protocollogin.cpp

/**
 * The Forgotten Server - a free and open-source MMORPG server emulator
 * Copyright (C) 2016  Mark Samman <mark.samman@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "otpch.h"

#include "protocollogin.h"

#include "outputmessage.h"
#include "tasks.h"

#include "configmanager.h"
#include "iologindata.h"
#include "ban.h"
#include "game.h"

extern ConfigManager g_config;
extern Game g_game;

void ProtocolLogin::disconnectClient(const std::string& message, uint16_t version)
{
    auto output = OutputMessagePool::getOutputMessage();

    output->addByte(version >= 1076 ? 0x0B : 0x0A);
    output->addString(message);
    send(output);

    disconnect();
}

void ProtocolLogin::getCharacterList(const std::string& accountName, const std::string& password, const std::string& token, uint16_t version)
{
    Account account;
    if (!IOLoginData::loginserverAuthentication(accountName, password, account)) {
        disconnectClient("Account name or password is not correct.", version);
        return;
    }

    auto output = OutputMessagePool::getOutputMessage();
    if (!account.key.empty()) {
        int32_t ticks = static_cast<int32_t>(time(nullptr) / AUTHENTICATOR_PERIOD);
        if (token.empty() || !(token == generateToken(account.key, ticks) || token == generateToken(account.key, ticks - 1) || token == generateToken(account.key, ticks + 1))) {
            output->addByte(0x0D);
            output->addByte(0);
            send(output);
            disconnect();
            return;
        }
        output->addByte(0x0C);
        output->addByte(0);
    }

    //Update premium days
    Game::updatePremium(account);

    const std::string& motd = g_config.getString(ConfigManager::MOTD);
    if (!motd.empty()) {
        //Add MOTD
        output->addByte(0x14);

        std::ostringstream ss;
        ss << g_game.getMotdNum() << "\n" << motd;
        output->addString(ss.str());
    }

    //Add session key
    output->addByte(0x28);
    output->addString(accountName + "\n" + password);

    //Add char list
    output->addByte(0x64);

    output->addByte(1); // number of worlds

    output->addByte(0); // world id
    output->addString(g_config.getString(ConfigManager::SERVER_NAME));
    output->addString(g_config.getString(ConfigManager::IP));
    output->add<uint16_t>(g_config.getNumber(ConfigManager::GAME_PORT));
    output->addByte(0);

    uint8_t size = std::min<size_t>(std::numeric_limits<uint8_t>::max(), account.characters.size());
    output->addByte(size);
    for (uint8_t i = 0; i < size; i++) {
        output->addByte(0);
        output->addString(account.characters[i]);
    }

    //Add premium days
    output->addByte(0);
    if (g_config.getBoolean(ConfigManager::FREE_PREMIUM)) {
        output->addByte(1);
        output->add<uint32_t>(0);
    } else {
        output->addByte(0);
        output->add<uint32_t>(time(nullptr) + (account.premiumDays * 86400));
    }

    send(output);

    disconnect();
}

void ProtocolLogin::onRecvFirstMessage(NetworkMessage& msg)
{
    if (g_game.getGameState() == GAME_STATE_SHUTDOWN) {
        disconnect();
        return;
    }

    msg.skipBytes(2); // client OS

    uint16_t version = msg.get<uint16_t>();
    if (version >= 971) {
        msg.skipBytes(17);
    } else {
        msg.skipBytes(12);
    }
    /*
     * Skipped bytes:
     * 4 bytes: protocolVersion
     * 12 bytes: dat, spr, pic signatures (4 bytes each)
     * 1 byte: 0
     */

    if (version <= 760) {
        std::ostringstream ss;
        ss << "Only clients with protocol " << CLIENT_VERSION_STR << " allowed!";
        disconnectClient(ss.str(), version);
        return;
    }

    if (!Protocol::RSA_decrypt(msg)) {
        disconnect();
        return;
    }

    uint32_t key[4];
    key[0] = msg.get<uint32_t>();
    key[1] = msg.get<uint32_t>();
    key[2] = msg.get<uint32_t>();
    key[3] = msg.get<uint32_t>();
    enableXTEAEncryption();
    setXTEAKey(key);

    if (version < CLIENT_VERSION_MIN || version > CLIENT_VERSION_MAX) {
        std::ostringstream ss;
        ss << "Only clients with protocol " << CLIENT_VERSION_STR << " allowed!";
        disconnectClient(ss.str(), version);
        return;
    }

    if (g_game.getGameState() == GAME_STATE_STARTUP) {
        disconnectClient("Gameworld is starting up. Please wait.", version);
        return;
    }

    if (g_game.getGameState() == GAME_STATE_MAINTAIN) {
        disconnectClient("Gameworld is under maintenance.\nPlease re-connect in a while.", version);
        return;
    }

    BanInfo banInfo;
    auto connection = getConnection();
    if (!connection) {
        return;
    }

    if (IOBan::isIpBanned(connection->getIP(), banInfo)) {
        if (banInfo.reason.empty()) {
            banInfo.reason = "(none)";
        }

        std::ostringstream ss;
        ss << "Your IP has been banned until " << formatDateShort(banInfo.expiresAt) << " by " << banInfo.bannedBy << ".\n\nReason specified:\n" << banInfo.reason;
        disconnectClient(ss.str(), version);
        return;
    }

    std::string accountName = msg.getString();
    if (accountName.empty()) {
        disconnectClient("Invalid account name.", version);
        return;
    }

    std::string password = msg.getString();
    if (password.empty()) {
        disconnectClient("Invalid password.", version);
        return;
    }

    // read authenticator token and stay logged in flag from last 128 bytes
    msg.skipBytes((msg.getLength() - 128) - msg.getBufferPosition());
    if (!Protocol::RSA_decrypt(msg)) {
        disconnectClient("Invalid authentification token.", version);
        return;
    }

    std::string authToken = msg.getString();

    auto thisPtr = std::static_pointer_cast<ProtocolLogin>(shared_from_this());
    g_dispatcher.addTask(createTask(std::bind(&ProtocolLogin::getCharacterList, thisPtr, accountName, password, authToken, version)));
}