Refactor some server-side string types into newtypes.

server/app.ts

@@ -9,7 +9,7 @@ import {promises as fs} from "graceful-fs";
 
 import {config} from "./config";
 import type {CleartextPassword, PasswordHash, Username} from "./types";
-import {isString} from "./types";
+import {isString, lift2, to} from "./types";
 import Logger from "./logger";
 
 export const app: Express = express();
@@ -17,7 +17,7 @@ export const app: Express = express();
 /**
  * Used to have some password comparison in case the user does not exist to avoid timing attacks.
  */
-const INVALID_PASSWORD_HASH = "$2b$05$JebmV1q/ySuxa89GoJYlc.6SEnj1OZYBOfTf.TYAehcC5HLeJiWPi";
+const INVALID_PASSWORD_HASH: PasswordHash = to("$2b$05$JebmV1q/ySuxa89GoJYlc.6SEnj1OZYBOfTf.TYAehcC5HLeJiWPi");
 
 /**
  * Trying to implement a timing safe string compare.
@@ -50,15 +50,15 @@ async function isValidLogin(username: Username, password: CleartextPassword): Pr
 
     // Iterate over all users every time to reduce risk of timing attacks.
     for (const userConfig of config.server.internal.users) {
-        if (timingSafeEqual(username, userConfig.username)) {
+        if (lift2(timingSafeEqual)(username, userConfig.username)) {
             passwordHash = userConfig.passwordHash;
         }
     }
 
     // Always compare some password even if the user does not exist to reduce risk of timing attacks.
     const isValidPassword = await bcrypt.compare(
-        password,
+        password.value,
-        passwordHash || INVALID_PASSWORD_HASH
+        passwordHash?.value || INVALID_PASSWORD_HASH.value
     );
 
     // Make sure password is only considered valid is user exists and therefor passwordHash is not undefined.
@@ -73,8 +73,8 @@ export function init(): void {
         {
             realm: 'Knotenformular - Intern'
         },
-        function (username: Username, password: CleartextPassword, callback: BasicAuthCheckerCallback): void {
+        function (username: string, password: string, callback: BasicAuthCheckerCallback): void {
-            isValidLogin(username, password)
+            isValidLogin(to(username), to(password))
                 .then(result => callback(result))
                 .catch(err => {
                     Logger.tag('login').error(err);

server/resources/monitoringResource.ts

@@ -7,6 +7,7 @@ import * as Resources from "../utils/resources";
 import {normalizeString} from "../utils/strings";
 import {forConstraint} from "../validation/validator";
 import {Request, Response} from "express";
+import {MonitoringToken, to} from "../types";
 
 const isValidToken = forConstraint(CONSTRAINTS.token, false);
 
@@ -38,8 +39,9 @@ export function confirm(req: Request, res: Response): void {
     if (!isValidToken(token)) {
         return Resources.error(res, {data: 'Invalid token.', type: ErrorTypes.badRequest});
     }
+    const validatedToken: MonitoringToken = to(token);
 
-    MonitoringService.confirm(token)
+    MonitoringService.confirm(validatedToken)
         .then(node => Resources.success(res, {
             hostname: node.hostname,
             mac: node.mac,
@@ -57,8 +59,9 @@ export function disable(req: Request, res: Response): void {
     if (!isValidToken(token)) {
         return Resources.error(res, {data: 'Invalid token.', type: ErrorTypes.badRequest});
     }
+    const validatedToken: MonitoringToken = to(token);
 
-    MonitoringService.disable(token)
+    MonitoringService.disable(validatedToken)
         .then(node => Resources.success(res, {
             hostname: node.hostname,
             mac: node.mac,

server/resources/nodeResource.ts

@@ -10,7 +10,7 @@ import {forConstraint, forConstraints} from "../validation/validator";
 import * as Resources from "../utils/resources";
 import {Entity} from "../utils/resources";
 import {Request, Response} from "express";
-import {EnhancedNode, isNodeSortField, Node} from "../types";
+import {EnhancedNode, isNodeSortField, MAC, Node, to, Token} from "../types";
 
 const nodeFields = ['hostname', 'key', 'email', 'nickname', 'mac', 'coords', 'monitoring'];
 
@@ -49,13 +49,14 @@ export function update (req: Request, res: Response): void {
     if (!isValidToken(token)) {
         return Resources.error(res, {data: 'Invalid token.', type: ErrorTypes.badRequest});
     }
+    const validatedToken: Token = to(token);
 
     const node = getNormalizedNodeData(data);
     if (!isValidNode(node)) {
         return Resources.error(res, {data: 'Invalid node data.', type: ErrorTypes.badRequest});
     }
 
-    NodeService.updateNode(token, node)
+    NodeService.updateNode(validatedToken, node)
         .then(result => Resources.success(res, result))
         .catch(err => Resources.error(res, err));
 }
@@ -67,8 +68,9 @@ export function remove(req: Request, res: Response): void {
     if (!isValidToken(token)) {
         return Resources.error(res, {data: 'Invalid token.', type: ErrorTypes.badRequest});
     }
+    const validatedToken: Token = to(token);
 
-    NodeService.deleteNode(token)
+    NodeService.deleteNode(validatedToken)
         .then(() => Resources.success(res, {}))
         .catch(err => Resources.error(res, err));
 }
@@ -78,8 +80,9 @@ export function get(req: Request, res: Response): void {
     if (!isValidToken(token)) {
         return Resources.error(res, {data: 'Invalid token.', type: ErrorTypes.badRequest});
     }
+    const validatedToken: Token = to(token);
 
-    NodeService.getNodeDataByToken(token)
+    NodeService.getNodeDataByToken(validatedToken)
         .then(node => Resources.success(res, node))
         .catch(err => Resources.error(res, err));
 }
@@ -94,11 +97,11 @@ async function doGetAll(req: Request): Promise<{ total: number; pageNodes: any }
         !!node.token
     );
 
-    const macs = _.map(realNodes, (node: Node): string => node.mac);
+    const macs: MAC[] = _.map(realNodes, (node: Node): MAC => node.mac);
     const nodeStateByMac = await MonitoringService.getByMacs(macs);
 
     const enhancedNodes: EnhancedNode[] = _.map(realNodes, (node: Node): EnhancedNode => {
-        const nodeState = nodeStateByMac[node.mac];
+        const nodeState = nodeStateByMac[node.mac.value];
         if (nodeState) {
             return deepExtend({}, node, {
                 site: nodeState.site,

server/resources/statisticsResource.ts

@@ -5,7 +5,6 @@ import * as Resources from "../utils/resources";
 import {Request, Response} from "express";
 
 export function get (req: Request, res: Response): void {
-    // TODO: Promises and types.
     getNodeStatistics()
         .then(nodeStatistics => Resources.success(
             res,

server/services/monitoringService.test.ts

@@ -1,6 +1,6 @@
 import moment from 'moment';
 import {ParsedNode, parseNode, parseNodesJson, parseTimestamp} from "./monitoringService";
-import {OnlineState} from "../types";
+import {MAC, OnlineState, to} from "../types";
 import Logger from '../logger';
 import {MockLogger} from "../__mocks__/logger";
 
@@ -240,12 +240,12 @@ test('parseNode() should succeed parsing node without site and domain', () => {
 
     // then
     const expectedParsedNode: ParsedNode = {
-        mac: "12:34:56:78:90:AB",
+        mac: to("12:34:56:78:90:AB"),
         importTimestamp: importTimestamp,
         state: OnlineState.ONLINE,
         lastSeen: parseTimestamp(TIMESTAMP_VALID_STRING),
-        site: '<unknown-site>',
+        site: to("<unknown-site>"),
-        domain: '<unknown-domain>'
+        domain: to("<unknown-domain>"),
     };
     expect(parseNode(importTimestamp, nodeData)).toEqual(expectedParsedNode);
 });
@@ -272,12 +272,12 @@ test('parseNode() should succeed parsing node with site and domain', () => {
 
     // then
     const expectedParsedNode: ParsedNode = {
-        mac: "12:34:56:78:90:AB",
+        mac: to("12:34:56:78:90:AB"),
         importTimestamp: importTimestamp,
         state: OnlineState.ONLINE,
         lastSeen: parseTimestamp(TIMESTAMP_VALID_STRING),
-        site: 'test-site',
+        site: to("test-site"),
-        domain: 'test-domain'
+        domain: to("test-domain")
     };
     expect(parseNode(importTimestamp, nodeData)).toEqual(expectedParsedNode);
 });
@@ -461,12 +461,12 @@ test('parseNodesJson() should parse valid nodes', () => {
 
