- stunnel-users - stunnel.org

[patch] add new option send_client_info
by Henrik Riomar 14 Jul '09

14 Jul '09

Hi, The attached patch adds a new option that allows stunnel to pass on some client information to for instance a web service that uses stunnel for it's encryption. The first line of data contains the client info and if the new option is not enabled the patch does nothing. Regards, Henrik Riomar P.S. public domain.

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stunnel throttling and statistics
by Laurens Van Houtven 10 Jul '09

10 Jul '09

Hi! I'm using stunnel to secure an AMQP message broker (RabbitMQ, specifically) using pre-shared certificates. This means that my backends never get to see the SSL certificate that the client used to connect -- unfortunately, it's that very backend that's the first who can decide if a message is malicious or not. In order to sort-of fix this problem, I'm using UUIDs so that the keyspace is so absurdly huge that the odds that someone will guess a key are second to none. Still, if someone is misbehaving (trying a large number of bogus keys) it would be nice to know who it is so I could stop wasting CPU time and bandwidth on them. So, I was wondering if anyone has used stunnel (vanilla or modified) to keep statistical data about who connects (which certificates). Additionally, does anyone know of a decent way to throttle per-certificate (or limit the amount of tunnels that can be opened per certificate). If all else fails I could just do normal throttling on a per-IP basis, which should get me roughly the same thing. The reason I want this is because I want to prevent users from even *trying* a large number of such keys (even though it's statistically unlikely that they'll get one) since it still takes me CPU time to process that junk. Thanks in advance Laurens

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Re: [stunnel-users] Dynamic hosts
by Ludolf Holzheid 29 Jun '09

29 Jun '09

On Tue, 2009-06-23 20:52:30 -0400, Terry Riegel wrote: > > On Jun 23, 2009, at 11:01 AM, Ludolf Holzheid <lholzheid(a)bihl-wiedemann.de > > wrote: > > > >On Tue, 2009-06-23 10:33:14 -0400, Terry Riegel wrote: > >> > >>If I did it the way you are suggesting then 5 concurrent users would > >>fire up 30 processes. On my system starting the daemon starts 6 > >>processes, and if I start it up again I get another 6 processes. > > > >Is this still true with 'foreground = yes'? > > Yes. You are right. On detaching to the background, there is an additional fork(), but the parent dies early. So the number of persistent processes is the same. > >For reducing the number of processes, you might also try to configure > >stunnel with --disable-libwrap. > > I can try that wasn't aware of it as a configuration option There is also a '--with-threads=pthread' option that may help to lower the number of processes. However, on modern operating systems, fork()ing is not as expensive as it looks like. In most cases, the text segment is shared between the two processes and the pages on data/BSS segments are not copied until changed ('copy-on-write'). I don't know if the usage of OS resources is larger for the multi-threaded or the multi-tasked approach. Ludolf P.S.: Please reply to the list, so the community is able to follow all of the thread. -- --------------------------------------------------------------- Ludolf Holzheid Tel: +49 621 339960 Bihl+Wiedemann GmbH Fax: +49 621 3392239 Floßwörthstraße 41 e-mail: lholzheid(a)bihl-wiedemann.de D-68199 Mannheim, Germany ---------------------------------------------------------------

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stunnel - connection issue with larger number of connections
by Franjo Stipanovic 26 Jun '09

