openconnect.md

So the anyconnect client prevents forward of traffic from a VM to the VPN, which means virtual machines and docker containers which rely upon NAT won't work. OpenConnect allows you to get around this as it doesn't enforce ipfw rules upon you.

OpenConnect is a command-line client for Cisco's AnyConnect SSL VPN.

Here's how to get it set up on Mac OS X:

1. OpenConnect can be installed via homebrew:

    brew update
    brew install openconnect
   

2. (Optional) Running openconnect requires sudo, presumably because it affects resolution of DNS. So, I added password-less sudo ability for the openconnect command.

    sudo visudo -f /etc/sudoers
   

And added this line:

    %admin  ALL=(ALL) NOPASSWD: /usr/local/bin/openconnect

4. (Optional) When connecting to your SSL VPN, openconnect may complain about a "self-signed certificate" being in the chain and force you to explicitly accept it every time. The self-signed cert is actually the root certficate and (hopefully) is one with implicit trust (i.e. trusted by browsers), so we can safely trust it by specifying the CA file after exporting it from KeyChain:

5. Determine the name your root certificate (i.e. visit your SSL VPN in Chrome (https://vpn.ncsasports.org), click the green lock, click "Certificate Information")

6. Open the Keychain Access App

7. Search the "System Roots" keychain to find your root certificate and select it

8. File > Export Items... the certificate as a .pem file somewhere on your hard drive (I put it in ~/.ssh/<certificate name>.pem

9. Connect!

    sudo openconnect --user=<VPN username> --cafile=<.pem file from step 4.3> <your vpn hostname>
   

   The only thing you should be prompted for is your VPN password. I added the command to my aliases file.

   If the verification of the cert fails try:

    sudo openconnect --user=<VPN username> --no-cert-check --passwd-on-stdin --disable-ipv6 vpn.ncsasports.org
   

10. To disconnect, just Ctrl-c in the window where you started the VPN connection.

Note

I had an incident after an unclean VPN exit where later the VPN hostname could not be found. I guess the DNS resolver was messed up. I was forced to reboot to fix it so I could reconnect to the VPN.

Super elite IT pro tips:

Take DNS issues out of the equation and make connecting more reliable by adding an entry to your hosts file. If the IP were ever to change you would need to update this accordingly.

65.214.243.220  vpn.ncsasports.org

The following bash script will promtp you for your password once and use it to both sudo and connect the VPN. This does assume you use the same password for both. The script will then detach from the terminal session to stay running in the background and direct all stoud to ~/tmp/vpn.log. You may have to create the ~/tmp directory. Once the file is created chdmod a+x ~/file/path to make it executable.

#!/bin/bash
set -e

read -s -p "Passwd: " passwd
LOG_PATH=${HOME}/tmp/vpn.log
rm -f $LOG_PATH

sudo -S nohup openconnect --user=smook --no-cert-check --passwd-on-stdin --disable-ipv6 vpn.ncsasports.org > $LOG_PATH 2>&1 <<SECRET &
$passwd
$passwd
SECRET

echo 'Started OpenConnect...'