Source for javax.crypto.EncryptedPrivateKeyInfo

   1: /* EncryptedPrivateKeyInfo.java -- As in PKCS #8.
   2:    Copyright (C) 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 javax.crypto;
  40: 
  41: import gnu.java.security.OID;
  42: import gnu.java.security.der.DER;
  43: import gnu.java.security.der.DERReader;
  44: import gnu.java.security.der.DERValue;
  45: 
  46: import java.io.IOException;
  47: import java.security.AlgorithmParameters;
  48: import java.security.NoSuchAlgorithmException;
  49: import java.security.spec.InvalidKeySpecException;
  50: import java.security.spec.PKCS8EncodedKeySpec;
  51: import java.util.ArrayList;
  52: import java.util.List;
  53: 
  54: /**
  55:  * An implementation of the <code>EncryptedPrivateKeyInfo</code> ASN.1
  56:  * type as specified in <a
  57:  * href="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-8/">PKCS #8 -
  58:  * Private-Key Information Syntax Standard</a>.
  59:  *
  60:  * <p>The ASN.1 type <code>EncryptedPrivateKeyInfo</code> is:
  61:  *
  62:  * <blockquote>
  63:  * <pre>EncryptedPrivateKeyInfo ::= SEQUENCE {
  64:  *   encryptionAlgorithm EncryptionAlgorithmIdentifier,
  65:  *   encryptedData EncryptedData }
  66:  *
  67:  * EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
  68:  *
  69:  * EncrytpedData ::= OCTET STRING
  70:  *
  71:  * AlgorithmIdentifier ::= SEQUENCE {
  72:  *   algorithm  OBJECT IDENTIFIER,
  73:  *   parameters ANY DEFINED BY algorithm OPTIONAL }</pre>
  74:  * </blockquote>
  75:  *
  76:  * @author Casey Marshall (csm@gnu.org)
  77:  * @since 1.4
  78:  * @see java.security.spec.PKCS8EncodedKeySpec
  79:  */
  80: public class EncryptedPrivateKeyInfo
  81: {
  82: 
  83:   // Fields.
  84:   // ------------------------------------------------------------------------
  85: 
  86:   /** The encrypted data. */
  87:   private byte[] encryptedData;
  88: 
  89:   /** The encoded, encrypted key. */
  90:   private byte[] encoded;
  91: 
  92:   /** The OID of the encryption algorithm. */
  93:   private OID algOid;
  94: 
  95:   /** The encryption algorithm name. */
  96:   private String algName;
  97: 
  98:   /** The encryption algorithm's parameters. */
  99:   private AlgorithmParameters params;
 100: 
 101:   /** The encoded ASN.1 algorithm parameters. */
 102:   private byte[] encodedParams;
 103: 
 104:   // Constructors.
 105:   // ------------------------------------------------------------------------
 106: 
 107:   /**
 108:    * Create a new <code>EncryptedPrivateKeyInfo</code> object from raw
 109:    * encrypted data and the parameters used for encryption.
 110:    *
 111:    * <p>The <code>encryptedData</code> array is cloned.
 112:    *
 113:    * @param params        The encryption algorithm parameters.
 114:    * @param encryptedData The encrypted key data.
 115:    * @throws java.lang.IllegalArgumentException If the
 116:    *         <code>encryptedData</code> array is empty (zero-length).
 117:    * @throws java.security.NoSuchAlgorithmException If the algorithm
 118:    *         specified in the parameters is not supported.
 119:    * @throws java.lang.NullPointerException If <code>encryptedData</code>
 120:    *         is null.
 121:    */
 122:   public EncryptedPrivateKeyInfo(AlgorithmParameters params,
 123:                                  byte[] encryptedData)
 124:     throws IllegalArgumentException, NoSuchAlgorithmException
 125:   {
 126:     if (encryptedData.length == 0)
 127:       {
 128:         throw new IllegalArgumentException("0-length encryptedData");
 129:       }
 130:     this.params = params;
 131:     algName = params.getAlgorithm ();
 132:     algOid = getOid (algName);
 133:     this.encryptedData = (byte[]) encryptedData.clone();
 134:   }
 135: 
 136:   /**
 137:    * Create a new <code>EncryptedPrivateKeyInfo</code> from an encoded
 138:    * representation, parsing the ASN.1 sequence.
 139:    *
 140:    * @param encoded The encoded info.
 141:    * @throws java.io.IOException If parsing the encoded data fails.
 142:    * @throws java.lang.NullPointerException If <code>encoded</code> is
 143:    *         null.
 144:    */
 145:   public EncryptedPrivateKeyInfo(byte[] encoded)
 146:     throws IOException
 147:   {
 148:     this.encoded = (byte[]) encoded.clone();
 149:     decode();
 150:   }
 151: 
 152:   /**
 153:    * Create a new <code>EncryptedPrivateKeyInfo</code> from the cipher
 154:    * name and the encrytpedData.
 155:    *
 156:    * <p>The <code>encryptedData</code> array is cloned.
 157:    *
 158:    * @param algName       The name of the algorithm (as an object identifier).
 159:    * @param encryptedData The encrypted key data.
 160:    * @throws java.lang.IllegalArgumentException If the
 161:    *         <code>encryptedData</code> array is empty (zero-length).
