Payload support

[Minishlink]

• (done) use phpecc/phpecc in order to generate the encryption key in prime256v1
• when this PHP bug is fixed, replace phpecc by the PHP binding of OpenSSL (thanks @marco-c)
• use OpenSSL with AES 128 GCM mode to encrypt the payload (need to wait for the resolution of this other PHP bug.)

If you want to help: (thanks!)

• vote for the PHP bugs in the above linked pages
• or contribute to php/php-src in order to fix the bugs

[marco-c]

Hey Minishlink, IIRC phpecc has known vulnerabilities.
Directly using OpenSSL would probably be better, since you have to wait for https://bugs.php.net/bug.php?id=67304, you could wait for https://bugs.php.net/bug.php?id=61204 as well (hoping that they will be resolved soon enough).

[Minishlink]

Thanks for the info! :) It surely is worth waiting, I'll look into it.

[FallDi]

Hola. Is payload encryption works for firefox? I try run project it generated salt & publicKey, but payload not received by browser. This sample is works fine https://jrconlin.github.io/WebPushDataTestPage/, but in this sample shared key & encryption key length is less than in you code

[Minishlink]

Hi, payload is not yet supported because PHP doesn't provide enough access to OpenSSL yet. This will likely be the case with PHP 7.1.

This PR is here to implement the changes made to resolve the aforementioned bugs. Its development is paused since the bug fixes are not yet merged in any PHP version, beta or not.

As explained in the README, a workaround is to store the payload in your server, to send notifications without payload, and to make the client fetch the corresponding payload stored in the server, using the endpoint as identification.

But, if you really need "real" payload support, you will have to drop PHP for Node.js. Note that payload won't be delivered in Chrome (though it may have changed since the last time I checked).

[marco-c]

@Minishlink have you seen https://github.com/Spomky-Labs/jose/blob/master/src/Util/GCM.php? It was suggested in https://bugs.php.net/bug.php?id=67304.
OpenSSL is probably better security-wise, but at least that should make it possible to support push payloads in the meantime.

[Minishlink]

@marco-c Yep, I'll probably look into it this weekend. :) Thanks for the notification btw.

[marco-c]

The output is the same as my library.
The only difference I can see is that I'm using the normal GCM endpoint (not the experimental Web Push one) with the raw_data parameter.

[gauntface]

I'll have a look into what is needed to support normal GCM endpoint (in hindsight - it wasn't helpful using the other endpoint - apologies for not thinking it through)

[Minishlink]

Thanks. If I'm not mistaken, the temporary server has been updated as I can see that the aforementioned behavior now works well. :)