     // then
     const expectedParsedNode: ParsedNode = {
-        mac: "12:34:56:78:90:AB",
+        mac: to("12:34:56:78:90:AB"),
         importTimestamp: parseTimestamp(TIMESTAMP_VALID_STRING),
         state: OnlineState.ONLINE,
         lastSeen: parseTimestamp(TIMESTAMP_VALID_STRING),
-        site: 'test-site',
+        site: to("test-site"),
-        domain: 'test-domain'
+        domain: to("test-domain"),
     };
 
     expect(result.importTimestamp.isValid()).toBe(true);

server/services/monitoringService.ts

@@ -17,14 +17,19 @@ import {monitoringDisableUrl} from "../utils/urlBuilder";
 import CONSTRAINTS from "../validation/constraints";
 import {forConstraint} from "../validation/validator";
 import {
+    Domain,
+    equal,
     isMonitoringSortField,
     MAC,
     MailType,
     MonitoringSortField,
+    MonitoringToken,
     Node,
     NodeId,
     NodeStateData,
     OnlineState,
+    Site,
+    to,
     UnixTimestampSeconds
 } from "../types";
 
@@ -45,12 +50,12 @@ const DELETE_OFFLINE_NODES_AFTER_DURATION: { amount: number, unit: unitOfTime.Du
 };
 
 export type ParsedNode = {
-    mac: string,
+    mac: MAC,
     importTimestamp: Moment,
     state: OnlineState,
     lastSeen: Moment,
-    site: string,
+    site: Site,
-    domain: string,
+    domain: Domain,
 };
 
 export type NodesParsingResult = {
@@ -220,12 +225,12 @@ export function parseNode(importTimestamp: Moment, nodeData: any): ParsedNode {
     }
 
     return {
-        mac: mac,
+        mac: to(mac),
         importTimestamp: importTimestamp,
         state: isOnline ? OnlineState.ONLINE : OnlineState.OFFLINE,
         lastSeen: lastSeen,
-        site: site || '<unknown-site>',
+        site: to(site || '<unknown-site>'), // FIXME: Handle this
-        domain: domain || '<unknown-domain>'
+        domain: to(domain || '<unknown-domain>') // FIXME: Handle this
     };
 }
 
@@ -573,7 +578,7 @@ export async function getAll(restParams: RestParams): Promise<{ total: number, m
     return {monitoringStates, total};
 }
 
-export async function getByMacs(macs: MAC[]): Promise<{ [key: string]: NodeStateData }> {
+export async function getByMacs(macs: MAC[]): Promise<Record<string, NodeStateData>> {
     if (_.isEmpty(macs)) {
         return {};
     }
@@ -596,9 +601,9 @@ export async function getByMacs(macs: MAC[]): Promise<{ [key: string]: NodeState
     return nodeStateByMac;
 }
 
-export async function confirm(token: string): Promise<Node> {
+export async function confirm(token: MonitoringToken): Promise<Node> {
     const {node, nodeSecrets} = await NodeService.getNodeDataWithSecretsByMonitoringToken(token);
-    if (!node.monitoring || !nodeSecrets.monitoringToken || nodeSecrets.monitoringToken !== token) {
+    if (!node.monitoring || !nodeSecrets.monitoringToken || !equal(nodeSecrets.monitoringToken, token)) {
         throw {data: 'Invalid token.', type: ErrorTypes.badRequest};
     }
 
@@ -612,15 +617,15 @@ export async function confirm(token: string): Promise<Node> {
     return newNode;
 }
 
-export async function disable(token: string): Promise<Node> {
+export async function disable(token: MonitoringToken): Promise<Node> {
     const {node, nodeSecrets} = await NodeService.getNodeDataWithSecretsByMonitoringToken(token);
-    if (!node.monitoring || !nodeSecrets.monitoringToken || nodeSecrets.monitoringToken !== token) {
+    if (!node.monitoring || !nodeSecrets.monitoringToken || !equal(nodeSecrets.monitoringToken, token)) {
         throw {data: 'Invalid token.', type: ErrorTypes.badRequest};
     }
 
     node.monitoring = false;
     node.monitoringConfirmed = false;
-    nodeSecrets.monitoringToken = '';
+    nodeSecrets.monitoringToken = undefined;
 
     const {node: newNode} = await NodeService.internalUpdateNode(node.token, node, nodeSecrets);
     return newNode;

server/services/nodeService.ts

@@ -10,51 +10,69 @@ import Logger from "../logger";
 import * as MailService from "../services/mailService";
 import {normalizeString} from "../utils/strings";
 import {monitoringConfirmUrl, monitoringDisableUrl} from "../utils/urlBuilder";
-import {FastdKey, MonitoringState, MonitoringToken, Node, NodeSecrets, NodeStatistics, UnixTimestampSeconds, Token} from "../types";
+import {
+    FastdKey,
+    MAC,
+    MonitoringState,
+    MonitoringToken,
+    Node,
+    NodeSecrets,
+    NodeStatistics,
+    to,
+    Token,
+    unhandledEnumField,
+    UnixTimestampSeconds
+} from "../types";
 import util from "util";
 
 const pglob = util.promisify(glob);
 
 type NodeFilter = {
+    // TODO: Newtype
     hostname?: string,
-    mac?: string,
+    mac?: MAC,
-    key?: string,
+    key?: FastdKey,
     token?: Token,
-    monitoringToken?: string,
+    monitoringToken?: MonitoringToken,
 }
 
