December 2011 - stunnel-users

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 and hosts.allow
by Yousef Alhashemi 05 Jul '16

05 Jul '16

Hi, This may be a little bit off-topic, but does anyone here use stunnel with pan? My connections to stunnel (in pan) are always refused by libwrap. I was looking for the right rule to add to /etc/hosts.allow but nothing seems to work aside from "ALL : ALL" (which is obviously not good) and "nntps: KNOWN". Is the latter reasonable? The hosts_access(5) manpage is confusing to say the least. It mentions that daemon (the first token on any line) is the name of the daemon running the process, which would be "stunnel" in my case, but using "stunnel : LOCAL" or even "stunnel : ALL" doesn't work. The rule that seems to work, as mentioned, is "nntps : KNOWN" ("nntps" being the group name in stunnel.conf). What's even more confusing to me is that "nntps : LOCAL" does not work either. Nor does "nntps : localhost 127.0.0.1", "nntps : localhost", "nntps : 127.0.0.1", or "nntps : 192.168.1.". Pan is running on the same machine as stunnel so all connections must be coming from localhost. Why do these rules not trigger? Either way, I'd like to know the "least permissive" hosts.allow rule that would allow me to connect to my news provider from pan, and/or whether "nntps : KNOWN" is a safe option. Thanks, Yousef

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stunnel.conf in %USERAPPDATA%
by Sebastian Rose-Indorf 19 Mar '12

19 Mar '12

Hello, I use Stunnel with Windows. The configuration file "stunnel.conf" and the log file "stunnel.log" are in the %USERAPPDATA%\Stunnel folder. Stunnel starts and works without problems. But the GUI options "Edit stunnel.conf" and "Reload stunnel.conf" do not work. Is remedy possible? Sebastian

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patch for using stunnel as client with pkcs11-engine and opensc smartcard
by Märt Laak 29 Jan '12

29 Jan '12

Dear stunnel managers, I would like to inform you that there exist some incompatibility with stunnel and openssl pkcs11-engine with external PIN entry device (like RSA smartcard using opensc) in Linux. We use this config to load openssl engine stunnel.conf: --- engine=dynamic engineCtrl=SO_PATH:/usr/lib/engines/engine_pkcs11.so engineCtrl=ID:pkcs11 engineCtrl=LIST_ADD:1 engineCtrl=LOAD engineCtrl=MODULE_PATH:/usr/lib/opensc-pkcs11.so engineCtrl=INIT --- Problem is, with this setup stunnel does not allow user to enter PIN for the secret key. Instead it tries to get secret key without PIN, 3 times (and then therefore usually blocks card PIN) and retires: ---- Initializing engine 1 Engine 1 initialized PRNG seeded successfully Certificate: mart.pem Certificate loaded Key file: id_01 error queue: 26096080 : error:26096080:engine routines:ENGINE_load_private_key:failed loading private key error queue: 800050A0 : error:800050A0:PKCS11 library:PKCS11_login:PIN incorrect Wrong PIN: retrying error queue: 26096080 : error:26096080:engine routines:ENGINE_load_private_key:failed loading private key error queue: 800050A0 : error:800050A0:PKCS11 library:PKCS11_login:PIN incorrect Wrong PIN: retrying error queue: 26096080 : error:26096080:engine routines:ENGINE_load_private_key:failed loading private key ENGINE_load_private_key: 800050A0: error:800050A0:PKCS11 library:PKCS11_login:PIN incorrect ---- I discovered workaround that is valid form version 4.26 till current 4.34, as follows, NULL-ing the ui_data.method property in ctx.c: --- diff -cr stunnel-4.34/src/ctx.c stunnel-4.34-patched/src/ctx.c *** stunnel-4.34/src/ctx.c 2010-09-14 18:08:43.000000000 +0300 --- stunnel-4.34-patched/src/ctx.c 2010-09-28 21:56:36.219081931 +0300 *************** *** 304,309 **** --- 304,310 ---- UI_method_set_reader(ui_method, pin_cb); #else /* USE_WIN32 */ ui_method=UI_OpenSSL(); + ui_data.section = NULL; #endif /* USE_WIN32 */ if(section->engine) for(i=1; i<=3; i++) { --- After that patch private key loads correctly: --- Initializing engine 1 Engine 1 initialized PRNG seeded successfully Certificate: mart.pem Certificate loaded Key file: id_01 private key loaded --- It would be nice if: * somebody investigates more precisely why the OpenSSL PIN entry is not showing with unpached stunnel * include my or better patch for this situation Thank you very much for excellent piece of software! With best regards, Märt Laak

