README

PSR-15 Middleware that determines the client IP address and stores it as an ServerRequest attribute called ip_address. It optionally checks various common proxy headers and then falls back to $_SERVER['REMOTE_ADDR'].

Installation

Install via Composer:

composer require akrabat/ip-address-middleware

Configuration

The constructor takes 5 parameters which can be used to configure this middleware.

Check proxy headers

The proxy headers are only checked if the first parameter to the constructor is set to true. If it is set to false, then only $_SERVER['REMOTE_ADDR'] is used.

Trusted Proxies

If you enable checking of the proxy headers (first parameter is true), you have to provide an array as the second parameter. This is the list of IP addresses (supporting wildcards) of your proxy servers. If the array is empty, the proxy headers will always be used and the selection is based on the hop count (parameter 5).

If the array is not empty, it must contain strings with IP addresses (wildcard * is allowed in any given part) or networks in CIDR-notation. One of them must match the $_SERVER['REMOTE_ADDR'] variable in order to allow evaluating the proxy headers - otherwise the REMOTE_ADDR itself is returned. This list is not ordered and there is no requirement that any given proxy header includes all the listed proxies.

Attribute name

By default, the name of the attribute is 'ip_address'. This can be changed by the third constructor parameter.

Headers to inspect

By default, this middleware checks the 'Forwarded', 'X-Forwarded-For', 'X-Forwarded', 'X-Cluster-Client-Ip' and 'Client-Ip' headers. You can replace this list with your own using the fourth constructor parameter.

If you use the nginx, set_real_ip_from directive, then you should probably set this to:

$headersToInspect = [
    'X-Real-IP',
    'Forwarded',
    'X-Forwarded-For',
    'X-Forwarded',
    'X-Cluster-Client-Ip',
    'Client-Ip',
];

If you use CloudFlare, then according to the documentation you should probably set this to:

$headersToInspect = [
    'CF-Connecting-IP',
    'True-Client-IP',
    'Forwarded',
    'X-Forwarded-For',
    'X-Forwarded',
    'X-Cluster-Client-Ip',
    'Client-Ip',
];

hop count

Set this to the number of known proxies between ingress and the application. This is used to determine the number of proxies to check in the X-Forwarded-For header, and is generally used when the IP addresses of the proxies cannot be reliably determined. The default is 0.

Security considerations

A malicious client may send any header to your proxy, including any proxy headers, containing any IP address. If your proxy simply adds another IP address to the header, an attacker can send a fake IP. Make sure to setup your proxy in a way that removes any sent (and possibly faked) headers from the original request and replaces them with correct values (i.e. the currently used REMOTE_ADDR on the proxy server).

This library cannot by design ensure you get correct and trustworthy results if your network environment isn't setup properly.

Installation

composer require akrabat/ip-address-middleware

In Mezzio, copy Mezzio/config/ip_address.global.php.dist into your Mezzio Application config/autoload directory as ip_address.global.php

Usage

In Slim:

$checkProxyHeaders = true; // Note: Never trust the IP address for security processes!
$trustedProxies = ['10.0.0.1', '10.0.0.2']; // Note: Never trust the IP address for security processes!
$app->add(new RKA\Middleware\IpAddress($checkProxyHeaders, $trustedProxies));

$app->get('/', function ($request, $response, $args) {
    $ipAddress = $request->getAttribute('ip_address');

    return $response;
});

In Laminas or Mezzio, add to your pipeline.php config at the correct stage, usually just before the DispatchMiddleware:

# config/pipeline.php
# using default config
$app->add(RKA\Middleware\IpAddress::class);

If required, update your .env file with the environmental variables found in /config/autoload/ip_address.global.php.

Testing

• Code style: $ vendor/bin/phpcs
• Fix style: $ vendor/bin/phpcbf
• Unit tests: $ vendor/bin/phpunit
• Code coverage: $ vendor/bin/phpunit --coverage-html ./build

You can also use Composer scripts:

• Check both: $ composer check
• Code style: $ composer cs
• Fix style: $ composer cs-fix
• Unit tests: $ composer test