26 Jun '09

Hello, have anyone experienced a issue with stunnel when there's a larger number of concurrent connections (>50)? I've got my application service and stress tester for it. I've placed stunnel in front of application service because I allow clients only to connect to application service using SSL. When stress tester communicates directly with application service with 100 concurrent connections (threads) there's no issue, but when I connect over SSL (thru stunnel) more than 50% of connections fails with error : connection refused :( Seems like there's a limit in windows server for number of threads per process since stunnel does one thread per connection, right? Any idea on how can I test this further? stunnel information: stunnel 4.22 on x86-pc-mingw32-gnu with OpenSSL 0.9.8g 19 Oct 2007 Threading:WIN32 SSL:ENGINE Sockets:SELECT,IPv6 Global options debug = 5 RNDbytes = 64 RNDoverwrite = yes service = stunnel taskbar = yes Service-level options cert = stunnel.pem ciphers = AES:ALL:!aNULL:!eNULL:+RC4:@STRENGTH key = stunnel.pem session = 300 seconds stack = 65536 bytes sslVersion = SSLv3 for client, all for server TIMEOUTbusy = 300 seconds TIMEOUTclose = 60 seconds TIMEOUTconnect = 10 seconds TIMEOUTidle = 43200 seconds verify = none Socket option defaults: Option Accept Local Remote OS default SO_DEBUG -- -- -- 0 SO_DONTROUTE -- -- -- 0 SO_KEEPALIVE -- -- -- 0 SO_LINGER -- -- -- 0:0 SO_OOBINLINE -- -- -- 0 SO_RCVBUF -- -- -- 8192 SO_SNDBUF -- -- -- 8192 SO_RCVLOWAT -- -- -- -- SO_SNDLOWAT -- -- -- -- SO_RCVTIMEO -- -- -- 0:0 SO_SNDTIMEO -- -- -- 0:0 SO_REUSEADDR 1 -- -- 0 IP_TOS -- -- -- 0 IP_TTL -- -- -- 32 TCP_NODELAY -- -- -- 0 Software configuration: Windows Server 2003 R2 - Enterprise x64 Edition Hardware configuration: Intel Core 2 Duo 1 GB RAM Kind regards, fritz

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Re: [stunnel-users] Dynamic hosts
by Ludolf Holzheid 23 Jun '09

23 Jun '09

On Tue, 2009-06-23 10:33:14 -0400, Terry Riegel wrote: > Well, that would be one way of doing it. I would prefer to have > stunnel running as a daemon and just pass a FQDN and local port number > to it. But it may not be able to do that. You are right. Currently, stunnel's configuration can't be changed at run-time (and I still don't see a need for that). > If I did it the way you are suggesting then 5 concurrent users would > fire up 30 processes. On my system starting the daemon starts 6 > processes, and if I start it up again I get another 6 processes. Is this still true with 'foreground = yes'? For reducing the number of processes, you might also try to configure stunnel with --disable-libwrap. If you run stunnel from within a CGI, you will be accepting connections from localhost only anyway. HTH, Ludolf -- --------------------------------------------------------------- Ludolf Holzheid Tel: +49 621 339960 Bihl+Wiedemann GmbH Fax: +49 621 3392239 Floßwörthstraße 41 e-mail: lholzheid(a)bihl-wiedemann.de D-68199 Mannheim, Germany ---------------------------------------------------------------

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Re: [stunnel-users] Dynamic hosts
by Ludolf Holzheid 23 Jun '09

23 Jun '09

On Tue, 2009-06-23 08:13:08 -0400, Terry Riegel wrote: > Take a look at mail2web.com > > You type in your server, it dynamically connects secure or otherwise. Ah, o.k. you want to use stunnel from inside a CGI. You could have the CGI dynamically write the stunnel configuration file then. Maybe you should specify 'foreground = yes' in order to avoid detaching to the background and to get stunnel's log messages written to the web server log. This depends on the CGI, of course. Ludolf -- --------------------------------------------------------------- Ludolf Holzheid Tel: +49 621 339960 Bihl+Wiedemann GmbH Fax: +49 621 3392239 Floßwörthstraße 41 e-mail: lholzheid(a)bihl-wiedemann.de D-68199 Mannheim, Germany ---------------------------------------------------------------

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Dynamic hosts
by Terry Riegel 23 Jun '09

23 Jun '09

Hello, I have just set up stunnel to allow unsecured client pop3 connections to my secured pop3 server chroot = /stunnel/ pid = /stunnel.pid setuid = www setgid = www client = yes foreground=yes [995] accept = localhost:10110 connect = mail.clearimageonline.com:995 And it works as expected. Is there a way to set it up so it can dynamically connect to any server. Something like... connect = *:995 I was able to start a new instance of stunnel with a separate config file but this seems inefficient as it starts up 6 processes each time. What I would like to do is dynamically add/subtract servers that it can connect to. My goal here is to build a webmail client that can use stunnel to do the secure connections to either POP or IMAP servers. My client software uses unsecured sockets. Any help would be greatly appreciated. Terry Riegel

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Install, Starting & Using Stunnel on OS X (more)
by m i l e s 20 Jun '09

