Developer
<?php
namespace Stripe;
abstract class WebhookSignature
{
const EXPECTED_SCHEME = 'v1';
/**
* Verifies the signature header sent by Stripe. Throws an
* Exception\SignatureVerificationException exception if the verification fails for
* any reason.
*
* @param string $payload the payload sent by Stripe
* @param string $header the contents of the signature header sent by
* Stripe
* @param string $secret secret used to generate the signature
* @param int $tolerance maximum difference allowed between the header's
* timestamp and the current time
*
* @throws Exception\SignatureVerificationException if the verification fails
*
* @return bool
*/
public static function verifyHeader($payload, $header, $secret, $tolerance = null)
{
// Extract timestamp and signatures from header
$timestamp = self::getTimestamp($header);
$signatures = self::getSignatures($header, self::EXPECTED_SCHEME);
if (-1 === $timestamp) {
throw Exception\SignatureVerificationException::factory(
'Unable to extract timestamp and signatures from header',
$payload,
$header
);
}
if (empty($signatures)) {
throw Exception\SignatureVerificationException::factory(
'No signatures found with expected scheme',
$payload,
$header
);
}
// Check if expected signature is found in list of signatures from
// header
$signedPayload = "{$timestamp}.{$payload}";
$expectedSignature = self::computeSignature($signedPayload, $secret);
$signatureFound = false;
foreach ($signatures as $signature) {
if (Util\Util::secureCompare($expectedSignature, $signature)) {
$signatureFound = true;
break;
}
}
if (!$signatureFound) {
throw Exception\SignatureVerificationException::factory(
'No signatures found matching the expected signature for payload',
$payload,
$header
);
}
// Check if timestamp is within tolerance
if (($tolerance > 0) && (\abs(\time() - $timestamp) > $tolerance)) {
throw Exception\SignatureVerificationException::factory(
'Timestamp outside the tolerance zone',
$payload,
$header
);
}
return true;
}
/**
* Extracts the timestamp in a signature header.
*
* @param string $header the signature header
*
* @return int the timestamp contained in the header, or -1 if no valid
* timestamp is found
*/
private static function getTimestamp($header)
{
$items = \explode(',', $header);
foreach ($items as $item) {
$itemParts = \explode('=', $item, 2);
if ('t' === $itemParts[0]) {
if (!\is_numeric($itemParts[1])) {
return -1;
}
return (int) ($itemParts[1]);
}
}
return -1;
}
/**
* Extracts the signatures matching a given scheme in a signature header.
*
* @param string $header the signature header
* @param string $scheme the signature scheme to look for
*
* @return array the list of signatures matching the provided scheme
*/
private static function getSignatures($header, $scheme)
{
$signatures = [];
$items = \explode(',', $header);
foreach ($items as $item) {
$itemParts = \explode('=', $item, 2);
if (\trim($itemParts[0]) === $scheme) {
$signatures[] = $itemParts[1];
}
}
return $signatures;
}
/**
* Computes the signature for a given payload and secret.
*
* The current scheme used by Stripe ("v1") is HMAC/SHA-256.
*
* @param string $payload the payload to sign
* @param string $secret the secret used to generate the signature
*
* @return string the signature as a string
*/
private static function computeSignature($payload, $secret)
{
return \hash_hmac('sha256', $payload, $secret);
}
}
Developer
Welcome to the Kueue Pay Payment Gateway Solutions Developer API Documentation. This comprehensive guide will empower you to seamlessly integrate our advanced payment gateway into your website, enhancing your customers’ payment experience and enabling efficient transaction processing. The Kueue Pay Developer API is designed for developers and entrepreneurs who seek simplicity, security, and reliability in their payment processing solutions.
The Kueue Pay Developer API allows you to seamlessly integrate Kueue Pay’s Payment Gateway Solutions into your website, enabling secure and efficient debit and credit card transactions. With our API, you can initiate payments, check payment statuses, and even process refunds, all while ensuring a smooth and streamlined payment experience for your customers.