March 2014 - stunnel-users

stunnel FIPS mode 140-2/ Other Modes
by mehmet ozisik 19 Sep '25

19 Sep '25

Hi All, I would like to ask a question about stunnel fips mode. There are lots of question and answers on the internet related with this, but I could not find any answer related with mine. I am compiling with openssl (auto detecting fips) . Here is a part of confgiure output : checking for FIPS_mode_set... yes configure: FIPS mode detected So I am thinking that fips also is being included. Then I try to run stunnel on target platform (in stunnel.conf fips=yes) and it gives below error : Compiled/running with OpenSSL 0.9.8w-fips 23 Apr 2012 Threading:PTHREAD Sockets:POLL,IPv6 SSL:ENGINE,OCSP,FIPS Reading configuration from file stunnel.conf FIPS_mode_set: 2D06906E: error:2D06906E:FIPS routines:FIPS_CHECK_INCORE_FINGERPRINT:fingerprint does not match there are lots of information about this errror on internet. Then when I configure stunnel.conf with fips=no, stunnel is running successfully. I know that fips=yes means that enables FIPS 140-2 mode and I guess my fips canister does not supoort fips 140-2 mode (I do not know which fips mode it has supported). Now my question is coming : When I set fips=no, stunnel also starts with other available fips modes which the canister included? Or it skips running fips mode completely? Plase inform me if anyone has any idea? Regards

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Stunnel 4 failing to connect to gmail
by Asif Iqbal 11 Dec '20

11 Dec '20

I am faling to connect to gmail. Not sure what that bind error means. iqbala@ghar:~$ sudo stunnel4 2008.12.15 13:53:17 LOG7[3839:3083650736]: Snagged 64 random bytes from /home/iqbala/.rnd 2008.12.15 13:53:17 LOG7[3839:3083650736]: Wrote 1024 new random bytes to /home/iqbala/.rnd 2008.12.15 13:53:17 LOG7[3839:3083650736]: RAND_status claims sufficient entropy for the PRNG 2008.12.15 13:53:17 LOG7[3839:3083650736]: PRNG seeded successfully 2008.12.15 13:53:17 LOG7[3839:3083650736]: Certificate: /etc/stunnel/stunnel.pem 2008.12.15 13:53:17 LOG7[3839:3083650736]: Certificate loaded 2008.12.15 13:53:17 LOG7[3839:3083650736]: Key file: /etc/stunnel/stunnel.pem 2008.12.15 13:53:17 LOG7[3839:3083650736]: Private key loaded 2008.12.15 13:53:17 LOG7[3839:3083650736]: SSL context initialized for service ssmtp 2008.12.15 13:53:17 LOG5[3839:3083650736]: stunnel 4.22 on i486-pc-linux-gnu with OpenSSL 0.9.8g 19 Oct 2007 2008.12.15 13:53:17 LOG5[3839:3083650736]: Threading:PTHREAD SSL:ENGINE Sockets:POLL,IPv6 Auth:LIBWRAP 2008.12.15 13:53:17 LOG6[3839:3083650736]: file ulimit = 1024 (can be changed with 'ulimit -n') 2008.12.15 13:53:17 LOG6[3839:3083650736]: poll() used - no FD_SETSIZE limit for file descriptors 2008.12.15 13:53:17 LOG5[3839:3083650736]: 500 clients allowed 2008.12.15 13:53:17 LOG7[3839:3083650736]: FD 10 in non-blocking mode 2008.12.15 13:53:17 LOG7[3839:3083650736]: FD 11 in non-blocking mode 2008.12.15 13:53:17 LOG7[3839:3083650736]: FD 12 in non-blocking mode 2008.12.15 13:53:17 LOG7[3839:3083650736]: SO_REUSEADDR option set on accept socket 2008.12.15 13:53:17 LOG3[3839:3083650736]: Error binding ssmtp to 74.125.93.111:587 2008.12.15 13:53:17 LOG3[3839:3083650736]: bind: Cannot assign requested address (99) Here is how my conf file looks like iqbala@ghar:~$ cat /etc/stunnel/stunnel.conf | egrep -v "^;|^$" cert = /etc/stunnel/stunnel.pem foreground = yes sslVersion = SSLv3 chroot = /var/lib/stunnel4/ setuid = stunnel4 setgid = stunnel4 pid = /stunnel4.pid socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 debug = 7 output = /var/log/stunnel4/stunnel.log client = yes [ssmtp] accept = smtp.gmail.com:587 connect = 25 Asif Iqbal PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu

