Nordvpn support (#189), fix #178

internal/provider/nordvpn.go

@@ -0,0 +1,153 @@
+package provider
+
+import (
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/qdm12/golibs/network"
+	"github.com/qdm12/private-internet-access-docker/internal/constants"
+	"github.com/qdm12/private-internet-access-docker/internal/models"
+)
+
+type nordvpn struct{}
+
+func newNordvpn() *nordvpn {
+	return &nordvpn{}
+}
+
+func findServers(selection models.ServerSelection) (servers []models.NordvpnServer) {
+	for _, server := range constants.NordvpnServers() {
+		if strings.EqualFold(server.Region, selection.Region) {
+			if (selection.Protocol == constants.TCP && !server.TCP) || (selection.Protocol == constants.UDP && !server.UDP) {
+				continue
+			}
+			if selection.Number > 0 && server.Number == selection.Number {
+				return []models.NordvpnServer{server}
+			}
+			servers = append(servers, server)
+		}
+	}
+	return servers
+}
+
+func extractIPsFromServers(servers []models.NordvpnServer) (ips []net.IP) {
+	ips = make([]net.IP, len(servers))
+	for i := range servers {
+		ips[i] = servers[i].IP
+	}
+	return ips
+}
+
+func targetIPInIps(targetIP net.IP, ips []net.IP) error {
+	for i := range ips {
+		if targetIP.Equal(ips[i]) {
+			return nil
+		}
+	}
+	ipsString := make([]string, len(ips))
+	for i := range ips {
+		ipsString[i] = ips[i].String()
+	}
+	return fmt.Errorf("target IP address %s not found in IP addresses %s", targetIP, strings.Join(ipsString, ", "))
+}
+
+func (n *nordvpn) GetOpenVPNConnections(selection models.ServerSelection) (connections []models.OpenVPNConnection, err error) { //nolint:dupl
+	servers := findServers(selection)
+	ips := extractIPsFromServers(servers)
+	if len(ips) == 0 {
+		if selection.Number > 0 {
+			return nil, fmt.Errorf("no IP found for region %q, protocol %s and number %d", selection.Region, selection.Protocol, selection.Number)
+		}
+		return nil, fmt.Errorf("no IP found for region %q, protocol %s", selection.Region, selection.Protocol)
+	}
+	var IP net.IP
+	if selection.TargetIP != nil {
+		if err := targetIPInIps(selection.TargetIP, ips); err != nil {
+			return nil, err
+		}
+		IP = selection.TargetIP
+	} else {
+		IP = ips[0]
+	}
+	var port uint16
+	switch {
+	case selection.Protocol == constants.UDP:
+		port = 1194
+	case selection.Protocol == constants.TCP:
+		port = 443
+	default:
+		return nil, fmt.Errorf("protocol %q is unknown", selection.Protocol)
+	}
+	return []models.OpenVPNConnection{{IP: IP, Port: port, Protocol: selection.Protocol}}, nil
+}
+
+func (n *nordvpn) BuildConf(connections []models.OpenVPNConnection, verbosity, uid, gid int, root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) { //nolint:dupl
+	if len(cipher) == 0 {
+		cipher = aes256cbc
+	}
+	if len(auth) == 0 {
+		auth = "sha512"
+	}
+	lines = []string{
+		"client",
+		"dev tun",
+		"nobind",
+		"persist-key",
+		"remote-cert-tls server",
+
+		// Nordvpn specific
+		"resolv-retry infinite",
+		"tun-mtu 1500",
+		"tun-mtu-extra 32",
+		"mssfix 1450",
+		"ping 15",
+		"ping-restart 0",
+		"ping-timer-rem",
+		"reneg-sec 0",
+		"comp-lzo no",
+		"fast-io",
+		"key-direction 1",
+
+		// Added constant values
+		"auth-nocache",
+		"mute-replay-warnings",
+		"pull-filter ignore \"auth-token\"", // prevent auth failed loops
+		"auth-retry nointeract",
+		"remote-random",
+		"suppress-timestamps",
+
+		// Modified variables
+		fmt.Sprintf("verb %d", verbosity),
+		fmt.Sprintf("auth-user-pass %s", constants.OpenVPNAuthConf),
+		fmt.Sprintf("proto %s", string(connections[0].Protocol)),
+		fmt.Sprintf("cipher %s", cipher),
+		fmt.Sprintf("auth %s", auth),
+	}
+	if !root {
+		lines = append(lines, "user nonrootuser")
+	}
+	for _, connection := range connections {
+		lines = append(lines, fmt.Sprintf("remote %s %d", connection.IP.String(), connection.Port))
+	}
+	lines = append(lines, []string{
+		"<ca>",
+		"-----BEGIN CERTIFICATE-----",
+		constants.NordvpnCertificate,
+		"-----END CERTIFICATE-----",
+		"</ca>",
+	}...)
+	lines = append(lines, []string{
+		"<tls-auth>",
+		"-----BEGIN OpenVPN Static key V1-----",
+		constants.NordvpnOpenvpnStaticKeyV1,
+		"-----END OpenVPN Static key V1-----",
+		"</tls-auth>",
+		"",
+	}...)
+	return lines
+}
+
+func (n *nordvpn) GetPortForward(client network.Client) (port uint16, err error) {
+	panic("port forwarding is not supported for nordvpn")
+}