Source for gnu.java.security.provider.GnuDSAPrivateKey

   1: /* GnuDSAPrivateKey.java --- Gnu DSA Private Key
   2:    Copyright (C) 1999,2003,2004  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 gnu.java.security.provider;
  40: 
  41: import gnu.java.security.OID;
  42: import gnu.java.security.der.DER;
  43: import gnu.java.security.der.DERValue;
  44: import gnu.java.security.der.DERWriter;
  45: 
  46: import java.io.ByteArrayOutputStream;
  47: import java.io.IOException;
  48: import java.math.BigInteger;
  49: import java.security.interfaces.DSAParams;
  50: import java.security.interfaces.DSAPrivateKey;
  51: import java.security.spec.DSAParameterSpec;
  52: import java.util.ArrayList;
  53: 
  54: public class GnuDSAPrivateKey implements DSAPrivateKey
  55: {
  56:   private byte[] encodedKey;
  57:   BigInteger x;
  58:   BigInteger p;
  59:   BigInteger q;
  60:   BigInteger g;
  61: 
  62:   public GnuDSAPrivateKey(BigInteger x, BigInteger p, BigInteger q, BigInteger g )
  63:   {
  64:     this.x = x;
  65:     this.p = p;
  66:     this.q = q;
  67:     this.g = g;
  68:   }
  69: 
  70:   public String getAlgorithm()
  71:   {
  72:     return "DSA";
  73:   }
  74: 
  75:   public String getFormat()
  76:   {
  77:     return "PKCS#8";
  78:   }
  79: 
  80:   /**
  81:    * Encodes this key as a <code>PrivateKeyInfo</code>, as described in
  82:    * PKCS #8. The ASN.1 specification for this structure is:
  83:    *
  84:    * <blockquote><pre>
  85:    * PrivateKeyInfo ::= SEQUENCE {
  86:    *   version Version,
  87:    *   privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
  88:    *   privateKey PrivateKey,
  89:    *   attributes [0] IMPLICIT Attributes OPTIONAL }
  90:    *
  91:    * Version ::= INTEGER
  92:    *
  93:    * PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier
  94:    *
  95:    * PrivateKey ::= OCTET STRING
  96:    *
  97:    * Attributes ::= SET OF Attribute
  98:    * </pre></blockquote>
  99:    *
 100:    * <p>DSA private keys (in Classpath at least) have no attributes.
 101:    */
 102:   public byte[] getEncoded()
 103:   {
 104:     if (encodedKey != null)
 105:       return (byte[]) encodedKey.clone();
 106:     try
 107:       {
 108:         ByteArrayOutputStream out = new ByteArrayOutputStream();
 109:         ArrayList pki = new ArrayList(3);
 110:         pki.add(new DERValue(DER.INTEGER, BigInteger.ZERO));
 111:         ArrayList algId = new ArrayList(2);
 112:         algId.add(new DERValue(DER.OBJECT_IDENTIFIER,
 113:                   new OID("1.2.840.10040.4.1")));
 114:         ArrayList algParams = new ArrayList(3);
 115:         algParams.add(new DERValue(DER.INTEGER, p));
 116:         algParams.add(new DERValue(DER.INTEGER, q));
 117:         algParams.add(new DERValue(DER.INTEGER, g));
 118:         algId.add(new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, algParams));
 119:         pki.add(new DERValue(DER.OCTET_STRING, x.toByteArray()));
 120:         DERWriter.write(out, new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, pki));
 121:         return (byte[]) (encodedKey = out.toByteArray()).clone();
 122:       }
 123:     catch (IOException ioe)
 124:       {
 125:         return null;
 126:       }
 127:   }
 128: 
 129:   public DSAParams getParams()
 130:   {
 131:     return (DSAParams)(new DSAParameterSpec(p,q,g));
 132:   }
 133: 
 134:   public BigInteger getX()
 135:   {
 136:     return x;
 137:   }
 138: 
 139:   public String toString()
 140:   {
 141:     return "GnuDSAPrivateKey: x="
 142:       + (x != null ? x.toString(16) : "null") + " p="
 143:       + (p != null ? p.toString(16) : "null") + " q="
 144:       + (q != null ? q.toString(16) : "null") + " g="
 145:       + (g != null ? g.toString(16) : "null");
 146:   }
 147: }