X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FContent%2FText%2FHTML.php;h=0e117a2205b9a7676897dd9f15e2f9a35a61d69a;hb=e8becc153856debb927d7afac17bae5c80a0abb7;hp=8223aa183b2c3c5156c13738e3d144d5cb80ac10;hpb=312c01a517369c0b3e1ef818081a780c0d445f93;p=friendica.git

diff --git a/src/Content/Text/HTML.php b/src/Content/Text/HTML.php
index 8223aa183b..0e117a2205 100644
--- a/src/Content/Text/HTML.php
+++ b/src/Content/Text/HTML.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * @copyright Copyright (C) 2020, Friendica
+ * @copyright Copyright (C) 2010-2021, the Friendica project
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -143,6 +143,7 @@ class HTML
 	 */
 	public static function toBBCode($message, $basepath = '')
 	{
+		DI::profiler()->startRecording('rendering');
 		$message = str_replace("\r", "", $message);
 
 		$message = Strings::performWithEscapedBlocks($message, '#<pre><code.*</code></pre>#iUs', function ($message) {
@@ -167,6 +168,10 @@ class HTML
 
 			$message = mb_convert_encoding($message, 'HTML-ENTITIES', "UTF-8");
 
+			if (empty($message)) {
+				return '';
+			}
+
 			@$doc->loadHTML($message, LIBXML_HTML_NODEFDTD);
 
 			XML::deleteNode($doc, 'style');
@@ -392,6 +397,7 @@ class HTML
 			$message = self::qualifyURLs($message, $basepath);
 		}
 
+		DI::profiler()->stopRecording();
 		return $message;
 	}
 
@@ -581,6 +587,7 @@ class HTML
 	 */
 	public static function toPlaintext(string $html, $wraplength = 75, $compact = false)
 	{
+		DI::profiler()->startRecording('rendering');
 		$message = str_replace("\r", "", $html);
 
 		$doc = new DOMDocument();
@@ -588,6 +595,11 @@ class HTML
 
 		$message = mb_convert_encoding($message, 'HTML-ENTITIES', "UTF-8");
 
+		if (empty($message)) {
+			DI::profiler()->stopRecording();
+			return '';
+		}
+
 		@$doc->loadHTML($message, LIBXML_HTML_NODEFDTD);
 
 		$message = $doc->saveHTML();
@@ -597,6 +609,11 @@ class HTML
 		// Collecting all links
 		$urls = self::collectURLs($message);
 
+		if (empty($message)) {
+			DI::profiler()->stopRecording();
+			return '';
+		}
+
 		@$doc->loadHTML($message, LIBXML_HTML_NODEFDTD);
 
 		self::tagToBBCode($doc, 'html', [], '', '');
@@ -677,6 +694,7 @@ class HTML
 
 		$message = self::quoteLevel(trim($message), $wraplength);
 
+		DI::profiler()->stopRecording();
 		return trim($message);
 	}
 
@@ -689,9 +707,11 @@ class HTML
 	 */
 	public static function toMarkdown($html)
 	{
+		DI::profiler()->startRecording('rendering');
 		$converter = new HtmlConverter(['hard_break' => true]);
 		$markdown = $converter->convert($html);
 
+		DI::profiler()->stopRecording();
 		return $markdown;
 	}
 
@@ -789,22 +809,6 @@ class HTML
 		]);
 	}
 
-	/**
-	 * Get html for contact block.
-	 *
-	 * @deprecated since version 2019.03
-	 * @see ContactBlock::getHTML()
-	 * @return string
-	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
-	 * @throws \ImagickException
-	 */
-	public static function contactBlock()
-	{
-		$a = DI::app();
-
-		return ContactBlock::getHTML($a->profile);
-	}
-
 	/**
 	 * Format contacts as picture links or as text links
 	 *
@@ -953,4 +957,69 @@ class HTML
 	{
 		return str_replace('&amp;', '&', $s);
 	}
+
+	/**
+	 * Clean an HTML text for potentially harmful code
+	 *
+	 * @param string $text
+	 * @param array  $allowedIframeDomains List of allowed iframe source domains without the scheme
+	 * @return string
+	 */
+	public static function purify(string $text, array $allowedIframeDomains = []): string
+	{
+		// Allows cid: URL scheme
+		\HTMLPurifier_URISchemeRegistry::instance()->register('cid', new HTMLPurifier_URIScheme_cid());
+
+		$config = \HTMLPurifier_HTML5Config::createDefault();
+		$config->set('HTML.Doctype', 'HTML5');
+
+		// Used to remove iframe with src attribute filtered out
+		$config->set('AutoFormat.RemoveEmpty', true);
+
+		$config->set('HTML.SafeIframe', true);
+
+		array_walk($allowedIframeDomains, function (&$domain) {
+			// Allow the domain and all its eventual sub-domains
+			$domain = '(?:(?!-)[A-Za-z0-9-]{1,63}(?<!-)\.)*' . preg_quote(trim($domain, '/'), '%');
+		});
+
+		$config->set('URI.SafeIframeRegexp',
+			'%^https://(?:
+				' . implode('|', $allowedIframeDomains) . '
+			)
+			(?:/|$) # Prevents bogus domains like youtube.com.fake.tld
+			%xi'
+		);
+
+		$config->set('Attr.AllowedRel', [
+			'noreferrer' => true,
+			'noopener' => true,
+		]);
+		$config->set('Attr.AllowedFrameTargets', [
+			'_blank' => true,
+		]);
+
+		$config->set('AutoFormat.RemoveEmpty.Predicate', [
+			'colgroup' => [],        // |
+			'th'       => [],        // |
+			'td'       => [],        // |
+			'iframe'   => ['src'],   // ↳ Default HTMLPurify values
+			'i'        => ['class'], // Allows forkawesome icons
+		]);
+
+		// Uncomment to debug HTMLPurifier behavior
+		//$config->set('Core.CollectErrors', true);
+		//$config->set('Core.MaintainLineNumbers', true);
+
+		$HTMLPurifier = new \HTMLPurifier($config);
+
+		$text = $HTMLPurifier->purify($text);
+
+		/** @var \HTMLPurifier_ErrorCollector $errorCollector */
+		// Uncomment to debug HTML Purifier behavior
+		//$errorCollector = $HTMLPurifier->context->get('ErrorCollector');
+		//var_dump($errorCollector->getRaw());
+
+		return $text;
+	}
 }