CODEWITHSUNDEEP
c#openvpn
Julian Wefers
Julian Wefers

Reputation: 21

OpenVpn from C# - Weird Timeout

i am trying to start OpenVpn from my C# Windows Service. Basically like this:

VpnProcess = new Process();
VpnProcess.StartInfo.FileName = "<Path to openvpn.exe in Program dir>";
VpnProcess.StartInfo.Arguments = "--config " + "<vpnConfigName>" + " --log vpn.log";
VpnProcess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
VpnProcess.StartInfo.UseShellExecute = false;
VpnProcess.StartInfo.CreateNoWindow = true;
VpnProcess.StartInfo.WorkingDirectory = <Program dir>;
VpnProcess.Start();

so far so good, here is the resulting log:

Tue Sep 01 11:01:15 2015 OpenVPN 2.3.8 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [PKCS11] [IPv6] built on Aug  4 2015
Tue Sep 01 11:01:15 2015 library versions: OpenSSL 1.0.1p 9 Jul 2015, LZO 2.08
Tue Sep 01 11:01:16 2015 Socket Buffers: R=[8192->8192] S=[8192->8192]
Tue Sep 01 11:01:16 2015 UDPv4 link local: [undef]
Tue Sep 01 11:01:16 2015 UDPv4 link remote: [AF_INET]217.79.181.93:1194
Tue Sep 01 11:01:16 2015 TLS: Initial packet from [AF_INET]217.79.181.93:1194, sid=a7a52cba 93615557
Tue Sep 01 11:01:16 2015 VERIFY OK: depth=1, CN=<censored>
Tue Sep 01 11:01:16 2015 VERIFY OK: nsCertType=SERVER
Tue Sep 01 11:01:16 2015 VERIFY OK: depth=0, C=<censored>, ST=<censored>, L=<censored>, O=<censored>, OU=<censored>, CN=<censored>, name=<censored>, emailAddress=<censored>
Tue Sep 01 11:02:16 2015 [<censored>] Inactivity timeout (--ping-restart), restarting
Tue Sep 01 11:02:16 2015 SIGUSR1[soft,ping-restart] received, process restarting
Tue Sep 01 11:02:16 2015 Restart pause, 2 second(s)
Tue Sep 01 11:02:18 2015 Socket Buffers: R=[8192->8192] S=[8192->8192]
Tue Sep 01 11:02:19 2015 UDPv4 link local: [undef]
Tue Sep 01 11:02:19 2015 UDPv4 link remote: [AF_INET]217.79.181.93:1194
Tue Sep 01 11:02:19 2015 TLS: Initial packet from [AF_INET]217.79.181.93:1194, sid=4963868b 6f0eecb7
Tue Sep 01 11:02:20 2015 VERIFY OK: depth=1, CN=<censored>
Tue Sep 01 11:02:20 2015 VERIFY OK: nsCertType=SERVER
Tue Sep 01 11:02:20 2015 VERIFY OK: depth=0, C=<censored>, ST=<censored>, L=<censored>, O=<censored>, OU=<censored>, CN=<censored>, name=<censored>, emailAddress=<censored>
Tue Sep 01 11:02:21 2015 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
[...]
Tue Sep 01 11:02:28 2015 Initialization Sequence Completed

So, vpn hangs after VERIFY, then restarts itself, then its working fine. If i start openvn via cmd or Powershell with the exact same conditions and params, it connects successfully in the first try.

I spent several days trying to find out why this happens, no success. I tried all sensible combinations of StartInfo-Properties and checked whether the executing user changes after the soft restart. Nope, both times it's LocalSystem.

Upvotes: 0

Views: 1760

Answers (2)

Alojzy Kluska
Alojzy Kluska

Reputation: 1

Check your OpenVPN config file do you have option 'auth-nocache'. I got a similar effect when I've added this option to client configuration. I use username / password to authenticate.

Upvotes: 0

Julian Wefers
Julian Wefers

Reputation: 21

Cause: server time was 1 minute ahead of time. So the freshly downloaded certificate on client was 'from the future', leading to rejection by the server. Server log showed this, but never client log

Upvotes: 2

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