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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         byte[] otherString = ((KeyIdentifier)other).octetString;
    152         return java.util.Arrays.equals(octetString, otherString);
    153     }
    154 }
    155