overhauling proxy_url

- Decode possible HTML entities in the input URL
- Add the safe extension for the shortpath as well
- Formatting
- Documentation

diff --git a/mod/proxy.php b/mod/proxy.php
index a4fbdd24408183e3fc7eaa7794d58cdc2f612623..4d53c9801c8de3c11c35ef2f4abacfef79646dbb 100644 (file)
--- a/mod/proxy.php
+++ b/mod/proxy.php
@@ -233,66 +233,87 @@ function proxy_init() {
        killme();
 }
 
-function proxy_url($url, $writemode = false, $size = "") {
-       global $_SERVER;
-
+/**
+ * @brief Transform a remote URL into a local one
+ *
+ * This function only performs the URL replacement on http URL and if the
+ * provided URL isn't local, "the isn't deactivated" (sic) and if the config
+ * system.proxy_disabled is set to false.
+ *
+ * @param string $url       The URL to proxyfy
+ * @param bool   $writemode Returns a local path the remote URL should be saved to
+ * @param string $size      One of the PROXY_SIZE_* constants
+ *
+ * @return string The proxyfied URL or relative path
+ */
+function proxy_url($url, $writemode = false, $size = '') {
        $a = get_app();
 
        if (substr($url, 0, strlen('http')) !== 'http') {
-               return($url);
+               return $url;
        }
 
        // Only continue if it isn't a local image and the isn't deactivated
        if (proxy_is_local_image($url)) {
-               $url = str_replace(normalise_link($a->get_baseurl())."/", $a->get_baseurl()."/", $url);
-               return($url);
+               $url = str_replace(normalise_link($a->get_baseurl()) . '/', $a->get_baseurl() . '/', $url);
+               return $url;
        }
 
-       if (get_config("system", "proxy_disabled"))
-               return($url);
+       if (get_config('system', 'proxy_disabled')) {
+               return $url;
+       }
+
+       // Image URL may have encoded ampersands for display which aren't desirable for proxy
+       $url = html_entity_decode($url, ENT_NOQUOTES, 'UTF8');
 
        // Creating a sub directory to reduce the amount of files in the cache directory
-       $basepath = $a->get_basepath()."/proxy";
+       $basepath = $a->get_basepath() . '/proxy';
 
-       $path = substr(hash("md5", $url), 0, 2);
+       $shortpath = hash('md5', $url);
+       $longpath = substr($shortpath, 0, 2);
 
-       if (is_dir($basepath) and $writemode)
-               if (!is_dir($basepath."/".$path)) {
-                       mkdir($basepath."/".$path);
-                       chmod($basepath."/".$path, 0777);
+       if (is_dir($basepath) and $writemode) {
+               if (!is_dir($basepath . '/' . $longpath)) {
+                       mkdir($basepath . '/' . $longpath);
+                       chmod($basepath . '/' . $longpath, 0777);
                }
+       }
 
-       $path .= "/".strtr(base64_encode($url), '+/', '-_');
+       $longpath .= '/' . strtr(base64_encode($url), '+/', '-_');
 
        // Checking for valid extensions. Only add them if they are safe
-       $pos = strrpos($url, ".");
+       $pos = strrpos($url, '.');
        if ($pos) {
-               $extension = strtolower(substr($url, $pos+1));
-               $pos = strpos($extension, "?");
-               if ($pos)
+               $extension = strtolower(substr($url, $pos + 1));
+               $pos = strpos($extension, '?');
+               if ($pos) {
                        $extension = substr($extension, 0, $pos);
+               }
        }
 
-       $extensions = array("jpg", "jpeg", "gif", "png");
-
-       if (in_array($extension, $extensions))
-               $path .= ".".$extension;
+       $extensions = array('jpg', 'jpeg', 'gif', 'png');
+       if (in_array($extension, $extensions)) {
+               $shortpath .= '.' . $extension;
+               $longpath .= '.' . $extension;
+       }
 
-       $proxypath = $a->get_baseurl()."/proxy/".$path;
+       $proxypath = $a->get_baseurl() . '/proxy/' . $longpath;
 
-       if ($size != "")
-               $size = ":".$size;
+       if ($size != '') {
+               $size = ':' . $size;
+       }
 
        // Too long files aren't supported by Apache
        // Writemode in combination with long files shouldn't be possible
-       if ((strlen($proxypath) > 250) AND $writemode)
-               return (hash("md5", $url));
-       elseif (strlen($proxypath) > 250)
-               return ($a->get_baseurl()."/proxy/".hash("md5", $url)."?url=".urlencode($url));
-       elseif ($writemode)
-               return ($path);
-       else
-               return ($proxypath.$size);
+       if ((strlen($proxypath) > 250) AND $writemode) {
+               return hash('md5', $url);
+       } elseif (strlen($proxypath) > 250) {
+               return $a->get_baseurl() . '/proxy/' . $shortpath . '?url=' . urlencode($url);
+       } elseif ($writemode) {
+               return $longpath;
+       } else {
+               return $proxypath . $size;
+       }
 }
 
 /**