init

source/utils/utils.ts

@@ -0,0 +1,97 @@
+/*
+* ClearURLs
+* Copyright (c) 2017-2020 Kevin Röbert
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU Lesser General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program 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 Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*jshint esversion: 6 */
+/*
+* This script is responsible for some tools.
+*/
+import { browser } from 'webextension-polyfill-ts'
+
+// Needed by the sha256 method
+const enc = new TextEncoder()
+
+export class Utils {
+    /**
+     * Checks if the current browser runs on android.
+     *
+     * @returns Promise with true, iff the current browser runs on android otherwise false
+     */
+    static async isAndroidOS() : Promise<boolean> {
+        return (await browser.runtime.getPlatformInfo()).os === 'android'
+    }
+
+    /**
+     * Returns the browser name.
+     *
+     * @returns the browser name
+     */
+    static getBrowser() : string {
+        if (typeof InstallTrigger !== 'undefined') {
+            return 'Firefox'
+        }
+
+        return 'Chrome'
+    }
+
+    /**
+     * Decodes an URL, also one that is encoded multiple times.
+     *
+     * @see https://stackoverflow.com/a/38265168
+     *
+     * @param url - the url, that should be decoded
+     * @returns the decoded URL
+     */
+    static decodeURL(url: string) : string {
+        let rtn = decodeURIComponent(url)
+
+        while (Utils.isEncodedURI(rtn)) {
+            rtn = decodeURIComponent(rtn)
+        }
+
+        return rtn
+    }
+
+    /**
+     * Returns true, iff the given URI is encoded
+     *
+     * @see https://stackoverflow.com/a/38265168
+     *
+     * @param uri - the URI to be checked
+     * @returns true, iff the given URI is encoded otherwise false
+     */
+    static isEncodedURI(uri: string) : boolean {
+        return uri !== decodeURIComponent(uri || '')
+    }
+
+    /**
+     * This method calculates the SHA-256 hash as HEX string of the given message.
+     * This method uses the native hashing implementations of the SubtleCrypto interface which is supported by all browsers
+     * that implement the Web Cryptography API specification and is based on:
+     * https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest
+     *
+     * @param message - message for which the hash should be calculated
+     * @returns SHA-256 of the given message
+     */
+    static async sha256(message: string): Promise<string> {
+        const msgUint8 = enc.encode(message)
+        const hashBuffer = await crypto.subtle.digest('SHA-256', msgUint8)
+        const hashArray = Array.from(new Uint8Array(hashBuffer))
+
+        return hashArray.map(b => b.toString(16).padStart(2, '0')).join('')
+    }
+}