+// TODO: Newtypes?
 type NodeFilenameParsed = {
     hostname?: string,
     mac?: string,
     key?: string,
-    token?: Token,
+    token?: string,
     monitoringToken?: string,
 }
 
-const linePrefixes = {
+enum LINE_PREFIX {
-    hostname: '# Knotenname: ',
+    HOSTNAME = "# Knotenname: ",
-    nickname: '# Ansprechpartner: ',
+    NICKNAME = "# Ansprechpartner: ",
-    email: '# Kontakt: ',
+    EMAIL = "# Kontakt: ",
-    coords: '# Koordinaten: ',
+    COORDS = "# Koordinaten: ",
-    mac: '# MAC: ',
+    MAC = "# MAC: ",
-    token: '# Token: ',
+    TOKEN = "# Token: ",
-    monitoring: '# Monitoring: ',
+    MONITORING = "# Monitoring: ",
-    monitoringToken: '# Monitoring-Token: '
+    MONITORING_TOKEN = "# Monitoring-Token: ",
-};
+}
 
 const filenameParts = ['hostname', 'mac', 'key', 'token', 'monitoringToken'];
 
-function generateToken(): Token {
+function generateToken<Type extends { readonly __tag: symbol, value: any } =
-    return crypto.randomBytes(8).toString('hex');
+    { readonly __tag: unique symbol, value: never }>(): Type {
+    return to<Type>(crypto.randomBytes(8).toString('hex'));
 }
 
 function toNodeFilesPattern(filter: NodeFilter): string {
-    const pattern = _.join(
+    const fields: (string | undefined)[] = [
-        _.map(
+        filter.hostname,
-            filenameParts,
+        filter.mac?.value,
-            field => field in filter ? (filter as {[key: string]: string | undefined})[field] : '*'),
+        filter.key?.value,
-        '@'
+        filter.token?.value,
-    );
+        filter.monitoringToken?.value,
+    ];
+
+    const pattern = fields.map((value) => value || '*').join('@');
 
     return config.server.peersPath + '/' + pattern.toLowerCase();
 }
@@ -104,7 +122,7 @@ function isDuplicate(filter: NodeFilter, token: Token | null): boolean {
         return true;
     }
 
-    return parseNodeFilename(files[0]).token !== token;
+    return parseNodeFilename(files[0]).token !== token.value;
 }
 
 function checkNoDuplicates(token: Token | null, node: Node, nodeSecrets: NodeSecrets): void {
@@ -138,6 +156,34 @@ function toNodeFilename(token: Token, node: Node, nodeSecrets: NodeSecrets): str
         ).toLowerCase();
 }
 
+function getNodeValue(prefix: LINE_PREFIX, node: Node, nodeSecrets: NodeSecrets): string {
+    switch (prefix) {
+        case LINE_PREFIX.HOSTNAME:
+            return node.hostname;
+        case LINE_PREFIX.NICKNAME:
+            return node.nickname;
+        case LINE_PREFIX.EMAIL:
+            return node.email;
+        case LINE_PREFIX.COORDS:
+            return node.coords || "";
+        case LINE_PREFIX.MAC:
+            return node.mac.value;
+        case LINE_PREFIX.TOKEN:
+            return node.token.value;
+        case LINE_PREFIX.MONITORING:
+            if (node.monitoring && node.monitoringConfirmed) {
+                return "aktiv";
+            } else if (node.monitoring && !node.monitoringConfirmed) {
+                return "pending";
+            }
+            return "";
+        case LINE_PREFIX.MONITORING_TOKEN:
+            return nodeSecrets.monitoringToken?.value || "";
+        default:
+            return unhandledEnumField(prefix);
+    }
+}
+
 async function writeNodeFile(
     isUpdate: boolean,
     token: Token,
@@ -146,35 +192,13 @@ async function writeNodeFile(
 ): Promise<{ token: Token, node: Node }> {
     const filename = toNodeFilename(token, node, nodeSecrets);
     let data = '';
-    _.each(linePrefixes, function (prefix, key) {
-        let value;
-        switch (key) {
-            case 'monitoring':
-                if (node.monitoring && node.monitoringConfirmed) {
-                    value = 'aktiv';
-                } else if (node.monitoring && !node.monitoringConfirmed) {
-                    value = 'pending';
-                } else {
-                    value = '';
-                }
-            break;
 
