auth.setDateHeader(request.getHeader("Date"));
auth.setContentTypeHeader(request.getHeader("Content-Type"));
auth.setContentMD5Header(request.getHeader("Content-MD5"));
auth.setHostHeader(request.getHeader("Host"));
auth.setQueryString(request.getQueryString());
auth.addUriPath(request.getRequestURI());
// -> are their any Amazon specific (i.e. 'x-amz-' ) headers?
HeaderParam[] headers = params.getHeaders();
for (int i = 0; null != headers && i < headers.length; i++) {
String headerName = headers[i].getName();