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62 lines
1.2 KiB
Lua
62 lines
1.2 KiB
Lua
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---- Adapted from https://cybersecurity.att.com/blogs/labs-research/luhn-checksum-algorithm-lua-implementation
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local bit = require("bit")
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local band, bor, bxor = bit.band, bit.bor, bit.bxor
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function luhn_checksum(card)
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local num = 0
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local nDigits = card:len()
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odd = band(nDigits, 1)
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for count = 0,nDigits-1 do
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digit = tonumber(string.sub(card, count+1,count+1))
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if (bxor(band(count, 1),odd)) == 0
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then
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digit = digit * 2
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end
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if digit > 9 then
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digit = digit - 9
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end
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num = num + digit
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end
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return num
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end
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function luhn_digit (s)
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local num = luhn_checksum (s)
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return (10 - (num % 10))
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end
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function is_valid_luhn (s)
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local num = luhn_checksum (s)
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return ((num % 10) == 0)
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end
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function make_imei (premei)
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local imei = premei .. tostring(luhn_digit(premei .. "0"))
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if is_valid_luhn (imei) then print ("Valid " .. imei) end
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return imei
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end
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function make_random_imei ()
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local nDigits = 13
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local premei = ""
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for count = 0, nDigits-1 do
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premei = premei .. tostring (math.random (0, 9))
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end
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local imei = make_imei (tostring (premei))
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return imei
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end
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print (make_imei ("354809108035177"))
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