tunnelkit/TunnelKit/Sources/Core/OptionsBundle.swift

793 lines
28 KiB
Swift

//
// OptionsBundle.swift
// TunnelKit
//
// Created by Davide De Rosa on 4/3/19.
// Copyright (c) 2019 Davide De Rosa. All rights reserved.
//
// https://github.com/keeshux
//
// This file is part of TunnelKit.
//
// TunnelKit is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// TunnelKit is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with TunnelKit. If not, see <http://www.gnu.org/licenses/>.
//
import Foundation
import SwiftyBeaver
import __TunnelKitNative
private let log = SwiftyBeaver.self
/// Wraps together all recognized options from either configuration files or PUSH_REPLY.
public struct OptionsBundle {
struct Regex {
// MARK: General
static let cipher = NSRegularExpression("^cipher +[^,\\s]+")
static let auth = NSRegularExpression("^auth +[\\w\\-]+")
static let compLZO = NSRegularExpression("^comp-lzo.*")
static let compress = NSRegularExpression("^compress.*")
static let keyDirection = NSRegularExpression("^key-direction +\\d")
static let ping = NSRegularExpression("^ping +\\d+")
static let renegSec = NSRegularExpression("^reneg-sec +\\d+")
static let blockBegin = NSRegularExpression("^<[\\w\\-]+>")
static let blockEnd = NSRegularExpression("^<\\/[\\w\\-]+>")
// MARK: Client
static let proto = NSRegularExpression("^proto +(udp6?|tcp6?)")
static let port = NSRegularExpression("^port +\\d+")
static let remote = NSRegularExpression("^remote +[^ ]+( +\\d+)?( +(udp6?|tcp6?))?")
static let eku = NSRegularExpression("^remote-cert-tls +server")
static let remoteRandom = NSRegularExpression("^remote-random")
// MARK: Server
static let authToken = NSRegularExpression("^auth-token +[a-zA-Z0-9/=+]+")
static let peerId = NSRegularExpression("^peer-id +[0-9]+")
// MARK: Routing
static let topology = NSRegularExpression("^topology +(net30|p2p|subnet)")
static let ifconfig = NSRegularExpression("^ifconfig +[\\d\\.]+ [\\d\\.]+")
static let ifconfig6 = NSRegularExpression("^ifconfig-ipv6 +[\\da-fA-F:]+/\\d+ [\\da-fA-F:]+")
static let route = NSRegularExpression("^route +[\\d\\.]+( +[\\d\\.]+){0,2}")
static let route6 = NSRegularExpression("^route-ipv6 +[\\da-fA-F:]+/\\d+( +[\\da-fA-F:]+){0,2}")
static let gateway = NSRegularExpression("^route-gateway +[\\d\\.]+")
static let dns = NSRegularExpression("^dhcp-option +DNS6? +[\\d\\.a-fA-F:]+")
static let domain = NSRegularExpression("^dhcp-option +DOMAIN +[^ ]+")
// MARK: Unsupported
// static let fragment = NSRegularExpression("^fragment +\\d+")
static let fragment = NSRegularExpression("^fragment")
static let proxy = NSRegularExpression("^\\w+-proxy")
static let externalFiles = NSRegularExpression("^(ca|cert|key|tls-auth|tls-crypt) ")
static let connection = NSRegularExpression("^<connection>")
}
private enum Topology: String {
case net30
case p2p
case subnet
}
/// The lines of the configuration file stripped of any sensitive data. Lines that
/// the parser does not recognize are discarded in the first place.
///
/// - Seealso: `OptionsBundle.init(...)`
public let strippedLines: [String]?
/// Holds an optional `OptionsError` that didn't block the parser, but it would be worth taking care of.
public let warning: OptionsError?
// MARK: General
/// The cipher algorithm for data encryption.
public let cipher: SessionProxy.Cipher?
/// The digest algorithm for HMAC.
public let digest: SessionProxy.Digest?
/// Compression framing, disabled by default.
public let compressionFraming: SessionProxy.CompressionFraming?
/// Compression algorithm, disabled by default.
public let compressionAlgorithm: SessionProxy.CompressionAlgorithm?
/// The CA for TLS negotiation (PEM format).
public let ca: CryptoContainer?
/// The optional client certificate for TLS negotiation (PEM format).
public let clientCertificate: CryptoContainer?
/// The private key for the certificate in `clientCertificate` (PEM format).
public let clientKey: CryptoContainer?
/// The optional TLS wrapping.
public let tlsWrap: SessionProxy.TLSWrap?
