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

   1: /* GnuRSAPrivateKey.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.Configuration;
  44: import gnu.java.security.action.GetPropertyAction;
  45: import gnu.java.security.Registry;
  46: import gnu.java.security.key.IKeyPairCodec;
  47: 
  48: import java.math.BigInteger;
  49: import java.security.AccessController;
  50: import java.security.PrivateKey;
  51: import java.security.interfaces.RSAPrivateCrtKey;
  52: import java.security.interfaces.RSAPrivateKey;
  53: 
  54: /**
  55:  * An object that embodies an RSA private key.
  56:  * <p>
  57:  * References:
  58:  * <ol>
  59:  * <li><a
  60:  * href="http://www.cosic.esat.kuleuven.ac.be/nessie/workshop/submissions/rsa-pss.zip">
  61:  * RSA-PSS Signature Scheme with Appendix, part B.</a><br>
  62:  * Primitive specification and supporting documentation.<br>
  63:  * Jakob Jonsson and Burt Kaliski.</li>
  64:  * </ol>
  65:  */
  66: public class GnuRSAPrivateKey
  67:     extends GnuRSAKey
  68:     implements PrivateKey, RSAPrivateCrtKey
  69: {
  70:   /** The first prime divisor of the modulus. */
  71:   private final BigInteger p;
  72: 
  73:   /** The second prime divisor of the modulus. */
  74:   private final BigInteger q;
  75: 
  76:   /** The private exponent of an RSA private key. */
  77:   private final BigInteger d;
  78: 
  79:   /** The first factor's exponent. */
  80:   private final BigInteger dP;
  81: 
  82:   /** The second factor's exponent. */
  83:   private final BigInteger dQ;
  84: 
  85:   /** The CRT (Chinese Remainder Theorem) coefficient. */
  86:   private final BigInteger qInv;
  87: 
  88:   /** String representation of this key. Cached for speed. */
  89:   private transient String str;
  90: 
  91:   /**
  92:    * Convenience constructor. Calls the constructor with 5 arguments passing
  93:    * {@link Registry#RAW_ENCODING_ID} as the identifier of the preferred
  94:    * encoding format.
  95:    *
  96:    * @param p the modulus first prime divisor.
  97:    * @param q the modulus second prime divisor.
  98:    * @param e the public exponent.
  99:    * @param d the private exponent.
 100:    */
 101:   public GnuRSAPrivateKey(BigInteger p, BigInteger q, BigInteger e, BigInteger d)
 102:   {
 103:     this(Registry.RAW_ENCODING_ID, p, q, e, d);
 104:   }
 105: 
 106:   /**
 107:    * Constructs a new instance of a <code>GnuRSAPrivateKey</code> given the
 108:    * designated arguments.
 109:    *
 110:    * @param preferredFormat the indetifier of the preferred encoding format to
 111:    *          use when externalizing this key.
 112:    * @param p the modulus first prime divisor.
 113:    * @param q the modulus second prime divisor.
 114:    * @param e the public exponent.
 115:    * @param d the private exponent.
 116:    */
 117:   public GnuRSAPrivateKey(int preferredFormat, BigInteger p, BigInteger q,
 118:                           BigInteger e, BigInteger d)
 119:   {
 120:     this(preferredFormat,
 121:          p.multiply(q),
 122:          e, d, p, q,
 123:          e.modInverse(p.subtract(BigInteger.ONE)),
 124:          e.modInverse(q.subtract(BigInteger.ONE)),
 125:          q.modInverse(p));
 126:   }
 127: 
 128:   /**
 129:    * Constructs a new instance of a <code>GnuRSAPrivateKey</code> given the
 130:    * designated arguments.
 131:    *
 132:    * @param preferredFormat the indetifier of the preferred encoding format to
 133:    *          use when externalizing this key.
 134:    * @param n the public modulus, which is also the product of <code>p</code>
 135:    *          and <code>q</code>.
 136:    * @param e the public exponent.
 137:    * @param d the private exponent.
 138:    * @param p the modulus first prime divisor.
 139:    * @param q the modulus second prime divisor.
 140:    * @param dP the first prime's exponen. A positive integer less than
 141:    *          <code>p</code> and <code>q</code>, satisfying
 142:    *          <code>e * dP = 1 (mod p-1)</code>.
 143:    * @param dQ the second prime's exponent. A positive integer less than
 144:    *          <code>p</code> and <code>q</code>, satisfying
 145:    *          <code>e * dQ = 1 (mod p-1)</code>.
 146:    * @param qInv the Chinese Remainder Theorem coefiicient. A positive integer
 147:    *          less than <code>p</code>, satisfying
 148:    *          <code>q * qInv = 1 (mod p)</code>.
 149:    */
 150:   public GnuRSAPrivateKey(int preferredFormat, BigInteger n, BigInteger e,
 151:                           BigInteger d, BigInteger p, BigInteger q,
 152:                           BigInteger dP, BigInteger dQ, BigInteger qInv)
 153:   {
 154:     super(preferredFormat == Registry.ASN1_ENCODING_ID ? Registry.PKCS8_ENCODING_ID
 155:                                                        : preferredFormat,
 156:           n, e);
 157:     this.d = d;
 158:     this.p = p;
 159:     this.q = q;
 160:     // the exponents dP and dQ are positive integers less than p and q
 161:     // respectively satisfying
 162:     // e * dP = 1 (mod p-1);
 163:     // e * dQ = 1 (mod q-1),
 164:     this.dP = dP;
 165:     this.dQ = dQ;
 166:     // the CRT coefficient qInv is a positive integer less than p satisfying
 167:     // q * qInv = 1 (mod p).
