August 2011 - stunnel-users

stunnel4 tcp_nodelay
by Madhu R 21 Aug '11

21 Aug '11

Hi, We are using stunnel in order to tunnel http proxy traffic. Is it better in this case to turn on Nagle's algo? I have tried to set socket=l:TCP_NODELAY=0 and socket=r:TCP_NODELAY=0 in the global config, but when I look at debug log it keeps saying option tcp_nodelay is set on local and remote socket. Is this a bug, or is there a different way of turning off tcp_nodelay (since I understand this is on by default now) Regds

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Security issue in 4.4X effect older version?
by Richard L. Houston 19 Aug '11

19 Aug '11

Hi All, Sorry if this has been asked and answered. Saw the security warning about Stunnel 4.40 and 4.41 at http://www.securityfocus.com/bid/49254/info Are older version vulnerable as well or just those two specific versions? Specificity in the 4.2X series? Thanks for your help. +------------------------------------+ Best regards, -Richard Houston -R.L.H. Consulting -E-Mail rhouston(a)rlhc.net -WWW http://www.rlhc.net -Blog http://www.rlhc.net/blog/ -Twitter http://www.twitter.com/rlhc/

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centos 6 - stunnel 4.42 unusable (libssl trap divide error) in FIPS mode (default)
by draeath 19 Aug '11

19 Aug '11

I just finished building and configuring stunnel 4.42 on my x86_64 CentOS6 box. It appears to run, but not long into the SSL connection stunnel dies. Log info below. This only happens if I do NOT specify --disable-fips during ./configure (as it enables FIPS by default). I assume this is because FIPS compliancy requires a key to have a passphrase, which my key does not have? [root@host stunnel]# tail -f /var/log/stunnel.log /var/log/messages ==> /var/log/stunnel.log <== 2011.08.19 16:27:36 LOG7[31681:139656510936832]: Option TCP_NODELAY set on local socket 2011.08.19 16:27:36 LOG5[31681:139656510936832]: Service ntop accepted connection from 12.117.176.190:13258 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): before/accept initialization 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 read client hello A 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 write server hello A 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 write certificate A 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 write key exchange A 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 write server done A 2011.08.19 16:27:36 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 flush data 2011.08.19 16:27:37 LOG7[31681:139656510936832]: SSL state (accept): SSLv3 read client key exchange A ==> /var/log/messages <== Aug 19 16:27:24 host stunnel: LOG5[31680:139656510941120]: FIPS mode enabled Aug 19 16:27:24 host stunnel: LOG6[31680:139656510941120]: Initializing SSL context for service ntop Aug 19 16:27:24 host stunnel: LOG4[31680:139656510941120]: Insecure file permissions on /usr/local/etc/stunnel/stunnel.pem Aug 19 16:27:24 host stunnel: LOG6[31680:139656510941120]: SSL context initialized Aug 19 16:27:24 host stunnel: LOG5[31680:139656510941120]: Configuration successful Aug 19 16:27:36 host stunnel: LOG5[31681:139656510936832]: Service ntop accepted connection from 12.117.176.190:13257 Aug 19 16:27:36 host stunnel: LOG3[31681:139656510936832]: SSL_accept: 1408F10B: error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number Aug 19 16:27:36 host stunnel: LOG5[31681:139656510936832]: Connection reset: 0 bytes sent to SSL, 0 bytes sent to socket Aug 19 16:27:36 host stunnel: LOG5[31681:139656510936832]: Service ntop accepted connection from 12.117.176.190:13258 Aug 19 16:27:37 host kernel: stunnel[31724] trap divide error ip:7f044fd0d3d1 sp:7f0450b98a40 error:0 in libssl.so.1.0.0[7f044fce2000+53000]

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Tr:SIP encryption with stunnel
by margot.basa 19 Aug '11