20 Jun '09

Hi, I forgot a few things in my last msg, that were implied but not explicitly stated. 1.) I downloaded and installed stunnel-4.27. 2.) Im not running darwin ports. 3.) When I installed I entered the commands on the command line without ever touching xCode. 4.) I am running MAC OS 10.5.7. I will have to do a later install on MAC OS 10.4.11. 5.) I need to connect my laptop (test machine) to an ldap server. The ldap server is NOT running stunnel, and I have no control over the ldap server. I am wanting to create a secure connection from my machine to the target server. +++++++++++++++++++++ Previous Msg Below. +++++++++++++++++++++ Hi I'm a newbie to stunnel. I have a couple of questions....ok, a zillion. However I'll stick to the basics. I found this in the archives that apply to my situation: http://marc.info/?l=stunnel-users&m=121848237124000&w=2 I followed those instructions that Tom Shaw gave, and I can't tell whether or not this thing is installed at all. http://marc.info/?l=stunnel-users&m=121848703131936&w=2 I think that the files are in the right places. And now when I type in stunnel on the command line, I get this as a response: 2009.06.20 12:27:37 LOG7[582:2691602208]: Snagged 64 random bytes from /Users/miles/.rnd 2009.06.20 12:27:37 LOG7[582:2691602208]: Wrote 1024 new random bytes to /Users/miles/.rnd 2009.06.20 12:27:37 LOG7[582:2691602208]: RAND_status claims sufficient entropy for the PRNG 2009.06.20 12:27:37 LOG7[582:2691602208]: PRNG seeded successfully 2009.06.20 12:27:37 LOG3[582:2691602208]: stunnel.pem: No such file or directory (2) I suppose that's an improvement over the command line returning no response for stunnel. So I guess it installed. I have a feeling that the config file (the sample that came with) is what's causing it to respond the way that it is... However, I also see that its throwing an error about the PEM file, that it thinks that its not there. Is there any way to check to see if its pointing at the right file for the pem ? Or to use another crt file ? Now the question becomes how the hell do I start this thing ? (I'm running leopard [10.5.7] for test purposes, but I'll have to do this all over again for a tiger install [10.4.11]...) Then once I get it started, how the hell do I initiate what needs doing ? I tried this ->> stunnel -o /Users/Miles/config.lgo -c -d 80 -r 134.84.119.230:636 Which returns -> 2009.06.20 13:34:32 LOG3[738:2691602208]: -o: No such file or directory (2) Obviously its yapping about a file, in this case I'm assuming the log file where its being referenced. Here's what I'm trying to do: I'm trying to set up a secure tunnel to an ldap server at umn.edu. I got this to work a while back but now I have to set this up from scratch....it was set up for me the last time. I wasn't paying attention and now Im kicking myself. The example I post is running in client mode and not server mode ? I was looking at THIS page: http://radio.weblogs.com/0100683/stories/2002/03/23/settingUpStunnelUnderMa… I'm not entirely certain that what I want to do is run in client mode given what I'm wanting to do... Any help would be a great relief. Thanks ahead of time... Sincerely, Miles.

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Install, Starting & Using Stunnel on OS X.
by m i l e s 20 Jun '09

20 Jun '09

Hi I'm a newbie to stunnel. I have a couple of questions....ok, a zillion. However I'll stick to the basics. I found this in the archives that apply to my situation: http://marc.info/?l=stunnel-users&m=121848237124000&w=2 I followed those instructions that Tom Shaw gave, and I can't tell whether or not this thing is installed at all. http://marc.info/?l=stunnel-users&m=121848703131936&w=2 I think that the files are in the right places. And now when I type in stunnel on the command line, I get this as a response: 2009.06.20 12:27:37 LOG7[582:2691602208]: Snagged 64 random bytes from /Users/miles/.rnd 2009.06.20 12:27:37 LOG7[582:2691602208]: Wrote 1024 new random bytes to /Users/miles/.rnd 2009.06.20 12:27:37 LOG7[582:2691602208]: RAND_status claims sufficient entropy for the PRNG 2009.06.20 12:27:37 LOG7[582:2691602208]: PRNG seeded successfully 2009.06.20 12:27:37 LOG3[582:2691602208]: stunnel.pem: No such file or directory (2) I suppose that's an improvement over the command line returning no response for stunnel. So I guess it installed. I have a feeling that the config file (the sample that came with) is what's causing it to respond the way that it is... However, I also see that its throwing an error about the PEM file, that it thinks that its not there. Is there any way to check to see if its pointing at the right file for the pem ? Or to use another crt file ? Now the question becomes how the hell do I start this thing ? (I'm running leopard [10.5.7] for test purposes, but I'll have to do this all over again for a tiger install [10.4.11]...) Then once I get it started, how the hell do I initiate what needs doing ? I tried this ->> stunnel -o /Users/Miles/config.lgo -c -d 80 -r 134.84.119.230:636 Which returns -> 2009.06.20 13:34:32 LOG3[738:2691602208]: -o: No such file or directory (2) Obviously its yapping about a file, in this case I'm assuming the log file where its being referenced. Here's what I'm trying to do: I'm trying to set up a secure tunnel to an ldap server at umn.edu. I got this to work a while back but now I have to set this up from scratch....it was set up for me the last time. I wasn't paying attention and now Im kicking myself. The example I post is running in client mode and not server mode ? I was looking at THIS page: http://radio.weblogs.com/0100683/stories/2002/03/23/settingUpStunnelUnderMa… I'm not entirely certain that what I want to do is run in client mode given what I'm wanting to do... Any help would be a great relief. Thanks ahead of time... Sincerely, Miles.

