Влад Зайцев

function app_rtc_date2epoch(year,month,day,hour,minute,second)
    local leap = 0

    local t_month = {0,31,59,90,120,151,181,212,243,273,304,334}
    local t_leapyear = {72,76,80,84,88,92,96,00,04,08,12,16,20,24,28,32,36}
    local sum_year = 0

    function get_leapyear(year)
       for key,value in pairs(t_leapyear) do
          if (value + 1900) == year then return 1 end
       end   
       for key,value in pairs(t_leapyear) do
          if (value + 2000) == year then return 1 end
       end   
    return nil
    end
    if year < 1970 or year > 2038 then
       return nil
    elseif month < 1 or month > 12 then
       return nil
    elseif hour < 0 or hour > 23 then
       return nil
    elseif minute < 0 or minute > 59 then
       return nil
    elseif second < 0 or second > 59 then
       return nil
    end
    if day > 28 and get_leapyear(year) == nil then
       return nil
    end
    if day > 29 then return nil end
    for y = 1971,year do
       sum_year = sum_year + 31536000
    if    get_leapyear(y) ~= nil then sum_year = sum_year + 86400 end
    end
    sum_month = (t_month[month]*86400)
    tsp = sum_year + sum_month + ((day-1)*86400) + hour*3600 + minute*60 + second
    return tsp
end

function HashBE(bytes)
	function rot(byte)
	    result = 0
	    for i = 0, 7 do
	        result = result + bit.lshift(bit.band(bit.rshift(byte, i), 1), 7 - i)
	    end
	    return bit.band(result, 0xFF)
	end
    hash = 0
    for i = 1, #bytes do
        hash = bit.band(hash + rot(bytes[i]), 0xFF)
    end
    return rot(hash)
end