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/* * Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.crypto.spec; import java.security.spec.AlgorithmParameterSpec; /** * This class specifies the parameters used with the * <a href="http://tools.ietf.org/html/rfc2040"><i>RC5</i></a> * algorithm. * * <p> The parameters consist of a version number, a rounds count, a word * size, and optionally an initialization vector (IV) (only in feedback mode). * * <p> This class can be used to initialize a {@code Cipher} object that * implements the <i>RC5</i> algorithm as supplied by * <a href="http://www.rsa.com">RSA Security LLC</a>, * or any parties authorized by RSA Security. * * @author Jan Luehe * * @since 1.4 */ public class RC5ParameterSpec implements AlgorithmParameterSpec { private byte[] iv = null; private int version; private int rounds; private int wordSize; // the word size in bits /** * Constructs a parameter set for RC5 from the given version, number of * rounds and word size (in bits). * * @param version the version. * @param rounds the number of rounds. * @param wordSize the word size in bits. */ public RC5ParameterSpec(int version, int rounds, int wordSize) { this.version = version; this.rounds = rounds; this.wordSize = wordSize; } /** * Constructs a parameter set for RC5 from the given version, number of * rounds, word size (in bits), and IV. * * <p> Note that the size of the IV (block size) must be twice the word * size. The bytes that constitute the IV are those between * {@code iv[0]} and {@code iv[2*(wordSize/8)-1]} inclusive. * * @param version the version. * @param rounds the number of rounds. * @param wordSize the word size in bits. * @param iv the buffer with the IV. The first {@code 2*(wordSize/8)} * bytes of the buffer are copied to protect against subsequent * modification. * @exception IllegalArgumentException if {@code iv} is * {@code null} or {@code (iv.length < 2 * (wordSize / 8))} */ public RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv) { this(version, rounds, wordSize, iv, 0); } /** * Constructs a parameter set for RC5 from the given version, number of * rounds, word size (in bits), and IV. * * <p> The IV is taken from {@code iv}, starting at * {@code offset} inclusive. * Note that the size of the IV (block size), starting at * {@code offset} inclusive, must be twice the word size. * The bytes that constitute the IV are those between * {@code iv[offset]} and {@code iv[offset+2*(wordSize/8)-1]} * inclusive. * * @param version the version. * @param rounds the number of rounds. * @param wordSize the word size in bits. * @param iv the buffer with the IV. The first {@code 2*(wordSize/8)} * bytes of the buffer beginning at {@code offset} * inclusive are copied to protect against subsequent modification. * @param offset the offset in {@code iv} where the IV starts. * @exception IllegalArgumentException if {@code iv} is * {@code null} or * {@code (iv.length - offset < 2 * (wordSize / 8))} */ public RC5ParameterSpec(int version, int rounds, int wordSize, byte[] iv, int offset) { this.version = version; this.rounds = rounds; this.wordSize = wordSize; if (iv == null) throw new IllegalArgumentException("IV missing"); int blockSize = (wordSize / 8) * 2; if (iv.length - offset < blockSize) { throw new IllegalArgumentException("IV too short"); } this.iv = new byte[blockSize]; System.arraycopy(iv, offset, this.iv, 0, blockSize); } /** * Returns the version. * * @return the version. */ public int getVersion() { return this.version; } /** * Returns the number of rounds. * * @return the number of rounds. */ public int getRounds() { return this.rounds; } /** * Returns the word size in bits. * * @return the word size in bits. */ public int getWordSize() { return this.wordSize; } /** * Returns the IV or null if this parameter set does not contain an IV. * * @return the IV or null if this parameter set does not contain an IV. * Returns a new array each time this method is called. */ public byte[] getIV() { return (iv == null ? null : iv.clone()); } /** * Tests for equality between the specified object and this * object. Two RC5ParameterSpec objects are considered equal if their * version numbers, number of rounds, word sizes, and IVs are equal. * (Two IV references are considered equal if both are {@code null}.) * * @param obj the object to test for equality with this object. * * @return true if the objects are considered equal, false if * {@code obj} is null or otherwise. */ public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof RC5ParameterSpec)) { return false; } RC5ParameterSpec other = (RC5ParameterSpec) obj; return ((version == other.version) && (rounds == other.rounds) && (wordSize == other.wordSize) && java.util.Arrays.equals(iv, other.iv)); } /** * Calculates a hash code value for the object. * Objects that are equal will also have the same hashcode. */ public int hashCode() { int retval = 0; if (iv != null) { for (int i = 1; i < iv.length; i++) { retval += iv[i] * i; } } retval += (version + rounds + wordSize); return retval; } }