How to Fix 403 Invalid Signature After Email Verification

A 403 “Invalid signature” error in Laravel typically occurs when there’s an issue with the signed URL or the signature verification process. Laravel provides a way to generate and verify signed URLs using URL::signedRoute or URL::temporarySignedRoute for temporary signed URLs. Here are some common reasons for this error and how to fix them:

1. URL Expiry: If you are using a temporary signed URL, check if the URL has expired.
2. URL Tampering: Ensure that the URL hasn’t been modified after being generated. Even a minor change can invalidate the signature.
3. Configuration Issues: Verify that your application’s URL configuration matches the environment in which the URL is being generated and verified.
4. Middleware: Ensure that the middleware for validating the signature is correctly applied.

Here’s a step-by-step guide to troubleshoot and fix the issue:

Step 1: Ensure Middleware is Applied

Make sure the route that uses the signed URL has the signed middleware applied.

use Illuminate\Support\Facades\Route;

Route::get('/your-protected-route', 'YourController@yourMethod')->name('protected.route')->middleware('signed');

Step 2: Generate a Signed URL

Generate the signed URL in your controller or wherever you need it. You can use URL::signedRoute for a permanent link or URL::temporarySignedRoute for a temporary link.

Example of generating a permanent signed URL:

use Illuminate\Support\Facades\URL;

public function generateSignedUrl()
{
    $url = URL::signedRoute('protected.route', ['param' => 'value']);
    return $url;
}

Example of generating a temporary signed URL:

use Illuminate\Support\Facades\URL;

public function generateTemporarySignedUrl()
{
    $url = URL::temporarySignedRoute('protected.route', now()->addMinutes(30), ['param' => 'value']);
    return $url;
}

Step 3: Verify the URL and Parameters

Ensure that the URL generated and the parameters passed match exactly. Any discrepancies will result in an invalid signature.

Step 4: Verify Application URL Configuration

Ensure that the APP_URL in your .env file matches the URL used to access your application.

APP_URL=https://your-app-url.com

Step 5: Handle the Invalid Signature Exception

If the signature is invalid, Laravel will throw an Illuminate\Routing\Exceptions\InvalidSignatureException. You can handle this exception in your Handler.php file:

use Illuminate\Routing\Exceptions\InvalidSignatureException;

public function render($request, Exception $exception)
{
    if ($exception instanceof InvalidSignatureException) {
        return response()->view('errors.403', [], 403);
    }

    return parent::render($request, $exception);
}

Step 6: Debugging Tips

1. Check for URL modifications: Ensure that the URL is not being modified in any way after generation.
2. Compare URLs: Print and compare the generated URL and the URL being accessed to ensure they match exactly.
3. Check Expiry Time: If using a temporary signed URL, make sure it hasn’t expired.

Example of Full Controller and Route Setup

// web.php
use Illuminate\Support\Facades\Route;

Route::get('/your-protected-route', 'YourController@yourMethod')->name('protected.route')->middleware('signed');

// YourController.php
use Illuminate\Support\Facades\URL;

class YourController extends Controller
{
    public function generateSignedUrl()
    {
        $url = URL::signedRoute('protected.route', ['param' => 'value']);
        return $url;
    }

    public function generateTemporarySignedUrl()
    {
        $url = URL::temporarySignedRoute('protected.route', now()->addMinutes(30), ['param' => 'value']);
        return $url;
    }

    public function yourMethod(Request $request)
    {
        // Your method logic
    }
}

By following these steps, you should be able to identify and fix the cause of the 403 “Invalid signature” error in your Laravel application.