Source for gnu.java.security.key.dss.DSSKeyPairPKCS8Codec

   1: /* DSSKeyPairPKCS8Codec.java -- PKCS#8 Encoding/Decoding handler
   2:    Copyright (C) 2006 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.key.dss;
  40: 
  41: import gnu.java.security.Configuration;
  42: import gnu.java.security.OID;
  43: import gnu.java.security.Registry;
  44: import gnu.java.security.der.DER;
  45: import gnu.java.security.der.DERReader;
  46: import gnu.java.security.der.DERValue;
  47: import gnu.java.security.der.DERWriter;
  48: import gnu.java.security.key.IKeyPairCodec;
  49: import gnu.java.security.util.DerUtil;
  50: import gnu.java.security.util.Util;
  51: 
  52: import java.io.ByteArrayOutputStream;
  53: import java.io.IOException;
  54: import java.math.BigInteger;
  55: import java.security.InvalidParameterException;
  56: import java.security.PrivateKey;
  57: import java.security.PublicKey;
  58: import java.util.ArrayList;
  59: import java.util.logging.Logger;
  60: 
  61: /**
  62:  * An implementation of an {@link IKeyPairCodec} that knows how to encode /
  63:  * decode PKCS#8 ASN.1 external representation of DSS private keys.
  64:  *
  65:  * @author Casey Marshall (rsdio@metastatic.org)
  66:  */
  67: public class DSSKeyPairPKCS8Codec
  68:     implements IKeyPairCodec
  69: {
  70:   private static final Logger log = Logger.getLogger(DSSKeyPairPKCS8Codec.class.getName());
  71:   private static final OID DSA_ALG_OID = new OID(Registry.DSA_OID_STRING);
  72: 
  73:   // implicit 0-arguments constructor
  74: 
  75:   public int getFormatID()
  76:   {
  77:     return PKCS8_FORMAT;
  78:   }
  79: 
  80:   /**
  81:    * @throws InvalidParameterException ALWAYS.
  82:    */
  83:   public byte[] encodePublicKey(PublicKey key)
  84:   {
  85:     throw new InvalidParameterException("Wrong format for public keys");
  86:   }
  87: 
  88:   /**
  89:    * Returns the PKCS#8 ASN.1 <i>PrivateKeyInfo</i> representation of a DSA
  90:    * private key. The ASN.1 specification is as follows:
  91:    *
  92:    * <pre>
  93:    *   PrivateKeyInfo ::= SEQUENCE {
  94:    *     version              INTEGER, -- MUST be 0
  95:    *     privateKeyAlgorithm  AlgorithmIdentifier,
  96:    *     privateKey           OCTET STRING
  97:    *   }
  98:    *
  99:    *   AlgorithmIdentifier ::= SEQUENCE {
 100:    *     algorithm   OBJECT IDENTIFIER,
 101:    *     parameters  ANY DEFINED BY algorithm OPTIONAL
 102:    *   }
 103:    *
 104:    *   DssParams ::= SEQUENCE {
 105:    *     p   INTEGER,
 106:    *     q   INTEGER,
 107:    *     g   INTEGER
 108:    *   }
 109:    * </pre>
 110:    *
 111:    * @return the DER encoded form of the ASN.1 representation of the
 112:    *         <i>PrivateKeyInfo</i> field in an X.509 certificate.
 113:    * @throw InvalidParameterException if an error occurs during the marshalling
 114:    *        process.
 115:    */
 116:   public byte[] encodePrivateKey(PrivateKey key)
 117:   {
 118:     if (! (key instanceof DSSPrivateKey))
 119:       throw new InvalidParameterException("Wrong key type");
 120: 
 121:     DERValue derVersion = new DERValue(DER.INTEGER, BigInteger.ZERO);
 122: 
 123:     DERValue derOID = new DERValue(DER.OBJECT_IDENTIFIER, DSA_ALG_OID);
 124: 
 125:     DSSPrivateKey pk = (DSSPrivateKey) key;
 126:     BigInteger p = pk.getParams().getP();
 127:     BigInteger q = pk.getParams().getQ();
 128:     BigInteger g = pk.getParams().getG();
 129:     BigInteger x = pk.getX();
 130: 
 131:     ArrayList params = new ArrayList(3);
 132:     params.add(new DERValue(DER.INTEGER, p));
 133:     params.add(new DERValue(DER.INTEGER, q));
 134:     params.add(new DERValue(DER.INTEGER, g));
 135:     DERValue derParams = new DERValue(DER.CONSTRUCTED | DER.SEQUENCE, params);
 136: 
 137:     ArrayList algorithmID = new ArrayList(2);
 138:     algorithmID.add(derOID);
 139:     algorithmID.add(derParams);
 140:     DERValue derAlgorithmID = new DERValue(DER.CONSTRUCTED | DER.SEQUENCE,
 141:                                            algorithmID);
 142: 
 143:     // The OCTET STRING is the DER encoding of an INTEGER.
