Fixed a possible buffer overflow in handling CA descriptors

1 files changed, 21 insertions, 1 deletions

diff --git a/tools.h b/tools.h
index f2ba3157..73cca5a3 100644
--- a/tools.h
+++ b/tools.h
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: tools.h 4.4 2016/12/13 12:13:46 kls Exp $
+ * $Id: tools.h 4.5 2016/12/23 13:56:35 kls Exp $
  */
 
 #ifndef __TOOLS_H
@@ -775,6 +775,26 @@ public:
   bool Load(const char *Directory, bool DirsOnly = false);
   };
 
+class cDynamicBuffer {
+private:
+  uchar *buffer;
+  int initialSize;
+  int size; // the total size of the buffer (bytes in memory)
+  int used; // the number of used bytes, starting at the beginning of the buffer
+  bool Realloc(int NewSize);
+  bool Assert(int NewSize) { return size < NewSize ? Realloc(NewSize) : true; } // inline for performance!
+public:
+  cDynamicBuffer(int InitialSize = 1024);
+  ~cDynamicBuffer();
+  void Append(const uchar *Data, int Length);
+  void Append(uchar Data) { if (Assert(used + 1)) buffer[used++] = Data; }
+  void Set(int Index, uchar Data) { if (Assert(Index + 1)) buffer[Index] = Data; }
+  uchar Get(int Index) { return Index < used ? buffer[Index] : 0; }
+  void Clear(void) { used = 0; }
+  uchar *Data(void) { return buffer; }
+  int Length(void) { return used; }
+  };
+
 class cHashObject : public cListObject {
   friend class cHashBase;
 private: