1 /* GnuDHPrivateKey.java -- 2 Copyright (C) 2003, 2006 Free Software Foundation, Inc. 3 4 This file is a part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or (at 9 your option) any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19 USA 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.javax.crypto.key.dh; 40 41 import gnu.java.security.Configuration; 42 import gnu.java.security.Registry; 43 import gnu.java.security.action.GetPropertyAction; 44 import gnu.java.security.key.IKeyPairCodec; 45 46 import java.math.BigInteger; 47 import java.security.AccessController; 48 49 import javax.crypto.interfaces.DHPrivateKey; 50 51 /** 52 * An implementation of the Diffie-Hellman private key. 53 * <p> 54 * Reference: 55 * <ol> 56 * <li><a href="http://www.ietf.org/rfc/rfc2631.txt">Diffie-Hellman Key 57 * Agreement Method</a><br> 58 * Eric Rescorla.</li> 59 * </ol> 60 */ 61 public class GnuDHPrivateKey 62 extends GnuDHKey 63 implements DHPrivateKey 64 { 65 /** The private exponent. */ 66 private final BigInteger x; 67 /** String representation of this key. Cached for speed. */ 68 private transient String str; 69 70 /** 71 * Convenience constructor. Calls the constructor with five arguments passing 72 * {@link Registry#RAW_ENCODING_ID} as the value of its first argument. 73 * 74 * @param q a prime divisor of p-1. 75 * @param p the public prime. 76 * @param g the generator of the group. 77 * @param x the private value x. 78 */ GnuDHPrivateKey(BigInteger q, BigInteger p, BigInteger g, BigInteger x)79 public GnuDHPrivateKey(BigInteger q, BigInteger p, BigInteger g, BigInteger x) 80 { 81 this(Registry.RAW_ENCODING_ID, q, p, g, x); 82 } 83 84 /** 85 * Constructs a new instance of <code>GnuDHPrivateKey</code> given the 86 * designated parameters. 87 * 88 * @param preferredFormat the identifier of the encoding format to use by 89 * default when externalizing the key. 90 * @param q a prime divisor of p-1. 91 * @param p the public prime. 92 * @param g the generator of the group. 93 * @param x the private value x. 94 */ GnuDHPrivateKey(int preferredFormat, BigInteger q, BigInteger p, BigInteger g, BigInteger x)95 public GnuDHPrivateKey(int preferredFormat, BigInteger q, BigInteger p, 96 BigInteger g, BigInteger x) 97 { 98 super(preferredFormat == Registry.ASN1_ENCODING_ID ? Registry.PKCS8_ENCODING_ID 99 : preferredFormat, 100 q, p, g); 101 this.x = x; 102 } 103 104 /** 105 * A class method that takes the output of the <code>encodePrivateKey()</code> 106 * method of a DH keypair codec object (an instance implementing 107 * {@link IKeyPairCodec} for DH keys, and re-constructs an instance of this 108 * object. 109 * 110 * @param k the contents of a previously encoded instance of this object. 111 * @exception ArrayIndexOutOfBoundsException if there is not enough bytes, in 112 * <code>k</code>, to represent a valid encoding of an 113 * instance of this object. 114 * @exception IllegalArgumentException if the byte sequence does not represent 115 * a valid encoding of an instance of this object. 116 */ valueOf(byte[] k)117 public static GnuDHPrivateKey valueOf(byte[] k) 118 { 119 // try RAW codec 120 if (k[0] == Registry.MAGIC_RAW_DH_PRIVATE_KEY[0]) 121 try 122 { 123 return (GnuDHPrivateKey) new DHKeyPairRawCodec().decodePrivateKey(k); 124 } 125 catch (IllegalArgumentException ignored) 126 { 127 } 128 // try PKCS#8 codec 129 return (GnuDHPrivateKey) new DHKeyPairPKCS8Codec().decodePrivateKey(k); 130 } 131 getX()132 public BigInteger getX() 133 { 134 return x; 135 } 136 137 /** 138 * Returns the encoded form of this private key according to the designated 139 * format. 140 * 141 * @param format the desired format identifier of the resulting encoding. 142 * @return the byte sequence encoding this key according to the designated 143 * format. 144 * @exception IllegalArgumentException if the format is not supported. 145 * @see DHKeyPairRawCodec 146 */ getEncoded(int format)147 public byte[] getEncoded(int format) 148 { 149 byte[] result; 150 switch (format) 151 { 152 case IKeyPairCodec.RAW_FORMAT: 153 result = new DHKeyPairRawCodec().encodePrivateKey(this); 154 break; 155 case IKeyPairCodec.PKCS8_FORMAT: 156 result = new DHKeyPairPKCS8Codec().encodePrivateKey(this); 157 break; 158 default: 159 throw new IllegalArgumentException("Unsupported encoding format: " 160 + format); 161 } 162 return result; 163 } 164 165 /** 166 * Returns <code>true</code> if the designated object is an instance of 167 * {@link DHPrivateKey} and has the same parameter values as this one. 168 * 169 * @param obj the other non-null DH key to compare to. 170 * @return <code>true</code> if the designated object is of the same type 171 * and value as this one. 172 */ equals(Object obj)173 public boolean equals(Object obj) 174 { 175 if (obj == null) 176 return false; 177 178 if (! (obj instanceof DHPrivateKey)) 179 return false; 180 181 DHPrivateKey that = (DHPrivateKey) obj; 182 return super.equals(that) && x.equals(that.getX()); 183 } 184 toString()185 public String toString() 186 { 187 if (str == null) 188 { 189 String ls = (String) AccessController.doPrivileged 190 (new GetPropertyAction("line.separator")); 191 str = new StringBuilder(this.getClass().getName()).append("(") 192 .append(super.toString()).append(",").append(ls) 193 .append("x=0x").append(Configuration.DEBUG ? x.toString(16) 194 : "**...*").append(ls) 195 .append(")") 196 .toString(); 197 } 198 return str; 199 } 200 } 201