PayWithAmazon\IpnHandler::__construct PHP Method

    public function __construct($headers, $body, $ipnConfig = null)
    {
        $this->headers = array_change_key_case($headers, CASE_LOWER);
        $this->body = $body;
        if ($ipnConfig != null) {
            $this->checkConfigKeys($ipnConfig);
        }
        // Get the list of fields that we are interested in
        $this->fields = array("Timestamp" => true, "Message" => true, "MessageId" => true, "Subject" => false, "TopicArn" => true, "Type" => true);
        // Validate the IPN message header [x-amz-sns-message-type]
        $this->validateHeaders();
        // Converts the IPN [Message] to Notification object
        $this->getMessage();
        // Checks if the notification [Type] is Notification and constructs the signature fields
        $this->checkForCorrectMessageType();
        // Verifies the signature against the provided pem file in the IPN
        $this->constructAndVerifySignature();
    }