001/*
002 * Copyright 2007-2022 Ping Identity Corporation
003 * All Rights Reserved.
004 */
005/*
006 * Copyright 2007-2022 Ping Identity Corporation
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *    http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020/*
021 * Copyright (C) 2007-2022 Ping Identity Corporation
022 *
023 * This program is free software; you can redistribute it and/or modify
024 * it under the terms of the GNU General Public License (GPLv2 only)
025 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
026 * as published by the Free Software Foundation.
027 *
028 * This program is distributed in the hope that it will be useful,
029 * but WITHOUT ANY WARRANTY; without even the implied warranty of
030 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
031 * GNU General Public License for more details.
032 *
033 * You should have received a copy of the GNU General Public License
034 * along with this program; if not, see <http://www.gnu.org/licenses>.
035 */
036package com.unboundid.ldap.sdk.controls;
037
038
039
040import com.unboundid.asn1.ASN1Element;
041import com.unboundid.asn1.ASN1OctetString;
042import com.unboundid.asn1.ASN1Sequence;
043import com.unboundid.ldap.sdk.Control;
044import com.unboundid.ldap.sdk.LDAPException;
045import com.unboundid.ldap.sdk.ResultCode;
046import com.unboundid.util.Debug;
047import com.unboundid.util.NotMutable;
048import com.unboundid.util.NotNull;
049import com.unboundid.util.Nullable;
050import com.unboundid.util.StaticUtils;
051import com.unboundid.util.ThreadSafety;
052import com.unboundid.util.ThreadSafetyLevel;
053
054import static com.unboundid.ldap.sdk.controls.ControlMessages.*;
055
056
057
058/**
059 * This class provides an implementation of the LDAP pre-read request control
060 * as defined in <A HREF="http://www.ietf.org/rfc/rfc4527.txt">RFC 4527</A>.  It
061 * may be used to request that the server retrieve a copy of the target entry as
062 * it appeared immediately before processing a delete, modify, or modify DN
063 * operation.
064 * <BR><BR>
065 * If this control is included in a delete, modify, or modify DN request, then
066 * the corresponding response may include a {@link PreReadResponseControl}
067 * containing a version of the entry as it before after applying that change.
068 * Note that this response control will only be included if the operation was
069 * successful, so it will not be provided if the operation failed for some
070 * reason (e.g., if the change would have violated the server schema, or if the
071 * requester did not have sufficient permission to perform that operation).
072 * <BR><BR>
073 * The value of this control should contain a set of requested attributes to
074 * include in the entry that is returned.  The server should treat this set of
075 * requested attributes exactly as it treats the requested attributes from a
076 * {@link com.unboundid.ldap.sdk.SearchRequest}.  As is the case with a search
077 * request, if no attributes are specified, then all user attributes will be
078 * included.
079 * <BR><BR>
080 * The use of the LDAP pre-read request control is virtually identical to the
081 * use of the LDAP post-read request control.  See the documentation for the
082 * {@link PostReadRequestControl} for an example that illustrates its use.
083 */
084@NotMutable()
085@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
086public final class PreReadRequestControl
087       extends Control
088{
089  /**
090   * The OID (1.3.6.1.1.13.1) for the pre-read request control.
091   */
092  @NotNull public static final String PRE_READ_REQUEST_OID = "1.3.6.1.1.13.1";
093
094
095
096  /**
097   * The set of requested attributes that will be used if none are provided.
098   */
099  @NotNull private static final String[] NO_ATTRIBUTES = StaticUtils.NO_STRINGS;
100
101
102
103  /**
104   * The serial version UID for this serializable class.
105   */
106  private static final long serialVersionUID = 1205235290978028739L;
107
108
109
110  // The set of requested attributes to retrieve from the target entry.
111  @NotNull private final String[] attributes;
112
113
114
115  /**
116   * Creates a new pre-read request control that will retrieve the specified set
117   * of attributes from the target entry.  It will be marked critical.
118   *
119   * @param  attributes  The set of attributes to retrieve from the target
120   *                     entry.  It behaves in the same way as the set of
121   *                     requested attributes for a search operation.  If this
122   *                     is empty or {@code null}, then all user attributes
123   *                     will be returned.
124   */
125  public PreReadRequestControl(@Nullable final String... attributes)
126  {
127    this(true, attributes);
128  }
129
130
131
132  /**
133   * Creates a new pre-read request control that will retrieve the specified set
134   * of attributes from the target entry.
