Move model helpers to model directory

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 200 insertions, 0 deletions

diff --git a/WireGuard/Shared/Model/TunnelConfiguration+WgQuickConfig.swift b/WireGuard/Shared/Model/TunnelConfiguration+WgQuickConfig.swift
new file mode 100644
index 0000000..94e1079
--- /dev/null
+++ b/WireGuard/Shared/Model/TunnelConfiguration+WgQuickConfig.swift
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018 WireGuard LLC. All Rights Reserved.
+
+import Foundation
+
+extension TunnelConfiguration {
+
+    enum ParserState {
+        case inInterfaceSection
+        case inPeerSection
+        case notInASection
+    }
+
+    enum ParseError: Error {
+        case invalidLine(_ line: String.SubSequence)
+        case noInterface
+        case invalidInterface
+        case multipleInterfaces
+        case multiplePeersWithSamePublicKey
+        case invalidPeer
+    }
+
+    //swiftlint:disable:next function_body_length cyclomatic_complexity
+    convenience init(fromWgQuickConfig wgQuickConfig: String, called name: String? = nil) throws {
+        var interfaceConfiguration: InterfaceConfiguration?
+        var peerConfigurations = [PeerConfiguration]()
+
+        let lines = wgQuickConfig.split(separator: "\n")
+
+        var parserState = ParserState.notInASection
+        var attributes = [String: String]()
+
+        for (lineIndex, line) in lines.enumerated() {
+            var trimmedLine: String
+            if let commentRange = line.range(of: "#") {
+                trimmedLine = String(line[..<commentRange.lowerBound])
+            } else {
+                trimmedLine = String(line)
+            }
+
+            trimmedLine = trimmedLine.trimmingCharacters(in: .whitespaces)
+
+            guard !trimmedLine.isEmpty else { continue }
+            let lowercasedLine = line.lowercased()
+
+            if let equalsIndex = line.firstIndex(of: "=") {
+                // Line contains an attribute
+                let key = line[..<equalsIndex].trimmingCharacters(in: .whitespaces).lowercased()
+                let value = line[line.index(equalsIndex, offsetBy: 1)...].trimmingCharacters(in: .whitespaces)
+                let keysWithMultipleEntriesAllowed: Set<String> = ["address", "allowedips", "dns"]
+                if let presentValue = attributes[key], keysWithMultipleEntriesAllowed.contains(key) {
+                    attributes[key] = presentValue + "," + value
+                } else {
+                    attributes[key] = value
+                }
+            } else if lowercasedLine != "[interface]" && lowercasedLine != "[peer]" {
+                throw ParseError.invalidLine(line)
+            }
+
+            let isLastLine = lineIndex == lines.count - 1
+
+            if isLastLine || lowercasedLine == "[interface]" || lowercasedLine == "[peer]" {
+                // Previous section has ended; process the attributes collected so far
+                if parserState == .inInterfaceSection {
+                    guard let interface = TunnelConfiguration.collate(interfaceAttributes: attributes) else { throw ParseError.invalidInterface }
+                    guard interfaceConfiguration == nil else { throw ParseError.multipleInterfaces }
+                    interfaceConfiguration = interface
+                } else if parserState == .inPeerSection {
+                    guard let peer = TunnelConfiguration.collate(peerAttributes: attributes) else { throw ParseError.invalidPeer }
+                    peerConfigurations.append(peer)
+                }
+            }
+
+            if lowercasedLine == "[interface]" {
+                parserState = .inInterfaceSection
+                attributes.removeAll()
+            } else if lowercasedLine == "[peer]" {
+                parserState = .inPeerSection
+                attributes.removeAll()
+            }
+        }
+
+        let peerPublicKeysArray = peerConfigurations.map { $0.publicKey }
+        let peerPublicKeysSet = Set<Data>(peerPublicKeysArray)
+        if peerPublicKeysArray.count != peerPublicKeysSet.count {
+            throw ParseError.multiplePeersWithSamePublicKey
+        }
+
+        if let interfaceConfiguration = interfaceConfiguration {
+            self.init(name: name, interface: interfaceConfiguration, peers: peerConfigurations)
+        } else {
+            throw ParseError.noInterface
+        }
+    }
+
+    func asWgQuickConfig() -> String {
+        var output = "[Interface]\n"
+        output.append("PrivateKey = \(interface.privateKey.base64EncodedString())\n")
+        if let listenPort = interface.listenPort {
+            output.append("ListenPort = \(listenPort)\n")
+        }
+        if !interface.addresses.isEmpty {
