Add token generation

dist/lib/Token.js

@@ -0,0 +1,51 @@
+"use strict";
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+const crypto_1 = require("crypto");
+const otp_1 = __importDefault(require("./otp"));
+class TokenGenerator {
+    constructor(secret, epoch = 1546300800000, seed = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz!@#$-', version = 1) {
+        this.EPOCH = epoch;
+        this.secret = secret;
+        this.VERSION = version;
+        this._otp = new otp_1.default(seed);
+    }
+    generate(ID) {
+        const parts = [
+            Buffer.from(ID).toString('base64'),
+            Buffer.from(this.tokenTime.toString()).toString('base64')
+        ];
+        return `${parts.join('.').replace(/=/g, '')}.${this._computeHmac(parts.join('.').replace(/=/g, ''))}`;
+    }
+    upgrade(token, mfa, secret, counter = -1) {
+        if (!token.startsWith('mfa.') &&
+            ((counter === -1 && this._otp.validateTotp(mfa, secret)) ||
+                (counter !== -1 && this._otp.validateHotp(mfa, secret, counter)))) {
+            const parts = token.split('.');
+            return `mfa.${parts[0]}.${parts[1]}.${this._computeHmac(`mfa.${parts[0]}.${parts[1]}`)}`;
+        }
+        return null;
+    }
+    validate(token, fetcher) {
+        const isMfa = token.startsWith('mfa.');
+        const partitions = token.replace(/^mfa\./, '').split('.');
+        if (partitions.length !== 3)
+            return false;
+        const signatureStr = `${isMfa ? 'mfa.' : ''}${partitions[0]}.${partitions[1]}`;
+        if (partitions[2] !== this._computeHmac(signatureStr))
+            return false;
+        const ID = Buffer.from(partitions[0], 'base64').toString('utf8');
+        const time = Buffer.from(partitions[1], 'base64').toString('utf8');
+        const accountDetails = fetcher(ID);
+        return time > accountDetails.tokensValidSince && isMfa === accountDetails.hasMfa;
+    }
+    get tokenTime() {
+        return Math.floor((Date.now() - this.EPOCH) / 1000);
+    }
+    _computeHmac(string) {
+        return crypto_1.createHmac('sha256', this.secret).update(`TTF.${this.VERSION}.${string}`).digest('base64').replace(/=/g, '');
+    }
+}
+exports.default = TokenGenerator;