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Stunnel 4.33 last one to work with VM & IMAP
by Drew McDermott 11 Jan '12

11 Jan '12

I am running VM 8.1, the Emacs mail reader, connecting via imap to gmail. It can be made to work with stunnel 4.33 providing the encryption, but any version after that causes VM to choke when fetching messages, generating the following error message: vm-imap-protocol-error: IMAP protocol error: "unexpected char (10)" Not being an expert in any of the programs that are chained together to make my e-mail setup work, I was able to trace this no deeper than the point where VM reads the buffer Emacs uses for interprocess communication. Sure enough, there is a linefeed in a place where it isn't expected, but it also happens to be the first character in the sequence: " Process IMAP over SSL finished " which may be there because of problems deeper than the representation of "newline." At the end of this message I give my attempt to represent the complete contents of the buffer with name "trace of IMAP over SSL session to imap.gmail.com." The ^M's were inserted by hand because cutting and pasting didn't seem to reproduce them. I realize that I am providing quite a bit of information from VM, and none from stunnel, which is frustrating in an stunnel forum, but I am a complete newbie regarding stunnel. I would be glad to run further experiments with guidance on how to get stunnel itself to generate more useful information. The only reason I suspect it is that installing version 4.33 fixes the problem; but I realize it may be that VM or some other component is violating the rules somehow. When I say "any version after" 4.33, I mean that I have tried 4.35, the version installed by MacPorts; and 4.49, the latest stable version, recompiled by hand. They behave identically. -- Drew McDermott Professor of Computer Science Yale Computer Science Department The interprocess-communication buffer (everything between the dashes, including the newline after "finished," but not including the newline before "starting"): --------------- starting IMAP over SSL session Tue Nov 29 14:20:01 2011 connecting to imap.gmail.com:993 connected * OK Gimap ready for requests from 128.36.148.241 s17if7011003qao.19 VM CAPABILITY Process IMAP over SSL finished ---------------

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Stunnel is not working on one computer
by Reuven Sabi 01 Jan '12

01 Jan '12

Hello to all! I have a problem i have installed on my laptop in order to work with one service , i have to say it works like a charm , but it doesn't work on my PC both computers have Windows 7 No firewall in windows No firewall in router I can not understand what is missing , why is it working on what computer and on other is not This is my sunnel.conf client= yes debug= 7 output= stunnel.log [Rates] accept = 127.0.0.1:11009 connect = XXXXXXXXX.com:14009 [Deals] accept = 127.0.0.1:12009 connect = XXXXXXXXX.com:15009 Thanks in advance i appreciate any help.

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Missing bytes?
by Arthur Murray 01 Jan '12

01 Jan '12

Hello, When I telnet to my pop3 server and "QUIT" this is what I see: Escape character is '^]'. +OK InterMail POP3 server ready. QUIT +OK ? InterMail POP3 server signing off. Connection closed by foreign host. When I setup an stunnel 4.5 to the same pop3 server: [pop3s] accept = 995 connect = server:110 and connect with "openssl s_client -connect localhost:995" this is what I see: +OK InterMail POP3 server ready. QUIT DONE And the stunnel log reports: Connection closed: 34 bytes sent to SSL, 0 bytes sent to socket What happened to the last line "+OK ? InterMail POP3 server signing off." and why aren't the counters counting the 5 bytes I sent ("QUIT\n") and the last line of 41 sent over the SSL? Example 2 through stunnel: +OK InterMail POP3 server ready. USER -ERR a user name MUST be entered QUIT DONE Connection closed: 68 bytes sent to SSL, 5 bytes sent to socket (still missing the last bytes)

