OnetimePasswordAuthenticator.java

/**
 * Licensed to the Austrian Association for Software Tool Integration (AASTI)
 * under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership. The AASTI licenses this file to you under the Apache License,
 * Version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.openengsb.core.services;


import org.apache.commons.lang.ObjectUtils;
import org.apache.commons.lang.math.NumberRange;
import org.openengsb.core.api.AliveState;
import org.openengsb.core.api.security.Credentials;
import org.openengsb.core.api.security.model.Authentication;
import org.openengsb.core.api.security.service.UserDataManager;
import org.openengsb.core.api.security.service.UserNotFoundException;
import org.openengsb.core.common.AbstractOpenEngSBService;
import org.openengsb.domain.authentication.AuthenticationDomain;
import org.openengsb.domain.authentication.AuthenticationException;

public class OnetimePasswordAuthenticator extends AbstractOpenEngSBService implements AuthenticationDomain {

    private static final Integer MAXCODE = 1000000;

    private static final NumberRange NUMBER_RANGE = new NumberRange(0, MAXCODE);

    private UserDataManager userManager;

    @Override
    public Authentication authenticate(String username, Credentials credentials) throws AuthenticationException {
        Integer code = ((OneTimeValue) credentials).getValue();
        if (!NUMBER_RANGE.containsInteger(code)) {
            throw new AuthenticationException("value is outside the specified range");
        }
        String baseCodeString;
        String counterString;
        try {
            baseCodeString = userManager.getUserCredentials(username, "onetime-basecode");
            counterString = userManager.getUserCredentials(username, "onetime-counter");
            Integer baseCode = Integer.parseInt(baseCodeString);
            Integer counter = Integer.parseInt(counterString);
            Integer expectedCode = (baseCode * counter) % MAXCODE;
            if (ObjectUtils.notEqual(code, expectedCode)) {
                throw new AuthenticationException("wrong auth-code");
            }
            userManager.setUserCredentials(username, "counter", Integer.toString(counter + 1));
        } catch (UserNotFoundException e) {
            throw new AuthenticationException(e);
        }
        return new Authentication(username);
    }

    @Override
    public boolean supports(Credentials credentials) {
        return credentials instanceof OneTimeValue;
    }

    @Override
    public AliveState getAliveState() {
        return userManager != null ? AliveState.ONLINE : AliveState.OFFLINE;
    }

    public void setUserManager(UserDataManager userManager) {
        this.userManager = userManager;
    }

}