Making a Two-step VPN Connection using a Transparent Proxy behind OpenVPN

Shojajou

1/10/24, 11:08 PM

I have two VPSs and I'm trying to make a two-step VPN connection as follows:

[start] >> Client <-> OpenVPN on Server A <-> Proxy (ex: SQUID) on Server B <-> Internet

So far:

I set up the OpenVPN server correctly on an interface named tun0 and there is no trouble in connection between the Client and the Server A.
I configured a squid transparent proxy server which can handle SSL with ssl-bump using a self-signed certificate on ther Server B.
On the Server A I created some different NAT prerouting routing policies with iptables to route tcp/udp incoming packets destinated to tun0 to the Server B each for http and https.

Trouble:

I checked iptables -t nat -L -v results. Obviously, the outgoing packets are going through PREROUTING rule to the desired IP address (Server B), But it seems there will be no response from the Server A back to the Server B. I also inserted the rule -A POSTROUTING -s <Server A's IP> -o tun0 -j MASQUERADE before the OpenVPN masquerading rule in the NAT table. Still no success.

124

0 + 0

proxy

iptables

openvpn

squid

transparent-proxy

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Making a Two-step VPN Connection using a Transparent Proxy behind OpenVPN

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.