OpenConnect client

This article relies on the following:

Accessing web interface / command-line interface
Managing configs / packages / services / logs

This how-to describes the method for setting up OpenConnect client on OpenWrt.
Follow OpenConnect server for server setup and OpenConnect extras for additional tuning.

Encrypt your internet connection to enforce security and privacy.
- Prevent traffic leaks and spoofing on the client side.
Bypass regional restrictions using commercial providers.
- Escape client side content filters and internet censorship.
Access your LAN services remotely without port forwarding.

Install the required packages. Specify configuration parameters for VPN client.

# Install packages
opkg update
opkg install openconnect openssl-util
 
# Configuration parameters
VPN_IF="vpn"
VPN_SERV="SERVER_ADDRESS"
VPN_PORT="4443"
VPN_USER="USERNAME"
VPN_PASS="PASSWORD"

Transfer server certificate to VPN client. Generate certificate hash.

# Generate certificate hash
VPN_CERT="server-cert.pem"
VPN_HASH="pin-sha256:$(openssl x509 -in ${VPN_CERT} -pubkey -noout \
| openssl pkey -pubin -outform der \
| openssl dgst -sha256 -binary \
| openssl enc -base64)"

You can fetch server certificate remotely. Beware of possible MITM.

openssl s_client -showcerts -connect ${VPN_SERV}:${VPN_PORT} \
< /dev/null > server-cert.pem

Consider VPN network as public. Assign VPN interface to WAN zone to minimize firewall setup.

# Configure firewall
uci rename firewall.@zone[0]="lan"
uci rename firewall.@zone[1]="wan"
uci del_list firewall.wan.network="${VPN_IF}"
uci add_list firewall.wan.network="${VPN_IF}"
uci commit firewall
/etc/init.d/firewall restart

Set up VPN interface.

# Configure network
uci -q delete network.${VPN_IF}
uci set network.${VPN_IF}="interface"
uci set network.${VPN_IF}.proto="openconnect"
uci set network.${VPN_IF}.server="${VPN_SERV}"
uci set network.${VPN_IF}.port="${VPN_PORT}"
uci set network.${VPN_IF}.username="${VPN_USER}"
uci set network.${VPN_IF}.password="${VPN_PASS}"
uci set network.${VPN_IF}.serverhash="${VPN_HASH}"
uci commit network
/etc/init.d/network restart

Configure dynamic connection if necessary.

Establish the VPN connection. Verify your routing with traceroute and traceroute6.

traceroute openwrt.org
traceroute6 openwrt.org

Check your IP and DNS provider.

Collect and analyze the following information.

# Restart services
/etc/init.d/log restart; /etc/init.d/network restart; sleep 10
 
# Log and status
logread -e openconnect
 
# Runtime configuration
pgrep -f -a openconnect
ip address show; ip route show table all
ip rule show; ip -6 rule show; nft list ruleset
 
# Persistent configuration
uci show network; uci show firewall

OpenConnect client

Introduction

Goals

Command-line instructions

1. Preparation

2. Key management

3. Firewall

4. Network

Testing

Troubleshooting