| /* |
| * Copyright (c) 2018, 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; |
| import java.util.Objects; |
| |
| /** |
| * This class specifies the parameters used with the |
| * <a href="https://tools.ietf.org/html/rfc7539"><i>ChaCha20</i></a> |
| * algorithm. |
| * |
| * <p> The parameters consist of a 12-byte nonce and an initial |
| * counter value expressed as a 32-bit integer. |
| * |
| * <p> This class can be used to initialize a {@code Cipher} object that |
| * implements the <i>ChaCha20</i> algorithm. |
| * |
| * @since 11 |
| */ |
| public final class ChaCha20ParameterSpec implements AlgorithmParameterSpec { |
| |
| // The nonce length is defined by the spec as 96 bits (12 bytes) in length. |
| private static final int NONCE_LENGTH = 12; |
| |
| private final byte[] nonce; |
| private final int counter; |
| |
| /** |
| * Constructs a parameter set for ChaCha20 from the given nonce |
| * and counter. |
| * |
| * @param nonce a 12-byte nonce value |
| * @param counter the initial counter value |
| * |
| * @throws NullPointerException if {@code nonce} is {@code null} |
| * @throws IllegalArgumentException if {@code nonce} is not 12 bytes |
| * in length |
| */ |
| public ChaCha20ParameterSpec(byte[] nonce, int counter) { |
| this.counter = counter; |
| |
| Objects.requireNonNull(nonce, "Nonce must be non-null"); |
| this.nonce = nonce.clone(); |
| if (this.nonce.length != NONCE_LENGTH) { |
| throw new IllegalArgumentException( |
| "Nonce must be 12-bytes in length"); |
| } |
| } |
| |
| /** |
| * Returns the nonce value. |
| * |
| * @return the nonce value. This method returns a new array each time |
| * this method is called. |
| */ |
| public byte[] getNonce() { |
| return nonce.clone(); |
| } |
| |
| /** |
| * Returns the configured counter value. |
| * |
| * @return the counter value |
| */ |
| public int getCounter() { |
| return counter; |
| } |
| } |