135   *
136   * @param  isCritical  Indicates whether this control should be marked
137   *                     critical.
138   * @param  attributes  The set of attributes to retrieve from the target
139   *                     entry.  It behaves in the same way as the set of
140   *                     requested attributes for a search operation.  If this
141   *                     is empty or {@code null}, then all user attributes
142   *                     will be returned.
143   */
144  public PreReadRequestControl(final boolean isCritical,
145                               @Nullable final String... attributes)
146  {
147    super(PRE_READ_REQUEST_OID, isCritical, encodeValue(attributes));
148
149    if (attributes == null)
150    {
151      this.attributes = NO_ATTRIBUTES;
152    }
153    else
154    {
155      this.attributes = attributes;
156    }
157  }
158
159
160
161  /**
162   * Creates a new pre-read request control which is decoded from the provided
163   * generic control.
164   *
165   * @param  control  The generic control to be decoded as a pre-read request
166   *                  control.
167   *
168   * @throws  LDAPException  If the provided control cannot be decoded as a
169   *                         pre-read request control.
170   */
171  public PreReadRequestControl(@NotNull final Control control)
172         throws LDAPException
173  {
174    super(control);
175
176    final ASN1OctetString value = control.getValue();
177    if (value == null)
178    {
179      throw new LDAPException(ResultCode.DECODING_ERROR,
180                              ERR_PRE_READ_REQUEST_NO_VALUE.get());
181    }
182
183    try
184    {
185      final ASN1Element valueElement = ASN1Element.decode(value.getValue());
186      final ASN1Element[] attrElements =
187           ASN1Sequence.decodeAsSequence(valueElement).elements();
188      attributes = new String[attrElements.length];
189      for (int i=0; i < attrElements.length; i++)
190      {
191        attributes[i] =
192             ASN1OctetString.decodeAsOctetString(attrElements[i]).stringValue();
193      }
194    }
195    catch (final Exception e)
196    {
197      Debug.debugException(e);
198      throw new LDAPException(ResultCode.DECODING_ERROR,
199                              ERR_PRE_READ_REQUEST_CANNOT_DECODE.get(e), e);
200    }
201  }
202
203
204
205  /**
206   * Encodes the provided information into an octet string that can be used as
207   * the value for this control.
208   *
209   * @param  attributes  The set of attributes to retrieve from the target
210   *                     entry.  It behaves in the same way as the set of
211   *                     requested attributes for a search operation.  If this
212   *                     is empty or {@code null}, then all user attributes
213   *                     will be returned.
214   *
215   * @return  An ASN.1 octet string that can be used as the value for this
216   *          control.
217   */
218  @NotNull()
219  private static ASN1OctetString encodeValue(
220                                      @Nullable final String[] attributes)
221  {
222    if ((attributes == null) || (attributes.length == 0))
223    {
224      return new ASN1OctetString(new ASN1Sequence().encode());
225    }
226
227    final ASN1OctetString[] elements = new ASN1OctetString[attributes.length];
228    for (int i=0; i < attributes.length; i++)
229    {
230      elements[i] = new ASN1OctetString(attributes[i]);
231    }
232
233    return new ASN1OctetString(new ASN1Sequence(elements).encode());
234  }
235
236
237
238  /**
239   * Retrieves the set of attributes that will be requested for inclusion in the
240   * entry returned in the response control.
241   *
242   * @return  The set of attributes that will be requested for inclusion in the
243   *          entry returned in the response control, or an empty array if all
244   *          user attributes should be returned.
245   */
246  @NotNull()
247  public String[] getAttributes()
248  {
249    return attributes;
250  }
251
252
253
254  /**
255   * {@inheritDoc}
256   */
257  @Override()
258  @NotNull()
259  public String getControlName()
260  {
261    return INFO_CONTROL_NAME_PRE_READ_REQUEST.get();
262  }
263
264
265
266  /**
267   * {@inheritDoc}
268   */
269  @Override()
270  public void toString(@NotNull final StringBuilder buffer)
271  {
272    buffer.append("PreReadRequestControl(attributes={");
273    for (int i=0; i < attributes.length; i++)
274    {
275      if (i > 0)
276      {
277        buffer.append(", ");
278      }
279      buffer.append('\'');
280      buffer.append(attributes[i]);
281      buffer.append('\'');
282    }
283    buffer.append("}, isCritical=");
284    buffer.append(isCritical());
285    buffer.append(')');
286  }
287}