(feat): backend for captcha - front#646

Controllers/api/v1/register.php

@@ -45,9 +45,9 @@ class register implements Interfaces\Api, Interfaces\ApiIgnorePam
         }
 
         try {
-            $captcha = Core\Di\Di::_()->get('Security\ReCaptcha');
-            $captcha->setAnswer($_POST['captcha']);
-            if (isset($_POST['captcha']) && !$captcha->validate()) {
+            $captcha = Core\Di\Di::_()->get('Captcha\Manager');
+            
+            if (isset($_POST['captcha']) && !$captcha->verifyFromClientJson($_POST['captcha'])) {
                 throw new \Exception('Captcha failed');
             }
 

Controllers/api/v2/captcha.php

+<?php
+/**
+ * API for returning a captcha
+ */
+namespace Minds\Controllers\api\v2;
+
+use Minds\Api\Factory;
+use Minds\Common\Cookie;
+use Minds\Core\Di\Di;
+use Minds\Core\Config;
+use Minds\Core\Session;
+use Minds\Interfaces;
+
+class captcha implements Interfaces\Api
+{
+    public function get($pages)
+    {
+        $captchaManager = Di::_()->get('Captcha\Manager');
+        $captcha = $captchaManager->build();
+        return Factory::response(
+            $captcha->export()
+        );
+    }
+
+    public function post($pages)
+    {
+        return Factory::response([]);
+    }
+
+    public function put($pages)
+    {
+        return Factory::response([]);
+    }
+
+    public function delete($pages)
+    {
+        return Factory::response([]);
+    }
+}

Core/Captcha/Captcha.php

+<?php
+/**
+ * Captcha Model
+ */
+namespace Minds\Core\Captcha;
+
+use Minds\Traits\MagicAttributes;
+
+class Captcha
+{
+    use MagicAttributes;
+
+    /** @var string */
+    private $jwtToken;
+
+    /** @var string */
+    private $clientText;
+
+    /** @var string */
+    private $base64Image;
+
+    /**
+     * Export the captcha
+     * @param array $extras
+     * @return array
+     */
+    public function export(array $extras = []): array
+    {
+        return [
+            'jwt_token' => $this->jwtToken,
+            'base64_image' => $this->base64Image,
+        ];
+    }
+}

Core/Captcha/ImageGenerator.php

+<?php
+namespace Minds\Core\Captcha;
+
+class ImageGenerator
+{
+    /** @var int */
+    protected $width = 250;
+    
+    /** @var int */
+    protected $height = 100;
+
+    /** @var string */
+    protected $text;
+
+    /**
+     * Set the width
+     * @param int $width
+     * @return self
+     */
+    public function setWidth(int $width): self
+    {
+        $this->width = $width;
+        return $this;
+    }
+    /**
+     * Set the height
+     * @param int $height
+     * @return self
+     */
+    public function setHeight(int $height): self
+    {
+        $this->height = $height;
+        return $this;
+    }
+    /**
+     * Set the text to output
+     * @param string $text
+     * @return self
+     */
+    public function setText(string $text): self
+    {
+        $this->text = $text;
+        return $this;
+    }
+
+    /**
+     * Outputs the captcha image
+     * @return string
+     */
+    public function build(): string
+    {
+        $image = imagecreatetruecolor($this->width, $this->height);
+        
+        // Slight grey background
+        $backgroundColor = imagecolorallocate($image, 240, 240, 240);
+        
+        // Builds the image background
+        imagefilledrectangle($image, 0, 0, $this->width, $this->height, $backgroundColor);
+
+        // Set the line thickness
+        imagesetthickness($image, 3);
+ 
+        // Dark grey lines
+        $lineColor = imagecolorallocate($image, 74, 74, 74);
+        $numberOfLines = rand(4, 10);
+ 
+        for ($i = 0; $i < $numberOfLines; $i++) {
+            imagesetthickness($image, rand(1, 3));
+            imageline($image, 0, rand() % $this->height, $this->width, rand() % $this->height, $lineColor);
+        }
+ 
+        for ($i = 0; $i< $this->width * 4; $i++) {
+            $pixelColor = imagecolorallocate($image, rand(0, 255), rand(0, 255), rand(0, 255));
+            imagesetpixel($image, rand() % $this->width, rand() % $this->height, $pixelColor);
+        }
+ 
+        $font = __MINDS_ROOT__ . '/Assets/fonts/Roboto-Medium.ttf';
+
+        $angle = rand(-6, 6);
+        $size = rand($this->height * 0.25, $this->height * 0.55);
+        $x = 10;
+        $y = ($this->height / 2) + ($size / 2);
+        $color = imagecolorallocate($image, 64, 64, 64);
+
+        // Write the text to the image
+        imagettftext($image, $size, $angle, $x, $y, $color, $font, $this->text);
+
+        ob_start();
+        imagepng($image);
+        $imagedata = ob_get_clean();
+        $base64 = base64_encode($imagedata);
+        imagedestroy($image);
+        
+        return "data:image/png;base64,$base64";
+    }
+}

