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Re: [stunnel-users] Enhancement request - Increase thread stack size
by Mccue, Richard Alan 26 Mar '08

26 Mar '08

Michal Trojnara wrote: >> I load an engine into Stunnel to access the private key. The engine loads >> without incident, but Stunnel consistently aborts when creating a session >> with the first peer because the thread stack is too small. > > I'm not sure if it's a good idea to sacrifice stunnel scalability for > compatibility with this engine. Thread stack size is one of the main > limitations for the number of concurrent threads on 32-bit platforms. IMHO > it's better to fix the engine code to allocate its buffers on the heap.> > > What do you think? All things considered, I must agree that reducing the engine use of the stack would be the better solution. I'll look it over and see if I can find anything sizable on the stack to move. Thanks for the suggestion! - Rich

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New libwrap code
by Randy McMurchy 26 Mar '08

26 Mar '08

Hi all, My apologies if this has been discussed (I've reviewed the archives since 4.21 was released), and if so please just point me in the right direction. I read in some of the messages there's been a revamp (overhaul, changes, whatever) of the libwrap code in Stunnel-4.21. I'm not having any issues using the new version, however, I'm seeing it spawn 5 processes where in every other version I've used in the past there has always only been one process spawned. Here's what I see: root 3408 1 0 17:50 pts/10 00:00:00 /usr/bin/stunnel root 3409 1 0 17:50 pts/10 00:00:00 /usr/bin/stunnel root 3410 1 0 17:50 pts/10 00:00:00 /usr/bin/stunnel root 3411 1 0 17:50 pts/10 00:00:00 /usr/bin/stunnel root 3412 1 0 17:50 pts/10 00:00:00 /usr/bin/stunnel stunnel 3413 1 0 17:50 ? 00:00:00 /usr/bin/stunnel Is this a product of the new libwrap code? I turned debug messages WAY up and I see over and over startup messages for all 5 processes. Example of one: 2008.03.25 17:50:24 LOG5[3407:3082803904]: stunnel 4.21 on i686-pc-linux-gnu with OpenSSL 0.9.8e 23 Feb 2007 2008.03.25 17:50:24 LOG5[3407:3082803904]: Threading:PTHREAD SSL:ENGINE Sockets:POLL,IPv4 Auth:LIBWRAP 2008.03.25 17:50:24 LOG6[3407:3082803904]: file ulimit = 1024 (can be changed with 'ulimit -n') 2008.03.25 17:50:24 LOG6[3407:3082803904]: poll() used - no FD_SETSIZE limit for file descriptors 2008.03.25 17:50:24 LOG5[3407:3082803904]: 500 clients allowed 2008.03.25 17:50:24 LOG7[3407:3082803904]: FD 9 in non-blocking mode 2008.03.25 17:50:24 LOG7[3407:3082803904]: FD 10 in non-blocking mode 2008.03.25 17:50:24 LOG7[3407:3082803904]: FD 11 in non-blocking mode 2008.03.25 17:50:24 LOG7[3407:3082803904]: SO_REUSEADDR option set on accept socket 2008.03.25 17:50:24 LOG7[3407:3082803904]: swat bound to 0.0.0.0:904 2008.03.25 17:50:24 LOG7[3413:3082803904]: Created pid file /run/stunnel.pid 2008.03.25 17:50:42 LOG7[3413:3082803904]: swat accepted FD=12 from 192.168.11.212:1535 2008.03.25 17:50:42 LOG7[3413:3086076816]: swat started 2008.03.25 17:50:42 LOG7[3413:3086076816]: FD 12 in non-blocking mode 2008.03.25 17:50:42 LOG7[3413:3086076816]: Waiting for a libwrap process 2008.03.25 17:50:42 LOG7[3413:3086076816]: Acquired libwrap process #0 2008.03.25 17:50:42 LOG7[3413:3086076816]: Releasing libwrap process #0 2008.03.25 17:50:42 LOG7[3413:3086076816]: Released libwrap process #0 2008.03.25 17:50:42 LOG7[3413:3086076816]: swat permitted by libwrap from 192.168.11.212:1535 2008.03.25 17:50:42 LOG5[3413:3086076816]: swat accepted connection from 192.168.11.212:1535 When I connect to swat (Samba config tool) it again goes through a process of using all 5 of the system processes. Sorry for being so verbose here. My question is: Has something changed so that there is more than one process spawned (and used) when Stunnel is started? Any help would be appreciated. -- Randy

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Enhancement request - Increase thread stack size
by Mccue, Richard Alan 25 Mar '08