-            case 'monitoringToken':
+    for (const prefix of Object.values(LINE_PREFIX)) {
-                value = nodeSecrets.monitoringToken || '';
+        data += `${prefix}${getNodeValue(prefix, node, nodeSecrets)}\n`;
-            break;
+    }
 
-            default:
-                value = key === 'token' ? token : (node as {[key: string]: any})[key];
-                if (_.isUndefined(value)) {
-                    const nodeSecret = (nodeSecrets as {[key: string]: string})[key];
-                    value = _.isUndefined(nodeSecret) ? '' : nodeSecret;
-                }
-            break;
-        }
-        data += prefix + value + '\n';
-    });
     if (node.key) {
-        data += 'key "' + node.key + '";\n';
+        data += `key "${node.key}";\n`;
     }
 
     // since node.js is single threaded we don't need a lock
@@ -190,8 +214,7 @@ async function writeNodeFile(
         const file = files[0];
         try {
             oldFs.unlinkSync(file);
-        }
+        } catch (error) {
-        catch (error) {
             Logger.tag('node', 'save').error('Could not delete old node file: ' + file, error);
             throw {data: 'Could not remove old node data.', type: ErrorTypes.internalError};
         }
@@ -202,8 +225,7 @@ async function writeNodeFile(
     try {
         oldFs.writeFileSync(filename, data, 'utf8');
         return {token, node};
-    }
+    } catch (error) {
-    catch (error) {
         Logger.tag('node', 'save').error('Could not write node file: ' + filename, error);
         throw {data: 'Could not write node data.', type: ErrorTypes.internalError};
     }
@@ -213,8 +235,7 @@ async function deleteNodeFile(token: Token): Promise<void> {
     let files;
     try {
         files = await findNodeFiles({token: token});
-    }
+    } catch (error) {
-    catch (error) {
         Logger.tag('node', 'delete').error('Could not find node file: ' + files, error);
         throw {data: 'Could not delete node.', type: ErrorTypes.internalError};
     }
@@ -225,82 +246,109 @@ async function deleteNodeFile(token: Token): Promise<void> {
 
     try {
         oldFs.unlinkSync(files[0]);
-    }
+    } catch (error) {
-    catch (error) {
         Logger.tag('node', 'delete').error('Could not delete node file: ' + files, error);
         throw {data: 'Could not delete node.', type: ErrorTypes.internalError};
     }
 }
 
+class NodeBuilder {
+    public token: Token = to(""); // FIXME: Either make token optional in Node or handle this!
+    public nickname: string = "";
+    public email: string = "";
+    public hostname: string = ""; // FIXME: Either make hostname optional in Node or handle this!
+    public coords?: string;
+    public key?: FastdKey;
+    public mac: MAC = to(""); // FIXME: Either make mac optional in Node or handle this!
+    public monitoring: boolean = false;
+    public monitoringConfirmed: boolean = false;
+    public monitoringState: MonitoringState = MonitoringState.DISABLED;
+
+    constructor(
+        public readonly modifiedAt: UnixTimestampSeconds,
+    ) {
+    }
+
+    public build(): Node {
+        return {
+            token: this.token,
+            nickname: this.nickname,
+            email: this.email,
+            hostname: this.hostname,
+            coords: this.coords,
+            key: this.key,
+            mac: this.mac,
+            monitoring: this.monitoring,
+            monitoringConfirmed: this.monitoringConfirmed,
+            monitoringState: this.monitoringState,
+            modifiedAt: this.modifiedAt,
+        }
+    }
+}
+
+function setNodeValue(prefix: LINE_PREFIX, node: NodeBuilder, nodeSecrets: NodeSecrets, value: string) {
+    switch (prefix) {
+        case LINE_PREFIX.HOSTNAME:
+            node.hostname = value;
+            break;
+        case LINE_PREFIX.NICKNAME:
+            node.nickname = value;
+            break;
+        case LINE_PREFIX.EMAIL:
+            node.email = value;
+            break;
+        case LINE_PREFIX.COORDS:
+            node.coords = value;
+            break;
+        case LINE_PREFIX.MAC:
+            node.mac = to(value);
+            break;
+        case LINE_PREFIX.TOKEN:
+            node.token = to(value);
+            break;
+        case LINE_PREFIX.MONITORING:
+            const active = value === 'aktiv';
+            const pending = value === 'pending';
+            node.monitoring = active || pending;
+            node.monitoringConfirmed = active;
+            node.monitoringState =
+                active ? MonitoringState.ACTIVE : (pending ? MonitoringState.PENDING : MonitoringState.DISABLED);
+            break;
+        case LINE_PREFIX.MONITORING_TOKEN:
+            nodeSecrets.monitoringToken = to<MonitoringToken>(value);
+            break;
+        default:
+            return unhandledEnumField(prefix);
+    }
+}
+
 async function parseNodeFile(file: string): Promise<{ node: Node, nodeSecrets: NodeSecrets }> {
     const contents = await fs.readFile(file);
     const stats = await fs.lstat(file);
     const modifiedAt = Math.floor(stats.mtimeMs / 1000);
 
