otclient/modules/gamelib/game.lua

local currentRsa

function g_game.getRsa()
  return currentRsa
end

function g_game.chooseRsa(host)
  if currentRsa ~= CIPSOFT_RSA and currentRsa ~= OTSERV_RSA then return end
  if string.ends(host, '.tibia.com') or string.ends(host, '.cipsoft.com') then
    g_game.setRsa(CIPSOFT_RSA)

    if g_app.getOs() == 'windows' then
      g_game.setCustomOs(OsTypes.Windows)
    else
      g_game.setCustomOs(OsTypes.Linux)
    end
  else
    if currentRsa == CIPSOFT_RSA then
      g_game.setCustomOs(-1)
    end
    g_game.setRsa(OTSERV_RSA)
  end
end

function g_game.setRsa(rsa, e)
  e = e or '65537'
  g_crypt.rsaSetPublicKey(rsa, e)
  currentRsa = rsa
end

function g_game.isOfficialTibia()
  return currentRsa == CIPSOFT_RSA
end

function g_game.getSupportedProtocols()
  return {
    810, 811, 840, 842, 850, 853, 854,
    860, 861, 862, 870, 910, 940, 944,
    953, 954, 960, 961, 963, 970, 971,
    973, 974, 975, 976, 977, 978, 979,
	980, 1010
  }
end

function g_game.getSupportedClients(protocol)
  clients = {
    [971] = {980},
    [973] = {981},
    [974] = {982},
	[975] = {983},
	[976] = {984},
	[977] = {985},
	[978] = {986},
	[979] = {1001},
	[980] = {1002}
  }
  return clients[protocol] or {protocol}
end

g_game.setRsa(OTSERV_RSA)