25 Mar '08

I load an engine into Stunnel to access the private key. The engine loads without incident, but Stunnel consistently aborts when creating a session with the first peer because the thread stack is too small. I rebuilt Stunnel 4.21 on my test machine after increasing the stack size parameter and it fixed the problem. Here is the diff: --------------------- # diff -b common.h common.h_orig 33c33 < #define STACK_SIZE 32768*4 --- > #define STACK_SIZE 32768 42c42 < #define STACK_SIZE 65536*4 --- > #define STACK_SIZE 65536 --------------------- Could this enhancement be included in the next Stunnel release? Regards, Rich

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HTTPS being redirected back to HTTP
by Steven Buehler 25 Mar '08

25 Mar '08

I have tested several versions of stunnel up to version 4.21 on SLES 9 and 10. I am trying to use stunnel to implement TLS 1.0 for HTTPS on a Lotus Domino server. I am able to connect to the Domino server with a web browser with HTTPS successfully. However, once I log into the server it drops me back down to HTTP. I suspect the Domino server is sending a redirect back to HTTP during the login because if I change the URL back to HTTPS in the browser after the login, it re-establishes the HTTPS connection. I've checked with Lotus support and there is nothing that can be done on the Domino server to prevent this. Is there anyway to handle this in stunnel so that the requests remain as HTTPS requests to the browser? Here is the services section of my stunnel.conf [https] sslVersion = TLSv1 accept = gsvatestm02.er.usgs.gov:443 connect = gsvatestm02.er.usgs.gov:80 TIMEOUTclose = 0

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possible stunnel memory leak
by Stefano Stabellini 25 Mar '08

25 Mar '08

Hi all, I may have found a possible memory leak in stunnel (version 4.15) when used with pthreads. What I am seeing is the memory usage going up when connections open and never going down, no matter if all the connections close. It is really easy to reproduce it: I have started two stunnel instances communicating with each other, the first one acting as a server (config file stunnel.1) and executing cat, the second one acting as a client (config file stunnel.2) and opening port 5556. Then I execute the script I have attached that simply opens 500 connections using netcat to port 5556. If you cat /proc/<stunnel pid>/status you can see that the memory usage is about 300MB. The problem is that even after all the connections are closed the memory usage stays (more or less) the same. I tried to find the bug myself using valgrind, but I couldn't get far, it seems that valgrind gets confused by openssl so doesn't print very useful informations. I really appreciate any help you can give me; just tell me if you need any other info. Best Regards, Stefano Stabellini #!/bin/bash i=1 while test $i -lt 520 do cat script | nc 127.0.0.1 5556 &>/dev/null & echo $i i=$(( $i + 1 )) done foreground = yes [test] accept = 5555 cert = /etc/ssl/certs/stunnel.pem exec = cat foreground = yes [test] accept = 5556 cert = /etc/ssl/certs/stunnel.pem client = yes connect = 5555

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IMAPS stunnel on older OSX Mac: SSL3_GET_RECORD:wrong version number
by Tom Shaw 23 Mar '08