-    const lines = contents.toString();
+    const lines = contents.toString().split("\n");
 
-    const node: {[key: string]: any} = {};
+    const node = new NodeBuilder(modifiedAt);
-    const nodeSecrets: {[key: string]: any} = {};
+    const nodeSecrets: NodeSecrets = {};
 
-    _.each(lines.split('\n'), function (line) {
+    for (const line of lines) {
-        const entries: {[key: string]: string} = {};
+        if (line.substring(0, 5) === 'key "') {
-
+            node.key = to<FastdKey>(normalizeString(line.split('"')[1]));
-        for (const key of Object.keys(linePrefixes)) {
+        } else {
-            const prefix = (linePrefixes as {[key: string]: string})[key];
+            for (const prefix of Object.values(LINE_PREFIX)) {
                 if (line.substring(0, prefix.length) === prefix) {
-                entries[key] = normalizeString(line.substr(prefix.length));
+                    const value = normalizeString(line.substring(prefix.length));
+                    setNodeValue(prefix, node, nodeSecrets, value);
                     break;
                 }
             }
-
-        if (_.isEmpty(entries) && line.substring(0, 5) === 'key "') {
-            entries.key = normalizeString(line.split('"')[1]);
         }
-
-        _.each(entries, function (value, key) {
-            switch (key) {
-                case 'mac':
-                    node.mac = value;
-                    node.mapId = _.toLower(value).replace(/:/g, '');
-                    break;
-
-                case 'monitoring':
-                    const active = value === 'aktiv';
-                    const pending = value === 'pending';
-                    node.monitoring = active || pending;
-                    node.monitoringConfirmed = active;
-                    node.monitoringState =
-                        active ? MonitoringState.ACTIVE : (pending ? MonitoringState.PENDING : MonitoringState.DISABLED);
-                    break;
-
-                case 'monitoringToken':
-                    nodeSecrets.monitoringToken = value;
-                    break;
-
-                default:
-                   node[key] = value;
-                   break;
     }
-        });
-    });
 
     return {
-        node: {
+        node: node.build(),
-            token: node.token as Token || '',
+        nodeSecrets,
-            nickname: node.nickname as string || '',
-            email: node.email as string || '',
-            hostname: node.hostname as string || '',
-            coords: node.coords as string || undefined,
-            key: node.key as FastdKey || undefined,
-            mac: node.mac as string || '',
-            monitoring: !!node.monitoring,
-            monitoringConfirmed: !!node.monitoringConfirmed,
-            monitoringState: node.monitoringState as MonitoringState || MonitoringState.DISABLED,
-            modifiedAt,
-        },
-        nodeSecrets: {
-            monitoringToken: nodeSecrets.monitoringToken as MonitoringToken || undefined,
-        },
     };
 }
 
@@ -349,13 +397,13 @@ async function sendMonitoringConfirmationMail(node: Node, nodeSecrets: NodeSecre
 }
 
 export async function createNode(node: Node): Promise<{ token: Token, node: Node }> {
-    const token = generateToken();
+    const token: Token = generateToken();
     const nodeSecrets: NodeSecrets = {};
 
     node.monitoringConfirmed = false;
 
     if (node.monitoring) {
-        nodeSecrets.monitoringToken = generateToken();
+        nodeSecrets.monitoringToken = generateToken<MonitoringToken>();
     }
 
     const written = await writeNodeFile(false, token, node, nodeSecrets);
@@ -371,13 +419,13 @@ export async function updateNode (token: Token, node: Node): Promise<{token: Tok
     const {node: currentNode, nodeSecrets} = await getNodeDataWithSecretsByToken(token);
 
     let monitoringConfirmed = false;
-    let monitoringToken = '';
+    let monitoringToken: MonitoringToken | undefined;
 
     if (node.monitoring) {
         if (!currentNode.monitoring) {
             // monitoring just has been enabled
             monitoringConfirmed = false;
-            monitoringToken = generateToken();
+            monitoringToken = generateToken<MonitoringToken>();
 
