March 2019 - stunnel-users

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?

4 3

Re: [stunnel-users] CPU 100%
by Eric Eberhard 06 Nov '24

06 Nov '24

Long ago I had a server with a bad network card. Every once in a while it would spew uncontrollable bytes onto the network. If you open a stunnel connection and it does that this could very well be the problem. If it cheap, try changing the network card. If not, you should be able to look in your firewall/router and it will tell you who is sending what bytes to whomever. See if that machine is indeed streaming the bytes in massive quantities. If not, I would suspect your stunnel is getting stuck in it's own loop. There are a million reasons this can happen (well a few less than a million) - such as maybe a bad library in the FreeBSD or a bad choice in the Makefile - such as doing threads or something in a way your O/S does not like (I use threads=fork or whatever it is, instead of actual threading). You might tinker with some of the options that make the stunnel build and try different ones. Especially if stunnel was compiled on a different version of the O/S - could be differences in bytes in things and who knows what. That is all I can suggest beyond setting the debug level to 7 (I think is highest) and then watching the log file. Eric From: stunnel-users [mailto:[email protected]] On Behalf Of Murrey, Brian J. Sent: Wednesday, October 17, 2018 10:57 AM To: stunnel-users(a)stunnel.org Subject: [stunnel-users] CPU 100% We are running stunnel 5.49 on FreeBSD 11.2 and we're running into a problem once in a while. CPU pegs at 100% when we get an stunnel connection from one of our external devices. This affects 100% of all cores and we can't even log in to console. To mitigate this temporarily, we have a script running in the background to watch when stunnel begins to spike and restarts the daemon. It doesn't happen 100% of the time, and so far I have been unable to distinguish what makes the connection do this to the CPU. Have any of you run in to this issue? Sincerely, Brian Murrey System Engineer II, IT Infrastructure _____ NOTICE: This message may contain privileged and confidential information and/or protected health information intended solely for the use of the named recipient and may be privileged or otherwise protected by law. If you are not the intended recipient of this message, you should immediately notify the sender and delete this message. Do not disseminate, reproduce, or review this message or attachments if you are not the intended recipient. The sender or others may have legal rights restricting the dissemination of the information contained in this message and, as a result, remedies against you in the event of the improper dissemination of confidential information, trade secrets, personal information or privileged communications. This message is the work of the sender and does not necessarily reflect the position, views, or policies of TriMedx LLC or its affiliates. WARNING: The integrity and security of this message cannot be guaranteed and may contain or transmit a virus or other illicit code. Neither TriMedx LLC or its affiliates accept liability for any damage attributable to viruses or illicit code transmitted through this message or an attachment.

2 1

older browsers, stunnel and privoxy
by kovacs janos 04 Mar '24

04 Mar '24

sorry to bother, im trying to make older browsers be able to display TLS 1.1 and TLS 1.2 sites. i heard stunnel cant be configured to always forward to the current site address dynamically, thats why i would use privoxy. the browser is configured to send to: 127.0.0.1 443 stunnel config has this at the end: [Tunnel_in] client = yes accept = 127.0.0.1:443 connect = 127.0.0.1:8118 verifyChain = yes CAfile = ca-certs.pem checkHost = localhost 127.0.0.1:8118 is the privoxy address. this is what stunnel writes: LOG5[main]: Configuration successful LOG5[0]: Service [Tunnel_in] accepted connection from 127.0.0.1:3261 LOG5[0]: s_connect: connected 127.0.0.1:8118 LOG5[0]: Service [Tunnel_in] connected remote server from 127.0.0.1:3262 and the browser infinitely loads, and never loads anything or leaves the page. if i remove the last 3 lines, its the same just with this line added: LOG4[main]: Service [Tunnel_in] needs authentication to prevent MITM attacks but it doesnt give an error or anything. with a configuration like: [Tunnel_out] client = no accept = 127.0.0.1:443 connect = 127.0.0.1:8118 cert = stunnel.pem this is what it gives: LOG5[3]: Service [Tunnel_out] accepted connection from 127.0.0.1:3294 LOG3[3]: SSL_accept: 1407609B: error:1407609B:SSL routines:SSL23_GET_CLIENT_HELLO:https proxy request LOG5[3]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket and browser gives a server not found error immediately. im not even sure if i should use client or server configuration in a case like this, but none of them works anyway. all i would need is for my browser to get the pages decrypted, or at least in less than TLS1.1. like how on newipnow.com i can access sites with any encryption, since they are sent to the browser without encryption. the browser just gives an "unencrypted tunnel" warning, which is how i found stunnel, and which is exactly what i need, just locally.

