June 2017 - 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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Error on startup of Stunnel
by Shelstone Lorde 30 Jun '17

30 Jun '17

I installed version 5.41, the latest version, on a Windows 10 Pro machine. I placed a link to the Stunnel.exe file in the Startup folder. I am getting the error "The ordinal 3253 could not be located in the dynamic link library c:\Users\...Programs\Startup\stunnel.exe". May be there has been a previous posting concerning this error but I have not been able to find it. Any help or suggestion will be appreciated. Thanks.

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Re: [stunnel-users] Stunnel Connectivity Issue
by Ludolf Holzheid 13 Jun '17

13 Jun '17

On Tue, 2017-06-13 22:51:27 +0530, Dheeraj Gautam wrote: > Hi Browne, > > > > I am not understand like what config I have to do in stunnel config file. > > > > As per application it will trigger 8228 port of remote server, but at the momen stunnel is working only when I am trying to telnet localhost on 9233 port. > Dheeraj, I'm afraid you confused the directions: In you configuration file, you told Stunnel to accept connections on localhost, port 9233 ("accept = 127.0.0.1:9233"). Then, you told Stunnel, if such a connection is accepted, to connect to a remote server at port 8228 ("connect = 69.191.198.34:8228"). As long as both connections are established, Stunnel will forward data from localhost to 69.191.198.34 and vice versa, while encrypting the data in the localhost -> 69.191.198.34 direction and decrypting the data in the opposite direction (69.191.198.34 -> localhost). With this setup, a client program (such as Thunderbird) sends and receives plain-text data to/from a Stunnel instance on the same machine, while a server program on a remote machine (such as the Google mail server) sends and receives encrypted data to/from Stunnel. Is this about the setup you have in mind? Is your application server or client? Does it send and receive plain-text data or encrypted data? Ludolf -- Ludolf Holzheid Bihl+Wiedemann GmbH Floßwörthstraße 41 68199 Mannheim, Germany Tel: +49 621 33996-0 Fax: +49 621 3392239 mailto:lholzheid@bihl-wiedemann.de http://www.bihl-wiedemann.de Sitz der Gesellschaft: Mannheim Geschäftsführer: Jochen Bihl, Bernhard Wiedemann Amtsgericht Mannheim, HRB 5796

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Configuring stunnel and openssl on Windows to support TLS 1.2
by Liz Turi 13 Jun '17

13 Jun '17

Good morning, I'm hoping you can help point me in the right direction. The problem I'm trying to solve is enabling TLS 1.2 connections on a Windows (environment has both Windows 2008 and Windows 10 environments) platform. Currently, my private keys are managed by the Windows certificate store, using the capi engineId within stunnel (v 5.41), which uses OpenSSL 1.0.1. Because of this, stunnel can only negotiate a TLS 1.1 connection. I've tried compiling OpenSSL 1.1.0f and stunnel 5.41, but no luck either cross compiling under CentOS, nor under Windows using either MSYS2/MINGW32 or Cygwin. What I'm looking for is any one of the following 1) solid current cross-compiling examples or references 2) solid current Windows compiling examples or references using extant versions 3) a way to manage the pfx/p12 (private key) in stunnel without resorting to the Windows certificate store. Option 3 is preferred. I see how to manage pkcs11, but not pkcs12. Thank you in advance! Liz Turi Sr. Consultant Massachusetts eHealth Collaborative 860 Winter Street, Waltham, MA 02451 (m) 339-222-6614 (o) 781-907-7204 (f) 781-207-8589 www.maehc.org<http://www.maehc.org> [fb_icon]<https://www.facebook.com/massachusettsehealthcollab?fref=nf>[li_icon]<https://www.linkedin.com/company/massachusetts-ehealth-collaborative?trk=ty…>[tw_icon]<https://twitter.com/MAeHC_org> CONFIDENTIALITY NOTICE The information contained in this email transmission is legally privileged and confidential information intended only for the use of the addressee named above. If the reader of this message is not the intended recipient you are hereby notified that any dissemination, distribution or copying of this email transmission is strictly prohibited. If you have received this email transmission in error, please notify us immediately. Thank you.

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Memleak sTunnel Win32 5.41 ?
by Dod 12 Jun '17

12 Jun '17

Hello, I just noticed that stunnel memory usage is growing slowly but surely using 5.41 on Win7 64 Bits. Using a few POP3 SSL tunnels. Now it is using 290MB memory I don't know if it is since 5.41 (didn't pay attention). Is there a way to trace/log something that could be useful ? (apart from the process memory usage curve that I guess will not help). regards.

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TLS-SRP patch
by Kevin Sheldrake 06 Jun '17

06 Jun '17

Hello I recently produced a patch that permits use of TLS-SRP; it is based on the TLS-PSK code and this blog post: https://matthewarcus.wordpress.com/2014/05/10/srp-in-openssl/ It’s not the cleanest of code but it does work as a POC. The patch is available here: https://github.com/rtfcode/tls-srp The README.txt provides some info on testing the patch and how it might be used to help dev web browsers and servers that support TLS-SRP (for IoT work). There is a page on the forthcoming OWASP Summit ‘TLS for Local IoT’ workshop (for which it was developed) at: https://owaspsummit.org/Working-Sessions/IoT/TLS-for-Local-IoT.html In terms of using TLS-SRP support in stunnel as a proxy, it might be useful as a replacement for TLS-PSK where the credentials are user-memorable (pass phrase, for example) as TLS-SRP has lower entropy requirements than TLS-PSK. For example, the creds could be stored in the user’s head rather than in a file and be less open to compromise if a device was seized. I don’t know if that’s useful for anyone; it’s just a thought. Thanks Kev

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