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Re: [stunnel-users] 4.26 works OK, 4.27 will not POP email
by Jeff Salisbury 17 Jun '09

17 Jun '09

Guy, Your suggestion fixed the problem. Thank you! Regards, Jeff Guy wrote: > Jeff Salisbury wrote: > > >> Greetings, We have been using Stunnel 4.26 to facilitate the >> sending and receiving of email with an email client that is not >> SSL enabled. Version 4.26 has been working great. However, when >> we upgrade to 4.27, we are unable to POP email (we can send >> email). We did not change our Stunnel.conf file. >> >> Can anyone advise us what we need to do to get 4.27 working? >> I've included our Stunnel.conf file contents, and the Stunnel log >> output below. >> >> > > > > Try: sslVersion = TLSv1 > > > See below. > > > > Your Modified Configuration File: > > ##### > # GLOBAL OPTIONS > > client = yes > #output = C:\Documents and Settings\All Users\Application Data\stunnel-log.txt > debug = 7 > taskbar = yes > > sslVersion = TLSv1 > > # SERVICE-LEVEL OPTIONS > > [pop3] > accept=995 > connect=mail.OurPOP.com:995 > > [smtp] > accept=465 > connect=mail.OurSMTP.com:465 > # > ##### > > > > Configuration File Used: > > ##### > # > client = yes > debug = debug > output = _test.log > rndbytes = 256 > rndfile = t:\tmp\randseed.bin > socket = l:TCP_NODELAY=1 > socket = r:TCP_NODELAY=1 > > sslVersion = TLSv1 > > [YOUR-POP3S] > accept=TUNNEL-01:110 > connect=216.97.239.60:995 > > [YOUR-SMTPS] > accept=TUNNEL-01:25 > connect=216.97.239.60:465 > # > ##### > > > > Stunnel Debug Output Log: > > Snagged 256 random bytes from t:\tmp\randseed.bin > Wrote 1024 new random bytes to t:\tmp\randseed.bin > RAND_status claims sufficient entropy for the PRNG > PRNG seeded successfully > SSL context initialized for service YOUR-POP3S > SSL context initialized for service YOUR-SMTPS > stunnel 4.27 on x86-pc-mingw32-gnu with OpenSSL 0.9.8k 25 Mar 2009 > Threading:WIN32 SSL:ENGINE Sockets:SELECT,IPv6 > No limit detected for the number of clients > FD 1884 in non-blocking mode > SO_REUSEADDR option set on accept socket > YOUR-POP3S bound to 127.0.10.1:110 > FD 1876 in non-blocking mode > SO_REUSEADDR option set on accept socket > YOUR-SMTPS bound to 127.0.10.1:25 > YOUR-POP3S accepted FD=1860 from 127.0.10.1:1599 > Creating a new thread > New thread created > YOUR-POP3S started > FD 1860 in non-blocking mode > TCP_NODELAY option set on local socket > YOUR-POP3S accepted connection from 127.0.10.1:1599 > FD 1836 in non-blocking mode > connect_blocking: connecting 216.97.239.60:995 > connect_blocking: s_poll_wait 216.97.239.60:995: waiting 10 seconds > connect_blocking: connected 216.97.239.60:995 > YOUR-POP3S connected remote server from 10.10.10.10:1600 > Remote FD=1836 initialized > TCP_NODELAY option set on remote socket > SSL state (connect): before/connect initialization > SSL state (connect): SSLv3 write client hello A > SSL state (connect): SSLv3 read server hello A > SSL state (connect): SSLv3 read server certificate A > SSL state (connect): SSLv3 read server done A > SSL state (connect): SSLv3 write client key exchange A > SSL state (connect): SSLv3 write change cipher spec A > SSL state (connect): SSLv3 write finished A > SSL state (connect): SSLv3 flush data > SSL state (connect): SSLv3 read finished A > 1 items in the session cache > 1 client connects (SSL_connect()) > 1 client connects that finished > 0 client renegotiations requested > 0 server connects (SSL_accept()) > 0 server connects that finished > 0 server renegotiations requested > 0 