tibia-client/modules/gamelib/game.lua

function g_game.getRsa()
  return G.currentRsa
end

function g_game.findPlayerItem(itemId, subType)
    local localPlayer = g_game.getLocalPlayer()
    if localPlayer then
        for slot = InventorySlotFirst, InventorySlotLast do
            local item = localPlayer:getInventoryItem(slot)
            if item and item:getId() == itemId and (subType == -1 or item:getSubType() == subType) then
                return item
            end
        end
    end

    return g_game.findItemInContainers(itemId, subType)
end

function g_game.chooseRsa(host)
  if G.currentRsa ~= CIPSOFT_RSA and G.currentRsa ~= OTSERV_RSA then return end
  if host:ends('.tibia.com') or host:ends('.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 G.currentRsa == CIPSOFT_RSA then
      g_game.setCustomOs(-1)
    end
    g_game.setRsa(OTSERV_RSA)
  end

  -- Hack fix to resolve some 760 login issues
  if g_game.getClientVersion() <= 760 then
    g_game.setCustomOs(2)
  end
end

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

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

function g_game.getSupportedClients()
  return {
    740, 741, 750, 760, 770, 772,
    780, 781, 782, 790, 792,

    800, 810, 811, 820, 821, 822,
    830, 831, 840, 842, 850, 853,
    854, 855, 857, 860, 861, 862,
    870, 871,

    900, 910, 920, 931, 940, 943,
    944, 951, 952, 953, 954, 960,
    961, 963, 970, 971, 972, 973,
    980, 981, 982, 983, 984, 985,
    986,

    1000, 1001, 1002, 1010, 1011,
    1012, 1013, 1020, 1021, 1022,
    1030, 1031, 1032, 1033, 1034,
    1035, 1036, 1037, 1038, 1039,
    1040, 1041, 1050, 1051, 1052,
    1053, 1054, 1055, 1056, 1057,
    1058, 1059, 1060, 1061, 1062,
    1063, 1064, 1070, 1071, 1072,
    1073, 1074, 1075
  }
end

-- The client version and protocol version where
-- unsynchronized for some releases, not sure if this
-- will be the normal standard.

-- Client Version: Publicly given version when
-- downloading Cipsoft client.

-- Protocol Version: Previously was the same as
-- the client version, but was unsychronized in some
-- releases, now it needs to be verified and added here
-- if it does not match the client version.

-- Reason for defining both: The server now requires a
-- Client version and Protocol version from the client.

-- Important: Use getClientVersion for specific protocol
-- features to ensure we are using the proper version.

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

if not G.currentRsa then
  g_game.setRsa(OTSERV_RSA)
end