1/*
2 *  Licensed to the Apache Software Foundation (ASF) under one or more
3 *  contributor license agreements.  See the NOTICE file distributed with
4 *  this work for additional information regarding copyright ownership.
5 *  The ASF licenses this file to You under the Apache License, Version 2.0
6 *  (the "License"); you may not use this file except in compliance with
7 *  the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 */
17/**
18* @author Alexander Y. Kleymenov
19* @version $Revision$
20*/
21
22package javax.crypto.spec;
23
24import java.security.spec.AlgorithmParameterSpec;
25import java.util.Arrays;
26
27/**
28 * The algorithm parameter specification for an <i>initialization vector</i>.
29 */
30public class IvParameterSpec implements AlgorithmParameterSpec {
31
32    private final byte[] iv;
33
34    /**
35     * Creates a new <code>IvParameterSpec</code> instance with the bytes from
36     * the specified buffer <i>iv</i> used as <i>initialization vector</i>.
37     *
38     * @param iv
39     *            the buffer used as initialization vector.
40     * @throws NullPointerException
41     *             if the specified buffer is null.
42     */
43    public IvParameterSpec(byte[] iv) {
44        if (iv == null) {
45            throw new NullPointerException("iv == null");
46        }
47        this.iv = new byte[iv.length];
48        System.arraycopy(iv, 0, this.iv, 0, iv.length);
49    }
50
51    /**
52     * Creates a new <code>IvParameterSpec</code> instance with <code>byteCount</code>
53     * bytes from the specified buffer <code>iv</code> starting at
54     * <code>offset</code>.
55     *
56     * @throws IllegalArgumentException
57     *             if the specified buffer is null or <code>offset</code> and
58     *             <code>byteCount</code> do not specify a valid chunk in the
59     *             specified buffer.
60     * @throws ArrayIndexOutOfBoundsException
61     *             if <code>offset</code> or <code>byteCount</code> are negative.
62     */
63    public IvParameterSpec(byte[] iv, int offset, int byteCount) {
64        if ((iv == null) || (iv.length - offset < byteCount)) {
65            throw new IllegalArgumentException();
66        }
67        Arrays.checkOffsetAndCount(iv.length, offset, byteCount);
68        this.iv = new byte[byteCount];
69        System.arraycopy(iv, offset, this.iv, 0, byteCount);
70    }
71
72    /**
73     * Returns a copy of the <i>initialization vector</i> data.
74     *
75     * @return a copy of the initialization vector data.
76     */
77    public byte[] getIV() {
78        byte[] res = new byte[iv.length];
79        System.arraycopy(iv, 0, res, 0, iv.length);
80        return res;
81    }
82}
83