8 41

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

5 9

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

2 1

Is there a Win32 installer that supports sslVersionMin = TLS1.2?
by kent loving 01 Apr '19

01 Apr '19

I need to run a client on Win XP that connects to a server using TLS 1.2 or higher. Jose Alf posted that he made a test build of 5.50 in a win32 installer but uses OpenSSL 1.0.2p. And it does not seem to be official. The changelog says version 5.49, which has a win32 installer, also uses OpenSSL 1.0.2p. I can't tell if it supports TLS1.2. The man page implies I need OpenSSL 1.1.1 to get the sslVersionMin option. And, OpenSSL says v1.0.2 support ends in 9 months. Any advice is appreciated. Thanks, Kent Loving

3 2

OpenVPN with stunnel
by Heikki Lavaste 25 Mar '19

25 Mar '19

Hi, To bypass the office firewall to access home server, I'm trying to run openvpn over port 443 with stunnel. I managed to get to this point: Log on client side 2019.03.22 22:15:13 LOG5[38]: Connection closed: 352 byte(s) sent to TLS, 2067 byte(s) sent to socket 2019.03.22 22:15:19 LOG5[39]: Service [openvpn] accepted connection from 127.0.0.1:51265 2019.03.22 22:15:19 LOG5[39]: s_connect: connected x.x.x.x:443 2019.03.22 22:15:19 LOG5[39]: Service [openvpn] connected remote server from x.x.x.x:51266 2019.03.22 22:15:19 LOG5[39]: Connection closed: 352 byte(s) sent to TLS, 2067 byte(s) sent to socket Log on server side: Mar 22 22:21:54 ssh-server-heikki stunnel[2797]: LOG5[2797:140127128753920]: connect_blocking: connected 127.0.0.1:8443 Mar 22 22:21:54 ssh-server-heikki stunnel[2797]: LOG5[2797:140127128753920]: Service [openvpn] connected remote server from 127.0.0.1:49366 Mar 22 22:21:54 ssh-server-heikki stunnel[2797]: LOG5[2797:140127128753920]: Connection closed: 2067 byte(s) sent to SSL, 352 byte(s) sent to socket Config: Client [openvpn] client = yes accept = localhost:1337 connect = x.x.x.xg:443 cert = C:\Users\heikki_lavaste\Documents\stunnel\stunnel.pem verifyChain = yes verify = 2 CAfile = C:\Users\heikki_lavaste\Documents\stunnel\ca-cert.pem checkHost = stunnel.heikki-lab.local sslVersion = TLSv1 Server chroot = /var/run/stunnel sslVersion = TLSv1 pid = /stunnel.pid setuid = nobody setgid = nobody socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 cert = /etc/stunnel/stunnel.pem [openvpn] accept = 443 connect = localhost:8443 cert = /etc/stunnel/stunnel.pem The issue is probably nothing to do with stunnel but if somebody can help me figure this out, that'd be appreciated. Kind Regards Heikki

2 1

ERR_SSL_VERSION_INTERFERENCE on Google Chrome v 73.0.3683.86 and stunnel v5.51b1
by Kolan Koala 25 Mar '19

25 Mar '19

I cannot get TLS 1.3 to work with Chrome. TLS 1.3 works fine in firefox quantum v 66.0.1 over the same hardware, so this is not caused by middleboxes. It is a fault with stunnel or Chrome. ERR_SSL_VERSION_INTERFERENCE error occurs in Chrome and will not connect. For now the solution is to turn off TLS v1.3 in stunnel configuration and force TLS v1.2, but this is not a long term solution. Does anyone have a solution to use TLS 1.3 with chrome and stunnel together? Kolan

1 0

No more Win32 stunnel?
by John Hall 21 Mar '19

21 Mar '19

I've only just discovered that stunnel is seemingly no longer being updated for Win32; at any rate there has been no version 5.50 released for Win32. It would have been nice if there had been an announcement to that effect, as until now I was only subscribed to the announcements mailing list and had thus been in blissful ignorance. (For some reason I never saw ANY announcement for 5.50 - in fact I still seem to be on 5.47.) Given that there are a number of ports to different OSs by various people, is there any chance that someone might supply a Win32 port for future versions? (Sadly I lack the knowledge to do that myself.) -- John Hall

3 4

Verify peer immediately
by Phillip Hellewell 21 Mar '19

21 Mar '19

Hi, I have verifyPeer = yes in my client stunnel.conf. Is there any way to make it verify the peer right away instead of waiting until a connection is made (to the accept port)? I run stunnel with foreground = yes and would like it to exit right away if the peer doesn't have the appropriate cert/key. Thanks, Phillip

1 0