1 /*

     2  * Copyright (c) 2017, 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.krb5.internal.crypto;

    27 

    28 import sun.security.krb5.Checksum;

    29 import sun.security.krb5.KrbCryptoException;

    30 import sun.security.krb5.internal.*;

    31 import java.security.GeneralSecurityException;

    32 

    33 /*

    34  * This class encapsulates the checksum type for aes128-cts-sha256

    35  */

    36 

    37 public class HmacSha2Aes128CksumType extends CksumType {

    38 

    39     public HmacSha2Aes128CksumType() {

    40     }

    41 

    42     public int confounderSize() {

    43         return 16;

    44     }

    45 

    46     public int cksumType() {

    47         return Checksum.CKSUMTYPE_HMAC_SHA256_128_AES128;

    48     }

    49 

    50     public boolean isSafe() {

    51         return true;

    52     }

    53 

    54     public int cksumSize() {

    55         return 16;  // bytes

    56     }

    57 

    58     public int keyType() {

    59         return Krb5.KEYTYPE_AES;

    60     }

    61 

    62     public int keySize() {

    63         return 16;   // bytes

    64     }

    65 

    66     public byte[] calculateChecksum(byte[] data, int size) {

    67         return null;

    68     }

    69 

    70     /**

    71      * Calculates keyed checksum.

    72      * @param data the data used to generate the checksum.

    73      * @param size length of the data.

    74      * @param key the key used to encrypt the checksum.

    75      * @return keyed checksum.

    76      */

    77     public byte[] calculateKeyedChecksum(byte[] data, int size, byte[] key,

    78         int usage) throws KrbCryptoException {

    79 

    80          try {

    81             return Aes128Sha2.calculateChecksum(key, usage, data, 0, size);

    82          } catch (GeneralSecurityException e) {

    83             KrbCryptoException ke = new KrbCryptoException(e.getMessage());

    84             ke.initCause(e);

    85             throw ke;

    86          }

    87     }

    88 

    89     /**

    90      * Verifies keyed checksum.

    91      * @param data the data.

    92      * @param size the length of data.

    93      * @param key the key used to encrypt the checksum.

    94      * @param checksum the checksum.

    95      * @return true if verification is successful.

    96      */

    97     public boolean verifyKeyedChecksum(byte[] data, int size,

    98         byte[] key, byte[] checksum, int usage) throws KrbCryptoException {

    99 

   100          try {

   101             byte[] newCksum = Aes128Sha2.calculateChecksum(key, usage,

   102                                                         data, 0, size);

   103             return isChecksumEqual(checksum, newCksum);

   104          } catch (GeneralSecurityException e) {

   105             KrbCryptoException ke = new KrbCryptoException(e.getMessage());

   106             ke.initCause(e);

   107             throw ke;

   108          }

   109     }

   110 }