Source for gnu.java.security.key.rsa.GnuRSAKey

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