August 2016 - 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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Requests to cloud server that requires host header
by Lorne Kates 13 Nov '24

13 Nov '24

(related to Akamai message from before-- but I have better troubleshooting information). I'm tying to route traffic through stunnel to a "cloud" based-endpoint. That endpoint has a static server name-- test.authorize.net. (This is the dev sandbox for auth.net) But if you do an nslookup on test.authorize.net, you'll get back a different servername and IP, because it's so wonderfully "cloud". Stunnel apparently tries to connect to the nslookup value. The server rejects the request because it can't route it back to test.authorize.net. I've tried adding "delay = yes" and "sni = test.authorize.net", but neither work. To see this in action, a simple setup with any accept, then connect to test.authorize.net:443 in client = yes mode. This is what a valid response looks like (13 -- give me the darn merchant ID in a POST): https://test.authorize.net/gateway/transact.dll This is what you'll get if you try to use stunnel (400 invalid url) : https://23.195.204.150/gateway/transact.dll So how can I get stunnel to send the proper Request Header (host: test.authorize.net) make sure it's using http/1.1, etc?

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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 & Gmail security
by BOXI31 TEST 16 Oct '20

16 Oct '20

Hi all, To make "Stunnel 5.31" work with Gmail, I have to go in security settings of Gmail and "allow less secure apps to access my account". Is it mandatory ? Is it possible to set Stunnel to access Gmail without lowering it security level ? How ? I checked in log file TLS v1.2 is used by Stunnel but Gmail still consider it as a "less secure app." ! Regards, Steve

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Re: [stunnel-users] Public domain [PATCH] support environment variables in config file
by Dmitry Bakshaev 21 Dec '16

21 Dec '16

2016-05-31 12:02 GMT+04:00 Pierre Delaage <delaage.pierre(a)free.fr>: > Did not have a look at the code yet, but should it be possible to replace > envvars usage by some keys in the registry on windows platform and/or > %userprofile%/config-file ? > > Anyway, my opinion on the patch is that there is no real interest for > "generic/self-expanding" config file , and it is even dangerous : > I would not trust stunnel if, at run time, its config could be modified by > USER envvars... > which difference between %userprofile%/config-file and USER envvars? both are USER owned and USER controlled. certificate and keys also USER private data. and stunnel started by USER owned by USER. if stunnel started by SYSTEM/ADMIN he uses SYSTEM/ADMIN envvars (if needed), certs, keys, etc. global "generic/self-expanding" config file is ADMIN owned. USER has permissions to substitute some values, restricted by ADMIN.

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stunnel 5.x no answer in server mode?
by Ulli Horlacher 31 Aug '16

