libjava/classpath/gnu/java/security/key/rsa/GnuRSAKey.java

   1 /* GnuRSAKey.java --
   2    Copyright 2001, 2002, 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.java.security.key.rsa;
  40
  41 import gnu.classpath.SystemProperties;
  42 import gnu.java.security.Registry;
  43 import gnu.java.security.util.FormatUtil;
  44
  45 import java.math.BigInteger;
  46 import java.security.Key;
  47 import java.security.interfaces.RSAKey;
  48
  49 /**
  50  * <p>A base asbtract class for both public and private RSA keys.</p>
  51  */
  52 public abstract class GnuRSAKey implements Key, RSAKey
  53 {
  54
  55   // Constants and variables
  56   // -------------------------------------------------------------------------
  57
  58   /** The public modulus of an RSA key pair. */
  59   private final BigInteger n;
  60
  61   /** The public exponent of an RSA key pair. */
  62   private final BigInteger e;
  63
  64   /**
  65    * Identifier of the default encoding format to use when externalizing the
  66    * key material.
  67    */
  68   protected final int defaultFormat;
  69
  70   /** String representation of this key. Cached for speed. */
  71   private transient String str;
  72
  73   // Constructor(s)
  74   // -------------------------------------------------------------------------
  75
  76   /**
  77    * Trivial protected constructor.
  78    *
  79    * @param defaultFormat the identifier of the encoding format to use by
  80    *          default when externalizing the key.
  81    * @param n the public modulus <code>n</code>.
  82    * @param e the public exponent <code>e</code>.
  83    */
  84   protected GnuRSAKey(int defaultFormat, BigInteger n, BigInteger e)
  85   {
  86     super();
  87
  88     this.defaultFormat = defaultFormat <= 0 ? Registry.RAW_ENCODING_ID
  89                                             : defaultFormat;
  90     this.n = n;
  91     this.e = e;
  92   }
  93
  94   // Class methods
  95   // -------------------------------------------------------------------------
  96
  97   // Instance methods
  98   // -------------------------------------------------------------------------
  99
 100   // java.security.interfaces.RSAKey interface implementation ----------------
 101
 102   public BigInteger getModulus()
 103   {
 104     return getN();
 105   }
 106
 107   // java.security.Key interface implementation ------------------------------
 108
 109   public String getAlgorithm()
 110   {
 111     return Registry.RSA_KPG;
 112   }
 113
 114   /** @deprecated see getEncoded(int). */
 115   public byte[] getEncoded()
 116   {
 117     return getEncoded(defaultFormat);
 118   }
 119
 120   public String getFormat()
 121   {
 122     return FormatUtil.getEncodingShortName(defaultFormat);
 123   }
 124
 125   // Other instance methods --------------------------------------------------
 126
 127   /**
 128    * <p>Returns the modulus <code>n</code>.</p>
 129    *
 130    * @return the modulus <code>n</code>.
 131    */
 132   public BigInteger getN()
 133   {
 134     return n;
 135   }
 136
 137   /**
 138    * <p>Returns the public exponent <code>e</code>.</p>
 139    *
 140    * @return the public exponent <code>e</code>.
 141    */
 142   public BigInteger getPublicExponent()
 143   {
 144     return getE();
 145   }
 146
 147   /**
 148    * <p>Same as {@link #getPublicExponent()}.</p>
 149    *
 150    * @return the public exponent <code>e</code>.
 151    */
 152   public BigInteger getE()
 153   {
 154     return e;
 155   }
 156
 157   /**
 158    * <p>Returns <code>true</code> if the designated object is an instance of
 159    * {@link RSAKey} and has the same RSA parameter values as this one.</p>
 160    *
 161    * @param obj the other non-null RSA key to compare to.
 162    * @return <code>true</code> if the designated object is of the same type and
 163    * value as this one.
 164    */
 165   public boolean equals(final Object obj)
 166   {
 167     if (obj == null)
 168       {
 169         return false;
 170       }
 171     if (!(obj instanceof RSAKey))
 172       {
 173         return false;
 174       }
 175     final RSAKey that = (RSAKey) obj;
 176     return n.equals(that.getModulus());
 177   }
 178
 179   public String toString()
 180   {
 181     if (str == null)
 182       {
 183         String ls = SystemProperties.getProperty("line.separator");
 184         str = new StringBuilder().append(ls)
 185             .append("defaultFormat=").append(defaultFormat).append(",").append(ls)
 186             .append("n=0x").append(n.toString(16)).append(",").append(ls)
 187             .append("e=0x").append(e.toString(16))
 188             .toString();
 189       }
 190     return str;
 191   }
 192
 193   // abstract methods to be implemented by subclasses ------------------------
 194
 195   public abstract byte[] getEncoded(int format);
 196 }