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1   /*
2    * Copyright (c) 1997, 1999, 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 sun.security.x509;
27  
28  import java.io.IOException;
29  import java.security.PublicKey;
30  import java.security.MessageDigest;
31  import java.security.NoSuchAlgorithmException;
32  
33  import sun.misc.HexDumpEncoder;
34  import sun.security.util.*;
35  
36  /**
37   * Represent the Key Identifier ASN.1 object.
38   *
39   * @author Amit Kapoor
40   * @author Hemma Prafullchandra
41   */
42  public class KeyIdentifier {
43      private byte[] octetString;
44  
45      /**
46       * Create a KeyIdentifier with the passed bit settings.
47       *
48       * @param octetString the octet string identifying the key identifier.
49       */
50      public KeyIdentifier(byte[] octetString) {
51          this.octetString = octetString.clone();
52      }
53  
54      /**
55       * Create a KeyIdentifier from the DER encoded value.
56       *
57       * @param val the DerValue
58       */
59      public KeyIdentifier(DerValue val) throws IOException {
60          octetString = val.getOctetString();
61      }
62  
63      /**
64       * Creates a KeyIdentifier from a public-key value.
65       *
66       * <p>From RFC2459: Two common methods for generating key identifiers from
67       * the public key are:
68       * <ol>
69       * <li>The keyIdentifier is composed of the 160-bit SHA-1 hash of the
70       * value of the BIT STRING subjectPublicKey (excluding the tag,
71       * length, and number of unused bits).
72       * <p>
73       * <li>The keyIdentifier is composed of a four bit type field with
74       * the value 0100 followed by the least significant 60 bits of the
75       * SHA-1 hash of the value of the BIT STRING subjectPublicKey.
76       * </ol>
77       * <p>This method supports method 1.
78       *
79       * @param pubKey the public key from which to construct this KeyIdentifier
80       * @throws IOException on parsing errors
81       */
82      public KeyIdentifier(PublicKey pubKey)
83          throws IOException
84      {
85          DerValue algAndKey = new DerValue(pubKey.getEncoded());
86          if (algAndKey.tag != DerValue.tag_Sequence)
87              throw new IOException("PublicKey value is not a valid "
88                                    + "X.509 public key");
89  
90          AlgorithmId algid = AlgorithmId.parse(algAndKey.data.getDerValue());
91          byte[] key = algAndKey.data.getUnalignedBitString().toByteArray();
92  
93          MessageDigest md = null;
94          try {
95              md = MessageDigest.getInstance("SHA1");
96          } catch (NoSuchAlgorithmException e3) {
97              throw new IOException("SHA1 not supported");
98          }
99          md.update(key);
100         this.octetString = md.digest();
101     }
102 
103     /**
104      * Return the value of the KeyIdentifier as byte array.
105      */
106     public byte[] getIdentifier() {
107         return octetString.clone();
108     }
109 
110     /**
111      * Returns a printable representation of the KeyUsage.
112      */
113     public String toString() {
114         String s = "KeyIdentifier [\n";
115 
116         HexDumpEncoder encoder = new HexDumpEncoder();
117         s += encoder.encodeBuffer(octetString);
118         s += "]\n";
119         return (s);
120     }
121 
122     /**
123      * Write the KeyIdentifier to the DerOutputStream.
124      *
125      * @param out the DerOutputStream to write the object to.
126      * @exception IOException
127      */
128     void encode(DerOutputStream out) throws IOException {
129         out.putOctetString(octetString);
130     }
131 
132     /**
133      * Returns a hash code value for this object.
134      * Objects that are equal will also have the same hashcode.
135      */
136     public int hashCode () {
137         int retval = 0;
138         for (int i = 0; i < octetString.length; i++)
139             retval += octetString[i] * i;
140         return retval;
141     }
142 
143     /**
144      * Indicates whether some other object is "equal to" this one.
145      */
146     public boolean equals(Object other) {
147         if (this == other)
148             return true;
149         if (!(other instanceof KeyIdentifier))
150             return false;
151         return java.util.Arrays.equals(octetString,
152                                        ((KeyIdentifier)other).getIdentifier());
153     }
154 }