February 2018 - 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] Connect using TLS with public Web Server
by peter＠easthope.ca 06 Mar '18

06 Mar '18

From: Carlos Castro <carlos.castro.guerrero(a)gmail.com> Date: Fri, 2 Feb 2018 12:04:08 +0100 > I have older application and now I need connect with external server HTTPS > using TLS . My application doesn't support with TLS and I think use Stunnel > to connect with this Server HTTPS. Same requirement here. Have you tried this configuration? ; yourhost:/etc/stunnel4/stunnel.conf ... [https] client = yes accept = 443 transparent = destination Regards, ... Peter E. -- 123456789 123456789 123456789 123456789 123456789 123456789 123456789 Tel: +1 360 639 0202 Pender Is.: +1 250 629 3757 http://easthope.ca/Peter.html Bcc: peter at easthope. ca https://en.wikibooks.org/wiki/Medical_Suction_Machines https://en.wikibooks.org/wiki/Oberon

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Client cert auth ?
by Brian Ipsen 27 Feb '18

27 Feb '18

Hi I am trying to see if I can get stunnel to authenticate using a client certificate towards a F5 setup - but I am having trouble getting it to work. Certificates are issued froma Microsoft PKI - where the F5 checks validity via an OCSP responder. In my stunnel config file, I have: [F5Cert] client=yes accept = 127.0.0.1:1598 connect = F5test.xxx.dk:443 delay = yes CAFile = GlobalSign-cert-Chain.pem Cert = BaaSClientCertificatePlain.pem key = BaaSClientCertificatePlain.key verify = 2 In the CAFile, I have the root CA and issuing certificate from GlobalSign - which have created the SSL certificate being used on the F5 (server side). Cert and Key points to the certificate and private key from my internal Microsoft based PKI.. But should the certificate chain from my internal PKI be listed somewhere as well ? Is this the way to do it - and is stunnel capable of handling client certificate validation ? Regards Brian

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Question on reconnection after TCP RST
by Chawla, Vikas 27 Feb '18

27 Feb '18

Hi, We ran into an issue where stunnel after TCP RST from server, retries to re-establish connection after 5 seconds with exponential back off. Wanted to check if there is configuration parameter for us to modify the reconnection time to be a lower number. Thanks, Vikas

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[PATCH] Address already in use (98) when binding to localhost
by Christian Kujau 06 Feb '18

06 Feb '18

Hi, I reported the following to the Fedora bugtracker[0], but only then realized that this happens with the upstream version too. In short: since stunnel 5.44 I am no longer able to have stunnel bind to localhost, when "localhost" is literally mentioned in the configuration file: $ cat stunnel.test [test] client = yes protocol = smtp accept = localhost:12345 connect = localhost:2025 $ stunnel-5.44 stunnel.test [...] [ ] Binding service [test] [ ] Listening file descriptor created (FD=6) [ ] Option SO_REUSEADDR set on accept socket [ ] Service [test] (FD=6) bound to 127.0.0.1:12345 [ ] Listening file descriptor created (FD=7) [ ] Option SO_REUSEADDR set on accept socket [!] bind: Address already in use (98) [!] Error binding service [test] to 127.0.0.1:12345 [ ] Unbinding service [test] [ ] Service [test] closed (FD=6) [ ] Service [test] closed When using "127.0.0.1" or "::1" instead of "localhost" in the configuration file, stunnel-5.44 works. However, then one can only connect to either the IPv4 _or_ the IPv6 address, depending on what's configured. With stunnel-5.43 and "accept=localhost:12345" both IPv4 and IPv6 was available. I suspect that this is related to the following change log entry for 5.44: > Default accept address restored to INADDR_ANY. I have attached a patch to revert that (?) change and also included a test script that fails on my system when the patch is not applied. I see "Version 5.45" already mention in the changelog on the website, but now download yet? Thanks, Christian. [0] https://bugzilla.redhat.com/show_bug.cgi?id=1542361 -- BOFH excuse #424: operation failed because: there is no message for this error (#1014)

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Re: [stunnel-users] stunnel.log not generated in window server 2012 R2
by Zhang, Joanne 02 Feb '18

02 Feb '18

Hello. I installed a Stunnel-5.44-win32 on a Window Server 2012 R2 box. I am using it in client mode only as it is required by the Vendor. It works fine, I can connect to my Vendor's server via Stunnel . However, I don't see any stunnel.log generated when it is run as a service and I searched the entire directory on the server. I know the output path is working . As when I run Stunnel GUI Start, the log is created in the output folder specified in the conf file. Have anyone seen this problem before please? Here is my setting for stunnel.conf that relates to the debug log. debug = 7 output = C:\Program Files (x86)\stunnel\stunnel.log Thanks very much for your help ahead. Joanne _______________________________________________________________________ If you received this email in error, please advise the sender (by return email or otherwise) immediately. You have consented to receive the attached electronically at the above-noted email address; please retain a copy of this confirmation for future reference. Si vous recevez ce courriel par erreur, veuillez en aviser l'expéditeur immédiatement, par retour de courriel ou par un autre moyen. Vous avez accepté de recevoir le(s) document(s) ci-joint(s) par voie électronique à l'adresse courriel indiquée ci-dessus; veuillez conserver une copie de cette confirmation pour les fins de reference future.

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Connect using TLS with public Web Server
by Carlos Castro 02 Feb '18

02 Feb '18

Hi All, I have older application and now I need connect with external server HTTPS using TLS . My application doesn't support with TLS and I think use Stunnel to connect with this Server HTTPS. Wich is the mode I should choose to configurate this connection ? Proxy mode? or like examples created over gmail in default configuration File? The external server , is public server for all people ? should be necesary special certs ? or whit predeterminate certs inside windows (for use IE, chroome , firefox etc..etcc) is necesary ? Many thanks Regards

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