31 Aug '16

I use stunnel as a https proxy for my own http server (*). The server mode of stunnel 5.x does not work any more. It accepts the connection and then immediatelly closes it without sending back any data. stunnel 4.x is working fine (for many years!), with the same configuration. Here is my (test) config which shows the problem (host is Ubuntu 16.04): root@xerus:/tmp# cat stunnel.conf pid = /tmp/stunnel.pid output = /home/fex/spool/stunneld.log debug = debug fips = no foreground = yes [https] accept = 443 cert = /home/fex/etc/stunnel.pem sslVersion = all TIMEOUTclose = 1 exec = perl execargs = perl -T /home/fex/bin/fexsrv stunnel root@xerus:/tmp# /opt/stunnel-5.35/bin/stunnel stunnel.conf 2016.08.30 18:58:55 LOG7[ui]: Clients allowed=500 2016.08.30 18:58:55 LOG5[ui]: stunnel 5.35 on x86_64-unknown-linux-gnu platform 2016.08.30 18:58:55 LOG5[ui]: Compiled/running with OpenSSL 1.0.2g-fips 1 Mar 2016 2016.08.30 18:58:55 LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,FIPS,OCSP,PSK,SNI 2016.08.30 18:58:55 LOG7[ui]: errno: (*__errno_location ()) 2016.08.30 18:58:55 LOG5[ui]: Reading configuration from file /tmp/stunnel.conf 2016.08.30 18:58:55 LOG5[ui]: UTF-8 byte order mark not detected 2016.08.30 18:58:55 LOG5[ui]: FIPS mode disabled 2016.08.30 18:58:55 LOG7[ui]: Compression disabled 2016.08.30 18:58:55 LOG7[ui]: Snagged 64 random bytes from /root/.rnd 2016.08.30 18:58:55 LOG7[ui]: Wrote 1024 new random bytes to /root/.rnd 2016.08.30 18:58:55 LOG7[ui]: PRNG seeded successfully 2016.08.30 18:58:55 LOG6[ui]: Initializing service [https] 2016.08.30 18:58:55 LOG6[ui]: Loading certificate from file: /home/fex/etc/stunnel.pem 2016.08.30 18:58:55 LOG6[ui]: Certificate loaded from file: /home/fex/etc/stunnel.pem 2016.08.30 18:58:55 LOG6[ui]: Loading private key from file: /home/fex/etc/stunnel.pem 2016.08.30 18:58:55 LOG6[ui]: Private key loaded from file: /home/fex/etc/stunnel.pem 2016.08.30 18:58:55 LOG7[ui]: Private key check succeeded 2016.08.30 18:58:55 LOG7[ui]: DH initialization 2016.08.30 18:58:55 LOG7[ui]: Using DH parameters from /home/fex/etc/stunnel.pem 2016.08.30 18:58:55 LOG6[ui]: 1024-bit DH parameters loaded 2016.08.30 18:58:55 LOG7[ui]: ECDH initialization 2016.08.30 18:58:55 LOG7[ui]: ECDH initialized with curve prime256v1 2016.08.30 18:58:55 LOG7[ui]: SSL options: 0x03004004 (+0x03004000, -0x00000000) 2016.08.30 18:58:55 LOG5[ui]: Configuration successful 2016.08.30 18:58:55 LOG7[ui]: Listening file descriptor created (FD=7) 2016.08.30 18:58:55 LOG7[ui]: Option SO_REUSEADDR set on accept socket 2016.08.30 18:58:55 LOG7[ui]: Service [https] (FD=7) bound to 0.0.0.0:443 2016.08.30 18:58:55 LOG7[ui]: Created pid file /tmp/stunnel.pid (here comes the https client connect) 2016.08.30 18:59:20 LOG7[ui]: Found 1 ready file descriptor(s) 2016.08.30 18:59:20 LOG7[ui]: FD=4 events=0x2001 revents=0x0 2016.08.30 18:59:20 LOG7[ui]: FD=7 events=0x2001 revents=0x1 2016.08.30 18:59:20 LOG7[ui]: Service [https] accepted (FD=3) from 127.0.0.1:44166 2016.08.30 18:59:20 LOG7[0]: Service [https] started 2016.08.30 18:59:20 LOG7[0]: Option TCP_NODELAY set on local socket 2016.08.30 18:59:20 LOG5[0]: Service [https] accepted connection from 127.0.0.1:44166 2016.08.30 18:59:20 LOG6[0]: Peer certificate not required 2016.08.30 18:59:20 LOG7[0]: SSL state (accept): before/accept initialization 2016.08.30 18:59:20 LOG7[0]: SNI: no virtual services defined 2016.08.30 18:59:20 LOG7[0]: New session callback 2016.08.30 18:59:20 LOG7[0]: 1 server accept(s) requested 2016.08.30 18:59:20 LOG7[0]: 1 server accept(s) succeeded 2016.08.30 18:59:20 LOG7[0]: 0 server renegotiation(s) requested 2016.08.30 18:59:20 LOG7[0]: 0 session reuse(s) 2016.08.30 18:59:20 LOG7[0]: 0 internal session cache item(s) 2016.08.30 18:59:20 LOG7[0]: 0 internal session cache fill-up(s) 2016.08.30 18:59:20 LOG7[0]: 0 internal session cache miss(es) 2016.08.30 18:59:20 LOG7[0]: 0 external session cache hit(s) 2016.08.30 18:59:20 LOG7[0]: 0 expired session(s) retrieved 2016.08.30 18:59:20 LOG6[0]: SSL accepted: new session negotiated 2016.08.30 18:59:20 LOG6[0]: No peer certificate received 2016.08.30 18:59:20 LOG6[0]: Negotiated TLSv1.2 ciphersuite ECDHE-RSA-AES128-SHA256 (128-bit encryption) 2016.08.30 18:59:20 LOG7[0]: Compression: null, expansion: null 2016.08.30 18:59:20 LOG6[0]: Local mode child started (PID=30833) 2016.08.30 18:59:20 LOG7[0]: Option TCP_NODELAY set on remote socket 2016.08.30 18:59:20 LOG7[0]: Remote descriptor (FD=11) initialized 2016.08.30 18:59:20 LOG6[0]: Read socket closed (readsocket) 2016.08.30 18:59:20 LOG7[0]: Sending close_notify alert 2016.08.30 18:59:20 LOG7[0]: SSL alert (write): warning: close notify 2016.08.30 18:59:20 LOG6[0]: SSL_shutdown successfully sent close_notify alert 2016.08.30 18:59:20 LOG7[ui]: Found 1 ready file descriptor(s) 2016.08.30 18:59:20 LOG7[ui]: FD=4 events=0x2001 revents=0x1 2016.08.30 18:59:20 LOG7[ui]: FD=7 events=0x2001 revents=0x0 2016.08.30 18:59:20 LOG7[ui]: Dispatching signals from the signal pipe 2016.08.30 18:59:20 LOG7[ui]: Processing SIGCHLD 2016.08.30 18:59:20 LOG6[ui]: Child process 30833 finished with code 1 2016.08.30 18:59:20 LOG7[ui]: Signal pipe is empty 2016.08.30 18:59:20 LOG3[0]: socket fd: Broken pipe (32) 2016.08.30 18:59:20 LOG6[0]: writesocket: Socket is closed 2016.08.30 18:59:20 LOG5[0]: Connection closed: 0 byte(s) sent to SSL, 23 byte(s) sent to socket 2016.08.30 18:59:20 LOG7[0]: Remote descriptor (FD=11) closed 2016.08.30 18:59:20 LOG7[0]: Local descriptor (FD=3) closed 2016.08.30 18:59:20 LOG7[0]: Service [https] finished (0 left) The client receives no data at all, the connection is closed by the server (stunnel). As I wrote: with stunnel 4.27 everything works as expected. Does stunnel 5.x need another configuration? (*) http://fex.rus.uni-stuttgart.de/ -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlacher(a)tik.uni-stuttgart.de Allmandring 30a Tel: ++49-711-68565868 70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/ REF:<20160831074057.GA13703(a)rus.uni-stuttgart.de>

