libjava/gnu/java/security/provider/GnuDSAPrivateKey.java

   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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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
  49 import java.math.BigInteger;
  50
  51 import java.security.interfaces.DSAPrivateKey;
  52 import java.security.interfaces.DSAParams;
  53 import java.security.spec.DSAParameterSpec;
  54
  55 import java.util.ArrayList;
  56
  57 public class GnuDSAPrivateKey implements DSAPrivateKey
  58 {
  59   private byte[] encodedKey;
  60   BigInteger x;
  61   BigInteger p;
  62   BigInteger q;
  63   BigInteger g;
  64
  65   public GnuDSAPrivateKey(BigInteger x, BigInteger p, BigInteger q, BigInteger g )
  66   {
  67     this.x = x;
  68     this.p = p;
  69     this.q = q;
  70     this.g = g;
  71   }
  72
  73   public String getAlgorithm()
  74   {
  75     return "DSA";
  76   }
  77
  78   public String getFormat()
  79   {
  80     return "PKCS#8";
  81   }
  82
  83   /**
  84    * Encodes this key as a <code>PrivateKeyInfo</code>, as described in
  85    * PKCS #8. The ASN.1 specification for this structure is:
  86    *
  87    * <blockquote><pre>
  88    * PrivateKeyInfo ::= SEQUENCE {
  89    *   version Version,
  90    *   privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
  91    *   privateKey PrivateKey,
  92    *   attributes [0] IMPLICIT Attributes OPTIONAL }
  93    *
  94    * Version ::= INTEGER
  95    *
  96    * PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier
  97    *
  98    * PrivateKey ::= OCTET STRING
  99    *
 100    * Attributes ::= SET OF Attribute
 101    * </pre></blockquote>
 102    *
 103    * <p>DSA private keys (in Classpath at least) have no attributes.
 104    */
 105   public byte[] getEncoded()
 106   {
 107     if (encodedKey != null)
 108       return (byte[]) encodedKey.clone();
 109     try
 110       {
 111         ByteArrayOutputStream out = new ByteArrayOutputStream();
 112         ArrayList pki = new ArrayList(3);
 113         pki.add(new DERValue(DER.INTEGER, BigInteger.ZERO));
 114         ArrayList algId = new ArrayList(2);
 115         algId.add(new DERValue(DER.OBJECT_IDENTIFIER,
 116                   new OID("1.2.840.10040.4.1")));
 117         ArrayList algParams = new ArrayList(3);
 118         algParams.add(new DERValue(DER.INTEGER, p));
 119         algParams.add(new DERValue(DER.INTEGER, q));
 120         algParams.add(new DERValue(DER.INTEGER, g));
 121         algId.add(new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, algParams));
 122         pki.add(new DERValue(DER.OCTET_STRING, x.toByteArray()));
 123         DERWriter.write(out, new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, pki));
 124         return (byte[]) (encodedKey = out.toByteArray()).clone();
 125       }
 126     catch (IOException ioe)
 127       {
 128         return null;
 129       }
 130   }
 131
 132   public DSAParams getParams()
 133   {
 134     return (DSAParams)(new DSAParameterSpec(p,q,g));
 135   }
 136
 137   public BigInteger getX()
 138   {
 139     return x;
 140   }
 141
 142   public String toString()
 143   {
 144     return "GnuDSAPrivateKey: x="
 145       + (x != null ? x.toString(16) : "null") + " p="
 146       + (p != null ? p.toString(16) : "null") + " q="
 147       + (q != null ? q.toString(16) : "null") + " g="
 148       + (g != null ? g.toString(16) : "null");
 149   }
 150 }