1 /*
   2  * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.security.rsa;
  27 
  28 import java.io.IOException;
  29 import java.math.BigInteger;
  30 
  31 import java.security.*;
  32 import java.security.interfaces.*;
  33 
  34 import sun.security.util.*;
  35 import sun.security.pkcs.PKCS8Key;
  36 
  37 /**
  38  * Key implementation for RSA private keys, non-CRT form (modulus, private
  39  * exponent only). For CRT private keys, see RSAPrivateCrtKeyImpl. We need
  40  * separate classes to ensure correct behavior in instanceof checks, etc.
  41  *
  42  * Note: RSA keys must be at least 512 bits long
  43  *
  44  * @see RSAPrivateCrtKeyImpl
  45  * @see RSAKeyFactory
  46  *
  47  * @since   1.5
  48  * @author  Andreas Sterbenz
  49  */
  50 public final class RSAPrivateKeyImpl extends PKCS8Key implements RSAPrivateKey {
  51 
  52     private static final long serialVersionUID = -33106691987952810L;
  53 
  54     private final BigInteger n;         // modulus
  55     private final BigInteger d;         // private exponent
  56 
  57     /**
  58      * Construct a key from its components. Used by the
  59      * RSAKeyFactory and the RSAKeyPairGenerator.
  60      */
  61     RSAPrivateKeyImpl(BigInteger n, BigInteger d) throws InvalidKeyException {
  62         this.n = n;
  63         this.d = d;
  64         RSAKeyFactory.checkRSAProviderKeyLengths(n.bitLength(), null);
  65         // generate the encoding
  66         algid = RSAPrivateCrtKeyImpl.rsaId;
  67         try {
  68             DerOutputStream out = new DerOutputStream();
  69             out.putInteger(0); // version must be 0
  70             out.putInteger(n);
  71             out.putInteger(0);
  72             out.putInteger(d);
  73             out.putInteger(0);
  74             out.putInteger(0);
  75             out.putInteger(0);
  76             out.putInteger(0);
  77             out.putInteger(0);
  78             DerValue val =
  79                 new DerValue(DerValue.tag_Sequence, out.toByteArray());
  80             key = val.toByteArray();
  81         } catch (IOException exc) {
  82             // should never occur
  83             throw new InvalidKeyException(exc);
  84         }
  85     }
  86 
  87     // see JCA doc
  88     public String getAlgorithm() {
  89         return "RSA";
  90     }
  91 
  92     // see JCA doc
  93     public BigInteger getModulus() {
  94         return n;
  95     }
  96 
  97     // see JCA doc
  98     public BigInteger getPrivateExponent() {
  99         return d;
 100     }
 101 }