         } else {
             // monitoring is still enabled
@@ -385,12 +433,12 @@ export async function updateNode (token: Token, node: Node): Promise<{token: Tok
             if (currentNode.email !== node.email) {
                 // new email so we need a new token and a reconfirmation
                 monitoringConfirmed = false;
-                monitoringToken = generateToken();
+                monitoringToken = generateToken<MonitoringToken>();
 
             } else {
                 // email unchanged, keep token (fix if not set) and confirmation state
                 monitoringConfirmed = currentNode.monitoringConfirmed;
-                monitoringToken = nodeSecrets.monitoringToken || generateToken();
+                monitoringToken = nodeSecrets.monitoringToken || generateToken<MonitoringToken>();
             }
         }
     }
@@ -440,12 +488,12 @@ export async function getAllNodes(): Promise<Node[]> {
     return nodes;
 }
 
-export async function getNodeDataWithSecretsByMac (mac: string): Promise<{node: Node, nodeSecrets: NodeSecrets} | null> {
+export async function getNodeDataWithSecretsByMac(mac: MAC): Promise<{ node: Node, nodeSecrets: NodeSecrets } | null> {
-    return await findNodeDataByFilePattern({ mac: mac });
+    return await findNodeDataByFilePattern({mac});
 }
 
-export async function getNodeDataByMac (mac: string): Promise<Node | null> {
+export async function getNodeDataByMac(mac: MAC): Promise<Node | null> {
-    const result = await findNodeDataByFilePattern({ mac: mac });
+    const result = await findNodeDataByFilePattern({mac});
     return result ? result.node : null;
 }
 
@@ -481,8 +529,7 @@ export async function fixNodeFilenames(): Promise<void> {
         if (file !== expectedFilename) {
             try {
                 await fs.rename(file, expectedFilename);
-            }
+            } catch (error) {
-            catch (error) {
                 throw new Error(
                     'Cannot rename file ' + file + ' to ' + expectedFilename + ' => ' + error
                 );
@@ -518,10 +565,6 @@ export async function getNodeStatistics(): Promise<NodeStatistics> {
             nodeStatistics.withCoords += 1;
         }
 
-        function ensureExhaustive(monitoringState: never): void {
-            throw new Error('Add missing case for monitoring stat below: ' + monitoringState);
-        }
-
         const monitoringState = node.monitoringState;
         switch (monitoringState) {
             case MonitoringState.ACTIVE:
@@ -535,7 +578,7 @@ export async function getNodeStatistics(): Promise<NodeStatistics> {
                 break;
 
             default:
-                ensureExhaustive(monitoringState);
+                unhandledEnumField(monitoringState);
         }
     });
 

server/types/config.ts

@@ -1,17 +1,32 @@
 import {ArrayField, Field, RawJsonField} from "sparkson"
-import {ClientConfig} from "./shared";
+import {ClientConfig, to} from "./shared";
 
 // TODO: Replace string types by more specific types like URL, Password, etc.
 
-export type Username = string;
+export type Username = {
-export type CleartextPassword = string;
+    value: string;
-export type PasswordHash = string;
+    readonly __tag: unique symbol
+};
+export type CleartextPassword = {
+    value: string;
+    readonly __tag: unique symbol
+};
+export type PasswordHash = {
+    value: string;
+    readonly __tag: unique symbol
+};
 
 export class UsersConfig {
+    public username: Username;
+    public passwordHash: PasswordHash;
+
     constructor(
-        @Field("user") public username: Username,
+        @Field("user") username: string,
-        @Field("passwordHash") public passwordHash: PasswordHash,
+        @Field("passwordHash") passwordHash: string,
-    ) {}
+    ) {
+        this.username = to(username);
+        this.passwordHash = to(passwordHash);
+    }
 }
 
 export class LoggingConfig {

server/types/shared.ts

@@ -6,10 +6,37 @@ export type TypeGuard<T> = (arg: unknown) => arg is T;
 export type EnumValue<E> = E[keyof E];
 export type EnumTypeGuard<E> = TypeGuard<EnumValue<E>>;
 