/// Sends periodical keep-alive packets if set.
public let keepAliveSeconds: TimeInterval?
/// The number of seconds after which a renegotiation should be initiated. If `nil`, the client will never initiate a renegotiation.
public let renegotiateAfterSeconds: TimeInterval?
// MARK: Client
/// The server hostname (picked from first remote).
public let hostname: String?
/// The list of server endpoints (address, port, socket).
public let remotes: [(String, UInt16, SocketType)]
/// If true, checks EKU of server certificate.
public let checksEKU: Bool
/// Picks endpoint from `remotes` randomly.
public let randomizeEndpoint: Bool
// MARK: Server
/// The auth-token returned by the server.
public let authToken: String?
/// The peer-id returned by the server.
public let peerId: UInt32?
// MARK: Routing
/// The settings for IPv4.
public let ipv4: IPv4Settings?
/// The settings for IPv6.
public let ipv6: IPv6Settings?
/// The DNS servers.
public let dnsServers: [String]
/// The search domain.
public let searchDomain: String?
/**
Parses options from an array of lines.
- Parameter lines: The array of lines holding the options.
- Parameter returnsStripped: When `true`, stores the stripped lines into `strippedLines`. Defaults to `false`.
- Throws: `OptionsError` if the options are wrong or incomplete.
*/
public init(from lines: [String], returnsStripped: Bool = false) throws {
var optStrippedLines: [String]? = returnsStripped ? [] : nil
var optWarning: OptionsError?
var unsupportedError: OptionsError?
var currentBlockName: String?
var currentBlock: [String] = []
var optCipher: SessionProxy.Cipher?
var optDigest: SessionProxy.Digest?
var optCompressionFraming: SessionProxy.CompressionFraming?
var optCompressionAlgorithm: SessionProxy.CompressionAlgorithm?
var optCA: CryptoContainer?
var optClientCertificate: CryptoContainer?
var optClientKey: CryptoContainer?
var optKeyDirection: StaticKey.Direction?
var optTLSKeyLines: [Substring]?
var optTLSStrategy: SessionProxy.TLSWrap.Strategy?
var optKeepAliveSeconds: TimeInterval?
var optRenegotiateAfterSeconds: TimeInterval?
//
var optHostname: String?
var optDefaultProto: SocketType?
var optDefaultPort: UInt16?
var optRemotes: [(String, UInt16?, SocketType?)] = [] // address, port, socket
var optChecksEKU: Bool?
var optRandomizeEndpoint: Bool?
//
var optAuthToken: String?
var optPeerId: UInt32?
//
var optTopology: String?
var optIfconfig4Arguments: [String]?
var optIfconfig6Arguments: [String]?
var optGateway4Arguments: [String]?
var optRoutes4: [(String, String, String?)] = [] // address, netmask, gateway
var optRoutes6: [(String, UInt8, String?)] = [] // destination, prefix, gateway
var optDNSServers: [String] = []
var optSearchDomain: String?
log.verbose("Configuration file:")
for line in lines {
log.verbose(line)
var isHandled = false
var strippedLine = line
defer {
if isHandled {
optStrippedLines?.append(strippedLine)
}
}
// MARK: Unsupported
// check blocks first
Regex.connection.enumerateComponents(in: line) { (_) in
unsupportedError = OptionsError.unsupportedConfiguration(option: "<connection> blocks")
}
Regex.fragment.enumerateComponents(in: line) { (_) in
unsupportedError = OptionsError.unsupportedConfiguration(option: "fragment")
}
Regex.proxy.enumerateComponents(in: line) { (_) in
unsupportedError = OptionsError.unsupportedConfiguration(option: "proxy: \"\(line)\"")
}
Regex.externalFiles.enumerateComponents(in: line) { (_) in
unsupportedError = OptionsError.unsupportedConfiguration(option: "external file: \"\(line)\"")
}
if line.contains("mtu") || line.contains("mssfix") {
isHandled = true
}
// MARK: Inline content
if unsupportedError == nil {
if currentBlockName == nil {
Regex.blockBegin.enumerateComponents(in: line) {
isHandled = true
let tag = $0.first!
let from = tag.index(after: tag.startIndex)
let to = tag.index(before: tag.endIndex)
currentBlockName = String(tag[from..<to])
currentBlock = []
}
}
Regex.blockEnd.enumerateComponents(in: line) {
isHandled = true
let tag = $0.first!
