Implemented needed helpers and documentations.

utils/Helpers.js

@@ -1,83 +1,117 @@
-/*Generates a random long integer (8 bytes), which is optionally signed*/
-function generateRandomLong() {
-    let buf = Buffer.from(generateRandomBytes(8),); // 0x12345678 = 305419896
-    return (buf.readUInt32BE(0));
-}
-
-/*Generates a random bytes array*/
-function generateRandomBytes(count) {
-
-    const crypto = require('crypto');
-
-    return crypto.randomBytes(count);
-
-}
+const crypto = require('crypto');
+const fs = require("fs").promises;
 
-function loadSettings(path = "../api/settings") {
-    let settings = {};
-    let left, right, value_pair;
-    const fs = require("fs");
+class Helpers {
 
-    let data = fs.readFileSync(path, 'utf-8');
 
+    /**
+     * Generates a random long integer (8 bytes), which is optionally signed
+     * @returns {number}
+     */
+    static generateRandomLong() {
+        let buf = Buffer.from(this.generateRandomBytes(8)); // 0x12345678 = 305419896
+        return buf.readUInt32BE(0);
+    }
 
-    for (let line of data.toString().split('\n')) {
-        value_pair = line.split("=");
-        if (value_pair.length !== 2) {
-            break;
-        }
-        left = value_pair[0].replace(/ \r?\n|\r/g, '');
-        right = value_pair[1].replace(/ \r?\n|\r/g, '');
-        if (!isNaN(right)) {
-            settings[left] = Number.parseInt(right);
-        } else {
-            settings[left] = right;
-        }
+    /**
+     * Generates a random bytes array
+     * @param count
+     * @returns {Buffer}
+     */
+    static generateRandomBytes(count) {
+        return crypto.randomBytes(count);
     }
 
+    /**
+     * Loads the user settings located under `api/`
+     * @param path
+     * @returns {Promise<void>}
+     */
+    static async loadSettings(path = "../api/settings") {
+        let settings = {};
+        let left, right, value_pair;
+
+        let data = await fs.readFile(path, 'utf-8');
+
+        for (let line of data.toString().split('\n')) {
+            value_pair = line.split("=");
+            if (value_pair.length !== 2) {
+                break;
+            }
+            left = value_pair[0].replace(/ \r?\n|\r/g, '');
+            right = value_pair[1].replace(/ \r?\n|\r/g, '');
+            if (!isNaN(right)) {
+                settings[left] = Number.parseInt(right);
+            } else {
+                settings[left] = right;
+            }
+        }
 
-    return settings;
 
+        return settings;
 
 
-}
+    }
 
-/*Calculate the key based on Telegram guidelines, specifying whether it's the client or not*/
+    /**
+     * Calculate the key based on Telegram guidelines, specifying whether it's the client or not
+     * @param shared_key
+     * @param msg_key
+     * @param client
+     * @returns {[*, *]}
+     */
+
+    static calcKey(shared_key, msg_key, client) {
+        let x = client !== null ? 0 : 8;
+        let iv, key, sha1a, sha1b, sha1c, sha1d;
+        sha1a = this.sha1((msg_key + shared_key.slice(x, (x + 32))));
+        sha1b = this.sha1(((shared_key.slice((x + 32), (x + 48)) + msg_key) + shared_key.slice((x + 48), (x + 64))));
+        sha1c = this.sha1((shared_key.slice((x + 64), (x + 96)) + msg_key));
+        sha1d = this.sha1((msg_key + shared_key.slice((x + 96), (x + 128))));
+        key = ((sha1a.slice(0, 8) + sha1b.slice(8, 20)) + sha1c.slice(4, 16));
+        iv = (((sha1a.slice(8, 20) + sha1b.slice(0, 8)) + sha1c.slice(16, 20)) + sha1d.slice(0, 8));
+        return [key, iv];
 
-function calcKey(shared_key, msg_key, client) {
-   let x = client !== null ? 0 : 8;
-    let iv, key, sha1a, sha1b, sha1c, sha1d;
-    sha1a = sha1((msg_key + shared_key.slice(x, (x + 32))));
-    sha1b = sha1(((shared_key.slice((x + 32), (x + 48)) + msg_key) + shared_key.slice((x + 48), (x + 64))));
-    sha1c = sha1((shared_key.slice((x + 64), (x + 96)) + msg_key));
-    sha1d = sha1((msg_key + shared_key.slice((x + 96), (x + 128))));
-    key = ((sha1a.slice(0, 8) + sha1b.slice(8, 20)) + sha1c.slice(4, 16));
-    iv = (((sha1a.slice(8, 20) + sha1b.slice(0, 8)) + sha1c.slice(16, 20)) + sha1d.slice(0, 8));
-    return [key, iv];
 
+    }
 
-}
+    /**
+     * Calculates the message key from the given data
+     * @param data
+     * @returns {Buffer}
+     */
+    static calcMsgKey(data) {
+        return this.sha1(data).slice(4, 20);
 
-function calcMsgKey(data) {
-    return sha1(data).slice(4, 20);
 
+    }
 
-}
+    /**
+     * Generates the key data corresponding to the given nonces
+     * @param serverNonce
+     * @param newNonce
+     * @returns {{ivBuffer: Buffer, keyBuffer: Buffer}}
+     */
+    static generateKeyDataFromNonces(serverNonce, newNonce) {
+        let hash1 = this.sha1(Buffer.concat([newNonce, serverNonce]));
+        let hash2 = this.sha1(Buffer.concat([serverNonce, newNonce]));
+        let hash3 = this.sha1(Buffer.concat([newNonce, newNonce]));
+        let keyBuffer = Buffer.concat([hash1, hash1.slice(0, 12)]);
+        let ivBuffer = Buffer.concat([hash2.slice(12, 20), hash3, newNonce.slice(0, 4)]);
+        return {keyBuffer: keyBuffer, ivBuffer: ivBuffer}
+    }
 
-function generateKeyDataFromNonces() {
-    let hash1, hash2, hash3;
-    /*hash1 = sha1(bytes((new_nonce + server_nonce)));
-    hash2 = sha1(bytes((server_nonce + new_nonce)));
-    hash3 = sha1(bytes((new_nonce + new_nonce)));
-*/
+    /**
+     * Calculates the SHA1 digest for the given data
+     * @param data
+     * @returns {Buffer}
+     */
+    static sha1(data) {
+        let shaSum = crypto.createHash('sha1');
+        shaSum.update(data);
+        return shaSum.digest();
 
+    }
 }
-/*Calculates the SHA1 digest for the given data*/
-function sha1(data) {
-    const crypto = require('crypto')
-        , shasum = crypto.createHash('sha1');
-    shasum.update(data);
-    console.log(shasum.digest());
 
-}
-sha1("test");
+exports.helpers = Helpers;