[TypeScript] Convert background entry script to TypeScript (#419)

* Convert background entry file to typescript. Remove global forge & tldjs variables.

* Minor cleanup.

src/services/crypto.service.ts

@@ -1,3 +1,5 @@
+import * as forge from 'node-forge';
+
 import { EncryptionType } from '../enums/encryptionType.enum';
 
 import { CipherString } from '../models/domain/cipherString';
@@ -249,7 +251,7 @@ export default class CryptoService implements CryptoServiceInterface {
     }
 
     makeKey(password: string, salt: string): SymmetricCryptoKey {
-        const keyBytes: string = forge.pbkdf2(forge.util.encodeUtf8(password), forge.util.encodeUtf8(salt),
+        const keyBytes: string = (forge as any).pbkdf2(forge.util.encodeUtf8(password), forge.util.encodeUtf8(salt),
             5000, 256 / 8, 'sha256');
         return new SymmetricCryptoKey(keyBytes);
     }
@@ -261,7 +263,7 @@ export default class CryptoService implements CryptoServiceInterface {
             throw new Error('Invalid parameters.');
         }
 
-        const hashBits = forge.pbkdf2(key.key, forge.util.encodeUtf8(password), 1, 256 / 8, 'sha256');
+        const hashBits = (forge as any).pbkdf2(key.key, forge.util.encodeUtf8(password), 1, 256 / 8, 'sha256');
         return forge.util.encode64(hashBits);
     }
 
@@ -487,8 +489,8 @@ export default class CryptoService implements CryptoServiceInterface {
             }
         }
 
-        const ctBuffer = forge.util.createBuffer(ctBytes);
-        const decipher = forge.cipher.createDecipher('AES-CBC', theKey.encKey);
+        const ctBuffer = (forge as any).util.createBuffer(ctBytes);
+        const decipher = (forge as any).cipher.createDecipher('AES-CBC', theKey.encKey);
         decipher.start({ iv: ivBytes });
         decipher.update(ctBuffer);
         decipher.finish();
@@ -524,7 +526,7 @@ export default class CryptoService implements CryptoServiceInterface {
     }
 
     private computeMac(dataBytes: string, macKey: string, b64Output: boolean): string {
-        const hmac = forge.hmac.create();
+        const hmac = (forge as any).hmac.create();
         hmac.start('sha256', macKey);
         hmac.update(dataBytes);
         const mac = hmac.digest();
@@ -539,7 +541,7 @@ export default class CryptoService implements CryptoServiceInterface {
     // Safely compare two MACs in a way that protects against timing attacks (Double HMAC Verification).
     // ref: https://www.nccgroup.trust/us/about-us/newsroom-and-events/blog/2011/february/double-hmac-verification/
     private macsEqual(macKey: string, mac1: string, mac2: string): boolean {
-        const hmac = forge.hmac.create();
+        const hmac = (forge as any).hmac.create();
 
         hmac.start('sha256', macKey);
         hmac.update(mac1);

src/services/i18n.service.ts

@@ -0,0 +1,30 @@
+export default function i18nService() {
+    const edgeMessages: any = {};
+
+    if (navigator.userAgent.indexOf(' Edge/') !== -1) {
+        fetch('../_locales/en/messages.json')
+            .then((file) => {
+                return file.json();
+            })
+            .then((locales) => {
+                for (const prop in locales) {
+                    if (locales.hasOwnProperty(prop)) {
+                        edgeMessages[prop] = chrome.i18n.getMessage(prop);
+                    }
+                }
+            });
+
+        return edgeMessages;
+    }
+
+    return new Proxy({}, {
+        get(target, name) {
+            return chrome.i18n.getMessage(name);
+        },
+        set(target, name, value) {
+            throw new Error('set not allowed for i18n');
+            // @ts-ignore: Unreachable code error
+            return false;
+        },
+    });
+}

src/services/i18nService.js

@@ -1,26 +0,0 @@
-export default function i18nService() {
-    this.__edgeMessages = {};
-
-    if (navigator.userAgent.indexOf(' Edge/') !== -1) {
-        fetch('../_locales/en/messages.json').then((file) => {
-            return file.json();
-        }).then((locales) => {
-            for (const prop in locales) {
-                if (locales.hasOwnProperty(prop)) {
-                    this.__edgeMessages[prop] = chrome.i18n.getMessage(prop);
-                }
-            }
-        });
-
-        return this.__edgeMessages;
-    }
-
-    return new Proxy({}, {
-        get: function (target, name) {
-            return chrome.i18n.getMessage(name);
-        },
-        set: function (target, name, value) {
-            throw 'set not allowed for i18n';
-        }
-    });
-}