refactor(provider): adds signing to google maps provider requests geocode and reverse

ref #FSMWO-1806

Author: dobrea-v

src/provider/google-maps/command/google-maps-geocode.command.ts

@@ -3,17 +3,18 @@ import { GeocodeCommand } from '../../../command';
 import type { GeocodeQuery } from '../../../model';
 import type { GoogleMapsGeocodeQueryInterface } from '../interface';
 import { GoogleMapsLocationCommandMixin } from './mixin';
+import { urlSign } from '../../../util/url-signing';
 
 /**
  * @link {https://developers.google.com/maps/documentation/geocoding/intro#GeocodingRequests}
  */
 export class GoogleMapsGeocodeCommand extends GoogleMapsLocationCommandMixin(GeocodeCommand)<GoogleMapsGeocodeQueryInterface> {
-    constructor(httpClient: AxiosInstance, private readonly apiKey: string) {
-        super(httpClient, apiKey);
+    constructor(httpClient: AxiosInstance, private readonly apiKey: string, private readonly secret?: string) {
+        super(httpClient, apiKey, secret);
     }
 
     static getUrl(): string {
-        return 'https://maps.googleapis.com/maps/api/geocode/json';
+        return 'https://maps.googleapis.com/maps/api/geocode/json'
     }
 
     protected async buildQuery(query: GeocodeQuery): Promise<GoogleMapsGeocodeQueryInterface> {
@@ -46,6 +47,10 @@ export class GoogleMapsGeocodeCommand extends GoogleMapsLocationCommandMixin(Geo
             providerQuery.region = `.${query.countryCode.toLowerCase()}`;
         }
 
+        if (this.secret) {
+            providerQuery.signature = urlSign('/maps/api/geocode/json', providerQuery, this.secret);
+        }
+
         return providerQuery;
     }
 }

src/provider/google-maps/command/google-maps-reverse.command.ts

@@ -3,14 +3,15 @@ import { ReverseCommand } from '../../../command';
 import type { ReverseQuery } from '../../../model';
 import type { GoogleMapsReverseQueryInterface } from '../interface';
 import { GoogleMapsLocationCommandMixin } from './mixin';
+import { urlSign } from '../../../util/url-signing';
 
 /**
  * TODO implement result_type and location_type
  * @link {https://developers.google.com/maps/documentation/geocoding/intro#ReverseGeocoding}
  */
 export class GoogleMapsReverseCommand extends GoogleMapsLocationCommandMixin(ReverseCommand)<GoogleMapsReverseQueryInterface> {
-    constructor(httpClient: AxiosInstance, private readonly apiKey: string) {
-        super(httpClient, apiKey);
+    constructor(httpClient: AxiosInstance, private readonly apiKey: string, private readonly secret?: string) {
+        super(httpClient, apiKey, secret);
     }
 
     static getUrl(): string {
@@ -30,6 +31,10 @@ export class GoogleMapsReverseCommand extends GoogleMapsLocationCommandMixin(Rev
             providerQuery.region = `.${query.countryCode.toLowerCase()}`;
         }
 
+        if (this.secret) {
+            providerQuery.signature = urlSign('/maps/api/geocode/json', providerQuery, this.secret);
+        }
+
         return providerQuery;
     }
 }

src/provider/google-maps/google-maps.provider.ts

@@ -9,10 +9,10 @@ import {
 } from './command';
 
 export class GoogleMapsProvider extends AbstractHttpProvider {
-    constructor(httpClient: AxiosInstance, apiKey: string) {
+    constructor(httpClient: AxiosInstance, apiKey: string, secret?: string) {
         super({
-            geocode: new GoogleMapsGeocodeCommand(httpClient, apiKey),
-            reverse: new GoogleMapsReverseCommand(httpClient, apiKey),
+            geocode: new GoogleMapsGeocodeCommand(httpClient, apiKey, secret),
+            reverse: new GoogleMapsReverseCommand(httpClient, apiKey, secret),
             suggest: new GoogleMapsSuggestCommand(httpClient, apiKey),
             placeDetails: new GoogleMapsPlaceDetailsCommand(httpClient, apiKey),
             distance: new GoogleMapsDistanceCommand(httpClient, apiKey),

src/provider/google-maps/interface/google-maps-query.interface.ts

@@ -7,4 +7,9 @@ export interface GoogleMapsQueryInterface {
      */
     region?: string;
     language: string;
+    /**
+     * Signature for signed request to Google Maps API to bypass the 25k requests/day limit
+     * https://developers.google.com/maps/documentation/maps-static/digital-signature#server-side-signing
+     */
+    signature?: string;
 }

src/util/url-signing/index.ts

@@ -0,0 +1 @@
+export * from './url-signing';

src/util/url-signing/url-signing.ts

@@ -0,0 +1,62 @@
+/**
+ * Example from https://googlemaps.github.io/url-signing/urlSigner.js
+ */
+import crypto from 'crypto';
+
+/**
+ * Convert from 'web safe' base64 to true base64.
+ *
+ * @param  {string} safeEncodedString The code you want to translate
+ *                                    from a web safe form.
+ * @return {string}
+ */
+function removeWebSafe(safeEncodedString: string): string {
+    return safeEncodedString.replace(/-/g, '+').replace(/_/g, '/');
+}
+
+/**
+ * Convert from true base64 to 'web safe' base64
+ *
+ * @param  {string} encodedString The code you want to translate to a
+ *                                web safe form.
+ * @return {string}
+ */
+function makeWebSafe(encodedString: string): string {
+    return encodedString.replace(/\+/g, '-').replace(/\//g, '_');
+}
+
+/**
+ * Takes a base64 code and decodes it.
+ *
+ * @param  {string} code The encoded data.
+ * @return {Buffer}
+ */
+function decodeBase64Hash(code: string): Buffer {
+    // "new Buffer(...)" is deprecated. Use Buffer.from if it exists.
+    return Buffer.from ? Buffer.from(code, 'base64') : new Buffer(code, 'base64');
+}
+
+/**
+ * Takes a key and signs the data with it.
+ *
+ * @param  {string} key  Your unique secret key.
+ * @param  {string} data The url to sign.
+ * @return {string}
+ */
+function encodeBase64Hash(key: string, data: string): string {
+    return crypto.createHmac('sha1', key).update(data).digest('base64');
+}
+
+/**
+ * Sign a URL using a secret key.
+ *
+ * @param  {string} path   The url you want to sign.
+ * @param  {string} secret Your unique secret key.
+ * @param  {Object} query Query object
+ * @return {string}
+ */
+export function urlSign(path: string, query: any, secret: string, ): string {
+    const queryString = new URLSearchParams(JSON.stringify(query)).toString();
+    const safeSecret = decodeBase64Hash(removeWebSafe(secret)).toString('base64');
+    return makeWebSafe(encodeBase64Hash(safeSecret, path + queryString));
+}