+export function unhandledEnumField(field: never): never {
+    throw new Error(`Unhandled enum field: ${field}`);
+}
+
+export function to<Type extends { readonly __tag: symbol, value: any } = { readonly __tag: unique symbol, value: never }>(value: Type['value']): Type {
+    return value as any as Type;
+}
+
+export function lift2<Result, Type extends { readonly __tag: symbol, value: any }>(callback: (a: Type["value"], b: Type["value"]) => Result): (newtype1: Type, newtype2: Type) => Result {
+    return (a, b) => callback(a.value, b.value);
+}
+
+export function equal<Result, Type extends { readonly __tag: symbol, value: any }>(a: Type, b: Type): boolean {
+    return lift2((a, b) => a === b)(a, b);
+}
+
 export function isObject(arg: unknown): arg is object {
     return arg !== null && typeof arg === "object";
 }
 
+export function toIsNewtype<Type extends { readonly __tag: symbol, value: Value } = { readonly __tag: unique symbol, value: never }, Value = any>(isValue: TypeGuard<Value>): TypeGuard<Type> {
+    // TODO: Add validation pattern.
+    return (arg: unknown): arg is Type => {
+        if (!isObject(arg)) {
+            return false;
+        }
+        const newtype = arg as Type;
+        return isValue(newtype.value);
+    }
+}
+
 export function isArray<T>(arg: unknown, isT: TypeGuard<T>): arg is Array<T> {
     if (!Array.isArray(arg)) {
         return false;
@@ -248,19 +275,32 @@ export function isClientConfig(arg: unknown): arg is ClientConfig {
 }
 
 // TODO: Token type.
-export type Token = string;
+export type Token = {
-export const isToken = isString;
+    value: string;
+    readonly __tag: unique symbol
+};
+export const isToken = toIsNewtype<Token>(isString);
 
-export type FastdKey = string;
+export type FastdKey = {
-export const isFastdKey = isString;
+    value: string;
+    readonly __tag: unique symbol
+};
+export const isFastdKey = toIsNewtype<FastdKey>(isString);
 
-export type MAC = string;
+export type MAC = {
-export const isMAC = isString;
+    value: string;
+    readonly __tag: unique symbol
+};
+export const isMAC = toIsNewtype<MAC>(isString);
 
 export type UnixTimestampSeconds = number;
 export type UnixTimestampMilliseconds = number;
 
-export type MonitoringToken = string;
+export type MonitoringToken = {
+    value: string;
+    readonly __tag: unique symbol
+};
+
 export enum MonitoringState {
     ACTIVE = "active",
     PENDING = "pending",
@@ -269,9 +309,12 @@ export enum MonitoringState {
 
 export const isMonitoringState = toIsEnum(MonitoringState);
 
-export type NodeId = string;
+export type NodeId = {
-export const isNodeId = isString;
+    value: string;
+    readonly __tag: unique symbol
+};
 
+// TODO: More Newtypes
 export interface Node {
     token: Token;
     nickname: string;
@@ -310,13 +353,20 @@ export enum OnlineState {
     ONLINE = "ONLINE",
     OFFLINE = "OFFLINE",
 }
+
 export const isOnlineState = toIsEnum(OnlineState);
 
-export type Site = string;
+export type Site = {
-export const isSite = isString;
+    value: string;
+    readonly __tag: unique symbol
+};
+export const isSite = toIsNewtype<Site>(isString);
 
-export type Domain = string;
+export type Domain = {
-export const isDomain = isString;
+    value: string;
+    readonly __tag: unique symbol
+};
+export const isDomain = toIsNewtype<Domain>(isString);
 
 export interface EnhancedNode extends Node {
     site?: Site,
@@ -426,7 +476,10 @@ export enum MailSortField {
 
 export const isMailSortField = toIsEnum(MailSortField);
 
-export type GenericSortField = string;
+export type GenericSortField = {
+    value: string;
+    readonly __tag: unique symbol
+};
 
 export enum SortDirection {
     ASCENDING = "ASC",

server/utils/urlBuilder.ts

@@ -32,9 +32,9 @@ export function editNodeUrl (): string {
 }
 
 export function monitoringConfirmUrl(monitoringToken: MonitoringToken): string {
-    return formUrl('monitoring/confirm', { token: monitoringToken });
+    return formUrl('monitoring/confirm', {token: monitoringToken.value});
 }
 
 export function monitoringDisableUrl(monitoringToken: MonitoringToken): string {
-    return formUrl('monitoring/disable', { token: monitoringToken });
+    return formUrl('monitoring/disable', {token: monitoringToken.value});
 }