
>
>
>
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message