feat: implement TrustHosts middleware to handle FQDN and IP address trust logic

app/Http/Kernel.php

@@ -14,7 +14,7 @@ class Kernel extends HttpKernel
      * @var array<int, class-string|string>
      */
     protected $middleware = [
-        // \App\Http\Middleware\TrustHosts::class,
+        \App\Http\Middleware\TrustHosts::class,
         \App\Http\Middleware\TrustProxies::class,
         \Illuminate\Http\Middleware\HandleCors::class,
         \App\Http\Middleware\PreventRequestsDuringMaintenance::class,

app/Http/Middleware/TrustHosts.php

@@ -2,7 +2,9 @@
 
 namespace App\Http\Middleware;
 
+use App\Models\InstanceSettings;
 use Illuminate\Http\Middleware\TrustHosts as Middleware;
+use Spatie\Url\Url;
 
 class TrustHosts extends Middleware
 {
@@ -13,8 +15,25 @@ class TrustHosts extends Middleware
      */
     public function hosts(): array
     {
-        return [
-            $this->allSubdomainsOfApplicationUrl(),
-        ];
+        $trustedHosts = [];
+        // Trust the configured FQDN from InstanceSettings
+        try {
+            $settings = InstanceSettings::get();
+            if ($settings && $settings->fqdn) {
+                $url = Url::fromString($settings->fqdn);
+                $host = $url->getHost();
+                if ($host) {
+                    $trustedHosts[] = $host;
+                }
+            }
+        } catch (\Exception $e) {
+            // If instance settings table doesn't exist yet (during installation),
+            // fall back to APP_URL only
+        }
+
+        // Trust all subdomains of APP_URL as fallback
+        $trustedHosts[] = $this->allSubdomainsOfApplicationUrl();
+
+        return array_filter($trustedHosts);
     }
 }

tests/Feature/TrustHostsMiddlewareTest.php

@@ -0,0 +1,142 @@
+<?php
+
+use App\Http\Middleware\TrustHosts;
+use App\Models\InstanceSettings;
+
+uses(\Illuminate\Foundation\Testing\RefreshDatabase::class);
+
+it('trusts the configured FQDN from InstanceSettings', function () {
+    // Create instance settings with FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('coolify.example.com');
+});
+
+it('rejects password reset request with malicious host header', function () {
+    // Set up instance settings with legitimate FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // The malicious host should NOT be in the trusted hosts
+    expect($hosts)->not->toContain('coolify.example.com.evil.com');
+    expect($hosts)->toContain('coolify.example.com');
+});
+
+it('handles missing FQDN gracefully', function () {
+    // Create instance settings without FQDN
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => null]
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // Should still return APP_URL pattern without throwing
+    expect($hosts)->not->toBeEmpty();
+});
+
+it('filters out null and empty values from trusted hosts', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => '']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // Should not contain empty strings or null
+    foreach ($hosts as $host) {
+        if ($host !== null) {
+            expect($host)->not->toBeEmpty();
+        }
+    }
+});
+
+it('extracts host from FQDN with protocol and port', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'https://coolify.example.com:8443']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('coolify.example.com');
+});
+
+it('handles exception during InstanceSettings fetch', function () {
+    // Drop the instance_settings table to simulate installation
+    \Schema::dropIfExists('instance_settings');
+
+    $middleware = new TrustHosts($this->app);
+
+    // Should not throw an exception
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->not->toBeEmpty();
+});
+
+it('trusts IP addresses with port', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://65.21.3.91:8000']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('65.21.3.91');
+});
+
+it('trusts IP addresses without port', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://192.168.1.100']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    expect($hosts)->toContain('192.168.1.100');
+});
+
+it('rejects malicious host when using IP address', function () {
+    // Simulate an instance using IP address
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://65.21.3.91:8000']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // The malicious host attempting to mimic the IP should NOT be trusted
+    expect($hosts)->not->toContain('65.21.3.91.evil.com');
+    expect($hosts)->not->toContain('evil.com');
+    expect($hosts)->toContain('65.21.3.91');
+});
+
+it('trusts IPv6 addresses', function () {
+    InstanceSettings::updateOrCreate(
+        ['id' => 0],
+        ['fqdn' => 'http://[2001:db8::1]:8000']
+    );
+
+    $middleware = new TrustHosts($this->app);
+    $hosts = $middleware->hosts();
+
+    // IPv6 addresses are enclosed in brackets, getHost() should handle this
+    expect($hosts)->toContain('[2001:db8::1]');
+});