laipower/wp-content/plugins/easy-digital-downloads/includes/gateways/paypal/webhooks/class-webhook-validator.php

169 lines
3.6 KiB
PHP

<?php
/**
* Webhook Validator
*
* @link https://developer.paypal.com/docs/api/webhooks/v1/#verify-webhook-signature_post
*
* @package easy-digital-downloads
* @subpackage Gateways\PayPal\Webhooks
* @copyright Copyright (c) 2021, Sandhills Development, LLC
* @license GPL2+
* @since 2.11
*/
namespace EDD\Gateways\PayPal\Webhooks;
use EDD\Gateways\PayPal\API;
use EDD\Gateways\PayPal\Exceptions\API_Exception;
class Webhook_Validator {
/**
* Headers from the webhook
*
* @var array
* @since 2.11
*/
private $headers;
/**
* Webhook event
*
* @var object
* @since 2.11
*/
private $event;
/**
* Maps the incoming header key to the outgoing API request key.
*
* @var string[]
* @since 2.11
*/
private $header_map = array(
'PAYPAL-AUTH-ALGO' => 'auth_algo',
'PAYPAL-CERT-URL' => 'cert_url',
'PAYPAL-TRANSMISSION-ID' => 'transmission_id',
'PAYPAL-TRANSMISSION-SIG' => 'transmission_sig',
'PAYPAL-TRANSMISSION-TIME' => 'transmission_time'
);
/**
* Webhook_Validator constructor.
*
* @param array $headers
* @param object $event
*
* @since 2.11
*/
public function __construct( $headers, $event ) {
$this->headers = array_change_key_case( $headers, CASE_UPPER );
$this->event = $event;
}
/**
* Verifies the signature.
*
* @since 2.11
* @return true
* @throws API_Exception
* @throws \InvalidArgumentException
*/
public function verify_signature() {
$api = new API();
$response = $api->make_request( 'v1/notifications/verify-webhook-signature', $this->get_body() );
if ( 200 !== $api->last_response_code ) {
throw new API_Exception( sprintf(
'Invalid response code: %d. Response: %s',
$api->last_response_code,
json_encode( $response )
) );
}
if ( empty( $response->verification_status ) || 'SUCCESS' !== strtoupper( $response->verification_status ) ) {
throw new API_Exception( sprintf(
'Verification failure. Response: %s',
json_encode( $response )
) );
}
return true;
}
/**
* Validates that we have all the required headers.
*
* @since 2.11
* @throws \InvalidArgumentException
*/
private function validate_headers() {
foreach ( array_keys( $this->header_map ) as $required_key ) {
if ( ! array_key_exists( $required_key, $this->headers ) ) {
throw new \InvalidArgumentException( sprintf(
'Missing PayPal header %s',
$required_key
) );
}
}
}
/**
* Retrieves the webhook ID for the current mode.
*
* @since 2.11
* @return string
* @throws \Exception
*/
private function get_webhook_id() {
$id = get_webhook_id();
if ( empty( $id ) ) {
throw new \Exception( 'No webhook created in current mode.' );
}
return $id;
}
/**
* Builds arguments for the body of the API request.
*
* @return array
* @throws \InvalidArgumentException
* @throws \Exception
*/
private function get_body() {
$this->validate_headers();
$body = array(
'webhook_id' => $this->get_webhook_id(),
'webhook_event' => $this->event
);
// Add arguments from the headers.
foreach ( $this->header_map as $header_key => $body_key ) {
$body[ $body_key ] = $this->headers[ $header_key ];
}
return $body;
}
/**
* Validates the webhook from the current request.
*
* @param object $event Webhook event.
*
* @since 2.11
* @return true
* @throws API_Exception
* @throws \InvalidArgumentException
*/
public static function validate_from_request( $event ) {
$validator = new Webhook_Validator( getallheaders(), $event );
return $validator->verify_signature();
}
}