1 /*

     2  * Copyright (c) 1997, 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 com.sun.crypto.provider;

    27 

    28 import javax.crypto.SecretKey;

    29 import javax.crypto.SecretKeyFactorySpi;

    30 import javax.crypto.spec.DESedeKeySpec;

    31 import java.security.InvalidKeyException;

    32 import java.security.spec.KeySpec;

    33 import java.security.spec.InvalidKeySpecException;

    34 import javax.crypto.spec.SecretKeySpec;

    35 

    36 /**

    37  * This class implements the DES-EDE key factory of the Sun provider.

    38  *

    39  * @author Jan Luehe

    40  *

    41  */

    42 

    43 public final class DESedeKeyFactory extends SecretKeyFactorySpi {

    44 

    45     /**

    46      * Empty constructor

    47      */

    48     public DESedeKeyFactory() {

    49     }

    50 

    51     /**

    52      * Generates a <code>SecretKey</code> object from the provided key

    53      * specification (key material).

    54      *

    55      * @param keySpec the specification (key material) of the secret key

    56      *

    57      * @return the secret key

    58      *

    59      * @exception InvalidKeySpecException if the given key specification

    60      * is inappropriate for this key factory to produce a public key.

    61      */

    62     protected SecretKey engineGenerateSecret(KeySpec keySpec)

    63         throws InvalidKeySpecException {

    64 

    65         try {

    66             if (keySpec instanceof DESedeKeySpec) {

    67                 return new DESedeKey(((DESedeKeySpec)keySpec).getKey());

    68             }

    69             if (keySpec instanceof SecretKeySpec) {

    70                 return new DESedeKey(((SecretKeySpec)keySpec).getEncoded());

    71 

    72             }

    73             throw new InvalidKeySpecException

    74                 ("Inappropriate key specification");

    75         } catch (InvalidKeyException e) {

    76             throw new InvalidKeySpecException(e.getMessage());

    77         }

    78     }

    79 

    80     /**

    81      * Returns a specification (key material) of the given key

    82      * in the requested format.

    83      *

    84      * @param key the key

    85      *

    86      * @param keySpec the requested format in which the key material shall be

    87      * returned

    88      *

    89      * @return the underlying key specification (key material) in the

    90      * requested format

    91      *

    92      * @exception InvalidKeySpecException if the requested key specification is

    93      * inappropriate for the given key, or the given key cannot be processed

    94      * (e.g., the given key has an unrecognized algorithm or format).

    95      */

    96     protected KeySpec engineGetKeySpec(SecretKey key, Class<?> keySpec)

    97         throws InvalidKeySpecException {

    98 

    99         try {

   100             if ((key instanceof SecretKey)

   101                 && (key.getAlgorithm().equalsIgnoreCase("DESede"))

   102                 && (key.getFormat().equalsIgnoreCase("RAW"))) {

   103 

   104                 // Check if requested key spec is amongst the valid ones

   105                 if (DESedeKeySpec.class.isAssignableFrom(keySpec)) {

   106                     return new DESedeKeySpec(key.getEncoded());

   107 

   108                 } else {

   109                     throw new InvalidKeySpecException

   110                         ("Inappropriate key specification");

   111                 }

   112 

   113             } else {

   114                 throw new InvalidKeySpecException

   115                     ("Inappropriate key format/algorithm");

   116             }

   117         } catch (InvalidKeyException e) {

   118             throw new InvalidKeySpecException("Secret key has wrong size");

   119         }

   120     }

   121 

   122     /**

   123      * Translates a <code>SecretKey</code> object, whose provider may be

   124      * unknown or potentially untrusted, into a corresponding

   125      * <code>SecretKey</code> object of this key factory.

   126      *

   127      * @param key the key whose provider is unknown or untrusted

   128      *

   129      * @return the translated key

   130      *

   131      * @exception InvalidKeyException if the given key cannot be processed by

   132      * this key factory.

   133      */

   134     protected SecretKey engineTranslateKey(SecretKey key)

   135         throws InvalidKeyException {

   136 

   137         try {

   138 

   139             if ((key != null)

   140                 && (key.getAlgorithm().equalsIgnoreCase("DESede"))

   141                 && (key.getFormat().equalsIgnoreCase("RAW"))) {

   142                 // Check if key originates from this factory

   143                 if (key instanceof com.sun.crypto.provider.DESedeKey) {

   144                     return key;

   145                 }

   146                 // Convert key to spec

   147                 DESedeKeySpec desEdeKeySpec

   148                     = (DESedeKeySpec)engineGetKeySpec(key,

   149                                                       DESedeKeySpec.class);

   150                 // Create key from spec, and return it

   151                 return engineGenerateSecret(desEdeKeySpec);

   152 

   153             } else {

   154                 throw new InvalidKeyException

   155                     ("Inappropriate key format/algorithm");

   156             }

   157 

   158         } catch (InvalidKeySpecException e) {

   159             throw new InvalidKeyException("Cannot translate key");

   160         }

   161     }

   162 }