From 6854cb3f4d8219cf1829e32122eb2502a916eae9 Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Sat, 1 Feb 2020 09:05:48 +0100
Subject: initial checkin

---
 .../library/HTMLPurifier/URIScheme/data.php        | 136 +++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 vendor/ezyang/htmlpurifier/library/HTMLPurifier/URIScheme/data.php

(limited to 'vendor/ezyang/htmlpurifier/library/HTMLPurifier/URIScheme/data.php')

diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/URIScheme/data.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/URIScheme/data.php
new file mode 100644
index 0000000..41c49d5
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/URIScheme/data.php
@@ -0,0 +1,136 @@
+<?php
+
+/**
+ * Implements data: URI for base64 encoded images supported by GD.
+ */
+class HTMLPurifier_URIScheme_data extends HTMLPurifier_URIScheme
+{
+    /**
+     * @type bool
+     */
+    public $browsable = true;
+
+    /**
+     * @type array
+     */
+    public $allowed_types = array(
+        // you better write validation code for other types if you
+        // decide to allow them
+        'image/jpeg' => true,
+        'image/gif' => true,
+        'image/png' => true,
+    );
+    // this is actually irrelevant since we only write out the path
+    // component
+    /**
+     * @type bool
+     */
+    public $may_omit_host = true;
+
+    /**
+     * @param HTMLPurifier_URI $uri
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return bool
+     */
+    public function doValidate(&$uri, $config, $context)
+    {
+        $result = explode(',', $uri->path, 2);
+        $is_base64 = false;
+        $charset = null;
+        $content_type = null;
+        if (count($result) == 2) {
+            list($metadata, $data) = $result;
+            // do some legwork on the metadata
+            $metas = explode(';', $metadata);
+            while (!empty($metas)) {
+                $cur = array_shift($metas);
+                if ($cur == 'base64') {
+                    $is_base64 = true;
+                    break;
+                }
+                if (substr($cur, 0, 8) == 'charset=') {
+                    // doesn't match if there are arbitrary spaces, but
+                    // whatever dude
+                    if ($charset !== null) {
+                        continue;
+                    } // garbage
+                    $charset = substr($cur, 8); // not used
+                } else {
+                    if ($content_type !== null) {
+                        continue;
+                    } // garbage
+                    $content_type = $cur;
+                }
+            }
+        } else {
+            $data = $result[0];
+        }
+        if ($content_type !== null && empty($this->allowed_types[$content_type])) {
+            return false;
+        }
+        if ($charset !== null) {
+            // error; we don't allow plaintext stuff
+            $charset = null;
+        }
+        $data = rawurldecode($data);
+        if ($is_base64) {
+            $raw_data = base64_decode($data);
+        } else {
+            $raw_data = $data;
+        }
+        if ( strlen($raw_data) < 12 ) {
+            // error; exif_imagetype throws exception with small files,
+            // and this likely indicates a corrupt URI/failed parse anyway
+            return false;
+        }
+        // XXX probably want to refactor this into a general mechanism
+        // for filtering arbitrary content types
+        if (function_exists('sys_get_temp_dir')) {
+            $file = tempnam(sys_get_temp_dir(), "");
+        } else {
+            $file = tempnam("/tmp", "");
+        }
+        file_put_contents($file, $raw_data);
+        if (function_exists('exif_imagetype')) {
+            $image_code = exif_imagetype($file);
+            unlink($file);
+        } elseif (function_exists('getimagesize')) {
+            set_error_handler(array($this, 'muteErrorHandler'));
+            $info = getimagesize($file);
+            restore_error_handler();
+            unlink($file);
+            if ($info == false) {
+                return false;
+            }
+            $image_code = $info[2];
+        } else {
+            trigger_error("could not find exif_imagetype or getimagesize functions", E_USER_ERROR);
+        }
+        $real_content_type = image_type_to_mime_type($image_code);
+        if ($real_content_type != $content_type) {
+            // we're nice guys; if the content type is something else we
+            // support, change it over
+            if (empty($this->allowed_types[$real_content_type])) {
+                return false;
+            }
+            $content_type = $real_content_type;
+        }
+        // ok, it's kosher, rewrite what we need
+        $uri->userinfo = null;
+        $uri->host = null;
+        $uri->port = null;
+        $uri->fragment = null;
+        $uri->query = null;
+        $uri->path = "$content_type;base64," . base64_encode($raw_data);
+        return true;
+    }
+
+    /**
+     * @param int $errno
+     * @param string $errstr
+     */
+    public function muteErrorHandler($errno, $errstr)
+    {
+    }
+}
-- 
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