3 * @copyright Copyright (C) 2010-2022, the Friendica project
5 * @license GNU AGPL version 3 or any later version
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU Affero General Public License as
9 * published by the Free Software Foundation, either version 3 of the
10 * License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU Affero General Public License for more details.
17 * You should have received a copy of the GNU Affero General Public License
18 * along with this program. If not, see <https://www.gnu.org/licenses/>.
22 namespace Friendica\App;
24 use Friendica\Core\Config\Capability\IManageConfigValues;
27 * Container for the whole request
29 * @see https://www.php-fig.org/psr/psr-7/#321-psrhttpmessageserverrequestinterface
31 * @todo future container class for whole requests, currently it's not :-)
36 * A comma separated list of default headers that could contain the client IP in a proxy request
40 const DEFAULT_FORWARD_FOR_HEADER = 'HTTP_X_FORWARDED_FOR';
42 /** @var string The remote IP address of the current request */
43 protected $remoteAddress;
46 * @return string The remote IP address of the current request
48 * Do always use this instead of $_SERVER['REMOTE_ADDR']
50 public function getRemoteAddress(): string
52 return $this->remoteAddress;
55 public function __construct(IManageConfigValues $config, array $server = [])
57 $this->remoteAddress = $this->determineRemoteAddress($config, $server);
61 * Checks if given $remoteAddress matches given $trustedProxy.
62 * If $trustedProxy is an IPv4 IP range given in CIDR notation, true will be returned if
63 * $remoteAddress is an IPv4 address within that IP range.
64 * Otherwise, $remoteAddress will be compared to $trustedProxy literally and the result
67 * @param string $trustedProxy The current, trusted proxy to check
68 * @param string $remoteAddress The current remote IP address
71 * @return boolean true if $remoteAddress matches $trustedProxy, false otherwise
73 protected function matchesTrustedProxy(string $trustedProxy, string $remoteAddress): bool
75 $cidrre = '/^([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})\/([0-9]{1,2})$/';
77 if (preg_match($cidrre, $trustedProxy, $match)) {
79 $shiftbits = min(32, max(0, 32 - intval($match[2])));
80 $netnum = ip2long($net) >> $shiftbits;
81 $ipnum = ip2long($remoteAddress) >> $shiftbits;
83 return $ipnum === $netnum;
86 return $trustedProxy === $remoteAddress;
90 * Checks if given $remoteAddress matches any entry in the given array $trustedProxies.
91 * For details regarding what "match" means, refer to `matchesTrustedProxy`.
93 * @param string[] $trustedProxies A list of the trusted proxies
94 * @param string $remoteAddress The current remote IP address
96 * @return boolean true if $remoteAddress matches any entry in $trustedProxies, false otherwise
98 protected function isTrustedProxy(array $trustedProxies, string $remoteAddress): bool
100 foreach ($trustedProxies as $tp) {
101 if ($this->matchesTrustedProxy($tp, $remoteAddress)) {
110 * Determines the remote address, if the connection came from a trusted proxy
111 * and `forwarded_for_headers` has been configured then the IP address
112 * specified in this header will be returned instead.
114 * @param IManageConfigValues $config
115 * @param array $server The $_SERVER array
119 protected function determineRemoteAddress(IManageConfigValues $config, array $server): string
121 $remoteAddress = $server['REMOTE_ADDR'] ?? '0.0.0.0';
122 $trustedProxies = preg_split('/(\s*,*\s*)*,+(\s*,*\s*)*/', $config->get('proxy', 'trusted_proxies', ''));
124 if (\is_array($trustedProxies) && $this->isTrustedProxy($trustedProxies, $remoteAddress)) {
125 $forwardedForHeaders = preg_split('/(\s*,*\s*)*,+(\s*,*\s*)*/', $config->get('proxy', 'forwarded_for_headers', static::DEFAULT_FORWARD_FOR_HEADER));
127 foreach ($forwardedForHeaders as $header) {
128 if (isset($server[$header])) {
129 foreach (explode(',', $server[$header]) as $IP) {
132 // remove brackets from IPv6 addresses
133 if (strpos($IP, '[') === 0 && substr($IP, -1) === ']') {
134 $IP = substr($IP, 1, -1);
137 // skip trusted proxies in the list itself
138 if ($this->isTrustedProxy($trustedProxies, $IP)) {
142 if (filter_var($IP, FILTER_VALIDATE_IP) !== false) {
150 return $remoteAddress;