diff --git a/common/rdr/HexInStream.cxx b/common/rdr/HexInStream.cxx
new file mode 100644
index 0000000..80f8a79
--- /dev/null
+++ b/common/rdr/HexInStream.cxx
@@ -0,0 +1,117 @@
+/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#include <rdr/HexInStream.h>
+#include <rdr/Exception.h>
+
+#include <stdlib.h>
+#include <ctype.h>
+
+using namespace rdr;
+
+const int DEFAULT_BUF_LEN = 16384;
+
+static inline int min(int a, int b) {return a<b ? a : b;}
+
+HexInStream::HexInStream(InStream& is, int bufSize_)
+: bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_LEN), offset(0), in_stream(is)
+{
+  ptr = end = start = new U8[bufSize];
+}
+
+HexInStream::~HexInStream() {
+  delete [] start;
+}
+
+
+bool HexInStream::readHexAndShift(char c, int* v) {
+  c=tolower(c);
+  if ((c >= '0') && (c <= '9'))
+    *v = (*v << 4) + (c - '0');
+  else if ((c >= 'a') && (c <= 'f'))
+    *v = (*v << 4) + (c - 'a' + 10);
+  else
+    return false;
+  return true;
+}
+
+bool HexInStream::hexStrToBin(const char* s, char** data, int* length) {
+  int l=strlen(s);
+  if ((l % 2) == 0) {
+    delete [] *data;
+    *data = 0; *length = 0;
+    if (l == 0)
+      return true;
+    *data = new char[l/2];
+    *length = l/2;
+    for(int i=0;i<l;i+=2) {
+      int byte = 0;
+      if (!readHexAndShift(s[i], &byte) ||
+        !readHexAndShift(s[i+1], &byte))
+        goto decodeError;
+      (*data)[i/2] = byte;
+    }
+    return true;
+  }
+decodeError:
+  delete [] *data;
+  *data = 0;
+  *length = 0;
+  return false;
+}
+
+
+int HexInStream::pos() {
+  return offset + ptr - start;
+}
+
+int HexInStream::overrun(int itemSize, int nItems, bool wait) {
+  if (itemSize > bufSize)
+    throw Exception("HexInStream overrun: max itemSize exceeded");
+
+  if (end - ptr != 0)
+    memmove(start, ptr, end - ptr);
+
+  end -= ptr - start;
+  offset += ptr - start;
+  ptr = start;
+
+  while (end < ptr + itemSize) {
+    int n = in_stream.check(2, 1, wait);
+    if (n == 0) return 0;
+    const U8* iptr = in_stream.getptr();
+    const U8* eptr = in_stream.getend();
+    int length = min((eptr - iptr)/2, start + bufSize - end);
+
+    U8* optr = (U8*) end;
+    for (int i=0; i<length; i++) {
+      int v = 0;
+      readHexAndShift(iptr[i*2], &v);
+      readHexAndShift(iptr[i*2+1], &v);
+      optr[i] = v;
+    }
+
+    in_stream.setptr(iptr + length*2);
+    end += length;
+  }
+
+  if (itemSize * nItems > end - ptr)
+    nItems = (end - ptr) / itemSize;
+
+  return nItems;
+}