Merge pull request #3 from Ed-ITSolutions/error-images

Return image for errors

Readme.md

@@ -22,3 +22,6 @@ The image url will be encrypted with the sites nonce and then base64 encoded. Wh
 
 This ensures only your site can be used to generate valid WP-Camo urls.
 
+### Error Handling
+
+If WP-Camo encounters an error (404 on the image or bad nonce) it will return an image with the error in, which should prevent layouts from being broken by errors.

lib/class.php

@@ -25,12 +25,45 @@ public function returnResource(){
     }
 
     $hash = $wp_query->get('wp_camo');
-    $url = openssl_decrypt(base64_decode($hash), 'aes128', NONCE_KEY, 0, substr(NONCE_SALT, 0, 16));
+
+    $decoded = base64_decode($hash);
+
+    $url = openssl_decrypt($decoded, 'aes128', NONCE_KEY, 0, substr(NONCE_SALT, 0, 16));
+
+    if($url === false){
+      $this->errorImage(
+        '403',
+        __('URL not encrypted by this site.', 'wp-camo')
+      );
+      return;
+    }
 
     $file = wp_remote_get($url);
 
+
+    if($file->errors > 0){
+      $this->errorImage(
+        '404',
+        __('Could not find Image.', 'wp-camo')
+      );
+      return;
+    }
+
     header('Content-Type:' . $file['headers']['content-type']);
 
     echo($file['body']);
   }
+
+  public function errorImage($error, $message){
+    header("Content-type: image/png");
+    $image = imagecreate(300, 100);
+    $background = imagecolorallocate($image, 255, 255, 255);
+    $textColor = imagecolorallocate($image, 0, 0, 0);
+
+    imagestring($image, 4, 30, 25, 'Error ' . $error, $textColor);
+    imagestring($image, 4, 30, 65, $message, $textColor);
+
+
+    imagepng($image);
+  }
 }

wp-camo.php

@@ -2,7 +2,7 @@
 /**
 * Plugin Name: WP Camo
 * Description: Proxy URLS through your WordPress site to prevent mixed content warnings and 
-* Version: 0.0.3
+* Version: 0.0.4
 * Author: Ed-IT Solutions
 * Author URI: http://www.ed-itsolutions.com
 * Details URI: https://github.com/Ed-ITSolutions/wp-camo/releases