The Android Open Source Project | b5de22c | 2012-04-01 00:00:00 -0700 | [diff] [blame] | 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 | package javax.crypto.spec; |
| 19 | |
| 20 | import java.security.spec.AlgorithmParameterSpec; |
| 21 | import java.util.Arrays; |
| 22 | |
| 23 | /** |
| 24 | * The algorithm parameter specification for the <a |
| 25 | * href="http://www.ietf.org/rfc/rfc2040.txt">RC5</a> algorithm. |
| 26 | */ |
| 27 | public class RC5ParameterSpec implements AlgorithmParameterSpec { |
| 28 | |
| 29 | private final int version; |
| 30 | private final int rounds; |
| 31 | private final int wordSize; |
| 32 | private final byte[] iv; |
| 33 | |
| 34 | /** |
| 35 | * Creates a new <code>RC5ParameterSpec</code> instance with the specified |
| 36 | * version, round count an word size (in bits). |
| 37 | * |
| 38 | * @param version |
| 39 | * the version. |
| 40 | * @param rounds |
| 41 | * the round count. |
| 42 | * @param wordSize |
| 43 | * the word size (in bits). |
| 44 | */ |
| 45 | public RC5ParameterSpec(int version, int rounds, int wordSize) { |
| 46 | this.version = version; |
| 47 | this.rounds = rounds; |
| 48 | this.wordSize = wordSize; |
| 49 | this.iv = null; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Creates a new <code>RC5ParameterSpec</code> instance with the specified |
| 54 | * version, round count, word size (in bits) and an <i>initialization |
| 55 | * vector</i>. |
| 56 | * <p> |
| 57 | * The size of the <i>initialization vector</i> must be at least |
| 58 | * <code>2 * (wordSize / 8)</code> bytes which are copied to protect them |
| 59 | * against modification. |
| 60 | * |
| 61 | * @param version |
| 62 | * the version. |
| 63 | * @param rounds |
| 64 | * the round count. |
| 65 | * @param wordSize |
| 66 | * the word size (in bits). |
| 67 | * @param iv |
| 68 | * the initialization vector. |
| 69 | * @throws IllegalArgumentException |
| 70 | * if the initialization vector is null or shorter than <code>2 |
| 71 | * * (wordSize / 8)</code>. |
| 72 | */ |
| 73 | public RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv) { |
| 74 | if (iv == null) { |
| 75 | throw new IllegalArgumentException("iv == null"); |
| 76 | } |
| 77 | if (iv.length < 2 * (wordSize / 8)) { |
| 78 | throw new IllegalArgumentException("iv.length < 2 * (wordSize / 8)"); |
| 79 | } |
| 80 | this.version = version; |
| 81 | this.rounds = rounds; |
| 82 | this.wordSize = wordSize; |
| 83 | this.iv = new byte[2*(wordSize/8)]; |
| 84 | System.arraycopy(iv, 0, this.iv, 0, 2*(wordSize/8)); |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Creates a new <code>RC5ParameterSpec</code> instance with the specified |
| 89 | * version, round count, wordSize (in bits), an <i>initialization vector</i> |
| 90 | * and an offset. |
| 91 | * <p> |
| 92 | * The size of the <i>initialization vector</i> must be at least |
| 93 | * <code>offset + (2 * (wordSize / 8))</code> bytes. The bytes starting at |
| 94 | * <code>offset</code> are copied to protect them against modification. |
| 95 | * |
| 96 | * @param version |
| 97 | * the version. |
| 98 | * @param rounds |
| 99 | * the round count. |
| 100 | * @param wordSize |
| 101 | * the word size (in bits). |
| 102 | * @param iv |
| 103 | * the initialization vector. |
| 104 | * @param offset |
| 105 | * the offset in the initialization vector. |
| 106 | * @throws IllegalArgumentException |
| 107 | * if the initialization vector is null of shorter than |
| 108 | * <code>offset + (2 * (wordSize / 8))</code>. |
| 109 | * @throws ArrayIndexOutOfBoundsException |
| 110 | * if <code>offset</code> is negative. |
| 111 | */ |
| 112 | public RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv, int offset) { |
| 113 | if (iv == null) { |
| 114 | throw new IllegalArgumentException("iv == null"); |
| 115 | } |
| 116 | if (offset < 0) { |
| 117 | throw new ArrayIndexOutOfBoundsException("offset < 0: " + offset); |
| 118 | } |
| 119 | if (iv.length - offset < 2 * (wordSize / 8)) { |
| 120 | throw new IllegalArgumentException("iv.length - offset < 2 * (wordSize / 8)"); |
| 121 | } |
| 122 | this.version = version; |
| 123 | this.rounds = rounds; |
| 124 | this.wordSize = wordSize; |
| 125 | this.iv = new byte[offset+2*(wordSize/8)]; |
| 126 | System.arraycopy(iv, offset, this.iv, 0, 2*(wordSize/8)); |
| 127 | } |
| 128 | |
| 129 | /** |
| 130 | * Returns the version. |
| 131 | * |
| 132 | * @return the version. |
| 133 | */ |
| 134 | public int getVersion() { |
| 135 | return version; |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * Returns the round count. |
| 140 | * |
| 141 | * @return the round count. |
| 142 | */ |
| 143 | public int getRounds() { |
| 144 | return rounds; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Returns the word size (in bits). |
| 149 | * |
| 150 | * @return the word size (in bits). |
| 151 | */ |
| 152 | public int getWordSize() { |
| 153 | return wordSize; |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Returns a copy of the initialization vector. |
| 158 | * |
| 159 | * @return a copy of the initialization vector, or null if none specified. |
| 160 | */ |
| 161 | public byte[] getIV() { |
| 162 | if (iv == null) { |
| 163 | return null; |
| 164 | } |
| 165 | byte[] result = new byte[iv.length]; |
| 166 | System.arraycopy(iv, 0, result, 0, iv.length); |
| 167 | return result; |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * Compares the specified object with this <code>RC5ParameterSpec</code> |
| 172 | * instance. |
| 173 | * |
| 174 | * @param obj |
| 175 | * the object to compare. |
| 176 | * @return true if version, round count, word size and initializaion vector |
| 177 | * of both objects are equal, otherwise false. |
| 178 | */ |
| 179 | @Override |
| 180 | public boolean equals(Object obj) { |
| 181 | if (obj == this) { |
| 182 | return true; |
| 183 | } |
| 184 | if (!(obj instanceof RC5ParameterSpec)) { |
| 185 | return false; |
| 186 | } |
| 187 | RC5ParameterSpec ps = (RC5ParameterSpec) obj; |
| 188 | return (version == ps.version) |
| 189 | && (rounds == ps.rounds) |
| 190 | && (wordSize == ps.wordSize) |
| 191 | && (Arrays.equals(iv, ps.iv)); |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Returns the hash code of this <code>RC5ParameterSpec</code> instance. |
| 196 | * |
| 197 | * @return the hash code. |
| 198 | */ |
| 199 | @Override |
| 200 | public int hashCode() { |
| 201 | int result = version + rounds + wordSize; |
| 202 | if (iv == null) { |
| 203 | return result; |
| 204 | } |
| 205 | for (byte element : iv) { |
| 206 | result += element & 0xFF; |
| 207 | } |
| 208 | return result; |
| 209 | } |
| 210 | } |