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stunnel and hosts.allow
by Yousef Alhashemi 05 Jul '16

05 Jul '16

Hi, This may be a little bit off-topic, but does anyone here use stunnel with pan? My connections to stunnel (in pan) are always refused by libwrap. I was looking for the right rule to add to /etc/hosts.allow but nothing seems to work aside from "ALL : ALL" (which is obviously not good) and "nntps: KNOWN". Is the latter reasonable? The hosts_access(5) manpage is confusing to say the least. It mentions that daemon (the first token on any line) is the name of the daemon running the process, which would be "stunnel" in my case, but using "stunnel : LOCAL" or even "stunnel : ALL" doesn't work. The rule that seems to work, as mentioned, is "nntps : KNOWN" ("nntps" being the group name in stunnel.conf). What's even more confusing to me is that "nntps : LOCAL" does not work either. Nor does "nntps : localhost 127.0.0.1", "nntps : localhost", "nntps : 127.0.0.1", or "nntps : 192.168.1.". Pan is running on the same machine as stunnel so all connections must be coming from localhost. Why do these rules not trigger? Either way, I'd like to know the "least permissive" hosts.allow rule that would allow me to connect to my news provider from pan, and/or whether "nntps : KNOWN" is a safe option. Thanks, Yousef

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behavior change after enabling proxy protocol
by Philippe Anctil 05 Jun '14

05 Jun '14

Hello, We use stunnel to secure a proprietary tcp/ip protocol over the internet. More specifially we have - 1 balancer - 2 stunnel boxes - 1 app server The load balancer 'pings' stunnel boxes regularly to know if one is down. Recently, we have added support for the proxy protocol in our app and turned it on in our stunnel config. It works great except for one small new behavior: upon receiving a load balancer ping, stunnel performs a connection on our app (and sends the proxy header). I ran a tcpdump for a telnet on the stunnel port (8000). With proxy protocol disabled, stunnel does nothing while it waits for the certificate. The connection ended at my request. 17:33:08.537385 IP 127.0.0.1.6015 > 127.0.0.1.8000: S 356922015:356922015(0) win 32792 <mss 16396,sackOK,timestamp 1085620573 0,nop,wscale 7> 17:33:08.537386 IP 127.0.0.1.8000 > 127.0.0.1.6015: S 1525966521:1525966521(0) ack 356922016 win 32768 <mss 16396,sackOK,timestamp 1085620573 1085620573,nop,wscale 7> 17:33:08.537393 IP 127.0.0.1.6015 > 127.0.0.1.8000: . ack 1 win 257 <nop,nop,timestamp 1085620573 1085620573> 17:33:19.750431 IP 127.0.0.1.6015 > 127.0.0.1.8000: F 1:1(0) ack 1 win 257 <nop,nop,timestamp 1085631785 1085620573> 17:33:19.751065 IP 127.0.0.1.8000 > 127.0.0.1.6015: . ack 2 win 256 <nop,nop,timestamp 1085631786 1085631785> 17:33:19.751794 IP 127.0.0.1.8000 > 127.0.0.1.6015: R 1:1(0) ack 2 win 256 <nop,nop,timestamp 1085631787 1085631785> With proxy protocol enabled, stunnel establishes a connection to my app and sends the proxy protocol before even receiving the certificate. 17:34:35.370462 IP 127.0.0.1.6026 > 127.0.0.1.8000: S 2949098861:2949098861(0) win 32792 <mss 16396,sackOK,timestamp 1085707402 0,nop,wscale 7> 17:34:35.370475 IP 127.0.0.1.8000 > 127.0.0.1.6026: S 1044893129:1044893129(0) ack 2949098862 win 32768 <mss 16396,sackOK,timestamp 1085707402 1085707402,nop,wscale 7> 17:34:35.370481 IP 127.0.0.1.6026 > 127.0.0.1.8000: . ack 1 win 257 <nop,nop,timestamp 1085707402 1085707402> 17:34:35.371035 IP 127.0.0.1.37654 > 127.0.0.1.9000: S 801705083:801705083(0) win 32792 <mss 16396,sackOK,timestamp 1085707402 0,nop,wscale 7> 17:34:35.371046 IP 127.0.0.1.9000 > 127.0.0.1.37654: S 4068822820:4068822820(0) ack 801705084 win 32768 <mss 16396,sackOK,timestamp 1085707402 1085707402,nop,wscale 7> 17:34:35.371052 IP 127.0.0.1.37654 > 127.0.0.1.9000: . ack 1 win 257 <nop,nop,timestamp 1085707402 1085707402> 17:34:35.371583 IP 127.0.0.1.37654 > 127.0.0.1.9000: P 1:44(43) ack 1 win 257 <nop,nop,timestamp 1085707403 1085707402> 17:34:35.371595 IP 127.0.0.1.9000 > 127.0.0.1.37654: . ack 44 win 256 <nop,nop,timestamp 1085707403 1085707403> 17:34:50.484991 IP 127.0.0.1.9000 > 127.0.0.1.37654: F 1:1(0) ack 44 win 256 <nop,nop,timestamp 1085722515 1085707403> 17:34:50.485892 IP 127.0.0.1.37654 > 127.0.0.1.9000: . ack 2 win 257 <nop,nop,timestamp 1085722516 1085722515> 17:35:08.824661 IP 127.0.0.1.6026 > 127.0.0.1.8000: F 1:1(0) ack 1 win 257 <nop,nop,timestamp 1085740854 1085707402> 17:35:08.824906 IP 127.0.0.1.8000 > 127.0.0.1.6026: . ack 2 win 256 <nop,nop,timestamp 1085740854 1085740854> 17:35:08.824972 IP 127.0.0.1.37654 > 127.0.0.1.9000: R 44:44(0) ack 2 win 257 <nop,nop,timestamp 1085740854 1085722515> 17:35:08.825013 IP 127.0.0.1.8000 > 127.0.0.1.6026: R 1:1(0) ack 2 win 256 <nop,nop,timestamp 1085740855 1085740854> Note I used 'tcpdump -i lo -nn port 8000 or port 9000' for both traces. I see no good reason to connect to the application before the ssl session is established. Thank you for reading! -- Philippe Anctil

