core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/srvext/auth/SimpleNamePassAuthMethod.java

/*=============================================================================#
 # Copyright (c) 2009, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.rj.server.srvext.auth;

import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;
import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullLateInit;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import javax.security.auth.callback.Callback;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.login.FailedLoginException;
import javax.security.auth.login.LoginException;

import org.eclipse.statet.jcommons.collections.ImCollections;
import org.eclipse.statet.jcommons.collections.ImList;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.rj.RjException;
import org.eclipse.statet.rj.server.srvext.ServerAuthMethod;
import org.eclipse.statet.rj.server.util.ServerUtils;
import org.eclipse.statet.rj.server.util.ServerUtils.ArgKeyValue;


/**
 * Authentication method 'name-pass'
 * to authenticate against a given name password pair.
 */
@NonNullByDefault
public class SimpleNamePassAuthMethod extends ServerAuthMethod {
	
	
	private Map<String, byte[]> users= nonNullLateInit();
	
	private byte[] digestSash= nonNullLateInit();
	private MessageDigest digestService= nonNullLateInit();
	private Charset digestCharset= nonNullLateInit();
	
	
	public SimpleNamePassAuthMethod() {
		super("name-pass", true);
	}
	
	
	@Override
	public void doInit(final @Nullable String arg) throws RjException {
		final ArgKeyValue config= ServerUtils.getArgConfigValue(arg);
		try {
			this.digestSash= new byte[8];
			final SecureRandom random= SecureRandom.getInstance("SHA1PRNG");
			random.nextBytes(this.digestSash);
			this.digestService= MessageDigest.getInstance("SHA-512");
			this.digestCharset= StandardCharsets.UTF_8;
		}
		catch (final Exception e) {
			throw new RjException("", e);
		}
		
		final Properties read= new Properties();
		if (config.getKey().equals("file")) {
			final String fileName= config.getValue();
			if (fileName == null || fileName.isEmpty()) {
				throw new RjException("Missing password file name.", null);
			}
			final File file= new File(fileName);
			try {
				read.load(new FileInputStream(file));
			}
			catch (final IOException e) {
				throw new RjException("Reading password file failed.", null);
			}
		}
		else {
			throw new RjException(String.format("Unsupported configuration type '%1$s'.", config.getKey()));
		}
		this.digestService.update(this.digestSash);
		this.users= new HashMap<>();
		for (final Map.Entry<?, ?> entry : read.entrySet()) {
			final String username= nonNullAssert((String)entry.getKey());
			final byte[] password= this.digestService.digest(
					this.digestCharset.encode(nonNullAssert((String)entry.getValue())).array() );
			this.users.put(username, password);
		}
	}
	
	@Override
	protected ImList<Callback> doCreateLogin() throws RjException {
		return ImCollections.newList(
				new NameCallback("Loginname"),
				new PasswordCallback("Password", false) );
	}
	
	@Override
	protected String doPerformLogin(final ImList<Callback> callbacks) throws LoginException, RjException {
		final String loginName= ((NameCallback)callbacks.get(0)).getName();
		if (loginName != null) {
			final Object object= this.users.get(loginName);
			if (object instanceof byte[]) {
				final byte[] loginPassword= getPass((PasswordCallback)callbacks.get(1));
				if (Arrays.equals((byte[]) object, loginPassword)) {
					return loginName;
				}
			}
		}
		throw new FailedLoginException("Invalid loginname or password");
	}
	
	private byte[] getPass(final PasswordCallback callback) {
		final char[] loginPassword= callback.getPassword();
		final byte[] loginBytes;
		if (loginPassword == null) {
			return new byte[0];
		}
		this.digestService.update(this.digestSash);
		loginBytes= this.digestService.digest(
				this.digestCharset.encode(CharBuffer.wrap(loginPassword)).array() );
		callback.clearPassword();
		Arrays.fill(loginPassword, (char) 0);
		return loginBytes;
	}
	
}