function _encodeLength($length)
    {
        if ($length <= 0x7F) {
            return chr($length);
        }

        $temp = ltrim(pack('N', $length), chr(0));
        return pack('Ca*', 0x80 | strlen($temp), $temp);
    }
function _encodeLength($length)
    {
        if ($length <= 0x7F) {
            return chr($length);
        }

        $temp = ltrim(pack('N', $length), chr(0));
        return pack('Ca*', 0x80 | strlen($temp), $temp);
    }
function _encodeLength ( $ length ) { if ( $ length <= 0x7F ) { return chr ( $ length ) ; } $ temp = ltrim ( pack ( 'N' , $ length ) , chr ( 0 ) ) ; return pack ( 'Ca*' , 0x80 | strlen ( $ temp ) , $ temp ) ; }
DER-encode the length

DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4.  See
{@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13 X.690 paragraph 8.1.3} for more information.

@access private
@param int $length
@return string
DER - encode the length