vpnbook

#!/bin/sh
# The MIT License (MIT)
# Copyright (c) 2014 Tobias Bell <tobias.bell@gmail.com>

PROGRAM="vpnbook"
# URL to the site containing user and password
SITE="https://www.vpnbook.com/freevpn"
# URL to the site containing OpenVPN configs
OPENVPN_SITE="https://www.vpnbook.com"
# File where VPNBook credentials get stored
AUTH_FILE="./vpnbook.auth"
# Path to temporary file
AUTH_FILE_TMP="/tmp/vpnbook.$$"
# Folder where OpenVPN configs are created
CONFIG_FOLDER="./"
# Path to temporary folder for config generation
CONFIG_FOLDER_TEMP="/tmp/vpnbook-config.$$"

cleanup() {
	rm -f "$AUTH_FILE_TMP"
	rm -rf "$CONFIG_FOLDER_TEMP"
}

trap cleanup HUP INT TERM

usage() {
	cat << EOF
Usage: $PROGRAM <command> [parameter]

Commands are
    config  Generate OpenVPN configs for non-interactive usage based on configs provided
            on $OPENVPN_SITE
    auth    Extract user and password from $OPENVPN_SITE and save to auth-user-pass file
            (default: $AUTH_FILE)

Parameters are
    -a <file>    Path to the auth_user_pass file (default: $AUTH_FILE)
    -c <folder>  Folder where OpenVPN configs are generated (default: $CONFIG_FOLDER)
    -h           Show this help
EOF
}

download_site() {
	local site="$1"
	curl "$site" -s
}

extract_credentials() {
	awk -F '[<>]' '
	BEGIN { exit_value = 1 }
	/Username:/ && !user_found { print $5; user_found = 1; next }
	/Password:/ && user_found { print $5; exit_value = 0; exit } 
	END { exit exit_value }
	'
}

extract_config_urls() {
	local site="$1"
	awk -F '[<>]' -v site=$site '
	/free-openvpn-account/ { split($4, a, /"/); print site a[2] }
	'
}

generate_auth() {
	local data="$1"
	if (echo "$data" | extract_credentials) > "$AUTH_FILE_TMP"; then
		mv "$AUTH_FILE_TMP" "$AUTH_FILE"
		chmod 600 "$AUTH_FILE"
	fi
}

generate_vpn_config() {
	awk -v auth_file="$AUTH_FILE" '
	# Remove windows newline
	{ sub(/\r$/, "") }
	# Add both ports in config file and let OpenVPN select them remote-random
	/^remote/ {
		host = $2; print
		print $1, host, 25000
		if (!remote_random_printed) {
			print "remote-random"
			remote_random_printed = 1
		}
		next
	}
	# Switch authentication from interactive to file based
	/^auth-user-pass/ {
		print $1, auth_file
		print "auth-retry nointeract"
		next
	}
	# Let OpenVPN check the remote certificate
	/^<ca>/ {
		print "ns-cert-type server"
	}
	# Output everything else unchanged
	{ print }
	'
}

generate_config() {
	local data="$1"
	mkdir "$CONFIG_FOLDER_TEMP" || return
	for url in $(echo "$site_data" | extract_config_urls "$OPENVPN_SITE"); do
		local file="$CONFIG_FOLDER_TEMP/${url##*/}"
		local conf_file="vpnbook-${file##*-}"
		conf_file=${conf_file%.zip}.ovpn
		conf_file="$CONFIG_FOLDER/$(echo $conf_file | tr 'A-Z' 'a-z')"
		curl "$url" -o "$file" -s
		unzip -p "$file"  '*udp53*.ovpn' | generate_vpn_config > "$conf_file"
	done

	generate_auth "$data"
}

main() {
	case $1 in
		config | auth )
			generator_func="generate_$1"
			;;
		* )
			usage
			exit 1
			;;
	esac
	shift

	while getopts 'a:c:h' options; do
		case $options in
			a )
				auth_file=$OPTARG
				;;
			c )
				config_folder=$OPTARG
				;;
			h | \?)
				usage
				exit 1
				;;
		esac
	done

	AUTH_FILE=${auth_file:-$AUTH_FILE}
	CONFIG_FOLDER=${config_folder:-$CONFIG_FOLDER}

	local site_data="$(download_site "$SITE")"
	$generator_func "$site_data"
	retval=$?
	cleanup
	return $retval
}

if [ "$PROGRAM" = ${0##*/} ]; then
	main "$@"
	exit $?
fi