2 4

Segfault with stunnel
by yassine ayachi 23 Dec '11

23 Dec '11

Hi all, I'am trying to encrypt a connection between two hosts using stunnel. ----- here is my config file ---- cert = /usr/local/etc/stunnel/stunnel.pem chroot = /usr/local/var/lib/stunnel/ setuid = nobody setgid = nogroup pid = /stunnel.pid socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 debug = debug output = stunnel.log --- [rdps] accept = 1957 connect = remote_machine:3389 Avery think was working fine until I tried to telnet to the port 1957 on the machine running stunnel, the process stunnel was killed alone leaving this in /var/log/messages : Dec 20 16:58:01 alpha kernel: [4930384.164316] stunnel[14540]: segfault at 8 ip b7629b61 sp b758d16c error 6 in libc-2.7.so[b75bd000+138000] Does anybody have an idea about this problem, thanks in advance, Yassine

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Re: [stunnel-users] Configuring VeriSign certificate with STunnel
by Zubair Ali Mansoor 22 Dec '11

22 Dec '11

Hi Guys, Thanks for your replies. I tried following commands on verisign c certificate, for both of these do not work. There is error 'unable to load certificate'. openssl x509 -inform DER -in stunnel.pem -noout -text or openssl x509 -inform PEM -in stunnel.pem -noout -text however if I run same command (openssl x509 -inform PEM -in stunnel.pem -noout -text) on VeriSign root & Intermediate certificate it works. It shows format should be 'pem'. But somehow certificate is not valid. I am using following commands to create csr and private key. Are these correct ? openssl genrsa -des3 -out server.key 2048 openssl req -new -key server.key -out server.csr Thanks, Zubair -----Original Message----- From: stunnel-users-bounces(a)stunnel.org [mailto:stunnel-users-bounces@stunnel.org] On Behalf Of stunnel-users-request(a)stunnel.org Sent: Wednesday, December 21, 2011 9:27 PM To: stunnel-users(a)stunnel.org Subject: stunnel-users Digest, Vol 89, Issue 21 Send stunnel-users mailing list submissions to stunnel-users(a)stunnel.org To subscribe or unsubscribe via the World Wide Web, visit http://stunnel.mirt.net/mailman/listinfo/stunnel-users or, via email, send a message with subject or body 'help' to stunnel-users-request(a)stunnel.org You can reach the person managing the list at stunnel-users-owner(a)stunnel.org When replying, please edit your Subject line so it is more specific than "Re: Contents of stunnel-users digest..." Today's Topics: 1. Re: Configuring VeriSign certificate with STunnel (Michal Trojnara) 2. stunnel segfault, please advise (Mehdi Bennani) 3. Re: Configuring VeriSign certificate with STunnel (Ludovic LEVET) 4. Segfault with stunnel (yassine ayachi) 5. Re: Segfault with stunnel (Scott Damron) 6. unsubscribe (Brian McGinity) 7. Re: Missing bytes? (Arthur Murray) 8. Re: Segfault with stunnel (yassine ayachi) ---------------------------------------------------------------------- Message: 1 Date: Wed, 21 Dec 2011 13:30:45 +0100 From: Michal Trojnara <Michal.Trojnara(a)mirt.net> To: <stunnel-users(a)stunnel.org> Subject: Re: [stunnel-users] Configuring VeriSign certificate with STunnel Message-ID: <f039775ca5efe5be73a2858b88f0ebc2(a)mirt.net> Content-Type: text/plain; charset=UTF-8; format=flowed Zubair