stunnel used as jump host for SFTP
Hello, I am trying to test stunnel to see if it can provide the functionality we need. We are a Windows shop. What we need is for multiple client machines (I call these C1, C2, C3) to connect to our server (S). Server S will connect to a remote SFTP server (port 22). I call the remote SFTP server "R". C1, C2, C3 and S are all inside our firewall. Currently S can connect and send files to R using SFTP (port 22). The problem is that R does not accept a range of IP addresses, and has a limit on the number of IP addresses they can accept. So, what I need is for C1, C2, C3 to be able to connect to server R using S as a jump host.
From R's perspective, it should be like the connection is coming from S.
Question 1: can stunnel be used to accomplish this? Question 2: I have installed stunnel in a test server ("stunnel -install" actually from the bin folder), and configured the conf like this: [sftp] accept=127.0.0.1:22 connect=some.remote.server.com:22 I tried to use Winscp SFTP client to test a connection, but it times out. I then checked S, and I don't see anything listening on port 22. I did "netstat -a" and I don't see anything listening on port 22. Was something wrong in the "stunnel -install" command? Shouldn't it be listening on port 22? Also, I uncommented the entry for log, but I don't see any log file in the stunnel folder/subfolders ; Debugging stuff (may be useful for troubleshooting) debug = info output = stunnel.log Thanks for your help, Cecilia
Hi Cecilia, I don’t Think stunnel is the right tool for This job. If your target server R is outside your local net and has a limit on the IPs that can connect to it, you can configure your firewall to do NAT ( network address translation ). You just need to use the same outgoing public IP used by S for your other clients C1, C2, C3 when they connect to R. You can do NAT just for outgoing connections to R on port 22. Saludos Jose Alfredo Diaz
On Jun 19, 2018, at 1:12 PM, Schultz, Cecilia <[email protected]> wrote:
Hello,
I am trying to test stunnel to see if it can provide the functionality we need. We are a Windows shop. What we need is for multiple client machines (I call these C1, C2, C3) to connect to our server (S). Server S will connect to a remote SFTP server (port 22). I call the remote SFTP server “R”. C1, C2, C3 and S are all inside our firewall. Currently S can connect and send files to R using SFTP (port 22). The problem is that R does not accept a range of IP addresses, and has a limit on the number of IP addresses they can accept.
So, what I need is for C1, C2, C3 to be able to connect to server R using S as a jump host. From R’s perspective, it should be like the connection is coming from S.
Question 1: can stunnel be used to accomplish this?
Question 2: I have installed stunnel in a test server (“stunnel –install” actually from the bin folder), and configured the conf like this:
[sftp] accept=127.0.0.1:22 connect=some.remote.server.com:22
I tried to use Winscp SFTP client to test a connection, but it times out. I then checked S, and I don’t see anything listening on port 22. I did “netstat –a” and I don’t see anything listening on port 22.
Was something wrong in the “stunnel –install” command? Shouldn’t it be listening on port 22? Also, I uncommented the entry for log, but I don’t see any log file in the stunnel folder/subfolders
; Debugging stuff (may be useful for troubleshooting) debug = info output = stunnel.log
Thanks for your help, Cecilia
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Thank you very much for the suggestion Jose. From: Josealf.rm <[email protected]> Sent: Tuesday, June 19, 2018 5:22 PM To: Schultz, Cecilia <[email protected]> Cc: [email protected] Subject: Re: [stunnel-users] stunnel used as jump host for SFTP Hi Cecilia, I don’t Think stunnel is the right tool for This job. If your target server R is outside your local net and has a limit on the IPs that can connect to it, you can configure your firewall to do NAT ( network address translation ). You just need to use the same outgoing public IP used by S for your other clients C1, C2, C3 when they connect to R. You can do NAT just for outgoing connections to R on port 22. Saludos Jose Alfredo Diaz On Jun 19, 2018, at 1:12 PM, Schultz, Cecilia <[email protected]<mailto:[email protected]>> wrote: Hello, I am trying to test stunnel to see if it can provide the functionality we need. We are a Windows shop. What we need is for multiple client machines (I call these C1, C2, C3) to connect to our server (S). Server S will connect to a remote SFTP server (port 22). I call the remote SFTP server “R”. C1, C2, C3 and S are all inside our firewall. Currently S can connect and send files to R using SFTP (port 22). The problem is that R does not accept a range of IP addresses, and has a limit on the number of IP addresses they can accept. So, what I need is for C1, C2, C3 to be able to connect to server R using S as a jump host. From R’s perspective, it should be like the connection is coming from S. Question 1: can stunnel be used to accomplish this? Question 2: I have installed stunnel in a test server (“stunnel –install” actually from the bin folder), and configured the conf like this: [sftp] accept=127.0.0.1:22 connect=some.remote.server.com:22<http://some.remote.server.com:22> I tried to use Winscp SFTP client to test a connection, but it times out. I then checked S, and I don’t see anything listening on port 22. I did “netstat –a” and I don’t see anything listening on port 22. Was something wrong in the “stunnel –install” command? Shouldn’t it be listening on port 22? Also, I uncommented the entry for log, but I don’t see any log file in the stunnel folder/subfolders ; Debugging stuff (may be useful for troubleshooting) debug = info output = stunnel.log Thanks for your help, Cecilia _______________________________________________ stunnel-users mailing list [email protected]<mailto:[email protected]> https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users
You can accomplish this in Windows. Just add a port forwarding rule to S: netsh interface portproxy add v4tov4 listenport=22 listenaddress=[IP of S] connectport=22 connectaddress=[IP of R] -Doug
participants (3)
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Harris, Douglas (SSC/SPC) -
Josealf.rm -
Schultz, Cecilia