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Diffstat (limited to 'libjava/classpath/gnu/java/security/jce/hash/MessageDigestAdapter.java')
| -rw-r--r-- | libjava/classpath/gnu/java/security/jce/hash/MessageDigestAdapter.java | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/security/jce/hash/MessageDigestAdapter.java b/libjava/classpath/gnu/java/security/jce/hash/MessageDigestAdapter.java new file mode 100644 index 00000000000..9b8a73d55fd --- /dev/null +++ b/libjava/classpath/gnu/java/security/jce/hash/MessageDigestAdapter.java @@ -0,0 +1,147 @@ +/* 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.crypto 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 java.security.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 Crypto provider implement the {@link java.lang.Cloneable} interface.<p> + * + * @version $Revision: 1.1 $ + */ +class MessageDigestAdapter extends MessageDigestSpi implements Cloneable +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + /** Our underlying hash instance. */ + private IMessageDigest adaptee; + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** + * 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; + } + + // Class methods + // ------------------------------------------------------------------------- + + // java.security.MessageDigestSpi interface implementation + // ------------------------------------------------------------------------- + + 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(); + } +} |

