README

A simple Laravel package for generating and verifying One-Time Passwords (OTPs) using TOTP (Time-based One-Time Password) and HOTP (HMAC-based One-Time Password) algorithms.

Installation

You can install the package via Composer:

composer require mkd/laravel-otp

Example

Scan This QR Code using Authenticator app

Here's a simple example demonstrating how to generate and verify an OTP:

use MKD\LaravelOTP\LaravelOTP;

$secret = 'WSRNGQX4J57FL2POVHDAMBI6ZTK3CYUE'; // Base32 encoded secret
$otpService = LaravelOTP::make($secret);

// Generate current OTP
$currentOTP = $otpService->now();
echo "Current OTP: $currentOTP\n";

// Verify the OTP
$isValid = $otpService->verifyTOTP($currentOTP);
echo $isValid ? "OTP is valid!" : "OTP is invalid!";

Usage

Creating an Instance

You can create an instance of the LaravelOTP class by providing a secret key:

use MKD\LaravelOTP\LaravelOTP;

$otpService = LaravelOTP::make('your-secret-key');

Public Methods

now(): string

Returns the current TOTP for the current timeframe.

$otp = $otpService->now();

last(): string

Returns the TOTP for the previous timeframe (30 seconds earlier).

$otp = $otpService->last();

next(): string

Returns the TOTP for the next timeframe (30 seconds later).

$otp = $otpService->next();

at(int $offset = 0): string

Returns the TOTP for a custom timeframe based on the provided offset. An offset of 0 returns the current TOTP, -1 returns the last OTP, and 1 returns the next OTP.

$otp = $otpService->at(-1); // Last TOTP
$otp = $otpService->at(1);  // Next TOTP

generateSecretKey(): string

Generates a new secret key.

$secretKey = $otpService->generateSecretKey();

atCounter(int $counter): string

Returns the HOTP for a specific counter value.

$otp = $otpService->atCounter(1); // OTP for counter 1

verifyTOTP(string $otp, string|null $secret = null): bool

Verifies a given TOTP against the current, previous, and next timeframes. If a secret key is provided, it overrides the current secret.

$isValid = $otpService->verifyTOTP('123456'); // Validate TOTP

verifyHOTP(string $otp, int $counter, string|null $secret = null): bool

Verifies a given HOTP against a specific counter. If a secret key is provided, it overrides the current secret.

$isValid = $otpService->verifyHOTP('123456', 1); // Validate HOTP for counter 1

Google Authenticator Compatible

generateUrl(string $label, string $issuer, string $secretKey = null, int $counter = null): string

Generates an OTP Auth URL for use in generating a QR code. This URL can be used by OTP apps like Google Authenticator.

• Parameters:
  • string $label: A unique identifier for the OTP (usually the user's email or username).
  • string $issuer: The name of your application (used as the issuer for the OTP).
  • string|null $secretKey: An optional secret key. If not provided, the instance's secret key will be used.
  • int|null $counter: An optional counter for HOTP. If provided, the method will generate an HOTP URL instead of TOTP.

Usage Example:

$label = 'user@example.com';
$issuer = 'YourAppName';
$otpUrl = $otpService->generateUrl($label, $issuer);
echo "OTP Auth URL: $otpUrl" // otpauth://totp/Name?secret=WSRNGQX4J57FL2POVHDAMBI6ZTK3CYUE&issuer=APP;

License

This package is licensed under the MIT License. See the LICENSE file for more information.