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Re: [stunnel-users] public domain [Patch] Support multiple X509 client certificates with same CN
by Leon Winter 01 Apr '14

01 Apr '14

Hi Michal, > >What license do you need the patch to be? > > Preferably public domain, but any GPL-compatbile and non-copyleft license > should be fine. I hereby release my patches to stunnel for support of muliple client certificates with the same CN into the public domain. Best regards, Leon Winter

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Some troubles with PROXY protocol
by Alexey V. Drozdov 31 Mar '14

31 Mar '14

Hi, I try to use PROXY protocol ability for my virtual server, but this options work for root section only. E.g. it not work for this simple case: [virtual_server] accept = 443 connect = localhost:1081 cert = /etc/stunnel/serverCA.crt key = /etc/stunnel/serverCA.key verify = 2 CAfile = /etc/stunnel/serverCA.crt [server_ru] sni = virtual_server:server.ru cert = /etc/stunnel/server.cer key = /etc/stunnel/server.pem connect = localhost:7000 protocol = proxy <-- option don not work there This problem exist due some code bug: NOEXPORT void client_try(CLI *c) { init_local(c); if(!c->opt->option.client && c->opt->protocol<0) // <-- condition is true in spite of setup protorol=proxy { init_ssl(c); // we'll switch to target section (c->opt) there only! init_remote(c); } else { protocol(c, PROTOCOL_PRE_CONNECT); init_remote(c); protocol(c, PROTOCOL_PRE_SSL); init_ssl(c); protocol(c, PROTOCOL_POST_SSL); } ... Simple adhoc solution work for me: if(!c->opt->option.client && c->opt->protocol<0) // <-- condition is true in spite of setup protorol=proxy { init_ssl(c); init_remote(c); // force initiate PROXY protocol protocol(c, PROTOCOL_PRE_SSL); } It's crutch and not general solution certain. But some code refactoring needs for more correct fix. I think that this bug will be fixed in future versions. Thanks for stunnel! :) /Alexey V. Drozdov e-mail: anyquist(a)yandex.ru

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Build failure of stunned 5.00 under OS X.
by Marius Schamschula 28 Mar '14