+            let addressString = interface.addresses.map { $0.stringRepresentation }.joined(separator: ", ")
+            output.append("Address = \(addressString)\n")
+        }
+        if !interface.dns.isEmpty {
+            let dnsString = interface.dns.map { $0.stringRepresentation }.joined(separator: ", ")
+            output.append("DNS = \(dnsString)\n")
+        }
+        if let mtu = interface.mtu {
+            output.append("MTU = \(mtu)\n")
+        }
+
+        for peer in peers {
+            output.append("\n[Peer]\n")
+            output.append("PublicKey = \(peer.publicKey.base64EncodedString())\n")
+            if let preSharedKey = peer.preSharedKey {
+                output.append("PresharedKey = \(preSharedKey.base64EncodedString())\n")
+            }
+            if !peer.allowedIPs.isEmpty {
+                let allowedIPsString = peer.allowedIPs.map { $0.stringRepresentation }.joined(separator: ", ")
+                output.append("AllowedIPs = \(allowedIPsString)\n")
+            }
+            if let endpoint = peer.endpoint {
+                output.append("Endpoint = \(endpoint.stringRepresentation)\n")
+            }
+            if let persistentKeepAlive = peer.persistentKeepAlive {
+                output.append("PersistentKeepalive = \(persistentKeepAlive)\n")
+            }
+        }
+
+        return output
+    }
+
+    //swiftlint:disable:next cyclomatic_complexity
+    private static func collate(interfaceAttributes attributes: [String: String]) -> InterfaceConfiguration? {
+        // required wg fields
+        guard let privateKeyString = attributes["privatekey"] else { return nil }
+        guard let privateKey = Data(base64Encoded: privateKeyString), privateKey.count == TunnelConfiguration.keyLength else { return nil }
+        var interface = InterfaceConfiguration(privateKey: privateKey)
+        // other wg fields
+        if let listenPortString = attributes["listenport"] {
+            guard let listenPort = UInt16(listenPortString) else { return nil }
+            interface.listenPort = listenPort
+        }
+        // wg-quick fields
+        if let addressesString = attributes["address"] {
+            var addresses = [IPAddressRange]()
+            for addressString in addressesString.splitToArray(trimmingCharacters: .whitespaces) {
+                guard let address = IPAddressRange(from: addressString) else { return nil }
+                addresses.append(address)
+            }
+            interface.addresses = addresses
+        }
+        if let dnsString = attributes["dns"] {
+            var dnsServers = [DNSServer]()
+            for dnsServerString in dnsString.splitToArray(trimmingCharacters: .whitespaces) {
+                guard let dnsServer = DNSServer(from: dnsServerString) else { return nil }
+                dnsServers.append(dnsServer)
+            }
+            interface.dns = dnsServers
+        }
+        if let mtuString = attributes["mtu"] {
+            guard let mtu = UInt16(mtuString) else { return nil }
+            interface.mtu = mtu
+        }
+        return interface
+    }
+
+    //swiftlint:disable:next cyclomatic_complexity
+    private static func collate(peerAttributes attributes: [String: String]) -> PeerConfiguration? {
+        // required wg fields
+        guard let publicKeyString = attributes["publickey"] else { return nil }
+        guard let publicKey = Data(base64Encoded: publicKeyString), publicKey.count == TunnelConfiguration.keyLength else { return nil }
+        var peer = PeerConfiguration(publicKey: publicKey)
+        // wg fields
+        if let preSharedKeyString = attributes["presharedkey"] {
+            guard let preSharedKey = Data(base64Encoded: preSharedKeyString), preSharedKey.count == TunnelConfiguration.keyLength else { return nil }
+            peer.preSharedKey = preSharedKey
+        }
+        if let allowedIPsString = attributes["allowedips"] {
+            var allowedIPs = [IPAddressRange]()
+            for allowedIPString in allowedIPsString.splitToArray(trimmingCharacters: .whitespacesAndNewlines) {
+                guard let allowedIP = IPAddressRange(from: allowedIPString) else { return nil }
+                allowedIPs.append(allowedIP)
+            }
+            peer.allowedIPs = allowedIPs
+        }
+        if let endpointString = attributes["endpoint"] {
+            guard let endpoint = Endpoint(from: endpointString) else { return nil }
+            peer.endpoint = endpoint
+        }
+        if let persistentKeepAliveString = attributes["persistentkeepalive"] {
+            guard let persistentKeepAlive = UInt16(persistentKeepAliveString) else { return nil }
+            peer.persistentKeepAlive = persistentKeepAlive
+        }
+        return peer
+    }
+
+}