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1   /**
2    * Copyright 2005-2014 The Kuali Foundation
3    *
4    * Licensed under the Educational Community License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.opensource.org/licenses/ecl2.php
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.kuali.rice.kew.routeheader;
17  
18  import org.kuali.rice.krad.data.jpa.converters.EncryptionConverter;
19  
20  import javax.persistence.AttributeConverter;
21  import javax.persistence.Converter;
22  import java.util.regex.Matcher;
23  import java.util.regex.Pattern;
24  
25  /**
26   * A JPA Converter which supports mixed encrypted and non-encrypted document content XML.
27   *
28   * <p>Leverages behavior from the  standard {@link EncryptionConverter} but additionally when converting to the entity
29   * attribute value, it will detect whether or not the value is encrypted XML or plain text XML and decrypt if necessary.
30   * This allows for this situation where encryption is enabled at a later date. Using this mechanism, existing plain text
31   * docs can be loaded (but could potentially be saved back to the database encrypted if encryption is enabled).</p>
32   *
33   * <p>Note that the mixed mode only works one way. If you have been using encryption and then disable it, this
34   * converter will not be able to decrypt your old doc content for you since it will no longer have the encryption key
35   * available to it.</p>
36   *
37   * @author Kuali Rice Team (rice.collab@kuali.org)
38   */
39  @Converter
40  public class DocumentContentEncryptionConverter implements AttributeConverter<String, String> {
41  
42      /**
43       * It's XML if it starts with a '<' though there can be some whitespace in front of it as well. Encrypted and
44       * Base64 encoded content will *never* start with a '<' so this should be a safe check.
45       */
46      private static final Pattern IS_XML = Pattern.compile("^\\s*<");
47  
48      private static final EncryptionConverter encryptionConverter = new EncryptionConverter();
49  
50      @Override
51      public String convertToEntityAttribute(String dataValue) {
52          // can't pass 'null' to Matcher, so let's check that first
53          if (dataValue == null) {
54              return null;
55          }
56          Matcher matcher = IS_XML.matcher(dataValue);
57          if (matcher.lookingAt()) {
58              return dataValue;
59          }
60          return encryptionConverter.convertToEntityAttribute(dataValue);
61      }
62  
63      @Override
64      public String convertToDatabaseColumn(String attribute) {
65          return encryptionConverter.convertToDatabaseColumn(attribute);
66      }
67  }