28 Mar '14

Hi there, After having built many prior releases of stunned for OS X, I ran into the following issue with version 5.0: /bin/sh ../libtool --tag=CC --mode=link gcc -pthread -fstack-protector -fPIE -g -O2 -Wall -Wextra -Wno-long-long -pedantic -L/usr/local/ssl/lib64 -L/usr/local/ssl/lib -lssl -lcrypto -o stunnel stunnel-str.o stunnel-file.o stunnel-client.o stunnel-log.o stunnel-options.o stunnel-protocol.o stunnel-network.o stunnel-resolver.o stunnel-ssl.o stunnel-ctx.o stunnel-verify.o stunnel-sthreads.o stunnel-fd.o stunnel-stunnel.o stunnel-pty.o stunnel-libwrap.o stunnel-ui_unix.o -lz -lpthread -lwrap libtool: link: gcc -pthread -fstack-protector -fPIE -g -O2 -Wall -Wextra -Wno-long-long -pedantic -o stunnel stunnel-str.o stunnel-file.o stunnel-client.o stunnel-log.o stunnel-options.o stunnel-protocol.o stunnel-network.o stunnel-resolver.o stunnel-ssl.o stunnel-ctx.o stunnel-verify.o stunnel-sthreads.o stunnel-fd.o stunnel-stunnel.o stunnel-pty.o stunnel-libwrap.o stunnel-ui_unix.o -L/usr/local/ssl/lib64 -L/usr/local/ssl/lib -lssl -lcrypto -lz -lpthread -lwrap -pthread ld: warning: directory not found for option '-L/usr/local/ssl/lib64' Undefined symbols for architecture x86_64: "_load_icon_default", referenced from: _parse_global_option in stunnel-options.o "_load_icon_file", referenced from: _parse_global_option in stunnel-options.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status he ewxat same issue under 10.8 and 10.9. Makefile:471: recipe for target 'stunnel' failed make[2]: *** [stunnel] Error 1 make[2]: Leaving directory '/private/tmp/stunnel-5.00/src' Makefile:339: recipe for target 'all' failed make[1]: *** [all] Error 2 make[1]: Leaving directory '/private/tmp/stunnel-5.00/src' Makefile:365: recipe for target 'all-recursive' failed make: *** [all-recursive] Error 1 This is the OS X 10.7 build, but I had the same issue under 10.8 and 10.9. Marius -- Marius Schamschula

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Access to Packet Content
by Michael Carlino (RIT Student) 26 Mar '14

26 Mar '14

Hello stunnel users, I am working with what seems to be the standard stunnel HTTPS configuration. I have two instances of stunnel, one as a client and one as a server. The client accepts connections from a browser. The server sits in front of tomcat. If works like a charm (of course!). What I need to do seems simple, and I will try to keep my description of it generic. In the client stunnel I need to make a small change to the HTTP packet. I need to add some data to it. At the server side I need to access that added data. The server stunnel may close the SSL session based on that data. So, my question is: can I obtain access to the packet before it's encrypted and sent out over SSL? Can I get access to the decrypted packet before it's sent on to tomcat? I know that as a proxy stunnel has to be and tries to be general in nature. I am not concerned (right now) with developing a feature that will become available to others later. I don't mind if my changes make my development version of stunnel single-purpose. My work is academic and proof-of-concept in it's nature. I have collected references and a text book (Network Security with OpenSSL by Viega et al). I will continue to walk through and explore the code. Are there any programmer resources I can obtain? I see the occasional URL in the stunnel source code. I will have to check these URLs. --- I just now pursued http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt, and I see that there is a patch that allows stunnel to do an initial modification to the HTTP request to insert a X-Forwarded-For header. This sounds like what I need to do! I am going to look for that patch. I hope the source code for the patch is available. Please, if anyone has any advice, war stories, criticism, whatever... I would very much appreciate it. Regards.

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Tool Information
by "Cortenai Swoboda Reinbrecht" 14 Mar '14

14 Mar '14

1 0

stunnel.cnf should set keyUsage = keyCertSign
by Athir Nuaimi 11 Mar '14

11 Mar '14

I'm trying to write a go program to connect to an stunnel server and verify the certificate but it fails because the go language requires that self-signed certs have keyCertSign set in the keyUsages. the default stunnel.cnf does not set this. According to the following message thread this is required by RFC 5280. https://groups.google.com/forum/#!msg/golang-nuts/LfLHjVkeSj8/YyP-LSPEytEJ The solution to this is to add 'keyUsage = keyCertSign' to the stunnel.cnf.

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