May 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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Connect to sub-directory path
by Shamim Uz Zaman 25 May '17

25 May '17

Hi Looking for an example to connect to subdirectory path such that [connect] client = yes accept = 127.0.0.1:441 connect = xxx.website.com:443/Connect/topath verifyChain = yes verifyPeer=yes CAfile = ca-certs.pem checkHost = xxx.mywebsite.com OCSPaia = yes When I only use xxx.mywebsite.com:443 it works. However, below three url gives TCP error (Unknown TCP service) xxx.mywebsite.com:443/Connect/topath xxx.mywebsite.com/Connect/topath https://xxx.mywebsite.com/Connect/topath My proxy connection requires to translate to the directory path of the domain. Regards, *Shamim Zaman*

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Stunnel Connectivity Issue
by Dheeraj Gautam 24 May '17

24 May '17

Hi Team, We are using 5.41 release of Stunnel software to establish TCP connection with remote server using by TLSV1.2 protocol. Enclosed configuration file wherein we are trying to establish TCP connection with one my server along with provided certificate and key which are pointed in config file. Could you please let us know what parameters we are missing here due to which connection is not establishing with remote server. Although, stunnel logs indicating that configuration successful, but in logs no where is mentioned about the connection is it connected or not, below is the artifact for your easy ref. Could you please help us here to resolve this issue. Regards, Dheeraj Gautam -- www.arborfs.com This e-mail and any attachment are confidential and contain proprietary information, some or all of which may be legally privileged. It is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient, please notify the author immediately by telephone or by replying to this e-mail, and then delete all copies of the e-mail on your system. If you are not the intended recipient, you must not use, disclose, distribute, copy, print or rely on this e-mail. Whilst we have taken reasonable precautions to ensure that this e-mail and any attachment has been checked for viruses, we cannot guarantee that they are virus free and we cannot accept liability for any damage sustained as a result of software viruses. We would advise that you carry out your own virus checks, especially before opening an attachment.

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Stunnel on Suse 8.1, connections refused, pid remains
by InvalidPath 09 May '17

09 May '17

So I have this server, I can start stunnel via /etc/rc.d/stunnel start. The pid is there as witnessed by ps -aux | grep stunnel, I have 4 customers that access this server. The customers pull data files that contain certain client records. Anyway my test user connects to the server and is able to pull a handful of files before their process begins timing out. When this happens I can no longer SSH to the host without restarting stunnel. Weird thing is, is that I can see the pid still running when this happens. I have the debug = 7 but the log files according to stunnel - version is set to a level of 5. No clue where it''s getting a 5 from. But I am unable to determine why or what is causing this. And it's starting to cost the company lost revenue. Any help would be greatly appreciated. Ben

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Graceful config reload when -fd option was used
by z a 09 May '17

09 May '17

Hi, Since version 4.30, sending a HUP signal to a running stunnel process will cause it to gracefully reload with the given config file. Is there a way to accomplish this when the running stunnel process was started with the "-fd" flag as in the example below? cat foo.conf | stunnel-fd 0 I tried writing to /proc/$pid/fd/0 but that didn't work. I'm hoping someone here has overcome this issue and might be able to whisper a hint in my direction. I am on Centos 7.2. Thanks

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Trouble with stunnel.conf (version 5.41)
by Mark Garciano 02 May '17

02 May '17

Hi Stunnel users, Any ideas why I get a "server down" message"? Below is the conf file: ;--------------------------------------------------------------------------- ; ************************************************************************** ; * Global options * ; ************************************************************************** ; ; Debugging stuff (may useful for troubleshooting) debug = 7 output = stunnel.log ;Disable FIPS mode to allow non-approved protocols and algorithms fips = no ;************************************************************************** ; * Service defaults may also be specified in individual service sections * ; ************************************************************************** ; Disable support for insecure SSLv2 protocol options = NO_SSLv2 key = stunnel.pem cert = stunnel.pem client = yes accept = 5001 connect = XXXXXXXXXXX.com:6443 TIMEOUTclose = 0 TIMEOUTconnect = 200 TIMEOUTidle = 86400 ;--------------------------------------------------------------------------- HERE IS THE LOG WINDOW MESSAGE: [!] Server is down [ ] Running on Windows 6.1 [.] Reading configuration from file stunnel.conf [.] UTF-8 byte order mark detected [.] FIPS mode disabled [ ] Compression disabled [ ] Snagged 64 random bytes from C:/.rnd [ ] Wrote 1024 new random bytes to C:/.rnd [ ] PRNG seeded successfully [ ] Initializing inetd mode configuration [!] Service [(null)]: 'accept' option is only allowed in a [section] Mark Garciano Systems Programmer II USC Libraries Integrated Library Systems 213-740-3568

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