Added DNS validator

composer.json

@@ -15,6 +15,7 @@
             "Auth\\": "src/Auth",
             "Database\\": "src/Database",
             "Event\\": "src/Event",
+            "Network\\": "src/Network",
             "OpenSSL\\": "src/OpenSSL",
             "Resize\\": "src/Resize",
             "Storage\\": "src/Storage",

composer.lock

@@ -1935,12 +1935,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/ReflectionDocBlock.git",
-                "reference": "edea3e869367921987704325b997a80cdaea6d66"
+                "reference": "5463f8d32cf0f31f3d8e6230eb80170a2602b55a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/edea3e869367921987704325b997a80cdaea6d66",
-                "reference": "edea3e869367921987704325b997a80cdaea6d66",
+                "url": "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/5463f8d32cf0f31f3d8e6230eb80170a2602b55a",
+                "reference": "5463f8d32cf0f31f3d8e6230eb80170a2602b55a",
                 "shasum": ""
             },
             "require": {
@@ -1980,7 +1980,7 @@
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
-            "time": "2020-02-12T20:05:04+00:00"
+            "time": "2020-02-20T20:42:36+00:00"
         },
         {
             "name": "phpdocumentor/type-resolver",
@@ -1988,12 +1988,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpDocumentor/TypeResolver.git",
-                "reference": "70d7abb1fdad964379676d629923de0dd1918f4f"
+                "reference": "7462d5f123dfc080dfdf26897032a6513644fc95"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpDocumentor/TypeResolver/zipball/70d7abb1fdad964379676d629923de0dd1918f4f",
-                "reference": "70d7abb1fdad964379676d629923de0dd1918f4f",
+                "url": "https://api.github.com/repos/phpDocumentor/TypeResolver/zipball/7462d5f123dfc080dfdf26897032a6513644fc95",
+                "reference": "7462d5f123dfc080dfdf26897032a6513644fc95",
                 "shasum": ""
             },
             "require": {
@@ -2026,7 +2026,7 @@
                 }
             ],
             "description": "A PSR-5 based resolver of Class names, Types and Structural Element Names",
-            "time": "2020-02-14T12:50:24+00:00"
+            "time": "2020-02-18T18:59:58+00:00"
         },
         {
             "name": "phpspec/prophecy",

src/Network/Validators/CNAME.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace Network\Validators;
+
+use Utopia\Validator;
+
+class CNAME extends Validator
+{
+    /**
+     * @var int
+     */
+    protected $target;
+
+    /**
+     * @param string $target
+     */
+    public function __construct($target)
+    {
+        $this->target = $target;
+    }
+
+    public function getDescription()
+    {
+        return 'Inavlid CNAME record';
+    }
+
+    /**
+     * Check if CNAME record target value matches selected target
+     * 
+     * @param string $domain
+     *
+     * @return bool
+     */
+    public function isValid($domain)
+    {
+        try {
+            $records = dns_get_record($domain, DNS_CNAME);
+        } catch (\Throwable $th) {
+            return false;
+        }
+
+        if(!$records || !is_array($records)) {
+            return false;
+        }
+
+        foreach($records as $record) {
+            if(isset($record['target']) && $record['target'] === $this->target) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}

tests/unit/Network/Validators/CNAMETest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Appwrite\Tests;
+
+use Network\Validators\CNAME;
+use PHPUnit\Framework\TestCase;
+
+class CNAMETest extends TestCase
+{
+    /**
+     * @var CNAME
+     */
+    protected $object = null;
+
+    public function setUp()
+    {
+        $this->object = new CNAME('new.appwrite.io');
+    }
+
+    public function tearDown()
+    {
+    }
+
+    public function testValues()
+    {
+        $this->assertEquals($this->object->isValid(''), false);
+        $this->assertEquals($this->object->isValid(null), false);
+        $this->assertEquals($this->object->isValid(false), false);
+        $this->assertEquals($this->object->isValid('cert1.tests.appwrite.io'), true);
+        $this->assertEquals($this->object->isValid('cert2.tests.appwrite.io'), true);
+        $this->assertEquals($this->object->isValid('cert1.tests.appwrite.com'), false);
+        $this->assertEquals($this->object->isValid('cert1.tests.appwrite.com'), false);
+    }
+}