Improved human readability.

Now protecting against symbolic links to modules/files.
Removed useless denychars code.



git-svn-id: http://svn.3rd-infantry-division.org/testing/branches/Bayonet CMS v2@397 c5b2fb0a-d05d-0410-98c8-828840a80ff6

1 files changed, 65 insertions, 53 deletions

diff --git a/modules.php b/modules.php
index c35a351..e576881 100644
--- a/modules.php
+++ b/modules.php
@@ -18,41 +18,28 @@
  */ 
  
 define("MODULE_FILE",true);
-
 global $load,$index_module;
 
+/**
+ * Assign _GET variables
+ */
 if(isset($_GET['load']))
     $load = $_GET['load'];
 
 if(isset($_GET['file']))
     $file = $_GET['file'];
 
+/** 
+ * Determine the default module to load
+ */
 if(is_null($load))
 {
-  $load = $config['modules']['default'];
-}
-
-$deny_chars = $config['modules']['deny_chars'];
-
-$load_temp = $load;
-
-/*
- * broken i guess.
-for($chars = 0; $chars <= strlen($load_temp); ++$chars)
-{
-  foreach($deny_chars as $deny)
-  {
-    if($load_temp[$chars] == $deny)
-    {
-      OpenTable();
-      ReportHack("Invalid characters detected.\n");
-      CloseTable();       
-    } 
-  }
+	$load = $config['modules']['default'];
 }
-*/
 
-/* If the error stack has recieved messages, output each failure in a clean fashion */
+/**
+ * If the error stack has recieved messages, output each failure in a clean fashion 
+ */
 global $error_stack_messages;
 if(!empty($error_stack_messages))
 {
@@ -65,45 +52,70 @@ if(!empty($error_stack_messages))
 	//exit(1);
 }
 
-if(isset($load) && !empty($load) && !isset($file))
+$module_path = "modules/" . $load;
+$module_index = $module_path . "/index.php";
+$module_internal_file = "modules/" . $load . "/" . $file;
+
+/** Sanity Check
+ * If the module or a file associated with the module is a symbolic link then
+ * commit suicide.  Symbolic links to malicious code can be dangerous. 
+ */
+if(isset($load) || isset($file))
 {
-  if(file_exists("modules/" . $load))
-  {
-    include 'modules/' . $load . '/index.php';
-  	decho("'$load' module loaded");
-  }
-  else
-  {
-    ReportError("Cannot load module directory.<br>\n"); 
-  }
+	if(is_link($module_path))
+	{
+		decho("Refusing to follow symbolic link to '$load'");
+		exit(1);	
+	}
+	
+	if(is_link($module_internal_file))
+	{
+		decho("Refusing to follow symbolic link to '$file'");
+		exit(1);
+	}
 }
-elseif(isset($load) && isset($file))
-{
-  if(file_exists("modules/" . $load))
-  {
-    //$file_temp = explode('.',$file);
-    //$file = $file_temp[0];
-  
-    $run = "modules/" . $load . "/" . $file;
-    
-    if(file_exists($run))
-    {	
-      include $run;
-	  decho("Loaded '$file' file from $load module");     
+
+/** Sanity Check
+ * Determine if the module or file passed into $load actually exists
+ * If everything checks out, load the module or file, else commit suicide.
+ */
+if(isset($load) && !empty($load) && !isset($file))
+{	
+    if(file_exists($module_path))
+	{
+		include $module_index;
+		decho("'$load' module loaded");
     }
     else
     {
-      ReportError("Cannot load module directory.<br>\n");     
+        ReportError("Cannot load module directory.<br>\n"); 
     }
-  }
-  else
-  {
-    ReportError("Cannot load module file.<br>\n");
-  }
+}
+/**
+ * Load an internal module file
+ */
+elseif(isset($load) && isset($file))
+{
+	if(file_exists($module_path))
+	{    	
+    	if(file_exists($module_internal_file))
+    	{	
+      		include $module_internal_file;
+	  		decho("Loaded '$file' file from $load module");     
+    	}
+    	else
+    	{
+      		ReportError("Cannot load module directory.<br>\n");     
+    	}
+	}
+	else
+	{
+    	ReportError("Cannot load module file.<br>\n");
+	}
 }
 else
 {
-  ReportError("Failure to load module.<br>\n");  
+	ReportError("Failure to load module.<br>\n");  
 }