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
26package sun.security.x509;
27
28import java.io.IOException;
29import java.security.PublicKey;
30import java.security.MessageDigest;
31import java.security.NoSuchAlgorithmException;
32
33import sun.misc.HexDumpEncoder;
34import sun.security.util.*;
35
36/**
37 * Represent the Key Identifier ASN.1 object.
38 *
39 * @author Amit Kapoor
40 * @author Hemma Prafullchandra
41 */
42public 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}
155