private static long intArrayToLong(int[] buffer,
                                      int nStartIndex)
    {
        return (((long) buffer[nStartIndex]) << 32) |
                (((long) buffer[nStartIndex + 1]) & 0x0ffffffffL);
    }
converts values from an integer array to a long
@param buffer where to get the bytes
@param nStartIndex index from where to read the data
@return the 64bit integer
xmppserver/src/main/java/org/jivesoftware/util/Blowfish.java