 168:     this.qInv = qInv;
 169:   }
 170: 
 171:   /**
 172:    * A class method that takes the output of the <code>encodePrivateKey()</code>
 173:    * method of an RSA keypair codec object (an instance implementing
 174:    * {@link IKeyPairCodec} for RSA keys, and re-constructs an instance of this
 175:    * object.
 176:    *
 177:    * @param k the contents of a previously encoded instance of this object.
 178:    * @throws ArrayIndexOutOfBoundsException if there is not enough bytes, in
 179:    *           <code>k</code>, to represent a valid encoding of an instance
 180:    *           of this object.
 181:    * @throws IllegalArgumentException if the byte sequence does not represent a
 182:    *           valid encoding of an instance of this object.
 183:    */
 184:   public static GnuRSAPrivateKey valueOf(final byte[] k)
 185:   {
 186:     // try RAW codec
 187:     if (k[0] == Registry.MAGIC_RAW_RSA_PRIVATE_KEY[0])
 188:       try
 189:         {
 190:           return (GnuRSAPrivateKey) new RSAKeyPairRawCodec().decodePrivateKey(k);
 191:         }
 192:       catch (IllegalArgumentException ignored)
 193:         {
 194:         }
 195:     // try PKCS#8 codec
 196:     return (GnuRSAPrivateKey) new RSAKeyPairPKCS8Codec().decodePrivateKey(k);
 197:   }
 198: 
 199:   public BigInteger getPrimeP()
 200:   {
 201:     return p;
 202:   }
 203: 
 204:   public BigInteger getPrimeQ()
 205:   {
 206:     return q;
 207:   }
 208: 
 209:   public BigInteger getPrimeExponentP()
 210:   {
 211:     return dP;
 212:   }
 213: 
 214:   public BigInteger getPrimeExponentQ()
 215:   {
 216:     return dQ;
 217:   }
 218: 
 219:   public BigInteger getCrtCoefficient()
 220:   {
 221:     return qInv;
 222:   }
 223: 
 224:   public BigInteger getPrivateExponent()
 225:   {
 226:     return d;
 227:   }
 228: 
 229:   /**
 230:    * Returns the encoded form of this private key according to the designated
 231:    * format.
 232:    *
 233:    * @param format the desired format identifier of the resulting encoding.
 234:    * @return the byte sequence encoding this key according to the designated
 235:    *         format.
 236:    * @throws IllegalArgumentException if the format is not supported.
 237:    * @see RSAKeyPairRawCodec
 238:    * @see RSAKeyPairPKCS8Codec
 239:    */
 240:   public byte[] getEncoded(int format)
 241:   {
 242:     final byte[] result;
 243:     switch (format)
 244:       {
 245:       case IKeyPairCodec.RAW_FORMAT:
 246:         result = new RSAKeyPairRawCodec().encodePrivateKey(this);
 247:         break;
 248:       case IKeyPairCodec.PKCS8_FORMAT:
 249:         result = new RSAKeyPairPKCS8Codec().encodePrivateKey(this);
 250:         break;
 251:       default:
 252:         throw new IllegalArgumentException("Unsupported encoding format: "
 253:                                            + format);
 254:       }
 255:     return result;
 256:   }
 257: 
 258:   /**
 259:    * Returns <code>true</code> if the designated object is an instance of this
 260:    * class and has the same RSA parameter values as this one.
 261:    *
 262:    * @param obj the other non-null RSA key to compare to.
 263:    * @return <code>true</code> if the designated object is of the same type
 264:    *         and value as this one.
 265:    */
 266:   public boolean equals(final Object obj)
 267:   {
 268:     if (obj == null)
 269:       return false;
 270: 
 271:     if (obj instanceof RSAPrivateKey)
 272:       {
 273:         final RSAPrivateKey that = (RSAPrivateKey) obj;
 274:         return super.equals(that) && d.equals(that.getPrivateExponent());
 275:       }
 276:     if (obj instanceof RSAPrivateCrtKey)
 277:       {
 278:         final RSAPrivateCrtKey that = (RSAPrivateCrtKey) obj;
 279:         return super.equals(that) && p.equals(that.getPrimeP())
 280:                && q.equals(that.getPrimeQ())
 281:                && dP.equals(that.getPrimeExponentP())
 282:                && dQ.equals(that.getPrimeExponentQ())
 283:                && qInv.equals(that.getCrtCoefficient());
 284:       }
 285:     return false;
 286:   }
 287: 
 288:   public String toString()
 289:   {
 290:     if (str == null)
 291:       {
 292:         String ls = (String) AccessController.doPrivileged
 293:             (new GetPropertyAction("line.separator"));
 294:         str = new CPStringBuilder(this.getClass().getName()).append("(")
 295:             .append(super.toString()).append(",").append(ls)
 296:             .append("d=0x").append(Configuration.DEBUG ? d.toString(16)
 297:                                                        : "**...*").append(ls)
 298:             .append("p=0x").append(Configuration.DEBUG ? p.toString(16)
 299:                                                        : "**...*").append(ls)
 300:             .append("q=0x").append(Configuration.DEBUG ? q.toString(16)
 301:                                                        : "**...*").append(ls)
 302:             .append("dP=0x").append(Configuration.DEBUG ? dP.toString(16)
 303:                                                         : "**...*").append(ls)
 304:             .append("dQ=0x").append(Configuration.DEBUG ? dQ.toString(16)
 305:                                                         : "**...*").append(ls)
 306:             .append("qInv=0x").append(Configuration.DEBUG ? qInv.toString(16)
 307:                                                           : "**...*").append(ls)
 308:             .append(")")
 309:             .toString();
 310:       }
 311:     return str;
 312:   }
 313: }