- stunnel-users - stunnel.org

stunnel 4.33 stops (crashes?) after undetermined running time
by Markus Borst 07 Jun '10

07 Jun '10

Hi, I have a strange problem with current stunnel (4.33): It just crashes after some time. The time is variable, I suspect it stops after a number of connections. System: - Windows Server 2003 SP2 (also happens on Windows Server 2008R2) - stunnel runs as service - stunnel is configured to run as ssl server for imap and pop3 with our certificate (including key-chain) stunnel was running fine for years on the Windows Server 2003. After upgrade to stunnel 4.33, the stunnel service process first worked fine, the just stopped working after some time: - The windows service "stunnel" was stopped - the stunnel.log (standard debug level) showed not error or other entry at the time of the stop. - The windows eventlog shows: ====== Event 7034, Service Control Manager The stunnel service terminated unexpectedly. It has done this 1 time(s). ====== (I'm not 100% sure, whether this event log message corresponds to the stunnel crash I described or to another crash.) I have downgrade to version 4.32, the stunnel service now runs uninterrupted as before. Since the time of crash varies somewhat, seemingly with the current load of the server, I suspect that stunnel crashes after a certain amount of ssl connections, but I'm not sure. This has happened on two different servers (Windows Server 2003 SP2 and Windows Server 2008 R2). Is this a known problem? I'd love to do some further tests, but since this is a production system, I cannot test it in our normal environment. A program to generate random ssl connections would come handy to further analyze the problem. Greetings Markus Borst -- TU Darmstadt Hochschulrechenzentrum (HRZ) Markus Borst Adresse: Petersentrasse 30, 64287 Darmstadt, Germany Tel.: 06151/16-2056 Email: M.Borst(a)hrz.tu-darmstadt.de

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Three patches: DNS CommonName verification support, separated stderr/foreground options, and support for minimal ssl libs
by Tristan Schmelcher 07 Jun '10

07 Jun '10

Hello, Recently I started using stunnel in an embedded Linux product and I had need to add several features that I think other users would benefit from. I have attached them as separate patches against 4.33. I hereby release them into the public domain. Here is a description of each: stunnel-4.33-handle-minimal-ssl-libs.patch: Add support for building against a libssl/libcrypo that has had various non-essential features removed via the "no-<feature>" Configure options for openssl. This requires disabling non-essential Stunnel features at compile-time if they have dependencies on disabled libssl/libcrypto features. For memory-constrained embedded systems, this is a big win. With this patch I was able to cut the memory footprint of stunnel+openssl by about a third simply by disabling openssl features that I didn't need. stunnel-4.33-separate-stderr-option.patch This splits the stderr logging effect of the "foreground" option into a separate option named "stderr", so that users have the freedom to enable foreground without stderr logging, or vice versa. For backwards compatibility though, specifying foreground = yes implies stderr = yes unless followed in the config by stderr = no. This is useful on embedded Linux systems that lack an implementation of fork() (due to the processor not having an MMU), because on such systems every daemon has to be launched in a foreground mode and pre-daemonized with the simpler vfork() function, e.g. using "&" from a shell. In this mode, logging to stderr does not make sense, because in reality the process is still a daemon so the logging clutters the terminal. stunnel-4.33-dns-commonname-verify-support.patch: I saved the best for last. ;) This adds a "verify_dns" option to check the CommonName in peer certificates against their DNS name when verifying, much as web browsers do. I have seen posts from users asking for this feature in the past, so I think it's value is self-evident. I'd also like to take this opportunity to say that I'm a long-time user of Stunnel on my personal Linux desktop machine and it is a really excellent piece of software. Thank you for making it free and open source.

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Stunnel supports ECC certificate?
by Bao, Robert 03 Jun '10

03 Jun '10

I searched the entire archive, couldn't find the answer/solution I am looking for. I have to post to this group, and appreciate any help/suggestion from any you. I use the latest 1.0.0 OpenSSL and 4.33 Stunnel. I used OpenSSL commands that very similar to what is described in the following link to create the ECC certificate and the private key file. http://src.opensolaris.org/source/xref/sfw/usr/src/lib/openssl/openssl-0 .9.8n/demos/ssltest-ecc/ECC-RSAcertgen.sh Start Stunnel, see the following errors: Key file: (actual path to the private key file)\HOST.KEY error stack: 140B3009 : error:140B3009:SSL routines:SSL_CTX_use_RSAPrivateKey_file:PEM lib SSL_CTX_use_RSAPrivateKey_file: 607907F: error:0607907F:digital envelope routines:EVP_PKEY_get1_RSA:expecting an rsa key There was a similar posting 4-5 years ago, and Mike answered it (the answer was: Stunnel didn't support ECC at that time). http://stunnel.mirt.net/pipermail/stunnel-users/2005-October/000817.html Seems like this is still true today. Then, when the ECC support will be added to Stunnel? If Stunnel already supports ECC certificate, how do I make it work? Thanks. Robert Bao Software House Tyco International 978-577-4202 Explore our new Tyco Online Learning Center Web-based Training Bundles at: www.swhouse.com/support/tyco_online_learning_center.aspx This e-mail may contain or have attached to it information or technology the export or re-export of which is restricted by U.S. laws and regulations. By viewing this e-mail and any attachments, the recipient agrees to the following: (i) the recipient's use of the contents of this e-mail and any attachments shall comply with all applicable laws, rules and regulations, including, without limitation, U.S. international trade laws and regulations, and (ii) the recipient may not transfer or otherwise export or re-export any information or technology contained in this e-mail or any attachment except in full compliance with the export controls administered by the U.S. and other countries and any applicable import and use restrictions.

