1 /*
2  * Copyright (c) 1997, 2020, 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 java.security.InvalidKeyException;
29 import java.security.ProviderException;
30 import sun.security.util.ArrayUtil;
31 import java.util.Objects;
32 import jdk.internal.vm.annotation.IntrinsicCandidate;
33 
34 /**
35  * This class represents ciphers in electronic codebook (ECB) mode.
36  *
37  * <p>This mode is implemented independently of a particular cipher.
38  * Ciphers to which this mode should apply (e.g., DES) must be
39  * <i>plugged-in</i> using the constructor.
40  *
41  * <p>NOTE: This class does not deal with buffering or padding.
42  *
43  * @author Gigi Ankeny
44  */
45 
46 final class ElectronicCodeBook extends FeedbackCipher {
47 
ElectronicCodeBook(SymmetricCipher embeddedCipher)48     ElectronicCodeBook(SymmetricCipher embeddedCipher) {
49         super(embeddedCipher);
50     }
51 
52     /**
53      * Gets the name of the feedback mechanism
54      *
55      * @return the name of the feedback mechanism
56      */
getFeedback()57     String getFeedback() {
58         return "ECB";
59     }
60 
61     /**
62      * Resets the iv to its original value.
63      * This is used when doFinal is called in the Cipher class, so that the
64      * cipher can be reused (with its original iv).
65      */
reset()66     void reset() {
67         // empty
68     }
69 
70     /**
71      * Save the current content of this cipher.
72      */
save()73     void save() {}
74 
75     /**
76      * Restores the content of this cipher to the previous saved one.
77      */
restore()78     void restore() {}
79 
80     /**
81      * Initializes the cipher in the specified mode with the given key
82      * and iv.
83      *
84      * @param decrypting flag indicating encryption or decryption
85      * @param algorithm the algorithm name
86      * @param key the key
87      * @param iv the iv
88      *
89      * @exception InvalidKeyException if the given key is inappropriate for
90      * initializing this cipher
91      */
init(boolean decrypting, String algorithm, byte[] key, byte[] iv)92     void init(boolean decrypting, String algorithm, byte[] key, byte[] iv)
93             throws InvalidKeyException {
94         if ((key == null) || (iv != null)) {
95             throw new InvalidKeyException("Internal error");
96         }
97         embeddedCipher.init(decrypting, algorithm, key);
98     }
99 
100     @IntrinsicCandidate
implECBEncrypt(byte [] in, int inOff, int len, byte[] out, int outOff)101     private int implECBEncrypt(byte [] in, int inOff, int len, byte[] out, int outOff) {
102         for (int i = len; i >= blockSize; i -= blockSize) {
103             embeddedCipher.encryptBlock(in, inOff, out, outOff);
104             inOff += blockSize;
105             outOff += blockSize;
106         }
107         return len;
108     }
109 
110     /**
111      * Performs encryption operation.
112      *
113      * <p>The input plain text <code>in</code>, starting at
114      * <code>inOff</code> and ending at * <code>(inOff + len - 1)</code>,
115      * is encrypted. The result is stored in <code>out</code>, starting at
116      * <code>outOff</code>.
117      *
118      * @param in the buffer with the input data to be encrypted
119      * @param inOff the offset in <code>plain</code>
120      * @param len the length of the input data
121      * @param out the buffer for the result
122      * @param outOff the offset in <code>cipher</code>
123      * @exception ProviderException if <code>len</code> is not
124      * a multiple of the block size
125      * @return the length of the encrypted data
126      */
encrypt(byte[] in, int inOff, int len, byte[] out, int outOff)127     int encrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {
128         ArrayUtil.blockSizeCheck(len, blockSize);
129         ArrayUtil.nullAndBoundsCheck(in, inOff, len);
130         ArrayUtil.nullAndBoundsCheck(out, outOff, len);
131         return implECBEncrypt(in, inOff, len, out, outOff);
132     }
133 
134     @IntrinsicCandidate
implECBDecrypt(byte [] in, int inOff, int len, byte[] out, int outOff)135     private int implECBDecrypt(byte [] in, int inOff, int len, byte[] out, int outOff) {
136         for (int i = len; i >= blockSize; i -= blockSize) {
137             embeddedCipher.decryptBlock(in, inOff, out, outOff);
138             inOff += blockSize;
139             outOff += blockSize;
140         }
141         return len;
142     }
143 
144     /**
145      * Performs decryption operation.
146      *
147      * <p>The input cipher text <code>in</code>, starting at
148      * <code>inOff</code> and ending at * <code>(inOff + len - 1)</code>,
149      * is decrypted.The result is stored in <code>out</code>, starting at
150      * <code>outOff</code>.
151      *
152      * @param in the buffer with the input data to be decrypted
153      * @param inOff the offset in <code>cipherOffset</code>
154      * @param len the length of the input data
155      * @param out the buffer for the result
156      * @param outOff the offset in <code>plain</code>
157      * @exception ProviderException if <code>len</code> is not
158      * a multiple of the block size
159      * @return the length of the decrypted data
160      */
decrypt(byte[] in, int inOff, int len, byte[] out, int outOff)161     int decrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {
162         ArrayUtil.blockSizeCheck(len, blockSize);
163         ArrayUtil.nullAndBoundsCheck(in, inOff, len);
164         ArrayUtil.nullAndBoundsCheck(out, outOff, len);
165         return implECBDecrypt(in, inOff, len, out, outOff);
166    }
167 }
168