19 Aug '11

Hello all, Can someone give me information about SIP encryption with stunnel please ? Is it possible to transform a SIP message on TCP into a SIP TLS message with stunnel ? Thank you very much for your help, Regards > Message du 16/08/11 11:38 > De : "margot.basa" > A : stunnel-users(a)stunnel.org > Copie à : > Objet : SIP encryption with stunnel > > Hello all, I would like to know if stunnel is able to encrypt a SIP message (UDP or TCP => TLS...) For example: Terminal A can send/receive SIP messages on transport layer UDP or TCP but not TLS. Server B can send/receive SIP messages only in TLS. If terminal A sends a SIP REGISTER message to Server B, does stunnel is able to intercept the message and transform it ? port 5060 => port 5061 TCP => TLS sip uri => sips uri Do you think it's possible with stunnel ? Thank you very much for your input. Regards > > Une messagerie gratuite, garantie à vie et des services en plus, ça vous tente ? Je crée ma boîte mail www.laposte.net

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When X-FORWARDED-FOR for Stunnel ?
by Elodie BOSSIER 19 Aug '11

19 Aug '11

Greetings, Why you don't implement X-FORWARDED-FOR into stunnel ? I have found this patch : http://haproxy.1wt.eu/download/patches/stunnel-4.32-xforwarded-for.diff but this on is to much old, i'm with stunnel 4.41 and i can't go to 4.32 because i need SNI, implemented since 4.38 I have attempt to modify the patch to match with the current version, in begining it's ok but not after, all line code have changed and i'm not developer. X-FORWARDED-FOR is very important and exist on mostly all the frontend web and usuable by all the web server. Someone told me to switch to Nginx because X-FORWARDED-FOR don't exist in Stunnel ... I would like stay on Stunnel because it's only a light tunnel. The patch have only 219 lines, could you help me please to addapt it to the version 4.41 and/or add this feature into Stunnel please ? This is the "manual" to apply the patch : http://www.buro9.com/blog/2009/12/07/installing-haproxy-load-balance-http-a… Just need to add "xforwardedfor=yes" into your config file and should be OK. With this feature, I won't have need to "play" with this (censured) of transparent = source, iptables rules, tcpdump and root exec ... Thanks so much ... Elodie.

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stunnel 4.42 released
by Michal Trojnara 18 Aug '11

18 Aug '11

Dear Users, I have released version 4.42 of stunnel. This is a security bugfix release. Upgrade is highly recommended! The ChangeLog entry: Version 4.42, 2011.08.18, urgency: HIGH: * New features - New verify level 0 to request and ignore peer certificate. This feature is useful with the new Windows GUI menu to save cached peer certificate chains, as SSL client certificates are not sent by default. - Manual page has been updated. - Removed support for changing Windows Service name with "service" option. * Bugfixes - Fixed a heap corruption vulnerability in versions 4.40 and 4.41. It may possibly be leveraged to perform DoS or remote code execution attacks. - The -quiet commandline option was applied to *all* message boxes. - Silent install (/S option) no longer attempts to create stunnel.pem. Home page: http://www.stunnel.org/ Download: ftp://ftp.stunnel.org/stunnel/ SHA-256 hash for stunnel-4.42.tar.gz: d33c407bfc4f58070e818081bd082c38f91cab7691ccbb794da63143c535de3b Best regards, Mike

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stunnel transparent mode
by Julian D. Seifert 18 Aug '11

18 Aug '11

Hi List, I have a little issue trying to get stunnel running for encapsulating an existing service with SSL. We are running a really old legacy ircd service and would like to provide SSL for the users without having to actually hack that into the really old code base. (Yes we could just use another more modern software but let's just say there are "political" reasons as to why this is not an option) For an ircd we need transparency as in "the ircd should think the connection is not coming from localhost") ANYWAY... so I am working with stunnel 4.39 right now. First a question if I understand it correctly how stunnel will work. I have the ircd running on IP1:6667. I created a service section like this. [ircd] accept = 7000 connect = 6667 transparent = source (And applied the iptables/routing related stuff mentioned in the documentation) Should this already work? Will stunnel "manipulate" packets so that the IRCD "sees" connections from the Peers IP's? And will the Answers the ircd sends to the peers get "intercepted" by stunnel so it can "remanipulate" the answers into the SSL connection? If I try it like I get "local_bind (original port): Cannot assign requested address (99) stunnel" and clients get connection abort. Or is this what "transparent = both" is for? With 4.39 I had an issue trying to use "transparent = both". Stunnel always displayed an error message saying "Each service must define two endpoints" (more or less). I got it to compile by commenting out the one line in options.c causing the error... #### snip #### } else { /* standalone mode checks */ if((unsigned int)section->option.accept + (unsigned int)section->option.program + (unsigned int)section->option.remote + (unsigned int)section->option.sni #ifndef USE_WIN32 + (unsigned int)section->option.transparent_dst #endif /* USE_WIN32 */ !=2) { section_error(last_line, section->servname, "Each service must define two endpoints"); return 0; } ### snap ### Commented out the line within the ifndef. Anyway... I hope somebody can clarify for me how stunnel works and what transparent mode is the one I need. (I want to transparently provide the ircd service with connections so it seems they are directly from the peers and not from stunnel(localhost)) regards, Julian Seifert -- I hate mondays...

