BrineCrypt2.5B

Args = {...}
FF = fs.open(Args[2],"rb")
FF2 = fs.open("."..Args[2],"wb")
print("The longer the password the harder to crack a file "..
      "If the password is one character long then the "..
      "file is easy to crack")
write("Password: ")
z = read(string.char(4))
local Increm = {}
for i = 1,string.len(z) do
  table.insert(Increm,string.byte(string.sub(z,i,i+1)))
end

if Args[1] == "enc" then
  repeat
    for i = 1,#Increm do
      Char = FF.read()
      if Char ~= nil then
        for ii = i,#Increm do
          Char = Char+Increm[ii]
        end
        --Char = Char+string.byte(string.sub(z,i,string.len(z)-(string.len(z)-i)))
        while Char >= 255 do Char = Char-255 end
        FF2.write(Char)
      end
    end
  until Char == nil
elseif Args[1] == "dec" then
  repeat
    for i = 1,#Increm do
      Char = FF.read()
      if Char ~= nil then
        for ii = i,#Increm do
          Char = Char-Increm[ii]
        end
        --Char = Char-string.byte(string.sub(z,i,string.len(z)-(string.len(z)-i)))
        while Char <= 0 do Char = Char+255 end
        FF2.write(Char)
      end
    end
  until Char == nil
end

FF.close()
FF2.close()
fs.delete(Args[2])
fs.move("."..Args[2],Args[2])