View Javadoc
1   /*
2    * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package java.security;
27  
28  import java.io.*;
29  import java.security.cert.CertPath;
30  
31  /**
32   * This class encapsulates information about a code signer.
33   * It is immutable.
34   *
35   * @since 1.5
36   * @author Vincent Ryan
37   */
38  
39  public final class CodeSigner implements Serializable {
40  
41      private static final long serialVersionUID = 6819288105193937581L;
42  
43      /**
44       * The signer's certificate path.
45       *
46       * @serial
47       */
48      private CertPath signerCertPath;
49  
50      /*
51       * The signature timestamp.
52       *
53       * @serial
54       */
55      private Timestamp timestamp;
56  
57      /*
58       * Hash code for this code signer.
59       */
60      private transient int myhash = -1;
61  
62      /**
63       * Constructs a CodeSigner object.
64       *
65       * @param signerCertPath The signer's certificate path.
66       *                       It must not be {@code null}.
67       * @param timestamp A signature timestamp.
68       *                  If {@code null} then no timestamp was generated
69       *                  for the signature.
70       * @throws NullPointerException if {@code signerCertPath} is
71       *                              {@code null}.
72       */
73      public CodeSigner(CertPath signerCertPath, Timestamp timestamp) {
74          if (signerCertPath == null) {
75              throw new NullPointerException();
76          }
77          this.signerCertPath = signerCertPath;
78          this.timestamp = timestamp;
79      }
80  
81      /**
82       * Returns the signer's certificate path.
83       *
84       * @return A certificate path.
85       */
86      public CertPath getSignerCertPath() {
87          return signerCertPath;
88      }
89  
90      /**
91       * Returns the signature timestamp.
92       *
93       * @return The timestamp or {@code null} if none is present.
94       */
95      public Timestamp getTimestamp() {
96          return timestamp;
97      }
98  
99      /**
100      * Returns the hash code value for this code signer.
101      * The hash code is generated using the signer's certificate path and the
102      * timestamp, if present.
103      *
104      * @return a hash code value for this code signer.
105      */
106     public int hashCode() {
107         if (myhash == -1) {
108             if (timestamp == null) {
109                 myhash = signerCertPath.hashCode();
110             } else {
111                 myhash = signerCertPath.hashCode() + timestamp.hashCode();
112             }
113         }
114         return myhash;
115     }
116 
117     /**
118      * Tests for equality between the specified object and this
119      * code signer. Two code signers are considered equal if their
120      * signer certificate paths are equal and if their timestamps are equal,
121      * if present in both.
122      *
123      * @param obj the object to test for equality with this object.
124      *
125      * @return true if the objects are considered equal, false otherwise.
126      */
127     public boolean equals(Object obj) {
128         if (obj == null || (!(obj instanceof CodeSigner))) {
129             return false;
130         }
131         CodeSigner that = (CodeSigner)obj;
132 
133         if (this == that) {
134             return true;
135         }
136         Timestamp thatTimestamp = that.getTimestamp();
137         if (timestamp == null) {
138             if (thatTimestamp != null) {
139                 return false;
140             }
141         } else {
142             if (thatTimestamp == null ||
143                 (! timestamp.equals(thatTimestamp))) {
144                 return false;
145             }
146         }
147         return signerCertPath.equals(that.getSignerCertPath());
148     }
149 
150     /**
151      * Returns a string describing this code signer.
152      *
153      * @return A string comprising the signer's certificate and a timestamp,
154      *         if present.
155      */
156     public String toString() {
157         StringBuffer sb = new StringBuffer();
158         sb.append("(");
159         sb.append("Signer: " + signerCertPath.getCertificates().get(0));
160         if (timestamp != null) {
161             sb.append("timestamp: " + timestamp);
162         }
163         sb.append(")");
164         return sb.toString();
165     }
166 
167     // Explicitly reset hash code value to -1
168     private void readObject(ObjectInputStream ois)
169         throws IOException, ClassNotFoundException {
170      ois.defaultReadObject();
171      myhash = -1;
172     }
173 }