Install RSA_Encrypt Lib for CC:Tweaked (ComputerCraft)

function initBigNumInstall()
    if fs.exists(inst_folder.."BigNum.lua") then
        local input = ""
        term.write("BigNum.lua already exists. Overwrite?(y/n): ")
        input = read()
        while (input ~= "y") and input ~= "Y" and input ~= "n" and input ~= "N" do
            term.write("Invalid option. Input \"y\" or \"n\": ")
            input = read()
        end
        if input == "y" or input == "Y" then
            fs.delete(inst_folder.."BigNum.lua")
            installBigNum()
        end
    else
        installBigNum()
    end
end

function installBigNum()
    shell.run("wget https://raw.githubusercontent.com/ennorehling/euler/master/BigNum.lua "..inst_folder.."BigNum.lua")
    os.sleep(0.5)
    local bignum_file = fs.open(inst_folder.."BigNum.lua","a")
    bignum_file.write("\nreturn BigNum")
    bignum_file.close()
end

function installRSA()
    if fs.exists(inst_folder.."RSA.lua") then
        local input = ""
        term.write("RSA.lua already exists. Overwrite?(y/n): ")
        input = read()
        while (input ~= "y") and input ~= "Y" and input ~= "n" and input ~= "N" do
            term.write("Invalid option. Input \"y\" or \"n\": ")
            input = read()
        end
        if input == "y" or input == "Y" then
            fs.delete(inst_folder.."RSA.lua")
            shell.run("pastebin get BckQ1JyV "..inst_folder.."RSA.lua")
        end
    else
        shell.run("pastebin get BckQ1JyV "..inst_folder.."RSA.lua")
    end
end

term.write("Installation Folder?: ")
inst_folder = read()
if inst_folder:sub(#inst_folder,#inst_folder) ~= "/" then
    inst_folder = inst_folder.."/"
end

initBigNumInstall()
installRSA()

term.setTextColor(colors.green)
print("Installation finished successfully. Press any key to close this installer")
os.pullEvent("key")
term.setTextColor(colors.white)