1 /* DHParameterSpec.java -- Parameters for Diffie-Hellman keys. 2 Copyright (C) 2004 Free Software Foundation, Inc. 3 4 This file is 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, or (at your option) 9 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; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 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 javax.crypto.spec; 40 41 import java.math.BigInteger; 42 import java.security.spec.AlgorithmParameterSpec; 43 44 /** 45 * The base set of parameters necessary to perform Diffie-Hellman key 46 * exchange. Each party in the key exchange shares these parameters. 47 * 48 * <p>Each set of parameters consists of a <i>base generator</i> 49 * <code>g</code>, a <i>prime modulus</i> <code>p</code>, and an 50 * optional length, in bits, of the private exponent. 51 * 52 * <p>See <a href="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-3/">PKCS 53 * #3 - Diffie-Hellman Key Agreement Standard</a> for more information. 54 * 55 * @author Casey Marshall (csm@gnu.org) 56 * @since 1.4 57 * @see javax.crypto.KeyAgreement 58 */ 59 public class DHParameterSpec implements AlgorithmParameterSpec 60 { 61 62 // Variables. 63 // ------------------------------------------------------------------------ 64 65 /** The base generator g. */ 66 private BigInteger g; 67 68 /** The prime modulus p. */ 69 private BigInteger p; 70 71 /** The length, in bits, of the private exponent. */ 72 private int l; 73 74 // Constructors. 75 // ------------------------------------------------------------------------ 76 77 /** 78 * Create a new set of Diffie-Hellman parameters. 79 * 80 * @param p The prime modulus. 81 * @param g The base generator. 82 */ DHParameterSpec(BigInteger p, BigInteger g)83 public DHParameterSpec(BigInteger p, BigInteger g) 84 { 85 this(p, g, 0); 86 } 87 88 /** 89 * Create a new set of Diffie-Hellman parameters. 90 * 91 * @param p The prime modulus. 92 * @param g The base generator. 93 * @param l The size of the private exponent, in bits. 94 */ DHParameterSpec(BigInteger p, BigInteger g, int l)95 public DHParameterSpec(BigInteger p, BigInteger g, int l) 96 { 97 this.p = p; 98 this.g = g; 99 this.l = l; 100 } 101 102 // Instance methods. 103 // ------------------------------------------------------------------------ 104 105 /** 106 * Get the base generator, <i>g</i>. 107 * 108 * @return The base generator <i>g</i>. 109 */ getG()110 public BigInteger getG() 111 { 112 return g; 113 } 114 115 /** 116 * Get the length of the private exponent, in bits. 117 * 118 * @return The length of the private exponent, in bits, or 0 if this 119 * has not been explicitly set. 120 */ getL()121 public int getL() 122 { 123 return l; 124 } 125 126 /** 127 * Get the prime modulus, <i>p</i>. 128 * 129 * @return The prime modulus, <i>p</i>. 130 */ getP()131 public BigInteger getP() 132 { 133 return p; 134 } 135 } 136