Simple script to extract the ever-changing credentials from Twitter (Facebook) account of the VPN provider VPNBook. Especially useful on OpenWRT based routers.

vpnbook.sh

#!/bin/sh
# Extracts the user and password for the VPNBook free VPN service
# out of their social media
# based on https://gist.github.com/tobidope/8568487
#
# https://gist.github.com/SmartFinn/aec9267db348c0bffd6045e07294e2cd

readonly CONN_ID="vpnbook"
readonly WEBPAGE="https://nitter.net/vpnbook/rss"
readonly AUTH_FILE_TMP="/tmp/vpnbook.$$"
readonly AUTH_FILE="/etc/openvpn/vpnbook.auth"

_cleanup() {
	rm -f "$AUTH_FILE_TMP"
}

trap _cleanup HUP INT TERM

_info() {
	logger -s -p 6 -t "$(basename "$0")" "$@"
}

_success() {
	logger -s -p 6 -t "$(basename "$0")" "$@"
	_cleanup
	exit 0
}

_fail() {
	logger -s -p 3 -t "$(basename "$0")" "$@"
	_cleanup
	exit 1
}

_get_openvpn_instance() {
	pgrep -lf openvpn | awk -v pattern="$CONN_ID" '$0 ~ pattern { print $1 }'
}

_load_credentials() {
	curl -sk -o- "$WEBPAGE" | awk -v RS='<[^>]+>' -v OFS='\n' '
		BEGIN { exit_value = 1 }
		/Password:[ ]/ { print $5,$7; exit_value = 0; exit }
		END { exit exit_value }
		'
}

if _load_credentials > "$AUTH_FILE_TMP"; then
	if cmp -s "$AUTH_FILE_TMP" "$AUTH_FILE"; then
		_success "credentials are not changed"
	else
		mv -f "$AUTH_FILE_TMP" "$AUTH_FILE"
		_info "credentials are saved"

		if kill -HUP "$(_get_openvpn_instance)"; then
			_success "Trying to restart OpenVPN($CONN_ID)"
		else
			_fail "Unable to restart OpenVPN($CONN_ID)"
		fi
	fi
else
	_fail "Failed to get credentials"
fi

exit 1