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Issue with stunnel over squid
by Mike McPhee 30 Aug '16

30 Aug '16

Hello, I have a windows machine running as a stunnel client that establishes a session but then, when launching an SSH session to my loopback crashes. Putty reports that the "Server unexpectedly closed the network connection." Here are the logs: 2016.08.30 16:06:08 LOG5[main]: Reading configuration from file stunnel.conf 2016.08.30 16:06:08 LOG5[main]: UTF-8 byte order mark detected 2016.08.30 16:06:08 LOG5[main]: FIPS mode disabled 2016.08.30 16:06:08 LOG4[main]: Service [squid] needs authentication to prevent MITM attacks 2016.08.30 16:06:08 LOG5[main]: Configuration successful 2016.08.30 16:06:17 LOG5[2]: Service [squid] accepted connection from 127.0.0.1:55791 2016.08.30 16:06:17 LOG5[2]: s_connect: connected 10.5.8.74:8888 2016.08.30 16:06:17 LOG5[2]: Service [squid] connected remote server from 10.5.8.69:55792 2016.08.30 16:06:17 LOG5[2]: Connection closed: 28 byte(s) sent to SSL, 0 byte(s) sent to socket Here is the server-side stunnel.conf: sslVersion = all options = NO_SSLv2 client = no cert = /etc/stunnel/server.pem pid = /var/run/stunnel.pid output = /var/log/stunnel [squid] accept = 8888 connect = 127.0.0.1:3128 cert = /etc/stunnel/stunnel.pem [openvpn] client = no accept = 993 connect = 34567 Here is the client side (Windows 7): cert = stunnel.pem client = yes [squid] accept = 127.0.0.1:8080 connect = 10.5.8.74:8443 I seem to be negotiating all of the appropriate keys, openvpn and squid3 are verified running, and have iptables configured, so I am not sure what I am missing. Can anyone assist? Thanks in advance! Mike

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-reopen for Ubuntu?
by mguyre＠comcast.net 24 Aug '16

24 Aug '16

Are there any plans to add the -reopen functionality to other operating systems? Thanks Mike

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[Stunnel] [Android x86] Compilation
by John Fisherman 22 Aug '16

22 Aug '16

Dear all, I am currently trying to make stunnel work for an Android x86 architecture. The android binary found on the stunnel official website is not supported on x86 architecture, so I'd like to cross-compile it myself using the 'configure' options. I did not find much informations about this around the web, could you give me some advices or at least tell me if it is possible to make Stunnel work on an Android x86 device ? Thanks in advance, Regards, - John

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Stunnel exits with timeout
by SP 19 Aug '16