Core/Captcha/Manager.php

+<?php
+namespace Minds\Core\Captcha;
+
+use Minds\Common\Jwt;
+use Minds\Core\Config;
+use Minds\Core\Di\Di;
+
+class Manager
+{
+    /** @var ImageGenerator */
+    private $imageGenerator;
+
+    /** @var JWT */
+    private $jwt;
+
+    /** @var string */
+    private $secret;
+
+    public function __construct($imageGenerator = null, $jwt = null, $config = null)
+    {
+        $this->imageGenerator = $imageGenerator ?? new ImageGenerator;
+        $this->jwt = $jwt ?? new Jwt();
+        $config = $config ?? Di::_()->get('Config');
+        $this->secret = $config->get('captcha') ? $config->get('captcha')['jwt_secret'] : 'todo';
+        $this->jwt->setKey($this->secret);
+    }
+
+    /**
+     * Verify from client json
+     * @param string $json
+     * @return bool
+     */
+    public function verifyFromClientJson(string $json): bool
+    {
+        $data = json_decode($json, true);
+        $captcha = new Captcha();
+        $captcha->setJwtToken($data['jwtToken'])
+            ->setClientText($data['clientText']);
+        return $this->verify($captcha);
+    }
+
+    /**
+     * Verify if a captcha is valid
+     * @param Captcha $captcha
+     * @return bool
+     */
+    public function verify(Captcha $captcha): bool
+    {
+        $jwtToken = $captcha->getJwtToken();
+        $decodedJwtToken = $this->jwt->decode($jwtToken);
+        $salt = $decodedJwtToken['salt'];
+        $hash = $decodedJwtToken['public_hash'];
+
+        // This is what the client has said the captcha image has
+        $clientText = $captcha->getClientText();
+
+        // Now convert this back to our hash
+        $clientHash = $this->buildCaptchaHash($clientText, $salt);
+
+        return $clientHash === $hash;
+    }
+
+    /**
+     * Output the captcha
+     * @param string $forcedText
+     * @return void
+     */
+    public function build(string $forcedText = ''): Captcha
+    {
+        $text = $forcedText ?: $this->getRandomText(6);
+
+        $now = time();
+        $expires = $now + 300; // Captcha are good for 5 minutes
+
+        $salt = $this->jwt->randomString();
+        $jwtToken = $this->jwt
+            ->setKey($this->secret)
+            ->encode([
+                'public_hash' => $this->buildCaptchaHash($text, $salt),
+                'salt' => $salt,
+            ], $expires, $now);
+
+        $image = $this->imageGenerator
+            ->setText($text)
+            ->build();
+
+        $captcha = new Captcha();
+        $captcha->setBase64Image($image)
+            ->setJwtToken($jwtToken);
+
+        return $captcha;
+    }
+
+    /**
+     * Get the random text
+     * @param int $length
+     * @return sdtring
+     */
+    protected function getRandomText(int $length): string
+    {
+        $chars = array_merge(
+            range(1, 9),
+            range('A', 'N'),
+            range('P', 'Z'), // We don't want O's or 0s
+            range('a', 'n'),
+            range('p', 'z')
+        );
+        shuffle($chars);
+
+        $text="";
+        for ($i = 0; $i < $length; $i++) {
+            $text .= $chars[array_rand($chars)];
+        }
+
+        return $text;
+    }
+
+    /**
+     * Return hash based on text and salt with a secret
+     * @param string $text
+     * @param string $salt
+     * @return string
+     */
+    protected function buildCaptchaHash(string $text, string $salt): string
+    {
+        return hash('sha1', $text . $this->secret . $salt);
+    }
+}

