JDesrosiers\Silex\Provider\Cors

Complexity

Total Complexity

21

Size/Duplication

Total Lines	110
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	4

Test Coverage

Coverage

100%

Importance

Changes

0

10 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	4	1
A	isCorsRequest()	0	4	1
A	isPreflightRequest()	0	4	2
A	isMethodAllowed()	0	6	2
A	areHeadersAllowed()	0	9	2
A	domainToRegex()	0	4	1
A	allowCredentials()	0	4	2
A	__invoke()	0	13	1
B	cors()	0	32	5
A	allowOrigin()	0	16	4

<?php

namespace JDesrosiers\Silex\Provider;

use Silex\Application;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

class Cors
{
    private $options;

    public function __construct($options = [])
    {
        $this->options = $options;
    }

    public function __invoke(Request $request, Response $response, Application $app)
    {
        $defaults = [
            "allowOrigin" => $app["cors.allowOrigin"],
            "allowMethods" => $app["cors.allowMethods"],
            "allowHeaders" => $app["cors.allowHeaders"],
            "maxAge" => $app["cors.maxAge"],
            "allowCredentials" => $app["cors.allowCredentials"],
            "exposeHeaders" => $app["cors.exposeHeaders"]
        ];
        $cors = new Cors($this->options + $defaults);
        $cors->cors($request, $response);
    }

    private function cors(Request $request, Response $response)
    {
        $headers = [];

        if (!$this->isCorsRequest($request)) {
            return [];
        }

        if ($this->isPreflightRequest($request)) {
            $requestMethod = $request->headers->get("Access-Control-Request-Method");
            $allow = $response->headers->get("Allow");
            if (!$this->isMethodAllowed($requestMethod, $allow)) {
                return [];
            }

            $requestHeaders = $request->headers->get("Access-Control-Request-Headers");
            if (!$this->areHeadersAllowed($requestHeaders)) {
                return [];
            }

            $headers["Access-Control-Allow-Headers"] = $requestHeaders;
            $headers["Access-Control-Allow-Methods"] = $requestMethod;
            $headers["Access-Control-Max-Age"] = $this->options["maxAge"];
        } else {
            $headers["Access-Control-Expose-Headers"] = $this->options["exposeHeaders"];
        }

        $headers["Access-Control-Allow-Origin"] = $this->allowOrigin($request);
        $headers["Access-Control-Allow-Credentials"] = $this->allowCredentials();

        $response->headers->add(array_filter($headers));
    }

    private function isCorsRequest(Request $request)
    {
        return $request->headers->has("Origin");
    }

    private function isPreflightRequest(Request $request)
    {
        return $request->getMethod() === "OPTIONS" && $request->headers->has("Access-Control-Request-Method");
    }

    private function isMethodAllowed($requestMethod, $allow)
    {
        $commaSeparatedMethods = !is_null($this->options["allowMethods"]) ? $this->options["allowMethods"] : $allow;
        $allowedMethods = array_filter(preg_split("/\s*,\s*/", $commaSeparatedMethods));
        return in_array($requestMethod, $allowedMethods);
    }

    private function areHeadersAllowed($commaSeparatedRequestHeaders)
    {
        if ($this->options["allowHeaders"] === null) {
            return true;
        }
        $requestHeaders = array_filter(preg_split("/\s*,\s*/", $commaSeparatedRequestHeaders));
        $allowedHeaders = array_filter(preg_split("/\s*,\s*/", $this->options["allowHeaders"]));
        return array_diff($requestHeaders, $allowedHeaders) === [];
    }

    private function allowOrigin(Request $request)
    {
        $origin = $request->headers->get("Origin");
        if ($this->options["allowOrigin"] === "*") {
            $this->options["allowOrigin"] = $origin;
        }

        $origins = array_filter(preg_split('/\s+/', $this->options["allowOrigin"]));
        foreach ($origins as $domain) {
            if (preg_match($this->domainToRegex($domain), $origin)) {
                return $origin;
            }
        }

        return "null";
    }

    private function domainToRegex($domain)
    {
        return "/^" . preg_replace("/^\\\\\*/", "[^.]+", preg_quote($domain, "/")) . "$/";
    }

    private function allowCredentials()
    {
        return $this->options["allowCredentials"] === true ? "true" : null;
    }
}