let from = tag.index(tag.startIndex, offsetBy: 2)
let to = tag.index(before: tag.endIndex)
let blockName = String(tag[from..<to])
guard blockName == currentBlockName else {
return
}
// first is opening tag
currentBlock.removeFirst()
switch blockName {
case "ca":
optCA = CryptoContainer(pem: currentBlock.joined(separator: "\n"))
case "cert":
optClientCertificate = CryptoContainer(pem: currentBlock.joined(separator: "\n"))
case "key":
OptionsBundle.normalizeEncryptedPEMBlock(block: &currentBlock)
optClientKey = CryptoContainer(pem: currentBlock.joined(separator: "\n"))
case "tls-auth":
optTLSKeyLines = currentBlock.map { Substring($0) }
optTLSStrategy = .auth
case "tls-crypt":
optTLSKeyLines = currentBlock.map { Substring($0) }
optTLSStrategy = .crypt
default:
break
}
currentBlockName = nil
currentBlock = []
}
}
if let _ = currentBlockName {
currentBlock.append(line)
continue
}
// MARK: General
Regex.cipher.enumerateArguments(in: line) {
isHandled = true
guard let rawValue = $0.first else {
return
}
optCipher = SessionProxy.Cipher(rawValue: rawValue.uppercased())
if optCipher == nil {
unsupportedError = OptionsError.unsupportedConfiguration(option: "cipher \(rawValue)")
}
}
Regex.auth.enumerateArguments(in: line) {
isHandled = true
guard let rawValue = $0.first else {
return
}
optDigest = SessionProxy.Digest(rawValue: rawValue.uppercased())
if optDigest == nil {
unsupportedError = OptionsError.unsupportedConfiguration(option: "auth \(rawValue)")
}
}
Regex.compLZO.enumerateArguments(in: line) {
isHandled = true
optCompressionFraming = .compLZO
if !LZOIsSupported() {
guard let arg = $0.first else {
optWarning = optWarning ?? .unsupportedConfiguration(option: line)
return
}
guard arg == "no" else {
unsupportedError = .unsupportedConfiguration(option: line)
return
}
} else {
let arg = $0.first
optCompressionAlgorithm = (arg == "no") ? .disabled : .LZO
}
}
Regex.compress.enumerateArguments(in: line) {
isHandled = true
optCompressionFraming = .compress
if !LZOIsSupported() {
guard $0.isEmpty else {
unsupportedError = .unsupportedConfiguration(option: line)
return
}
} else {
if let arg = $0.first {
optCompressionAlgorithm = (arg == "lzo") ? .LZO : .other
} else {
optCompressionAlgorithm = .disabled
}
}
}
Regex.keyDirection.enumerateArguments(in: line) {
isHandled = true
guard let arg = $0.first, let value = Int(arg) else {
return
}
optKeyDirection = StaticKey.Direction(rawValue: value)
}
Regex.ping.enumerateArguments(in: line) {
isHandled = true
guard let arg = $0.first else {
return
}
optKeepAliveSeconds = TimeInterval(arg)
}
Regex.renegSec.enumerateArguments(in: line) {
isHandled = true
guard let arg = $0.first else {
return
}
optRenegotiateAfterSeconds = TimeInterval(arg)
}
// MARK: Client
Regex.proto.enumerateArguments(in: line) {
isHandled = true
guard let str = $0.first else {
return
}
optDefaultProto = SocketType(protoString: str)
if optDefaultProto == nil {
unsupportedError = OptionsError.unsupportedConfiguration(option: "proto \(str)")
}
}
Regex.port.enumerateArguments(in: line) {
isHandled = true
guard let str = $0.first else {
return
}
optDefaultPort = UInt16(str)
}
Regex.remote.enumerateArguments(in: line) {
isHandled = true
guard let hostname = $0.first else {
return
}
var port: UInt16?
var proto: SocketType?
