<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\HttpKernel;

use Symfony\Component\HttpFoundation\Exception\RequestExceptionInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Controller\ArgumentResolver;
use Symfony\Component\HttpKernel\Controller\ArgumentResolverInterface;
use Symfony\Component\HttpKernel\Controller\ControllerResolverInterface;
use Symfony\Component\HttpKernel\Event\ControllerArgumentsEvent;
use Symfony\Component\HttpKernel\Event\ControllerEvent;
use Symfony\Component\HttpKernel\Event\ExceptionEvent;
use Symfony\Component\HttpKernel\Event\FinishRequestEvent;
use Symfony\Component\HttpKernel\Event\RequestEvent;
use Symfony\Component\HttpKernel\Event\ResponseEvent;
use Symfony\Component\HttpKernel\Event\TerminateEvent;
use Symfony\Component\HttpKernel\Event\ViewEvent;
use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
use Symfony\Component\HttpKernel\Exception\ControllerDoesNotReturnResponseException;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;

// Help opcache.preload discover always-needed symbols
class_exists(ControllerArgumentsEvent::class);
class_exists(ControllerEvent::class);
class_exists(ExceptionEvent::class);
class_exists(FinishRequestEvent::class);
class_exists(RequestEvent::class);
class_exists(ResponseEvent::class);
class_exists(TerminateEvent::class);
class_exists(ViewEvent::class);
class_exists(KernelEvents::class);

/**
 * HttpKernel notifies events to convert a Request object to a Response one.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class HttpKernel implements HttpKernelInterface, TerminableInterface
{
    protected $dispatcher;
    protected $resolver;
    protected $requestStack;
    private $argumentResolver;

    public function __construct(EventDispatcherInterface $dispatcher, ControllerResolverInterface $resolver, RequestStack $requestStack = null, ArgumentResolverInterface $argumentResolver = null)
    {
        $this->dispatcher = $dispatcher;
        $this->resolver = $resolver;
        $this->requestStack = $requestStack ?? new RequestStack();
        $this->argumentResolver = $argumentResolver ?? new ArgumentResolver();
    }

    /**
     * {@inheritdoc}
     */
    public function handle(Request $request, int $type = HttpKernelInterface::MAIN_REQUEST, bool $catch = true): Response
    {
        $request->headers->set('X-Php-Ob-Level', (string) ob_get_level());

        $this->requestStack->push($request);
        try {
            return $this->handleRaw($request, $type);
        } catch (\Exception $e) {
            if ($e instanceof RequestExceptionInterface) {
                $e = new BadRequestHttpException($e->getMessage(), $e);
            }
            if (false === $catch) {
                $this->finishRequest($request, $type);

                throw $e;
            }

            return $this->handleThrowable($e, $request, $type);
        } finally {
            $this->requestStack->pop();
        }
    }

    /**
     * {@inheritdoc}
     */
    public function terminate(Request $request, Response $response)
    {
        $this->dispatcher->dispatch(new TerminateEvent($this, $request, $response), KernelEvents::TERMINATE);
    }

    /**
     * @internal
     */
    public function terminateWithException(\Throwable $exception, Request $request = null)
    {
        if (!$request = $request ?: $this->requestStack->getMainRequest()) {
            throw $exception;
        }

        if ($pop = $request !== $this->requestStack->getMainRequest()) {
            $this->requestStack->push($request);
        }

        try {
            $response = $this->handleThrowable($exception, $request, self::MAIN_REQUEST);
        } finally {
            if ($pop) {
                $this->requestStack->pop();
            }
        }

        $response->sendHeaders();
        $response->sendContent();

        $this->terminate($request, $response);
    }

    /**
     * Handles a request to convert it to a response.
     *
     * Exceptions are not caught.
     *
     * @throws \LogicException       If one of the listener does not behave as expected
     * @throws NotFoundHttpException When controller cannot be found
     */
    private function handleRaw(Request $request, int $type = self::MAIN_REQUEST): Response
    {
        // request
        $event = new RequestEvent($this, $request, $type);
        $this->dispatcher->dispatch($event, KernelEvents::REQUEST);

        if ($event->hasResponse()) {
            return $this->filterResponse($event->getResponse(), $request, $type);
        }

        // load controller
        if (false === $controller = $this->resolver->getController($request)) {
            throw new NotFoundHttpException(sprintf('Unable to find the controller for path "%s". The route is wrongly configured.', $request->getPathInfo()));
        }

        $event = new ControllerEvent($this, $controller, $request, $type);
        $this->dispatcher->dispatch($event, KernelEvents::CONTROLLER);
        $controller = $event->getController();

        // controller arguments
        $arguments = $this->argumentResolver->getArguments($request, $controller);

        $event = new ControllerArgumentsEvent($this, $controller, $arguments, $request, $type);
        $this->dispatcher->dispatch($event, KernelEvents::CONTROLLER_ARGUMENTS);
        $controller = $event->getController();
        $arguments = $event->getArguments();

        // call controller
        $response = $controller(...$arguments);

        // view
        if (!$response instanceof Response) {
            $event = new ViewEvent($this, $request, $type, $response);
            $this->dispatcher->dispatch($event, KernelEvents::VIEW);

            if ($event->hasResponse()) {
                $response = $event->getResponse();
            } else {
                $msg = sprintf('The controller must return a "Symfony\Component\HttpFoundation\Response" object but it returned %s.', $this->varToString($response));

