J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1998-2007 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 the parameters used with the |
| 32 | * <a href="http://www.ietf.org/rfc/rfc2268.txt"><i>RC2</i></a> |
| 33 | * algorithm. |
| 34 | * |
| 35 | * <p> The parameters consist of an effective key size and optionally |
| 36 | * an 8-byte initialization vector (IV) (only in feedback mode). |
| 37 | * |
| 38 | * <p> This class can be used to initialize a <code>Cipher</code> object that |
| 39 | * implements the <i>RC2</i> algorithm. |
| 40 | * |
| 41 | * @author Jan Luehe |
| 42 | * |
| 43 | * @since 1.4 |
| 44 | */ |
| 45 | public class RC2ParameterSpec implements AlgorithmParameterSpec { |
| 46 | |
| 47 | private byte[] iv = null; |
| 48 | private int effectiveKeyBits; |
| 49 | |
| 50 | /** |
| 51 | * Constructs a parameter set for RC2 from the given effective key size |
| 52 | * (in bits). |
| 53 | * |
| 54 | * @param effectiveKeyBits the effective key size in bits. |
| 55 | */ |
| 56 | public RC2ParameterSpec(int effectiveKeyBits) { |
| 57 | this.effectiveKeyBits = effectiveKeyBits; |
| 58 | } |
| 59 | |
| 60 | /** |
| 61 | * Constructs a parameter set for RC2 from the given effective key size |
| 62 | * (in bits) and an 8-byte IV. |
| 63 | * |
| 64 | * <p> The bytes that constitute the IV are those between |
| 65 | * <code>iv[0]</code> and <code>iv[7]</code> inclusive. |
| 66 | * |
| 67 | * @param effectiveKeyBits the effective key size in bits. |
| 68 | * @param iv the buffer with the 8-byte IV. The first 8 bytes of |
| 69 | * the buffer are copied to protect against subsequent modification. |
| 70 | * @exception IllegalArgumentException if <code>iv</code> is null. |
| 71 | */ |
| 72 | public RC2ParameterSpec(int effectiveKeyBits, byte[] iv) { |
| 73 | this(effectiveKeyBits, iv, 0); |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Constructs a parameter set for RC2 from the given effective key size |
| 78 | * (in bits) and IV. |
| 79 | * |
| 80 | * <p> The IV is taken from <code>iv</code>, starting at |
| 81 | * <code>offset</code> inclusive. |
| 82 | * The bytes that constitute the IV are those between |
| 83 | * <code>iv[offset]</code> and <code>iv[offset+7]</code> inclusive. |
| 84 | * |
| 85 | * @param effectiveKeyBits the effective key size in bits. |
| 86 | * @param iv the buffer with the IV. The first 8 bytes |
| 87 | * of the buffer beginning at <code>offset</code> inclusive |
| 88 | * are copied to protect against subsequent modification. |
| 89 | * @param offset the offset in <code>iv</code> where the 8-byte IV |
| 90 | * starts. |
| 91 | * @exception IllegalArgumentException if <code>iv</code> is null. |
| 92 | */ |
| 93 | public RC2ParameterSpec(int effectiveKeyBits, byte[] iv, int offset) { |
| 94 | this.effectiveKeyBits = effectiveKeyBits; |
| 95 | if (iv == null) throw new IllegalArgumentException("IV missing"); |
| 96 | int blockSize = 8; |
| 97 | if (iv.length - offset < blockSize) { |
| 98 | throw new IllegalArgumentException("IV too short"); |
| 99 | } |
| 100 | this.iv = new byte[blockSize]; |
| 101 | System.arraycopy(iv, offset, this.iv, 0, blockSize); |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * Returns the effective key size in bits. |
| 106 | * |
| 107 | * @return the effective key size in bits. |
| 108 | */ |
| 109 | public int getEffectiveKeyBits() { |
| 110 | return this.effectiveKeyBits; |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Returns the IV or null if this parameter set does not contain an IV. |
| 115 | * |
| 116 | * @return the IV or null if this parameter set does not contain an IV. |
| 117 | * Returns a new array each time this method is called. |
| 118 | */ |
| 119 | public byte[] getIV() { |
| 120 | return (iv == null? null:(byte[])iv.clone()); |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Tests for equality between the specified object and this |
| 125 | * object. Two RC2ParameterSpec objects are considered equal if their |
| 126 | * effective key sizes and IVs are equal. |
| 127 | * (Two IV references are considered equal if both are <tt>null</tt>.) |
| 128 | * |
| 129 | * @param obj the object to test for equality with this object. |
| 130 | * |
| 131 | * @return true if the objects are considered equal, false if |
| 132 | * <code>obj</code> is null or otherwise. |
| 133 | */ |
| 134 | public boolean equals(Object obj) { |
| 135 | if (obj == this) { |
| 136 | return true; |
| 137 | } |
| 138 | if (!(obj instanceof RC2ParameterSpec)) { |
| 139 | return false; |
| 140 | } |
| 141 | RC2ParameterSpec other = (RC2ParameterSpec) obj; |
| 142 | |
| 143 | return ((effectiveKeyBits == other.effectiveKeyBits) && |
| 144 | java.util.Arrays.equals(iv, other.iv)); |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Calculates a hash code value for the object. |
| 149 | * Objects that are equal will also have the same hashcode. |
| 150 | */ |
| 151 | public int hashCode() { |
| 152 | int retval = 0; |
| 153 | if (iv != null) { |
| 154 | for (int i = 1; i < iv.length; i++) { |
| 155 | retval += iv[i] * i; |
| 156 | } |
| 157 | } |
| 158 | return (retval += effectiveKeyBits); |
| 159 | } |
| 160 | } |