Source for javax.crypto.spec.DHParameterSpec

   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:    */
  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:    */
  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:    */
 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:    */
 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:    */
 131:   public BigInteger getP()
 132:   {
 133:     return p;
 134:   }
 135: }