1 /*
2 * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
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 de.smartics.properties.api.core.security;
17
18 import javax.crypto.Cipher;
19 import javax.crypto.SecretKey;
20
21 import org.apache.commons.codec.binary.Base64;
22
23 import de.smartics.properties.api.core.domain.PropertyDescriptor;
24 import de.smartics.properties.api.core.domain.PropertyDescriptorMessageBean;
25
26 /**
27 * Base implementation based on Java security.
28 */
29 public abstract class AbstractPropertyValueSecurity implements
30 PropertyValueSecurity
31 {
32 // ********************************* Fields *********************************
33
34 // --- constants ------------------------------------------------------------
35
36 /**
37 * The class version identifier.
38 */
39 private static final long serialVersionUID = 1L;
40
41 // --- members --------------------------------------------------------------
42
43 // ****************************** Initializer *******************************
44
45 // ****************************** Constructors ******************************
46
47 /**
48 * Default constructor.
49 */
50 protected AbstractPropertyValueSecurity()
51 {
52 }
53
54 // ****************************** Inner Classes *****************************
55
56 // ********************************* Methods ********************************
57
58 // --- init -----------------------------------------------------------------
59
60 // --- get&set --------------------------------------------------------------
61
62 // --- business -------------------------------------------------------------
63
64 /**
65 * Decrypts the given property value.
66 *
67 * @param descriptor the descriptor of the property.
68 * @param encryptedValue the encrypted value of the property to be decrypted.
69 * @param key the key used for decryption.
70 * @param cipher the cipher instance for decryption.
71 * @return the decrypted value.
72 * @throws NullPointerException may be thrown if {@code descriptor} is
73 * <code>null</code>.
74 * @throws SecurityException if the value cannot be decrypted.
75 */
76 protected String decrypt(final PropertyDescriptor descriptor,
77 final String encryptedValue, final SecretKey key, final Cipher cipher)
78 throws NullPointerException, SecurityException
79 {
80 try
81 {
82 cipher.init(Cipher.DECRYPT_MODE, key);
83 final byte[] decodedBytes = decodePropertyValue(encryptedValue);
84 final byte[] decryptedBytes = cipher.doFinal(decodedBytes);
85 final String plainValue = new String(decryptedBytes, "UTF-8");
86 return plainValue;
87 }
88 catch (final Exception e)
89 {
90 throw new SecurityException(new PropertyDescriptorMessageBean(
91 SecurityCode.DECRYPTION_FAILED, e, descriptor));
92 }
93 }
94
95 /**
96 * Encrypts the given property value.
97 *
98 * @param descriptor the descriptor of the property.
99 * @param plainValue the plain value of the property to be encrypted.
100 * @param key the key used for encryption.
101 * @param cipher the cipher instance for encryption.
102 * @return the encrypted value.
103 * @throws NullPointerException may be thrown if {@code descriptor} is
104 * <code>null</code>.
105 * @throws SecurityException if the value cannot be encrypted.
106 */
107 protected String encrypt(final PropertyDescriptor descriptor,
108 final String plainValue, final SecretKey key, final Cipher cipher)
109 throws NullPointerException, SecurityException
110 {
111 try
112 {
113 cipher.init(Cipher.ENCRYPT_MODE, key);
114 final byte[] bytes = plainValue.getBytes("UTF-8");
115 final byte[] encryptedBytes = cipher.doFinal(bytes);
116 final String encryptedValue = encodePropertyValue(encryptedBytes);
117 return encryptedValue;
118 }
119 catch (final Exception e)
120 {
121 throw new SecurityException(new PropertyDescriptorMessageBean(
122 SecurityCode.ENCRYPTION_FAILED, e, descriptor));
123 }
124 }
125
126 /**
127 * Decodes the encrypted property value.
128 *
129 * @param encryptedValue the encrypted value to decode.
130 * @return the decoded value.
131 */
132 protected byte[] decodePropertyValue(final String encryptedValue)
133 {
134 final byte[] decodedValue = Base64.decodeBase64(encryptedValue);
135 return decodedValue;
136 }
137
138 /**
139 * Encodes the encrypted bytes.
140 *
141 * @param encryptedBytes the bytes to encode.
142 * @return the encoded bytes.
143 */
144 protected String encodePropertyValue(final byte[] encryptedBytes)
145 {
146 final String encodedValue = Base64.encodeBase64String(encryptedBytes);
147 return encodedValue;
148 }
149
150 // --- object basics --------------------------------------------------------
151
152 }