| /* MessageDigestAdapter.java -- |
| Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.security.jce.hash; |
| |
| import gnu.java.security.hash.IMessageDigest; |
| import gnu.java.security.hash.HashFactory; |
| |
| import java.security.DigestException; |
| import java.security.MessageDigestSpi; |
| |
| /** |
| * The implementation of a generic {@link java.security.MessageDigest} adapter |
| * class to wrap GNU hash instances. |
| * <p> |
| * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) for |
| * the {@link java.security.MessageDigest} class, which provides the |
| * functionality of a message digest algorithm, such as MD5 or SHA. Message |
| * digests are secure one-way hash functions that take arbitrary-sized data and |
| * output a fixed-length hash value. |
| * <p> |
| * All the abstract methods in the {@link MessageDigestSpi} class are |
| * implemented by this class and all its sub-classes. |
| * <p> |
| * All the implementations which subclass this object, and which are serviced by |
| * the GNU provider implement the {@link Cloneable} interface. |
| */ |
| class MessageDigestAdapter |
| extends MessageDigestSpi |
| implements Cloneable |
| { |
| /** Our underlying hash instance. */ |
| private IMessageDigest adaptee; |
| |
| /** |
| * Trivial protected constructor. |
| * |
| * @param mdName the canonical name of the hash algorithm. |
| */ |
| protected MessageDigestAdapter(String mdName) |
| { |
| this(HashFactory.getInstance(mdName)); |
| } |
| |
| /** |
| * Private constructor for cloning purposes. |
| * |
| * @param adaptee a clone of the underlying hash algorithm instance. |
| */ |
| private MessageDigestAdapter(IMessageDigest adaptee) |
| { |
| super(); |
| |
| this.adaptee = adaptee; |
| } |
| |
| public Object clone() |
| { |
| return new MessageDigestAdapter((IMessageDigest) adaptee.clone()); |
| } |
| |
| public int engineGetDigestLength() |
| { |
| return adaptee.hashSize(); |
| } |
| |
| public void engineUpdate(byte input) |
| { |
| adaptee.update(input); |
| } |
| |
| public void engineUpdate(byte[] input, int offset, int len) |
| { |
| adaptee.update(input, offset, len); |
| } |
| |
| public byte[] engineDigest() |
| { |
| return adaptee.digest(); |
| } |
| |
| public int engineDigest(byte[] buf, int offset, int len) |
| throws DigestException |
| { |
| int result = adaptee.hashSize(); |
| if (len < result) |
| throw new DigestException(); |
| |
| byte[] md = adaptee.digest(); |
| System.arraycopy(md, 0, buf, offset, result); |
| return result; |
| } |
| |
| public void engineReset() |
| { |
| adaptee.reset(); |
| } |
| } |