vincent15000's avatar

Random Invalid Signature Exception when accessing to a signed URL

Hello,

I have a strange problem with an Invalid Signature Exception when accessing to a signed URL.

Sometimes I get this exception, sometimes I don't have it.

What could generate this exception ?

Here is the code that generates the signed URL.

$encryptedEmail = Crypt::encryptString($request->email);
$signedRoute = URL::signedRoute('events.results.guest', [
    'event' => $event,
    'email' => $encryptedEmail,
]);

Thanks for your help.

V

0 likes
8 replies
LaryAI's avatar
LaryAI
AI
2 years ago
Level 58

The Invalid Signature Exception occurs when the signature of the signed URL is invalid. This can happen if the URL has been tampered with or if the signature has expired. To fix this issue, you can try the following solutions:

  1. Increase the expiration time of the signed URL by passing a longer expiration time as the second parameter to the signedRoute method. For example, URL::signedRoute('events.results.guest', ['event' => $event, 'email' => $encryptedEmail], now()->addHours(1));

  2. Check if the URL has been tampered with by comparing the signature in the URL with the signature generated by the URL::signature method. For example:

$signature = URL::signature($request->fullUrl());
if (! hash_equals($signature, $request->query('signature'))) {
    throw new \Illuminate\Routing\Exceptions\InvalidSignatureException;
}

  1. Make sure that the encryption key used by the Crypt facade is the same across all instances of your application. You can set the encryption key in your .env file using the APP_KEY variable. For example, APP_KEY=base64:your_encryption_key_here.

  2. If you are using a load balancer or a reverse proxy, make sure that it is configured to forward the X-Forwarded-Proto header. This header is used by Laravel to determine if the request is secure or not. You can add the following code to your AppServiceProvider to enable this feature:

if ($this->app->environment('production')) {
    URL::forceScheme('https');
    $this->app['request']->server->set('HTTPS', true);
}

By using these solutions, you should be able to fix the Invalid Signature Exception when accessing a signed URL.

2 likes
silveira's avatar

@vincent15000 I add in my appserviceprovider

if ($this->app->environment('production')) {
    URL::forceScheme('https');
    $this->app['request']->server->set('HTTPS', true);
}
1 like
troccoli's avatar

I have to say that for once Lary was helpful.

I had the strangest error were Laravel thought the URL was invalid, when in fact it wasn't. I had checked the key used, the payload, and the signature when creating the signed URL and when Laravel checks it, and everything matched.

This is about a user email verification, so no custom code. It worked locally, but not on AWS.

I came to Laracast to ask for help and I stumble upon this thread. When I read about the load balancer I got a lightbulb moment.

I was already enforcing the https schema, but I did not set HTTPS to true in the request. And that saved me!!

1 like
vincent15000's avatar

I never had to take attention to the X-Forwarded-Proto, I will test this.

But I'd like to have some help from a real dev ;).

martinbean's avatar
martinbean
4 months ago
Best Answer
Level 80

@vincent15000 You need to log what URL is being signed when the signature is created, and what URL you’re getting the invalid signature error, as there’s obviously a different somewhere. The two usual culprits are different protocols (e.g. http:// vs. https://), and query strings.

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