J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2007 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.crypto.spec; |
| 27 | |
| 28 | import java.security.spec.AlgorithmParameterSpec; |
| 29 | |
| 30 | /** |
| 31 | * This class specifies an <i>initialization vector</i> (IV). |
| 32 | * Examples which use IVs are ciphers in feedback mode, |
| 33 | * e.g., DES in CBC mode and RSA ciphers with OAEP encoding |
| 34 | * operation. |
| 35 | * |
| 36 | * @author Jan Luehe |
| 37 | * |
| 38 | * @since 1.4 |
| 39 | */ |
| 40 | public class IvParameterSpec implements AlgorithmParameterSpec { |
| 41 | |
| 42 | private byte[] iv; |
| 43 | |
| 44 | /** |
| 45 | * Creates an IvParameterSpec object using the bytes in <code>iv</code> |
| 46 | * as the IV. |
| 47 | * |
| 48 | * @param iv the buffer with the IV. The contents of the |
| 49 | * buffer are copied to protect against subsequent modification. |
| 50 | * @throws NullPointerException if <code>iv</code> is <code>null</code> |
| 51 | */ |
| 52 | public IvParameterSpec(byte[] iv) { |
| 53 | this(iv, 0, iv.length); |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * Creates an IvParameterSpec object using the first <code>len</code> |
| 58 | * bytes in <code>iv</code>, beginning at <code>offset</code> |
| 59 | * inclusive, as the IV. |
| 60 | * |
| 61 | * <p> The bytes that constitute the IV are those between |
| 62 | * <code>iv[offset]</code> and <code>iv[offset+len-1]</code> inclusive. |
| 63 | * |
| 64 | * @param iv the buffer with the IV. The first <code>len</code> |
| 65 | * bytes of the buffer beginning at <code>offset</code> inclusive |
| 66 | * are copied to protect against subsequent modification. |
| 67 | * @param offset the offset in <code>iv</code> where the IV |
| 68 | * starts. |
| 69 | * @param len the number of IV bytes. |
| 70 | * @throws IllegalArgumentException if <code>iv</code> is <code>null</code> |
| 71 | * or <code>(iv.length - offset < len)</code> |
| 72 | * @throws ArrayIndexOutOfBoundsException is thrown if <code>offset</code> |
| 73 | * or <code>len</code> index bytes outside the <code>iv</code>. |
| 74 | */ |
| 75 | public IvParameterSpec(byte[] iv, int offset, int len) { |
| 76 | if (iv == null) { |
| 77 | throw new IllegalArgumentException("IV missing"); |
| 78 | } |
| 79 | if (iv.length - offset < len) { |
| 80 | throw new IllegalArgumentException |
| 81 | ("IV buffer too short for given offset/length combination"); |
| 82 | } |
| 83 | if (len < 0) { |
| 84 | throw new ArrayIndexOutOfBoundsException("len is negative"); |
| 85 | } |
| 86 | this.iv = new byte[len]; |
| 87 | System.arraycopy(iv, offset, this.iv, 0, len); |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Returns the initialization vector (IV). |
| 92 | * |
| 93 | * @return the initialization vector (IV). Returns a new array |
| 94 | * each time this method is called. |
| 95 | */ |
| 96 | public byte[] getIV() { |
| 97 | return (byte[])this.iv.clone(); |
| 98 | } |
| 99 | } |