23 Mar '08

1. compiled and installed stunnel on older OSX Mac. Tried connectiong via IMAPS and POP3S using Apple OSX Mail and I get the errors shown in line 4. Process works when I change my .conf file to contain sslVersion = SSLv2. I'm a neophyte to ssl and I have no idea what is wrong or where to start or if this situation is OK. Any help is appreciated. Also this needs to be backward compatible to OSX 10.3.9 which is why the compiling on Panther. 2. stunnel version 4.20 3. standalone via sudo from command line 4. error message Mar 23 10:49:52 musky stunnel: LOG5[2941:25192960]: imaps accepted connection from 206.208.58.127:37295 Mar 23 10:49:52 musky stunnel: LOG3[2941:25192960]: SSL_accept: 1408F10B: error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number Mar 23 10:49:52 musky stunnel: LOG5[2941:25192960]: Connection reset: 0 bytes sent to SSL, 0 bytes sent to socket 5. $ /usr/local/sbin/stunnel -version stunnel 4.20 on powerpc-apple-darwin7.9.0 with OpenSSL 0.9.7l 28 Sep 2006 Threading:PTHREAD SSL:ENGINE Sockets:SELECT,IPv4 Auth:LIBWRAP Global options debug = 5 pid = /usr/local/var/run/stunnel/stunnel.pid RNDbytes = 64 RNDfile = /dev/urandom RNDoverwrite = yes Service-level options cert = /usr/local/etc/stunnel/stunnel.pem ciphers = ALL:!ADH:+RC4:@STRENGTH key = /usr/local/etc/stunnel/stunnel.pem session = 300 seconds sslVersion = SSLv3 for client, all for server TIMEOUTbusy = 300 seconds TIMEOUTclose = 60 seconds TIMEOUTconnect = 10 seconds TIMEOUTidle = 43200 seconds verify = none 6. $ uname -a Darwin musky.oitc.com 7.9.0 Darwin Kernel Version 7.9.0: Wed Mar 30 20:11:17 PST 2005; root:xnu/xnu-517.12.7.obj~1/RELEASE_PPC Power Macintosh powerpc 7. Your libc version if you use Linux. 8. $ gcc -v Reading specs from /usr/libexec/gcc/darwin/ppc/3.3/specs Thread model: posix gcc version 3.3 20030304 (Apple Computer, Inc. build 1666) 9. $ openssl version OpenSSL 0.9.7l 28 Sep 2006 10. My conf ; Sample stunnel configuration file by Michal Trojnara 2002-2006 ; Some options used here may not be adequate for your particular configuration ; Please make sure you understand them (especially the effect of chroot jail) ; Certificate/key is needed in server mode and optional in client mode cert = /usr/local/etc/stunnel/secure_mail.pem ;key = /usr/local/etc/stunnel/secure_mail.pem ; Protocol version (all, SSLv2, SSLv3, TLSv1) sslVersion = SSLv2 ; Some security enhancements for UNIX systems - comment them out on Win32 ;chroot = /usr/local/var/lib/stunnel/ ;setuid = nobody ;setgid = nobody ;setgid = nogroup ; PID is created inside chroot jail pid = /var/run/stunnel.pid ; Some performance tunings socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 ;compression = rle ; Workaround for Eudora bug options = DONT_INSERT_EMPTY_FRAGMENTS ; Authentication stuff ;verify = 2 ; Don't forget to c_rehash CApath ; CApath is located inside chroot jail ;CApath = /certs ; It's often easier to use CAfile ;CAfile = /usr/local/etc/stunnel/certs.pem ; Don't forget to c_rehash CRLpath ; CRLpath is located inside chroot jail ;CRLpath = /crls ; Alternatively you can use CRLfile ;CRLfile = /usr/local/etc/stunnel/crls.pem ; Some debugging stuff useful for troubleshooting debug = 7 ;output = stunnel.log ; Use it for client mode ;client = yes ; Service-level configuration [pop3s] accept = 995 connect = 110 [imaps] accept = 993 connect = 143 [ssmtp] accept = 465 connect = 587 [sldap] accept = 636 connect = 389 ;[https] ;accept = 443 ;connect = 80 ;TIMEOUTclose = 0 ; vim:ft=dosini

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What is the stable version of Stunnel?
by Randy McMurchy 22 Mar '08

22 Mar '08

Hi all, Can anyone say for sure what is the stable version of Stunnel? On the main Stunnel web site page ( http://www.stunnel.org ) and in the announcement for the version it says the new 4.21 version is experimental. However, on the download page ( http://www.stunnel.org/download/source.html ) the 4.21 version is flagged as the stable version. Sort of confusing. -- Randy

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compiling stunnel 4.21 on solaris 10
by cod3fr3ak 14 Mar '08

14 Mar '08

Is this not compatible with Openssl 0.9.8f? I think 0.9.8g only reacently came out. Is this the only thing wrong. All my other applications work with this version of openssl. BTW I am using the sunfreeware version, because I wanted to avoid having to compile a bunch of software. i was planning to only compile Stunnel, and maybe swatch. I'll compile Openssl if there is no other way but I'd rather not. Any ideas? R

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bidirectional tunnel
by Leo Cherepanov 14 Mar '08

14 Mar '08

Hello. First of all - thanx a lot, I'm using stunnel every day and it helps me. It will help me even more :) if I can make bidirectional tunnel between external server S and computer C behind nat-proxy-firewall. Of course, C is initiator. I mean after tunnel is up, there is a port-forward C:port1->S:port2 (already works) _and_ S:port3->C:port4 Once again, S has an external ip, C has a private ip. Is this schema posible? Thanx en avance.

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SSLV3 decompression failure???
by Earl Stenlund 13 Mar '08

13 Mar '08

I've been running into the error below: SSL_connect: 14094406: error:14094406:SSL routines:SSL3_READ_BYTES:sslv3 alert decompression failure Running Vista SP1 with stunnel 4.21 connecting to newshosting. It seems to come and go. Any ideas on what is causing this or how to fix it? Thanks, Earl

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