var strippedComponents = ["remote", "<hostname>"]
if $0.count > 1 {
port = UInt16($0[1])
strippedComponents.append($0[1])
}
if $0.count > 2 {
proto = SocketType(protoString: $0[2])
strippedComponents.append($0[2])
}
optRemotes.append((hostname, port, proto))
// replace private data
strippedLine = strippedComponents.joined(separator: " ")
}
Regex.eku.enumerateComponents(in: line) { (_) in
isHandled = true
optChecksEKU = true
}
Regex.remoteRandom.enumerateComponents(in: line) { (_) in
isHandled = true
optRandomizeEndpoint = true
}
// MARK: Server
Regex.authToken.enumerateArguments(in: line) {
optAuthToken = $0[0]
}
Regex.peerId.enumerateArguments(in: line) {
optPeerId = UInt32($0[0])
}
// MARK: Routing
Regex.topology.enumerateArguments(in: line) {
optTopology = $0.first
}
Regex.ifconfig.enumerateArguments(in: line) {
optIfconfig4Arguments = $0
}
Regex.ifconfig6.enumerateArguments(in: line) {
optIfconfig6Arguments = $0
}
Regex.route.enumerateArguments(in: line) {
let routeEntryArguments = $0
let address = routeEntryArguments[0]
let mask = (routeEntryArguments.count > 1) ? routeEntryArguments[1] : "255.255.255.255"
let gateway = (routeEntryArguments.count > 2) ? routeEntryArguments[2] : nil // defaultGateway4
optRoutes4.append((address, mask, gateway))
}
Regex.route6.enumerateArguments(in: line) {
let routeEntryArguments = $0
let destinationComponents = routeEntryArguments[0].components(separatedBy: "/")
guard destinationComponents.count == 2 else {
return
}
guard let prefix = UInt8(destinationComponents[1]) else {
return
}
let destination = destinationComponents[0]
let gateway = (routeEntryArguments.count > 1) ? routeEntryArguments[1] : nil // defaultGateway6
optRoutes6.append((destination, prefix, gateway))
}
Regex.gateway.enumerateArguments(in: line) {
optGateway4Arguments = $0
}
Regex.dns.enumerateArguments(in: line) {
guard $0.count == 2 else {
return
}
optDNSServers.append($0[1])
}
Regex.domain.enumerateArguments(in: line) {
guard $0.count == 2 else {
return
}
optSearchDomain = $0[1]
}
//
if let error = unsupportedError {
throw error
}
}
//
strippedLines = optStrippedLines
warning = optWarning
// MARK: General
cipher = optCipher
digest = optDigest
compressionFraming = optCompressionFraming
compressionAlgorithm = optCompressionAlgorithm
ca = optCA
clientCertificate = optClientCertificate
clientKey = optClientKey
if let keyLines = optTLSKeyLines, let strategy = optTLSStrategy {
let optKey: StaticKey?
switch strategy {
case .auth:
optKey = StaticKey(lines: keyLines, direction: optKeyDirection)
case .crypt:
optKey = StaticKey(lines: keyLines, direction: .client)
}
if let key = optKey {
tlsWrap = SessionProxy.TLSWrap(strategy: strategy, key: key)
} else {
tlsWrap = nil
}
} else {
tlsWrap = nil
}
keepAliveSeconds = optKeepAliveSeconds
renegotiateAfterSeconds = optRenegotiateAfterSeconds
// MARK: Client
optDefaultProto = optDefaultProto ?? .udp
optDefaultPort = optDefaultPort ?? 1194
if !optRemotes.isEmpty {
hostname = optRemotes[0].0
var fullRemotes: [(String, UInt16, SocketType)] = []
let hostname = optRemotes[0].0
optRemotes.forEach {
guard $0.0 == hostname else {
return
}
guard let port = $0.1 ?? optDefaultPort else {
return
}
guard let socketType = $0.2 ?? optDefaultProto else {
return
}
fullRemotes.append((hostname, port, socketType))
}
remotes = fullRemotes
} else {
hostname = nil
remotes = []
}
checksEKU = optChecksEKU ?? false
randomizeEndpoint = optRandomizeEndpoint ?? false
// MARK: Server
authToken = optAuthToken
peerId = optPeerId
// MARK: Routing
//
// excerpts from OpenVPN manpage
//
// "--ifconfig l rn":
//
// Set TUN/TAP adapter parameters. l is the IP address of the local VPN endpoint. For TUN devices in point-to-point mode, rn is the IP address of
// the remote VPN endpoint. For TAP devices, or TUN devices used with --topology subnet, rn is the subnet mask of the virtual network segment which
// is being created or connected to.
//
// "--topology mode":
//
// Note: Using --topology subnet changes the interpretation of the arguments of --ifconfig to mean "address netmask", no longer "local remote".