Core/Captcha/Module.php

+<?php
+/**
+ * Captcha Module
+ */
+
+namespace Minds\Core\Captcha;
+
+use Minds\Interfaces\ModuleInterface;
+
+class Module implements ModuleInterface
+{
+    /**
+     * OnInit.
+     */
+    public function onInit()
+    {
+        $provider = new Provider();
+        $provider->register();
+    }
+}

Core/Captcha/Provider.php

+<?php
+/**
+ * Minds Captcha Provider.
+ */
+
+namespace Minds\Core\Captcha;
+
+use Minds\Core\Di\Provider as DiProvider;
+
+class Provider extends DiProvider
+{
+    public function register()
+    {
+        $this->di->bind('Captcha\Manager', function ($di) {
+            return new Manager();
+        }, ['useFactory' => true]);
+    }
+}

Core/Minds.php

@@ -33,6 +33,7 @@ class Minds extends base
         VideoChat\Module::class,
         Feeds\Module::class,
         Front\Module::class,
+        Captcha\Module::class,
     ];
 
     /**

Spec/Core/Captcha/ImageGeneratorSpec.php

+<?php
+
+namespace Spec\Minds\Core\Captcha;
+
+use Minds\Core\Captcha\ImageGenerator;
+use PhpSpec\ObjectBehavior;
+use Prophecy\Argument;
+
+class ImageGeneratorSpec extends ObjectBehavior
+{
+    public function it_is_initializable()
+    {
+        $this->shouldHaveType(ImageGenerator::class);
+    }
+}

Spec/Core/Captcha/ManagerSpec.php

+<?php
+
+namespace Spec\Minds\Core\Captcha;
+
+use Minds\Core\Captcha\Manager;
+use Minds\Core\Captcha\Captcha as CaptchaModel;
+use PhpSpec\ObjectBehavior;
+use Prophecy\Argument;
+
+class ManagerSpec extends ObjectBehavior
+{
+    public function it_is_initializable()
+    {
+        $this->shouldHaveType(Manager::class);
+    }
+
+    public function it_should_build_a_captcha()
+    {
+        $captcha = $this->build();
+        $jwtToken = $captcha->getJwtToken();
+        $jwtToken->shouldBeString();
+    }
+
+    public function it_should_verify_a_captcha()
+    {
+        $captcha = $this->build('abfu21')->getWrappedObject();
+        $captcha->setClientText('abfu21');
+        $this->verify($captcha)
+            ->shouldBe(true);
+    }
+
+    public function it_should_verify_a_captcha_with_fail()
+    {
+        $captcha = $this->build();
+        $captcha->setClientText('abfu21');
+        $this->verify($captcha)
+            ->shouldBe(false);
+    }
+}

settings.example.php

@@ -626,3 +626,8 @@ $CONFIG->set('unleash', [
     'pollingIntervalSeconds' => 300,
     'metricsIntervalSeconds' => 15
 ]);
+
+
+$CONFIG->set('captcha', [
+    'jwt_secret' => '{{site-secret}}',
+]);