telegram_backup/src/main/java/de/fabianonline/telegram_backup/UserManager.java

/* Telegram_Backup
 * Copyright (C) 2016 Fabian Schlenz
 * 
 * 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 3 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, see <http://www.gnu.org/licenses/>. */

package de.fabianonline.telegram_backup;

import com.github.badoualy.telegram.api.TelegramClient;
import com.github.badoualy.telegram.tl.api.auth.TLSentCode;
import com.github.badoualy.telegram.tl.api.auth.TLAuthorization;
import com.github.badoualy.telegram.tl.api.TLUser;
import com.github.badoualy.telegram.tl.api.TLUserFull;
import com.github.badoualy.telegram.tl.api.TLInputUserSelf;
import com.github.badoualy.telegram.tl.api.account.TLPassword;
import com.github.badoualy.telegram.tl.exception.RpcErrorException;
import com.github.badoualy.telegram.tl.core.TLBytes;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.io.IOException;
import java.io.File;

import org.slf4j.LoggerFactory;
import org.slf4j.Logger;

public class UserManager {
	public TLUser user = null;
	public String phone = null;
	private String code = null;
	private TelegramClient client = null;
	private TLSentCode sent_code = null;
	private TLAuthorization auth = null;
	private boolean password_needed = false;
	private static Logger logger = LoggerFactory.getLogger(UserManager.class);
	private static UserManager instance = null;
	
	public static void init(TelegramClient c) throws IOException {
		instance = new UserManager(c);
	}
	
	private UserManager(TelegramClient c) throws IOException {
		this.client = c;
		logger.debug("Calling getFullUser");
		try {
			TLUserFull full_user = this.client.usersGetFullUser(new TLInputUserSelf());
			this.user = full_user.getUser().getAsUser();
		} catch (RpcErrorException e) {
			// This may happen. Ignoring it.
			logger.debug("Ignoring exception:", e);
		}
	}
	
	public static UserManager getInstance() {
		if (instance==null) throw new RuntimeException("UserManager is not yet initialized.");
		return instance;
	}
	
	public boolean isLoggedIn() { return user!=null; }
	
	public void sendCodeToPhoneNumber(String number) throws RpcErrorException, IOException {
		this.phone = number;
		this.sent_code = this.client.authSendCode(false, this.phone, true);
	}
	
	public void verifyCode(String code) throws RpcErrorException, IOException {
		this.code = code;
		try {
			this.auth = client.authSignIn(phone, this.sent_code.getPhoneCodeHash(), this.code);
			this.user = auth.getUser().getAsUser();
		} catch (RpcErrorException e) {
			if (e.getCode()!=401 || !e.getTag().equals("SESSION_PASSWORD_NEEDED")) throw e;
			this.password_needed = true;
		}
	}
	
	public boolean isPasswordNeeded() { return this.password_needed; }
	
	public void verifyPassword(String pw) throws RpcErrorException, IOException {
		byte[] password = pw.getBytes("UTF-8");
		byte[] salt = ((TLPassword)client.accountGetPassword()).getCurrentSalt().getData();
		MessageDigest md = null;
		try {
			md = MessageDigest.getInstance("SHA-256");
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
			return;
		}
		byte[] salted = new byte[2*salt.length + password.length];
		System.arraycopy(salt,     0, salted, 0,                           salt.length);
		System.arraycopy(password, 0, salted, salt.length,                 password.length);
		System.arraycopy(salt,     0, salted, salt.length+password.length, salt.length);
		byte[] hash = md.digest(salted);
		auth = client.authCheckPassword(new TLBytes(hash));
		this.user = auth.getUser().getAsUser();
	}
	
	public String getUserString() {
		if (this.user==null) return "Not logged in";
		StringBuilder sb = new StringBuilder();
		if (this.user.getFirstName()!=null) {
			sb.append(this.user.getFirstName());
		}
		if (this.user.getLastName()!=null) {
			sb.append(" ");
			sb.append(this.user.getLastName());
		}
		if (this.user.getUsername()!=null) {
			sb.append(" (@");
			sb.append(this.user.getUsername());
			sb.append(")");
		}
		return sb.toString();
	}
	
	public TLUser getUser() { return this.user; }
	
	public String getFileBase() {
		return Config.FILE_BASE + File.separatorChar + "+" + this.user.getPhone() + File.separatorChar;
	}
}