19 Aug '16

Summary of problem (configuration and log details below): I am attempting to configure Stunnel to run a pop3s service on our server so that users can retrieve email securely. Stunnel is started as a systemctl service. If I include both the following in the stunnel.conf: accept = mail.myserver.net:995 connect = localhost:110 then systemctl will exit immediately with: Service [pop3s]: Each service must define two endpoints stunnel.service: Control process exited, code=exited status=1 Failed to start SSL tunnel for network daemons. If I comment the connect to 110 then it will start and hang then eventually timeout: stunnel.service: Failed with result 'timeout'. Below is my stunnel.conf and log excerpt from the start with the connect to 110 commented out. I would greatly appreciate any advice. ---stunnel.conf setuid = nobody setgid = nobody pid = /usr/local/var/lib/stunnel/var/run/stunnel.pid foreground = yes ;debug = info debug = 7 sslVersion = TLSv1.2 output = /usr/local/var/lib/stunnel/var/log/stunnel.log ;ciphers = HIGH:MEDIUM:+DH:!SSLv2:!aNULL:+SHA256:+SHA1:+MD5 ciphers = HIGH:+3DES:+DH:!aNULL:!SSLv2 transparent = yes delay = no fips = no compression = deflate client = no [pop3s] accept = mail.myserver.net:995 ;connect = localhost:110 cert = /etc/stunnel/stunnel.pem key = /etc/stunnel/stunnel.pem exec = /usr/local/sbin/gnu-pop3d execargs = --debug=000 --mdn --timeout=60 --ipv6 ----log excerpt ----- 2016.08.17 15:08:55 LOG7[ui]: Clients allowed=500 2016.08.17 15:08:55 LOG5[ui]: stunnel 5.35 on x86_64-unknown-linux-gnu platform 2016.08.17 15:08:55 LOG5[ui]: Compiled/running with OpenSSL 1.0.2h 3 May 2016 2016.08.17 15:08:55 LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,FIPS,OCSP,PSK,SNI 2016.08.17 15:08:55 LOG7[ui]: errno: (*__errno_location ()) 2016.08.17 15:08:55 LOG5[ui]: Reading configuration from file /etc/stunnel/stunnel.conf 2016.08.17 15:08:55 LOG5[ui]: UTF-8 byte order mark not detected 2016.08.17 15:08:55 LOG7[cron]: Cron thread initialized 2016.08.17 15:08:55 LOG5[ui]: FIPS mode disabled 2016.08.17 15:08:55 LOG6[ui]: Compression enabled: 1 method(s) 2016.08.17 15:08:55 LOG7[ui]: Snagged 64 random bytes from /dev/urandom 2016.08.17 15:08:55 LOG7[ui]: PRNG seeded successfully 2016.08.17 15:08:55 LOG6[ui]: Initializing service [pop3s] 2016.08.17 15:08:55 LOG6[ui]: Loading certificate from file: /etc/stunnel/stunnel.pem 2016.08.17 15:08:55 LOG6[ui]: Certificate loaded from file: /etc/stunnel/stunnel.pem 2016.08.17 15:08:55 LOG6[ui]: Loading private key from file: /etc/stunnel/stunnel.pem 2016.08.17 15:08:55 LOG6[ui]: Private key loaded from file: /etc/stunnel/stunnel.pem 2016.08.17 15:08:55 LOG7[ui]: Private key check succeeded 2016.08.17 15:08:55 LOG7[ui]: DH initialization 2016.08.17 15:08:55 LOG7[ui]: Could not load DH parameters from /etc/stunnel/stunnel.pem 2016.08.17 15:08:55 LOG6[ui]: Using dynamic DH parameters 2016.08.17 15:08:55 LOG7[ui]: ECDH initialization 2016.08.17 15:08:55 LOG7[ui]: ECDH initialized with curve prime256v1 2016.08.17 15:08:55 LOG7[ui]: SSL options: 0x03004004 (+0x03004000, -0x00000000) 2016.08.17 15:08:55 LOG5[ui]: Configuration successful 2016.08.17 15:08:55 LOG7[ui]: Listening file descriptor created (FD=7) 2016.08.17 15:08:55 LOG7[ui]: Option SO_REUSEADDR set on accept socket 2016.08.17 15:08:55 LOG7[ui]: Service [pop3s] (FD=7) bound to 60.62.114.105:995 2016.08.17 15:08:55 LOG6[cron]: Executing cron jobs 2016.08.17 15:08:55 LOG7[ui]: Created pid file /usr/local/var/lib/stunnel/var/run/stunnel.pid 2016.08.17 15:08:55 LOG5[cron]: Updating DH parameters 2016.08.17 15:10:01 LOG5[cron]: DH parameters updated 2016.08.17 15:10:01 LOG6[cron]: Cron jobs completed in 66 seconds 2016.08.17 15:10:01 LOG7[cron]: Waiting 86334 seconds 2016.08.17 15:10:25 LOG7[ui]: Found 1 ready file descriptor(s) 2016.08.17 15:10:25 LOG7[ui]: FD=4 events=0x2001 revents=0x1 2016.08.17 15:10:25 LOG7[ui]: FD=7 events=0x2001 revents=0x0 2016.08.17 15:10:25 LOG7[ui]: Dispatching signals from the signal pipe 2016.08.17 15:10:25 LOG7[ui]: Processing SIGNAL_TERMINATE 2016.08.17 15:10:25 LOG5[ui]: Terminated 2016.08.17 15:10:25 LOG7[ui]: Closing service [pop3s] 2016.08.17 15:10:25 LOG7[ui]: Service [pop3s] closed (FD=7) 2016.08.17 15:10:25 LOG7[ui]: Service [pop3s] closed 2016.08.17 15:10:25 LOG7[ui]: removing pid file /usr/local/var/lib/stunnel/var/run/stunnel.pid

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