Ali Mansoor wrote: > 2011.12.21 13:31:30 LOG3[5144:2256]: > SSL_CTX_use_certificate_chain_file: > D0680A8: error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong > tag I don't think this problem is specific to stunnel: https://encrypted.google.com/search?q=%22ASN1_CHECK_TLEN%3Awrong+tag%22+veri sign Mike ------------------------------ Message: 2 Date: Wed, 21 Dec 2011 07:34:19 -0500 From: Mehdi Bennani <mehdibennani(a)hotmail.com> To: <stunnel-users(a)stunnel.org> Subject: [stunnel-users] stunnel segfault, please advise Message-ID: <SNT134-W33BCBEA69CFD9694C37B7EC3A50(a)phx.gbl> Content-Type: text/plain; charset="iso-8859-1" Hi you guys, I proposed stunnel as a potential solution to our product about 4-5 months ago and I am in the process of testing a prototype I have built around that proposition. I am using stunnel v. 4.41. I am relatively new to stunnel myself. The env. is as follows: We are trying to secure an rdp connection from a java applet running in a web browser into a windows 2008 server machine behind our firewall. Presently, the java applet opens up an RDP connection into a machine (I will call it the SSL machine) where Stunnel is presently installed. Stunnel then forwards properly the incoming traffic (from portA) into its final destination (i.e: the windows Server 2008 machine) on port B. Further, I have configured Stunnel to use an SSL certificate. (Although, I have not been able to test that yet to make sure it works) Anyhow, it is all working as expected and I am pretty happy about the proof of concept. However, while testing it a bit, I noticed that it was relatively easy to bring stunnel down. The way I went about it, was to simply run a "telnet IP_of_MySSLMachine portA" from any DOS command window from any machine with internet access. From the Stunnel logs, I can tell that I get a response from Stunnel and on the DOS window side, I have a cursor waiting for input.... Writing any gibberish into that DOS windows and waiting a little bit makes stunnel stop and die in the SSL machine. I found nothing in the stunnel log, but grepping in the /var/log/, I found the segfault sslmahine:/var/log/# grep stunnel messages kernel: [1996904.624042] stunnel [19696]: segfault at 8 ip b768d361 sp b7601210 error 4 in libc-2.7.so[b7621000+138000] After another telnet execution, few days later: sslmahine:/var/log/# grep stunnel messages kernel: [4930384.164316] stunnel [14540]: segfault at 8 ip b7629b61 error 6 in libc-2.7.so[b75bd000+138000] Basically, if I don't issue that telnet command, stunnel works properly. As soon as I issue that command and start typing few things in that DOS console, stunnel dies. I have to manually restart it. Question: I was wondering if you guys could shed some light into this behavior. Is it a known behavior/bug? Is there a way to solve it by maybe upgrading into a later version of stunnel? Also, I was thinking to block telnet altogether at the firewall level, but then I am not sure what other protocols could people use to hack into the system...so should I block all of them? And, finally is there a more secure way to setup stunnel? Thank you in advance Mehdi/

2 1

building browser like client application based on OpenSSL
by Zubair Ali Mansoor 22 Dec '11