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deploy stunnel
by Arko-Quick, Patricia K 02 Jun '10

02 Jun '10

Is there a way to deploy stunnel to all users versus the current user logged in? I would like to deploy it with sms to all users of the machine.

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Default for TIMEOUTidle?
by Markus Borst 27 May '10

27 May '10

I want to modify TIMEOUTidle in our configuration. To be sure to set it to sensible values, I need to know the default value, but I can't find it in the docs. Greetings Markus Borst -- TU Darmstadt Hochschulrechenzentrum (HRZ) Markus Borst Adresse: Petersentrasse 30, 64287 Darmstadt, Germany Tel.: 06151/16-2056 Email: M.Borst(a)hrz.tu-darmstadt.de

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Transparent mode, alternative env.c
by Hans Werner Strube 25 May '10

25 May '10

The method for passing the remote address and port to an exec'ed program through getenv() calls in the preloaded libstunnel.so fails for programs that clean the environment initially. This can be circumvented placing getenv() in an _init() function and storing the results in static variables. Here is my alternative env.c (without the copyright and license), which I have been using for more than a year: * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * /* getpeername() can't be declared in the following includes */ #define getpeername no_getpeername #include <sys/types.h> #include <sys/socket.h> /* for AF_INET */ #include <netinet/in.h> #include <arpa/inet.h> /* for inet_addr() */ #include <stdlib.h> /* for getenv() */ #ifdef __BEOS__ #include <be/bone/arpa/inet.h> /* for AF_INET */ #include <be/bone/sys/socket.h> /* for AF_INET */ #else #include <sys/socket.h> /* for AF_INET */ #endif #undef getpeername static uint32_t rem_host=0; static uint16_t rem_port=0; /* Requires shared-library linking by ld, not cc (except with gcc -nostdlib) */ void _init() { char *value; if((value=getenv("REMOTE_HOST")) && *value != '\0') rem_host = inet_addr(value); if((value=getenv("REMOTE_PORT")) && *value != '\0') rem_port = htons(atoi(value)); } int getpeername(int s, struct sockaddr_in *name, int *len) { char *value; name->sin_family = AF_INET; name->sin_addr.s_addr = rem_host; name->sin_port = rem_port; return 0; } /* End of env.c */

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STRLEN in common.h may be too small
by Hans Werner Strube 25 May '10

25 May '10

In common.h of stunnel-4.x, the parameter STRLEN (used for many buffers) is set to 256. This is insufficient in some cases, e.g., the CAPABILITY response of an IMAP server or the pathname of a file may be too long, resulting in errors. If you encounter such cases (e.g., messages "Input line too long"), increase STRLEN, e.g., to 512.

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Using stunnel to RDP into a SSL-enabled Windows box
by Daren Krive 11 May '10

11 May '10

Hi everyone, First of all I apologize if this has been asked before or if I am totally misunderstanding the purpose of stunnel altogether. If so please bear with my ignorance. I am an IT consultant and I manage about 20+ Windows-based servers. Some of these servers are accessible via VPN while others are accessible directly via RDP over the Internet. For those that are exposed to the net I am using the SSL certificate feature of Remote Desktop by going into “Terminal Services Configuration” and configuring the connection to use an SSL (most of the time a self-signed cert). I can connect to these machines no problem from Windows and I get a “lock” icon in my RDP client. However I cannot connect to these machines using rdestkop under Ubuntu. I have determined that if I turn off the requirement to use SSL on the server side (and instead allow the connection to use the built-in encryption of RDP) then I am able to connect with rdesktop. I would very much like to avoid rebooting just to connect to these servers. I am also not willing to remove the requirement for the SSL connection. Is there a way I can use stunnel on my Ubuntu box to first establish a secure SSL connection and then use rdesktop over that connection? I have searched high and low for info on this and found nothing. I have found instructions on how to use the Windows version of stunnel to secure RDP but that isn’t what I am trying to do. The server is already using an SSL cert to encrypt the connection (not sure how many people know Windows 2003 and up can do this). I am looking to get around the apparent lack of SSL support in rdesktop. Best regards, Daren.

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running as a windows service
by Graham Chiu 10 May '10

10 May '10

I downloaded and ran the windows binary 4.33. When I use the stunnel.pem it runs fine as a service. I created my own pem ( using Openssl on OpenSolaris ) and it won't run now as a service. I get a timeout message. If I then uninstall it as a service, and run it as an application, it works. Ideas on getting to run as a service with my pem? The log says nothing of note. -- Graham Chiu

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Safari SSL Problems
by Rene Plattner 05 May '10

05 May '10

Hi, has anyone Problems with Safari? I habe Problems with Safari 3 + 4 on Windows with stunnel Version 4.27 + 4.33 Everytime if I want to connect to an SSL terminated (stunnel) webservice, Safari asks for an client certificate, allthough I set the option verify to default (=none). Kind regards, René Plattner -- -------------------------------------------------------------- Dipl.-Ing. René Plattner Zentraler Informatikdienst (Central IT-Services) Universität Innsbruck Technikerstrasse 23 Tel: ++43512/507-2360 6020 Innsbruck Fax: ++43512/507-2944 Austria E-Mail: rene.plattner(a)uibk.ac.at Homepage: http://www.uibk.ac.at/zid -------------------------------------------------------------- D92E 1AE3 A8AA 9A57 8E5B 9204 F5D0 95DB 4030 742D http://homepage.uibk.ac.at/~c1021058/keys/0x4030742D.pub --------------------------------------------------------------

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