/* * Copyright (c) 1998, 2007, 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://www.ietf.org/rfc/rfc2268.txt"><i>RC2</i></a> * algorithm. * * <p> The parameters consist of an effective key size and optionally * an 8-byte initialization vector (IV) (only in feedback mode). * * <p> This class can be used to initialize a <code>Cipher</code> object that * implements the <i>RC2</i> algorithm. * * @author Jan Luehe * * @since 1.4 */public class RC2ParameterSpec implements AlgorithmParameterSpec {     private byte[] iv = null;    private int effectiveKeyBits;     /**     * Constructs a parameter set for RC2 from the given effective key size     * (in bits).     *     * @param effectiveKeyBits the effective key size in bits.     */    public RC2ParameterSpec(int effectiveKeyBits) {        this.effectiveKeyBits = effectiveKeyBits;    }     /**     * Constructs a parameter set for RC2 from the given effective key size     * (in bits) and an 8-byte IV.     *     * <p> The bytes that constitute the IV are those between     * <code>iv[0]</code> and <code>iv[7]</code> inclusive.     *     * @param effectiveKeyBits the effective key size in bits.     * @param iv the buffer with the 8-byte IV. The first 8 bytes of     * the buffer are copied to protect against subsequent modification.     * @exception IllegalArgumentException if <code>iv</code> is null.     */    public RC2ParameterSpec(int effectiveKeyBits, byte[] iv) {        this(effectiveKeyBits, iv, 0);    }     /**     * Constructs a parameter set for RC2 from the given effective key size     * (in bits) and IV.     *     * <p> The IV is taken from <code>iv</code>, starting at     * <code>offset</code> inclusive.     * The bytes that constitute the IV are those between     * <code>iv[offset]</code> and <code>iv[offset+7]</code> inclusive.     *     * @param effectiveKeyBits the effective key size in bits.     * @param iv the buffer with the IV. The first 8 bytes     * of the buffer beginning at <code>offset</code> inclusive     * are copied to protect against subsequent modification.     * @param offset the offset in <code>iv</code> where the 8-byte IV     * starts.     * @exception IllegalArgumentException if <code>iv</code> is null.     */    public RC2ParameterSpec(int effectiveKeyBits, byte[] iv, int offset) {        this.effectiveKeyBits = effectiveKeyBits;        if (iv == null) throw new IllegalArgumentException("IV missing");        int blockSize = 8;        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 effective key size in bits.     *     * @return the effective key size in bits.     */    public int getEffectiveKeyBits() {        return this.effectiveKeyBits;    }     /**     * 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:(byte[])iv.clone());    }    /**     * Tests for equality between the specified object and this     * object. Two RC2ParameterSpec objects are considered equal if their     * effective key sizes and IVs are equal.     * (Two IV references are considered equal if both are <tt>null</tt>.)     *     * @param obj the object to test for equality with this object.     *     * @return true if the objects are considered equal, false if     * <code>obj</code> is null or otherwise.     */    public boolean equals(Object obj) {        if (obj == this) {            return true;        }        if (!(obj instanceof RC2ParameterSpec)) {            return false;        }        RC2ParameterSpec other = (RC2ParameterSpec) obj;         return ((effectiveKeyBits == other.effectiveKeyBits) &&                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;            }        }        return (retval += effectiveKeyBits);    }}