[5.3] json_decodes Pusher message from validAuthentiactoinResponse

[eahrold]

Addresses the (probably misplaced) issue laravel/echo#34.

Pusher by default encodes it's response as a string

    /**
     * Creates a socket signature.
     *
     * @param string $socket_id
     * @param string $custom_data
     *
     * @return string
     */
    public function socket_auth($channel, $socket_id, $custom_data = null)
    {
        $this->validate_channel($channel);
        $this->validate_socket_id($socket_id);

        if ($custom_data) {
            $signature = hash_hmac('sha256', $socket_id.':'.$channel.':'.$custom_data, $this->settings['secret'], false);
        } else {
            $signature = hash_hmac('sha256', $socket_id.':'.$channel, $this->settings['secret'], false);
        }

        $signature = array('auth' => $this->settings['auth_key'].':'.$signature);
        // add the custom data if it has been supplied
        if ($custom_data) {
            $signature['channel_data'] = $custom_data;
        }

        return json_encode($signature);
    }

Which in situations as described in the open issue, led to an incorrect response.

[GrahamCampbell]

Missing newline.

[eahrold]

@GrahamCampbell thanks.

[BrandonSurowiec]

Misspelled Response.

[eahrold]

@BrandonSurowiec thanks. Fixed in 487e985.

[taylorotwell]

I need to know exactly what is broken and what this is fixing.

[eahrold]

@taylorotwell Absolutely.
I reported the symptom here laravel/echo#34.
And while it's not universally broken, there are conditions that cause it to break.

For example, when using the PusherBroadcaster the response from the Broadcast::auth() route is returning a string. With a package like Barryvdh\Debugbar, when executing it's modifyResponse, determines it's a rendered response and injects itself onto the string. The new string is no longer correctly parsed on the front end.

This PR simply casts the pusher response so it's correctly typed as it moves up the chain.

Thanks.