1 /*
   2  * Copyright (c) 2003, 2011, 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</code>.
  67      * @param timestamp A signature timestamp.
  68      *                  If <code>null</code> then no timestamp was generated
  69      *                  for the signature.
  70      * @throws NullPointerException if <code>signerCertPath</code> is
  71      *                              <code>null</code>.
  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</code> 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 }