 162:    * @throws java.security.NoSuchAlgorithmException If algName is not
 163:    *         the name of a supported algorithm.
 164:    * @throws java.lang.NullPointerException If <code>encryptedData</code>
 165:    *         is null.
 166:    */
 167:   public EncryptedPrivateKeyInfo(String algName, byte[] encryptedData)
 168:     throws IllegalArgumentException, NoSuchAlgorithmException,
 169:            NullPointerException
 170:   {
 171:     if (encryptedData.length == 0)
 172:       {
 173:         throw new IllegalArgumentException("0-length encryptedData");
 174:       }
 175:     this.algName = algName.toString (); // do NP check
 176:     this.algOid = getOid (algName);
 177:     this.encryptedData = (byte[]) encryptedData.clone();
 178:   }
 179: 
 180:   /**
 181:    * Return the OID for the given cipher name.
 182:    *
 183:    * @param str The string.
 184:    * @throws NoSuchAlgorithmException If the OID is not known.
 185:    */
 186:   private static OID getOid (final String str)
 187:     throws NoSuchAlgorithmException
 188:   {
 189:     if (str.equalsIgnoreCase ("DSA"))
 190:       {
 191:         return new OID ("1.2.840.10040.4.3");
 192:       }
 193:     // FIXME add more
 194: 
 195:     try
 196:       {
 197:         return new OID (str);
 198:       }
 199:     catch (Throwable t)
 200:       {
 201:       }
 202:     throw new NoSuchAlgorithmException ("cannot determine OID for '" + str + "'");
 203:   }
 204: 
 205:   // Instance methods.
 206:   // ------------------------------------------------------------------------
 207: 
 208:   /**
 209:    * Return the name of the cipher used to encrypt this key.
 210:    *
 211:    * @return The algorithm name.
 212:    */
 213:   public String getAlgName()
 214:   {
 215:     return algOid.toString();
 216:   }
 217: 
 218:   public AlgorithmParameters getAlgParameters()
 219:   {
 220:     if (params == null && encodedParams != null)
 221:       {
 222:         try
 223:           {
 224:             params = AlgorithmParameters.getInstance(getAlgName());
 225:             params.init(encodedParams);
 226:           }
 227:         catch (NoSuchAlgorithmException ignore)
 228:           {
 229:             // FIXME throw exception?
 230:           }
 231:         catch (IOException ignore)
 232:           {
 233:           }
 234:       }
 235:     return params;
 236:   }
 237: 
 238:   public synchronized byte[] getEncoded() throws IOException
 239:   {
 240:     if (encoded == null) encode();
 241:     return (byte[]) encoded.clone();
 242:   }
 243: 
 244:   public byte[] getEncryptedData()
 245:   {
 246:     return encryptedData;
 247:   }
 248: 
 249:   public PKCS8EncodedKeySpec getKeySpec(Cipher cipher)
 250:     throws InvalidKeySpecException
 251:   {
 252:     try
 253:       {
 254:         return new PKCS8EncodedKeySpec(cipher.doFinal(encryptedData));
 255:       }
 256:     catch (Exception x)
 257:       {
 258:         throw new InvalidKeySpecException(x.toString());
 259:       }
 260:   }
 261: 
 262:   // Own methods.
 263:   // -------------------------------------------------------------------------
 264: 
 265:   private void decode() throws IOException
 266:   {
 267:     DERReader der = new DERReader(encoded);
 268:     DERValue val = der.read();
 269:     if (val.getTag() != DER.SEQUENCE)
 270:       throw new IOException("malformed EncryptedPrivateKeyInfo");
 271:     val = der.read();
 272:     if (val.getTag() != DER.SEQUENCE)
 273:       throw new IOException("malformed AlgorithmIdentifier");
 274:     int algpLen = val.getLength();
 275:     DERValue oid = der.read();
 276:     if (oid.getTag() != DER.OBJECT_IDENTIFIER)
 277:       throw new IOException("malformed AlgorithmIdentifier");
 278:     algOid = (OID) oid.getValue();
 279:     if (algpLen == 0)
 280:       {
 281:         val = der.read();
 282:         if (val.getTag() != 0)
 283:           {
 284:             encodedParams = val.getEncoded();
 285:             der.read();
 286:           }
 287:       }
 288:     else if (oid.getEncodedLength() < val.getLength())
 289:       {
 290:         val = der.read();
 291:         encodedParams = val.getEncoded();
 292:       }
 293:     val = der.read();
 294:     if (val.getTag() != DER.OCTET_STRING)
 295:       throw new IOException("malformed AlgorithmIdentifier");
 296:     encryptedData = (byte[]) val.getValue();
 297:   }
 298: 
 299:   private void encode() throws IOException
 300:   {
 301:     List algId = new ArrayList(2);
 302:     algId.add(new DERValue(DER.OBJECT_IDENTIFIER, algOid));
 303:     getAlgParameters();
 304:     if (params != null)
 305:       {
 306:         algId.add (DERReader.read (params.getEncoded()));
 307:       }
 308:     else
 309:       {
 310:         algId.add (new DERValue (DER.NULL, null));
 311:       }
 312:     List epki = new ArrayList(2);
 313:     epki.add(new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, algId));
 314:     epki.add(new DERValue(DER.OCTET_STRING, encryptedData));
 315:     encoded = new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, epki).getEncoded();
 316:   }
 317: }