m1m

function clear()
  term.clear()
  term.setCursorPos(1,1)
end

function rKey()
  local key = math.randomseed(os.time() * (10^9))
  key = math.random(0,9999999999)
  key = string.format("%x", key)
  return key
end


function hash(pw, key)

  local pw = pw
  local key = key

  local ascii   = {}
  local ascii_2 = {}

  for i = 1, #key do
    ascii[i] = string.byte(key, i)
  end

  for j = 1, #pw do
    ascii_2[j] = string.byte(pw, j)
  end

  local n = string.reverse(table.concat(ascii))
        n = tonumber(n)
  local m = string.reverse(table.concat(ascii_2))
        m = tonumber(m)

  local key_n = math.randomseed(n)
        key_n = math.random(0,9999999999)
  local key_m = math.randomseed(m)
        key_m = math.random(0,9999999999)

  local mod_n = key_n % #key
  local mod_m = key_m % #pw

  local xor = bit.bxor(key_n, key_m)
  local hex = string.format("%x", xor * (mod_n+mod_m+1))

  return hex

end

function store(user, key, pw)

  local user = user
  local key = key
  local pw = pw

  if fs.exists("/.users") == false then
    fs.makeDir("/.users")
  end

  local t = {"/.users/"}
  table.insert(t, user)
  t = table.concat(t)

  if fs.exists(t) == false then
    local x = fs.open(t, "w")
    x.writeLine(key)
    x.writeLine(pw)
    x.close()
    return true
  else
    printError("Username already taken")
    sleep(1)
    clear()
    return false
  end

end

function login()
  local a, b = 0, 0
  local t
  local u

  while true do
    term.setTextColor(colors.orange)
    print("Logging in")
    term.setTextColor(colors.white)
    term.write("Username: ")
    u = read()
    t = {"/.users/"}
    table.insert(t,u)
    t = table.concat(t)

    if fs.exists(t) == false then
      printError("User doesn't exist")
      a = a + 1
      print("Attempt: "..a)
      os.sleep(2)
      clear()
      if a >= 3 then
        printError("Shutting down")
        os.sleep(2)
        os.shutdown()
      end
    else
      break
    end
  end


  while true do

    local file = fs.open(t, "r")
    term.write("Password: ")
    local p = read('*')
    local nKey = file.readLine()
    local key = nKey
    nKey = file.readLine()
    local pw = nKey
    local comp = hash(p, key)
    file.close()

    if pw ~= comp then
      printError("Wrong password!")
      os.reboot()
    else
      term.setTextColor(colors.green)
      print("Succesfully logged in!")
      term.setTextColor(colors.white)
      os.sleep(2)
      clear()
      break
    end
  end

  return t
end


function register()
  while true do
    term.setTextColor(colors.orange)
    print("Registering!")
    term.setTextColor(colors.white)
    term.write("Username: ")
    local x = read()
    local y = rKey()
    term.write("Password: ")
    local z = read('*')
    local z = hash(z, y)
    if store(x,y,z) then
      term.setTextColor(colors.green)
      print("Succesfully registered")
      term.setTextColor(colors.white)
      os.sleep(2)
      clear()
      break
    end
  end
  login()
end

function deleteUser()
  user = login()
  term.setTextColor(colors.orange)
  print("Deleting account")
  term.setTextColor(colors.white)
  print("Are you sure? [y/n]")
  while true do
    event, key = os.pullEvent("key")
    if key == keys.y then
      fs.delete(user)
      term.setTextColor(colors.green)
      print("Deleted user")
      term.setTextColor(colors.white)
      os.sleep(2)
      clear()
      break
    elseif key == keys.n then
      term.setTextColor(colors.green)
      print("Cancelled deleting")
      term.setTextColor(colors.white)
      os.sleep(2)
      clear()
    end
  end
  selector()
end

function selector()

  local selector = 1

  term.setTextColor(colors.blue)
  print("[Login]")
  term.setTextColor(colors.white)
  print("Register")
  print("Delete user")

  while true do

    local event, key = os.pullEvent("key")

    if key == keys.down and selector < 3 then
      selector = selector + 1
    elseif key == keys.up and selector > 1 then
      selector = selector - 1
    end

    if selector == 1 then
      clear()
      term.setTextColor(colors.blue)
      print("[Login]")
      term.setTextColor(colors.white)
      print("Register")
      print("Delete user")
    elseif selector == 2 then
      clear()
      term.setTextColor(colors.white)
      print("Login")
      term.setTextColor(colors.blue)
      print("[Register]")
      term.setTextColor(colors.white)
      print("Delete user")
    elseif selector == 3 then
      clear()
      term.setTextColor(colors.white)
      print("Login")
      print("Register")
      term.setTextColor(colors.blue)
      print("[Delete user]")
    end

    if key == keys.enter and selector == 1 then
      clear()
      login()
      break
    elseif key == keys.enter and selector == 2 then
      clear()
      register()
      break
    elseif key == keys.enter and selector == 3 then
      clear()
      deleteUser()
      break
    end
  end
end

selector()