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[[email protected]: Bug#637932: stunnel4: segfault if certificate file cannot be read during verification]
by Rodrigo Gallardo 17 Aug '11

17 Aug '11

----- Forwarded message from Sebastian Leske <Sebastian.Leske(a)sleske.name> ----- Date: Mon, 15 Aug 2011 21:21:05 +0200 Package: stunnel4 Version: 3:4.40-1 Severity: normal I use certificate verification with stunnel4 (verify=2 in stunnel.conf). I accidentally changed the access rights of a PEM file required for verification to be unreadable. As a consequence, stunnel4 incorrectly reports "Verification error: self signed certificateVerification error: self signed certificate" (the cert in question is not self-signed), then segfaults. With stunnel4 version 4.29-1_i386, this does not occur: stunnel4 correctly reports that it cannot access the PEM file. Log and backtrace (generated with setting foreground=yes in stunnel.conf): Starting program: /usr/bin/stunnel4 /etc/stunnel/stunnel.conf [Thread debugging using libthread_db enabled] 2011.08.15 21:16:54 LOG5[9584:3082946768]: stunnel 4.40 on i486-pc-linux-gnu platform 2011.08.15 21:16:54 LOG5[9584:3082946768]: Compiled/running with OpenSSL 1.0.0d 8 Feb 2011 2011.08.15 21:16:54 LOG5[9584:3082946768]: Threading:PTHREAD SSL:ENGINE Auth:LIBWRAP Sockets:POLL,IPv6 2011.08.15 21:16:54 LOG5[9584:3082946768]: Reading configuration from file /etc/stunnel/stunnel.conf 2011.08.15 21:16:54 LOG6[9584:3082946768]: Compression enabled using zlib method 2011.08.15 21:16:54 LOG6[9584:3082946768]: Initializing SSL context for service pop3sl 2011.08.15 21:16:54 LOG6[9584:3082946768]: SSL context initialized 2011.08.15 21:16:54 LOG6[9584:3082946768]: Initializing SSL context for service https 2011.08.15 21:16:54 LOG6[9584:3082946768]: SSL context initialized 2011.08.15 21:16:54 LOG6[9584:3082946768]: Initializing SSL context for service ssmtp 2011.08.15 21:16:54 LOG6[9584:3082946768]: SSL context initialized 2011.08.15 21:16:54 LOG5[9584:3082946768]: Configuration successful [New Thread 0xb7fdfb70 (LWP 9593)] 2011.08.15 21:16:57 LOG5[9584:3086875504]: Service pop3sl accepted connection from 127.0.0.1:60903 2011.08.15 21:16:57 LOG6[9584:3086875504]: connect_blocking: connecting 213.187.93.221:995 2011.08.15 21:16:57 LOG5[9584:3086875504]: connect_blocking: connected 213.187.93.221:995 2011.08.15 21:16:57 LOG5[9584:3086875504]: Service pop3sl connected remote server from 192.168.1.101:39914 2011.08.15 21:16:57 LOG4[9584:3086875504]: CERT: Verification error: self signed certificate in certificate chain 2011.08.15 21:16:57 LOG4[9584:3086875504]: Certificate check failed: depth=2, /C=BE/O=GlobalSign nv-sa/OU=Root CA/CN=GlobalSign Root CA 2011.08.15 21:16:57 LOG3[9584:3086875504]: error queue: 14090086: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xb7fdfb70 (LWP 9593)] 0xb7ca2119 in ?? () from /lib/i386-linux-gnu/i686/cmov/libc.so.6 (gdb) bt #0 0xb7ca2119 in ?? () from /lib/i386-linux-gnu/i686/cmov/libc.so.6 #1 0xb7ca3c1b in calloc () from /lib/i386-linux-gnu/i686/cmov/libc.so.6 #2 0x0804cd20 in ?? () #3 0x080574bf in ?? () #4 0x08057529 in ?? () #5 0x08058129 in ?? () #6 0x0804d945 in ?? () #7 0x0804e79b in ?? () #8 0x0804fafe in ?? () #9 0xb7f98c39 in start_thread () from /lib/i386-linux-gnu/i686/cmov/libpthread.so.0 #10 0xb7d0196e in clone () from /lib/i386-linux-gnu/i686/cmov/libc.so.6 (gdb) -- System Information: Debian Release: squeeze/sid APT prefers testing APT policy: (500, 'testing'), (500, 'stable') Architecture: i386 (i686) Kernel: Linux 3.0.0-1-686-pae (SMP w/1 CPU core) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/bash Versions of packages stunnel4 depends on: ii adduser 3.110 add and remove users and groups ii libc6 2.13-10 Embedded GNU C Library: Shared lib ii libssl1.0.0 1.0.0d-3 SSL shared libraries ii libwrap0 7.6.q-16 Wietse Venema's TCP wrappers libra ii netbase 4.34 Basic TCP/IP networking system ii openssl 1.0.0d-3 Secure Socket Layer (SSL) binary a ii perl-modules 5.12.4-2 Core Perl modules stunnel4 recommends no packages. Versions of packages stunnel4 suggests: pn logcheck-database <none> (no description available) -- no debconf information ----- End forwarded message ----- -- Rodrigo Gallardo