//
if let ifconfig4Arguments = optIfconfig4Arguments {
guard ifconfig4Arguments.count == 2 else {
throw OptionsError.malformed(option: "ifconfig takes 2 arguments")
}
let address4: String
let addressMask4: String
let defaultGateway4: String
let topology = Topology(rawValue: optTopology ?? "") ?? .net30
switch topology {
case .subnet:
// default gateway required when topology is subnet
guard let gateway4Arguments = optGateway4Arguments, gateway4Arguments.count == 1 else {
throw OptionsError.malformed(option: "route-gateway takes 1 argument")
}
address4 = ifconfig4Arguments[0]
addressMask4 = ifconfig4Arguments[1]
defaultGateway4 = gateway4Arguments[0]
default:
address4 = ifconfig4Arguments[0]
addressMask4 = "255.255.255.255"
defaultGateway4 = ifconfig4Arguments[1]
}
let routes4 = optRoutes4.map { IPv4Settings.Route($0.0, $0.1, $0.2 ?? defaultGateway4) }
ipv4 = IPv4Settings(
address: address4,
addressMask: addressMask4,
defaultGateway: defaultGateway4,
routes: routes4
)
} else {
ipv4 = nil
}
if let ifconfig6Arguments = optIfconfig6Arguments {
guard ifconfig6Arguments.count == 2 else {
throw OptionsError.malformed(option: "ifconfig-ipv6 takes 2 arguments")
}
let address6Components = ifconfig6Arguments[0].components(separatedBy: "/")
guard address6Components.count == 2 else {
throw OptionsError.malformed(option: "ifconfig-ipv6 address must have a /prefix")
}
guard let addressPrefix6 = UInt8(address6Components[1]) else {
throw OptionsError.malformed(option: "ifconfig-ipv6 address prefix must be a 8-bit number")
}
let address6 = address6Components[0]
let defaultGateway6 = ifconfig6Arguments[1]
let routes6 = optRoutes6.map { IPv6Settings.Route($0.0, $0.1, $0.2 ?? defaultGateway6) }
ipv6 = IPv6Settings(
address: address6,
addressPrefixLength: addressPrefix6,
defaultGateway: defaultGateway6,
routes: routes6
)
} else {
ipv6 = nil
}
dnsServers = optDNSServers
searchDomain = optSearchDomain
}
private static func normalizeEncryptedPEMBlock(block: inout [String]) {
// if block.count >= 1 && block[0].contains("ENCRYPTED") {
// return true
// }
// XXX: restore blank line after encryption header (easier than tweaking trimmedLines)
if block.count >= 3 && block[1].contains("Proc-Type") {
block.insert("", at: 3)
// return true
}
// return false
}
}
/// Encapsulates the IPv4 settings for the tunnel.
public struct IPv4Settings: CustomStringConvertible {
/// Represents an IPv4 route in the routing table.
public struct Route: CustomStringConvertible {
/// The destination host or subnet.
public let destination: String
/// The address mask.
public let mask: String
/// The address of the gateway (uses default gateway if not set).
public let gateway: String?
fileprivate init(_ destination: String, _ mask: String?, _ gateway: String?) {
self.destination = destination
self.mask = mask ?? "255.255.255.255"
self.gateway = gateway
}
// MARK: CustomStringConvertible
/// :nodoc:
public var description: String {
return "{\(destination.maskedDescription)/\(mask) \(gateway?.maskedDescription ?? "default")}"
}
}
/// The address.
let address: String
/// The address mask.
let addressMask: String
/// The address of the default gateway.
let defaultGateway: String
/// The additional routes.
let routes: [Route]
// MARK: CustomStringConvertible
/// :nodoc:
public var description: String {
return "addr \(address.maskedDescription) netmask \(addressMask) gw \(defaultGateway.maskedDescription) routes \(routes.map { $0.maskedDescription })"
}
}
/// Encapsulates the IPv6 settings for the tunnel.
public struct IPv6Settings: CustomStringConvertible {
/// Represents an IPv6 route in the routing table.
public struct Route: CustomStringConvertible {
/// The destination host or subnet.
public let destination: String
/// The address prefix length.
public let prefixLength: UInt8
/// The address of the gateway (uses default gateway if not set).
public let gateway: String?
fileprivate init(_ destination: String, _ prefixLength: UInt8?, _ gateway: String?) {
self.destination = destination
self.prefixLength = prefixLength ?? 3
self.gateway = gateway
}
// MARK: CustomStringConvertible
/// :nodoc:
public var description: String {
return "{\(destination.maskedDescription)/\(prefixLength) \(gateway?.maskedDescription ?? "default")}"
}
}
/// The address.
public let address: String
/// The address prefix length.
public let addressPrefixLength: UInt8
/// The address of the default gateway.
public let defaultGateway: String
/// The additional routes.
public let routes: [Route]
// MARK: CustomStringConvertible
/// :nodoc:
public var description: String {
return "addr \(address.maskedDescription)/\(addressPrefixLength) gw \(defaultGateway.maskedDescription) routes \(routes.map { $0.maskedDescription })"
}
}
private extension SocketType {
init?(protoString: String) {
var str = protoString
if str.hasSuffix("6") {
str.removeLast()
}
self.init(rawValue: str.uppercased())
}
}