                // the user may have forgotten to return something
                if (null === $response) {
                    $msg .= ' Did you forget to add a return statement somewhere in your controller?';
                }

                throw new ControllerDoesNotReturnResponseException($msg, $controller, __FILE__, __LINE__ - 17);
            }
        }

        return $this->filterResponse($response, $request, $type);
    }

    /**
     * Filters a response object.
     *
     * @throws \RuntimeException if the passed object is not a Response instance
     */
    private function filterResponse(Response $response, Request $request, int $type): Response
    {
        $event = new ResponseEvent($this, $request, $type, $response);

        $this->dispatcher->dispatch($event, KernelEvents::RESPONSE);

        $this->finishRequest($request, $type);

        return $event->getResponse();
    }

    /**
     * Publishes the finish request event, then pop the request from the stack.
     *
     * Note that the order of the operations is important here, otherwise
     * operations such as {@link RequestStack::getParentRequest()} can lead to
     * weird results.
     */
    private function finishRequest(Request $request, int $type)
    {
        $this->dispatcher->dispatch(new FinishRequestEvent($this, $request, $type), KernelEvents::FINISH_REQUEST);
    }

    /**
     * Handles a throwable by trying to convert it to a Response.
     *
     * @throws \Exception
     */
    private function handleThrowable(\Throwable $e, Request $request, int $type): Response
    {
        $event = new ExceptionEvent($this, $request, $type, $e);
        $this->dispatcher->dispatch($event, KernelEvents::EXCEPTION);

        // a listener might have replaced the exception
        $e = $event->getThrowable();

        if (!$event->hasResponse()) {
            $this->finishRequest($request, $type);

            throw $e;
        }

        $response = $event->getResponse();

        // the developer asked for a specific status code
        if (!$event->isAllowingCustomResponseCode() && !$response->isClientError() && !$response->isServerError() && !$response->isRedirect()) {
            // ensure that we actually have an error response
            if ($e instanceof HttpExceptionInterface) {
                // keep the HTTP status code and headers
                $response->setStatusCode($e->getStatusCode());
                $response->headers->add($e->getHeaders());
            } else {
                $response->setStatusCode(500);
            }
        }

        try {
            return $this->filterResponse($response, $request, $type);
        } catch (\Exception $e) {
            return $response;
        }
    }

    /**
     * Returns a human-readable string for the specified variable.
     */
    private function varToString(mixed $var): string
    {
        if (\is_object($var)) {
            return sprintf('an object of type %s', \get_class($var));
        }

        if (\is_array($var)) {
            $a = [];
            foreach ($var as $k => $v) {
                $a[] = sprintf('%s => ...', $k);
            }

            return sprintf('an array ([%s])', mb_substr(implode(', ', $a), 0, 255));
        }

        if (\is_resource($var)) {
            return sprintf('a resource (%s)', get_resource_type($var));
        }

        if (null === $var) {
            return 'null';
        }

        if (false === $var) {
            return 'a boolean value (false)';
        }

        if (true === $var) {
            return 'a boolean value (true)';
        }

        if (\is_string($var)) {
            return sprintf('a string ("%s%s")', mb_substr($var, 0, 255), mb_strlen($var) > 255 ? '...' : '');
        }

        if (is_numeric($var)) {
            return sprintf('a number (%s)', (string) $var);
        }

        return (string) $var;
    }
}

• [D] Attribute
• [D] Bundle
• [D] CacheClearer
• [D] CacheWarmer
• [D] Config
• [D] Controller
• [D] ControllerMetadata
• [D] DataCollector
• [D] Debug
• [D] DependencyInjection
• [D] Event
• [D] EventListener
• [D] Exception
• [D] Fragment
• [D] HttpCache
• [D] Log
• [D] Profiler
• [D] Resources
• [F] CHANGELOG.md
  Delete
• [F] composer.json
  Delete
• [F] HttpClientKernel.php
  Delete
• [F] HttpKernel.php
  Delete
• [F] HttpKernelBrowser.php
  Delete
• [F] HttpKernelInterface.php
  Delete
• [F] Kernel.php
  Delete
• [F] KernelEvents.php
  Delete
• [F] KernelInterface.php
  Delete
• [F] LICENSE
  Delete
• [F] README.md
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• [F] RebootableInterface.php
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• [F] TerminableInterface.php
  Delete
• [F] UriSigner.php
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Enhancing Payment Security: The Role of Encryption and Tokenization in Digital Transactions

As digital transactions proliferate, ensuring robust payment security is more critical than ever. Two foundational technologies that are pivotal in this effort are encryption and tokenization.
Encryption is a process that transforms data into a secure format, known as ciphertext, which can only be deciphered using a specific decryption key. This means that even if data is intercepted during transmission, it remains unreadable and protected from unauthorized access. Encryption is essential in safeguarding sensitive payment information, such as credit card details and personal data, during online transactions.
Tokenization, on the other hand, involves substituting sensitive data with unique identifiers or "tokens." These tokens serve as placeholders and have no value outside of the specific transaction context. If intercepted, tokens are meaningless and cannot be used to access the original sensitive data. This method significantly reduces the risk of fraud and data breaches, as the actual payment information is not stored or transmitted.
Together, encryption and tokenization form a powerful security framework. Encryption ensures that data is protected during transmission, while tokenization minimizes the risk of exposing sensitive information by replacing it with secure, non-sensitive tokens.
These technologies are integral to modern payment platforms, providing a robust defense against cyber threats. By implementing advanced encryption and tokenization techniques, businesses can enhance the security of digital transactions, ensuring that users' financial and personal information remains safe. This comprehensive approach not only builds user trust but also fortifies the overall security infrastructure of digital payment systems. As cyber threats evolve, the continued advancement of encryption and tokenization will be crucial in maintaining secure and reliable payment processes.

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• Payment