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Sending "LOGOUT" when using StartTLS offloading?
by Markus Borst 17 Aug '11

17 Aug '11

I have to cope with a very unusual imap server behavior, but maybe stunnel can help me: Can stunnel send an imap command ("XX LOGOUT"), just before closing the tcp session? Setup: I use stunnel for SSL/TLS offloading, both via extra port (993) and StartTLS emulation (143). Our imap server (Mercury) has a very peculiar feature: If a tcp connection is closed without properly closing the imap session first (LOGOUT), the server discards certain attributes, specifically, it "forgets" all deletions since last logout. Since many imap clients just tear down the connection in certain cases (for example Thunderbird going into offline mode, many webmailers or stunnel reaching it's "TIMEOUTidle"), this causes mails to be undeleted. We currently use an older version of the mailserver, since only the newest is broken. Needless to say, this does not go well with our users. A fixed version of the imap server may never come, so, until we can switch all users to a new mail system: Is it possible to use stunnel to send an additional imap command before closing the tcp connection (something like "999 LOGOUT")? The command should be sent no matter why the connection is closed, either because the client closed it, a timeout is reached or stunnel is unloaded. If the connection is already cleanly logged out, this doesn't matter, in all other situations it would help. Would it be possible to send such a command, or could this be added as a new feature? Greetings Markus Borst -- ==== Achtung! Umzug: neuer Raum: ==== TU Darmstadt Hochschulrechenzentrum (HRZ) Markus Borst S4/14/2.4.06 Adresse: Mornewegstr. 30 64293 Darmstadt Tel.: 06151/16-2056 Email: M.Borst(a)hrz.tu-darmstadt.de

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SIP encryption with stunnel
by margot.basa 16 Aug '11

16 Aug '11

Hello all, I would like to know if stunnel is able to encrypt a SIP message (UDP or TCP => TLS...) For example: Terminal A can send/receive SIP messages on transport layer UDP or TCP but not TLS. Server B can send/receive SIP messages only in TLS. If terminal A sends a SIP REGISTER message to Server B, does stunnel is able to intercept the message and transform it ? port 5060 => port 5061 TCP => TLS sip uri => sips uri Do you think it's possible with stunnel ? Thank you very much for your input. Regards Une messagerie gratuite, garantie à vie et des services en plus, ça vous tente ? Je crée ma boîte mail www.laposte.net

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