I make ample use of SSH tunnels. They are easy which is the primary reason. But sometimes you need something a little more powerful, like for a phone so all your traffic can’t be snooped out of the air around you, or so that all your traffic not just SOCKS proxy aware apps can be sent over it. For that reason I decided to delve into VPN software over the weekend. After a pretty rushed survey I ended up going with StrongSwan. OpenVPN brings back nothing but memories of complexity and OpenSwan seemed a bit abandoned so I had to pick one of its decendands and StrongSwan seemed a bit more popular than LibreSwan. Unscientific and rushed, like I said.
So there are several scripts floating around that will just auto set it up for you, but where’s the fun (and understanding allowing tweeking) in that. So I found two guides and smashed them together to give me what I wanted:
strongSwan 5 based IPSec VPN, Ubuntu 14.04 LTS and PSK/XAUTH[local ref] has a few more details on a password based setup
Additional notes: I pretty much ended up doing the first one stright through except creating client certs. Also the XAUTH / IKE1 setup of the password tutorial seems incompatible with the Android StrongSwan client, so I used EAP / IKE2, pretty much straight out of the first one. Also seems like you still need to install the CA cert and vpnHost cert on the phone unless I was missing something.
Also, as an aside, and a curve ball to make things more dificult, this was done one a new server I am playing with. Even since I’d played with OpenBSD’s pf, I’ve been ruined for iptables. It’s just not as nice. So I’d been hearing about ufw from the Ubuntu community from a while and was curious if it was nicer and better. I figured after several years maybe it was mature enough to use on a server. I think maybe I misunderstood its point. Uncomplicated maybe meant not-featureful. Sure for unblocking ports for an app it’s cute and fast, and even for straight unblocking a port its syntax is a bit clearer I guess? But as I delved into it I realized I might have made a mistake. It’s built ontop of the same system iptables uses, but created all new tables so iptables isn’t really compatible with it. The real problem however is that the ufw command has no way to setup NAT masquerading. None. The interface cannot do that. Whoops. There is a hacky work around I found at OpenVPN – forward all client traffic through tunnel using UFW which involves editing config files in pretty much iptables style code. Not uncomplicated or easier or less messy like I’d been hopnig for.
So a little unimpressed with ufw (but learned a bunch about it so that’s good and I guess what I was going for) and had to add “remove ufw and replace with iptables on that server” to my todo list, but after a Sunday’s messing around I was able to get my phone to work over the VPN to my server and the internet. So a productive time.