001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2008 Sun Microsystems, Inc.
015 * Portions Copyright 2014-2015 ForgeRock AS.
016 */
017package org.opends.server.extensions;
018
019import static org.opends.messages.ExtensionMessages.*;
020
021import java.util.List;
022import java.util.Set;
023
024import org.forgerock.i18n.LocalizableMessage;
025import org.forgerock.i18n.LocalizableMessageBuilder;
026import org.forgerock.opendj.config.server.ConfigChangeResult;
027import org.forgerock.opendj.config.server.ConfigException;
028import org.forgerock.opendj.ldap.ByteString;
029import org.opends.server.api.PasswordValidator;
030import org.opends.server.types.*;
031import org.opends.server.util.LevenshteinDistance;
032import org.opends.server.admin.std.server.SimilarityBasedPasswordValidatorCfg;
033import org.opends.server.admin.server.ConfigurationChangeListener;
034
035/**
036 * This class provides a password validator that can ensure that the provided
037 * password meets minimum similarity requirements.
038 */
039public class SimilarityBasedPasswordValidator extends
040    PasswordValidator<SimilarityBasedPasswordValidatorCfg> implements
041    ConfigurationChangeListener<SimilarityBasedPasswordValidatorCfg>
042{
043
044  /** The current configuration for this password validator. */
045  private SimilarityBasedPasswordValidatorCfg currentConfig;
046
047
048  /**
049   * Creates a new instance of this password validator.
050   */
051  public SimilarityBasedPasswordValidator()
052  {
053    super();
054
055
056    // All initialization must be done in the initializePasswordValidator
057    // method.
058  }
059
060  /** {@inheritDoc} */
061  @Override
062  public void initializePasswordValidator(
063                   SimilarityBasedPasswordValidatorCfg configuration)
064         throws ConfigException, InitializationException
065  {
066    configuration.addSimilarityBasedChangeListener(this);
067
068    currentConfig = configuration;
069  }
070
071  /** {@inheritDoc} */
072  @Override
073  public void finalizePasswordValidator()
074  {
075    currentConfig.removeSimilarityBasedChangeListener(this);
076  }
077
078
079
080  /** {@inheritDoc} */
081  @Override
082  public boolean passwordIsAcceptable(ByteString newPassword,
083                                      Set<ByteString> currentPasswords,
084                                      Operation operation, Entry userEntry,
085                                      LocalizableMessageBuilder invalidReason)  {
086
087    int minDifference = currentConfig.getMinPasswordDifference();
088    ByteString passwd = newPassword == null
089                        ? ByteString.empty()
090                        : newPassword;
091
092    if (currentPasswords == null || currentPasswords.isEmpty()) {
093      // This validator requires access to at least one current password.
094      // If we don't have a current password, then we can't validate it, so
095      // we'll have to assume it is OK.  Ideally, the password policy should be
096      // configured to always require the current password, but even then the
097      // current password probably won't be available during an administrative
098      // password reset.
099      return true;
100    }
101
102    for (ByteString bs : currentPasswords) {
103        if (bs == null) {
104            continue;
105        }
106        int ldistance = LevenshteinDistance.calculate(passwd.toString(),
107                                                      bs.toString());
108        if (ldistance < minDifference) {
109          invalidReason.append(ERR_PWDIFFERENCEVALIDATOR_TOO_SMALL.get(
110                  minDifference));
111          return false;
112        }
113    }
114
115    return true;
116  }
117
118  /** {@inheritDoc} */
119  public boolean isConfigurationChangeAcceptable(
120                      SimilarityBasedPasswordValidatorCfg configuration,
121                      List<LocalizableMessage> unacceptableReasons)
122  {
123    return true;
124  }
125
126  /** {@inheritDoc} */
127  public ConfigChangeResult applyConfigurationChange(
128              SimilarityBasedPasswordValidatorCfg configuration)
129  {
130    currentConfig = configuration;
131    return new ConfigChangeResult();
132  }
133}