 144:     DERValue derX = new DERValue(DER.INTEGER, x);
 145:     DERValue derPrivateKey = new DERValue(DER.OCTET_STRING, derX.getEncoded());
 146: 
 147:     ArrayList pki = new ArrayList(3);
 148:     pki.add(derVersion);
 149:     pki.add(derAlgorithmID);
 150:     pki.add(derPrivateKey);
 151:     DERValue derPKI = new DERValue(DER.CONSTRUCTED | DER.SEQUENCE, pki);
 152: 
 153:     byte[] result;
 154:     ByteArrayOutputStream baos = new ByteArrayOutputStream();
 155:     try
 156:       {
 157:         DERWriter.write(baos, derPKI);
 158:         result = baos.toByteArray();
 159:       }
 160:     catch (IOException e)
 161:       {
 162:         InvalidParameterException y = new InvalidParameterException(e.getMessage());
 163:         y.initCause(e);
 164:         throw y;
 165:       }
 166:     return result;
 167:   }
 168: 
 169:   /**
 170:    * @throws InvalidParameterException ALWAYS.
 171:    */
 172:   public PublicKey decodePublicKey(byte[] input)
 173:   {
 174:     throw new InvalidParameterException("Wrong format for public keys");
 175:   }
 176: 
 177:   /**
 178:    * @param input the byte array to unmarshall into a valid DSS
 179:    *          {@link PrivateKey} instance. MUST NOT be null.
 180:    * @return a new instance of a {@link DSSPrivateKey} decoded from the
 181:    *         <i>PrivateKeyInfo</i> material fed as <code>input</code>.
 182:    * @throw InvalidParameterException if an exception occurs during the
 183:    *        unmarshalling process.
 184:    */
 185:   public PrivateKey decodePrivateKey(byte[] input)
 186:   {
 187:     if (Configuration.DEBUG)
 188:       log.entering(this.getClass().getName(), "decodePrivateKey");
 189:     if (input == null)
 190:       throw new InvalidParameterException("Input bytes MUST NOT be null");
 191: 
 192:     BigInteger version, p, q, g, x;
 193:     DERReader der = new DERReader(input);
 194:     try
 195:       {
 196:         DERValue derPKI = der.read();
 197:         DerUtil.checkIsConstructed(derPKI, "Wrong PrivateKeyInfo field");
 198: 
 199:         DERValue derVersion = der.read();
 200:         if (! (derVersion.getValue() instanceof BigInteger))
 201:           throw new InvalidParameterException("Wrong Version field");
 202: 
 203:         version = (BigInteger) derVersion.getValue();
 204:         if (version.compareTo(BigInteger.ZERO) != 0)
 205:           throw new InvalidParameterException("Unexpected Version: " + version);
 206: 
 207:         DERValue derAlgoritmID = der.read();
 208:         DerUtil.checkIsConstructed(derAlgoritmID, "Wrong AlgorithmIdentifier field");
 209: 
 210:         DERValue derOID = der.read();
 211:         OID algOID = (OID) derOID.getValue();
 212:         if (! algOID.equals(DSA_ALG_OID))
 213:           throw new InvalidParameterException("Unexpected OID: " + algOID);
 214: 
 215:         DERValue derParams = der.read();
 216:         DerUtil.checkIsConstructed(derParams, "Wrong DSS Parameters field");
 217: 
 218:         DERValue val = der.read();
 219:         DerUtil.checkIsBigInteger(val, "Wrong P field");
 220:         p = (BigInteger) val.getValue();
 221:         val = der.read();
 222:         DerUtil.checkIsBigInteger(val, "Wrong Q field");
 223:         q = (BigInteger) val.getValue();
 224:         val = der.read();
 225:         DerUtil.checkIsBigInteger(val, "Wrong G field");
 226:         g = (BigInteger) val.getValue();
 227: 
 228:         val = der.read();
 229:         if (Configuration.DEBUG)
 230:           log.fine("val = " + val);
 231:         byte[] xBytes = (byte[]) val.getValue();
 232:         if (Configuration.DEBUG)
 233:           log.fine(Util.dumpString(xBytes, "xBytes: "));
 234:         DERReader der2 = new DERReader(xBytes);
 235:         val = der2.read();
 236:         DerUtil.checkIsBigInteger(val, "Wrong X field");
 237:         x = (BigInteger) val.getValue();
 238:       }
 239:     catch (IOException e)
 240:       {
 241:         InvalidParameterException y = new InvalidParameterException(e.getMessage());
 242:         y.initCause(e);
 243:         throw y;
 244:       }
 245:     if (Configuration.DEBUG)
 246:       log.exiting(this.getClass().getName(), "decodePrivateKey");
 247:     return new DSSPrivateKey(Registry.PKCS8_ENCODING_ID, p, q, g, x);
 248:   }
 249: }