session cache hits > 0 session cache misses > 0 session cache timeouts > SSL connected: new session negotiated > Negotiated ciphers: AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 > Socket closed on read > SSL write shutdown > SSL alert (write): warning: close notify > SSL socket closed on SSL_shutdown > Socket write shutdown > Connection closed: 49 bytes sent to SSL, 90 bytes sent to socket > YOUR-POP3S finished (0 left) > YOUR-SMTPS accepted FD=1844 from 127.0.10.1:1601 > Creating a new thread > New thread created > YOUR-SMTPS started > FD 1844 in non-blocking mode > TCP_NODELAY option set on local socket > YOUR-SMTPS accepted connection from 127.0.10.1:1601 > FD 1836 in non-blocking mode > connect_blocking: connecting 216.97.239.60:465 > connect_blocking: s_poll_wait 216.97.239.60:465: waiting 10 seconds > connect_blocking: connected 216.97.239.60:465 > YOUR-SMTPS connected remote server from 10.10.10.10:1602 > Remote FD=1836 initialized > TCP_NODELAY option set on remote socket > SSL state (connect): before/connect initialization > SSL state (connect): SSLv3 write client hello A > SSL state (connect): SSLv3 read server hello A > SSL state (connect): SSLv3 read server certificate A > SSL state (connect): SSLv3 read server done A > SSL state (connect): SSLv3 write client key exchange A > SSL state (connect): SSLv3 write change cipher spec A > SSL state (connect): SSLv3 write finished A > SSL state (connect): SSLv3 flush data > SSL state (connect): SSLv3 read finished A > 1 items in the session cache > 1 client connects (SSL_connect()) > 1 client connects that finished > 0 client renegotiations requested > 0 server connects (SSL_accept()) > 0 server connects that finished > 0 server renegotiations requested > 0 session cache hits > 0 session cache misses > 0 session cache timeouts > SSL connected: new session negotiated > Negotiated ciphers: AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 > Socket closed on read > SSL write shutdown > SSL alert (write): warning: close notify > SSL socket closed on SSL_shutdown > Socket write shutdown > Connection closed: 78 bytes sent to SSL, 423 bytes sent to socket > YOUR-SMTPS finished (0 left) > > > > POP3 Transaction Log: > > CONNECT : Looking up host name TUNNEL-01... > CONNECT : Host name TUNNEL-01 found > CONNECT : Connecting to host TUNNEL-01 [127.0.10.1:110]... > CONNECT : Connected to host TUNNEL-01 [127.0.10.1:110] > POP REPLY : +OK Hello there. > POP SEND : USER username > POP REPLY : +OK Password required. > POP SEND : PASS ********** > POP REPLY : -ERR Login failed. > POP SEND : QUIT > POP REPLY : +OK Better luck next time. > DISCONNECT: Disconnected from server > > > > SMTP Transaction Log: > > CONNECT : Looking up host name TUNNEL-01... > CONNECT : Host name TUNNEL-01 found > CONNECT : Connecting to host TUNNEL-01 [127.0.10.1:25]... > CONNECT : Connected to host TUNNEL-01 [127.0.10.1:25] > SMTP REPLY: 220-crimson.lunarbreeze.com ESMTP Exim 4.69 #1 Tue, 16 Jun 2009 14:45:25 -0700 > SMTP SEND : EHLO computername > SMTP REPLY: 250-crimson.lunarbreeze.com Hello 123,123.123.123 [123,123.123.123] > SMTP REPLY: 250-SIZE 52428800 > SMTP REPLY: 250-PIPELINING > SMTP REPLY: 250-AUTH PLAIN LOGIN > SMTP REPLY: 250 HELP > SMTP SEND : AUTH PLAIN xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx== > SMTP REPLY: 535 Incorrect authentication data > SMTP SEND : QUIT > SMTP REPLY: 221 crimson.lunarbreeze.com closing connection > DISCONNECT: Disconnected from server > >

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