July 2012 - stunnel-users

Reverse tunnel with middle server
by Jorge A. 18 Jul '12

18 Jul '12

Hi everyone, I've search into archives trying to found a solution for my problem without success. The problem is simple: make a machine available on HTTP port when it's behind a e.g. common DSL. I have a middle server for which I have full access to install any program, linux. What I was trying to do is the following: Three machines: Middle server (Server), Target (linux machine behind DSL) and Client. Same stunnel version on both Server and Target. Latests. Server is available on the Internet, running stunnel Target is behind a nat router, e.g. inside a common DSL. I assume this must run stunnel as well. Client connects to Server and Server forwards traffic to Target seamlessly. As far as I know, running stunnel on client mode from e.g. Target and trying to connect to whichever service on Server does not work on reverse: you cannot connect backwards to target. Am I correct? If not, how do I configure both ends and how do I know port to use to connect to Target (log file?) ? What I've tested: 1. Run stunnel on Server on server mode accepting ('accept') connections on a fixed port, e.g. 5000. Here, as far as I know, you must define the 'connect' directive to forward traffic to either local or remote host. The problem is, from Server, you don't know Target ip nor it's accessible 2. Run stunnel on Server and, on Target launch stunnel on client mode to try Thanks in advance and congratulations as it's a great piece of software. Best regards, Jorge

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Stunnel on WIndows Server 2008 R2 SP1 x 64 fails - Microsoft.VC90.CRT.MANIFEST
by Rüdiger Konte 15 Jul '12

15 Jul '12

Hi Stunnel users, I am trying to run stunnel "4.53 installer.exe" on a MS Windows Server 2008 R2 SP1 64 Bit (under VMWARE Workstation 6.5 as a virtual system; Physical Host OS is WIN7 Ultimate 32 BIT) The installation of stunnel was done as an "Administrator" and it ran through without issues. But I cannot se any service running. And when I try to launch the stunnel shortcut on the desktop, i got a error message like: "The application was unable to start correctly (0xc0150002). Click OK to close the application." I assume it has something to do with the Microsoft.VC90.CRT.MANIFEST file. But i am not an expert. This is shown in the Event log: ########################## Protokollname: Application Quelle: SideBySide Datum: 15.07.2012 12:17:01 Ereignis-ID: 35 Aufgabenkategorie:Keine Ebene: Fehler Schlüsselwörter:Klassisch Benutzer: Nicht zutreffend Computer: WIN-C1K2E115MV1 Beschreibung: Fehler beim Generieren des Aktivierungskontextes für "C:\Program Files (x86)\stunnel\LIBEAY32.dll". Fehler in Manifest- oder Richtliniendatei "C:\Program Files (x86)\stunnel\Microsoft.VC90.CRT.MANIFEST" in Zeile 4. Die im Manifest gefundene Komponenten-ID stimmt nicht mit der ID der angeforderten Komponente überein. Verweis: Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.21022.8". Definition: Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.30729.6161". Verwenden Sie das Programm "sxstrace.exe" für eine detaillierte Diagnose. Ereignis-XML: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="SideBySide" /> <EventID Qualifiers="49409">35</EventID> <Level>2</Level> <Task>0</Task> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2012-07-15T10:17:01.000000000Z" /> <EventRecordID>197</EventRecordID> <Channel>Application</Channel> <Computer>WIN-C1K2E115MV1</Computer> <Security /> </System> <EventData> <Data>Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.21022.8"</Data> <Data>Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.30729.6161"</Data> <Data>C:\Program Files (x86)\stunnel\LIBEAY32.dll</Data> <Data>C:\Program Files (x86)\stunnel\Microsoft.VC90.CRT.MANIFEST</Data> <Data>4</Data> ########################## I ran the MS tool sxstrace.exe to get more details: See the outcome below: ######################################### INFORMATION: Die Manifestsdefinitionsidentität ist "Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.30729.6161"". FEHLER: Die im Manifest gefundene Komponentenidentität stimmt nicht mit der Identität der angeforderten Komponente überein. Verweis: Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.21022.8". Definition: Microsoft.VC90.CRT,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.30729.6161". FEHLER: Bei der Generierung des Aktivierungskontextes ist ein Fehler aufgetreten. Beendet die Generierung des Aktivierungskontextes. ######################################### Is anything missing? .NET or another library ? Note: I installed on the same server in a different snapshot stunnel version 4.4 and it seems to work, at least no error message. But i want to use the latest version. Any help would be nice. Best Rudi

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Conf question: HTTP to HTTPS with SNI
by John Moser 03 Jul '12

03 Jul '12

I have a particular task I need to accomplish in which an HTTP-only caching proxy server is to accept SSL. The architecture in mind is as follows: - Receive request { HTTP request: - Received by caching proxy at localhost:80 HTTPS request: - Received by Pound - Decoded to HTTP - X-FROM-SSL header added - Forwarded to localhost:80 (caching proxy) } Proxy receives HTTP request - Perform caching - If X-FROM-SSL, forward to localhost:8088 - Else forward to HTTP server It is at this point that two design options come into play, both using stunnel. Either use SNI or use stunnel and HTTP. Via SNI, this would appear as follows: Stunnel receives HTTP request - Forward to https://http-server:443/ with SNI This of course requires that stunnel can read the 'Host' header out of an HTTP request and use that for SNI automatically (there's some 300 virtual hosts on that server). If not, this is infeasible. Which is my question, of course: can this be done? If this isn't an option, then the next logical way to handle this problem is: Stunnel receives HTTP request: - SSL encrypt - Forward to http-server:8443 http-server receives HTTP over stunnel - stunnel receives on http-server:8443 - Decrypt and forward to http://localhost:80/ In this way the entire connection would be encrypted, and the HTTP server would see the Host: header and use that to figure out the virtual host etc. Is that the better/only way?

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more than 1000 concurrent connections?
by Trenton Ashburn 03 Jul '12

03 Jul '12

Hi There - I'd like to use stunnel as the SSL termination point for a bunch of persistent TCP connections. I'm running it on an EC2 instance and it's only allowing me about 1000 concurrent connections. It doesn't matter if the connections come from one client IP or two. How can I raise this limit? I've already raised the OS tcp connection limit with ulimit and it doesn't improve things. Thanks, T

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