22 Dec '11

Hi, Can I develop an application based on OpenSSL such that it can communicate with all trusted sites ? Like browser can communicates? Actually I have desktop application that uses SSL. Now this application may communicate with any trusted server application. How can I achieve this ? Thanks, Zubair -----Original Message----- From: stunnel-users-bounces(a)stunnel.org [mailto:stunnel-users-bounces@stunnel.org] On Behalf Of stunnel-users-request(a)stunnel.org Sent: Wednesday, December 21, 2011 9:27 PM To: stunnel-users(a)stunnel.org Subject: stunnel-users Digest, Vol 89, Issue 21 Send stunnel-users mailing list submissions to stunnel-users(a)stunnel.org To subscribe or unsubscribe via the World Wide Web, visit http://stunnel.mirt.net/mailman/listinfo/stunnel-users or, via email, send a message with subject or body 'help' to stunnel-users-request(a)stunnel.org You can reach the person managing the list at stunnel-users-owner(a)stunnel.org When replying, please edit your Subject line so it is more specific than "Re: Contents of stunnel-users digest..." Today's Topics: 1. Re: Configuring VeriSign certificate with STunnel (Michal Trojnara) 2. stunnel segfault, please advise (Mehdi Bennani) 3. Re: Configuring VeriSign certificate with STunnel (Ludovic LEVET) 4. Segfault with stunnel (yassine ayachi) 5. Re: Segfault with stunnel (Scott Damron) 6. unsubscribe (Brian McGinity) 7. Re: Missing bytes? (Arthur Murray) 8. Re: Segfault with stunnel (yassine ayachi) ---------------------------------------------------------------------- Message: 1 Date: Wed, 21 Dec 2011 13:30:45 +0100 From: Michal Trojnara <Michal.Trojnara(a)mirt.net> To: <stunnel-users(a)stunnel.org> Subject: Re: [stunnel-users] Configuring VeriSign certificate with STunnel Message-ID: <f039775ca5efe5be73a2858b88f0ebc2(a)mirt.net> Content-Type: text/plain; charset=UTF-8; format=flowed Zubair Ali Mansoor wrote: > 2011.12.21 13:31:30 LOG3[5144:2256]: > SSL_CTX_use_certificate_chain_file: > D0680A8: error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong > tag I don't think this problem is specific to stunnel: https://encrypted.google.com/search?q=%22ASN1_CHECK_TLEN%3Awrong+tag%22+veri sign Mike ------------------------------ Message: 2 Date: Wed, 21 Dec 2011 07:34:19 -0500 From: Mehdi Bennani <mehdibennani(a)hotmail.com> To: <stunnel-users(a)stunnel.org> Subject: [stunnel-users] stunnel segfault, please advise Message-ID: <SNT134-W33BCBEA69CFD9694C37B7EC3A50(a)phx.gbl> Content-Type: text/plain; charset="iso-8859-1" Hi you guys, I proposed stunnel as a potential solution to our product about 4-5 months ago and I am in the process of testing a prototype I have built around that proposition. I am using stunnel v. 4.41. I am relatively new to stunnel myself. The env. is as follows: We are trying to secure an rdp connection from a java applet running in a web browser into a windows 2008 server machine behind our firewall. Presently, the java applet opens up an RDP connection into a machine (I will call it the SSL machine) where Stunnel is presently installed. Stunnel then forwards properly the incoming traffic (from portA) into its final destination (i.e: the windows Server 2008 machine) on port B. Further, I have configured Stunnel to use an SSL certificate. (Although, I have not been able to test that yet to make sure it works) Anyhow, it is all working as expected and I am pretty happy about the proof of concept. However, while testing it a bit, I noticed that it was relatively easy to bring stunnel down. The way I went about it, was to simply run a "telnet IP_of_MySSLMachine portA" from any DOS command window from any machine with internet access. From the Stunnel logs, I can tell that I get a response from Stunnel and on the DOS window side, I have a cursor waiting for input.... Writing any gibberish into that DOS windows and waiting a little bit makes stunnel stop and die in the SSL machine. I found nothing in the stunnel log, but grepping in the /var/log/, I found the segfault sslmahine:/var/log/# grep stunnel messages kernel: [1996904.624042] stunnel [19696]: segfault at 8 ip b768d361 sp b7601210 error 4 in libc-2.7.so[b7621000+138000] After another telnet execution, few days later: sslmahine:/var/log/# grep stunnel messages kernel: [4930384.164316] stunnel [14540]: segfault at 8 ip b7629b61 error 6 in libc-2.7.so[b75bd000+138000] Basically, if I don't issue that telnet command, stunnel works properly. As soon as I issue that command and start typing few things in that DOS console, stunnel dies. I have to manually restart it. Question: I was wondering if you guys could shed some light into this behavior. Is it a known behavior/bug? Is there a way to solve it by maybe upgrading into a later version of stunnel? Also, I was thinking to block telnet altogether at the firewall level, but then I am not sure what other protocols could people use to hack into the system...so should I block all of them? And, finally is there a more secure way to setup stunnel? Thank you in advance Mehdi/

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