+++ /dev/null
-/* MessageDigestSpi.java --- The message digest service provider interface.
- Copyright (C) 1999 Free Software Foundation, Inc.
-
-This file is 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, 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; see the file COPYING. If not, write to the
-Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-02111-1307 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 java.security;
-
-/**
- This is the Service Provider Interface (SPI) for MessageDigest
- class in java.security. It provides the back end functionality
- for the MessageDigest class so that it can compute message
- hashes. The default hashes are SHA-1 and MD5. A message hash
- takes data of arbitrary length and produces a unique number
- representing it.
-
- Cryptography service providers who want to implement their
- own message digest hashes need only to subclass this class.
-
- The implementation of a Cloneable interface is left to up to
- the programmer of a subclass.
-
- @version 0.0
-
- @author Mark Benvenuto <ivymccough@worldnet.att.net>
- */
-public abstract class MessageDigestSpi
-{
- /**
- Default constructor of the MessageDigestSpi class
- */
- public MessageDigestSpi()
- {
- }
-
- /**
- Returns the length of the digest. It may be overridden by the
- provider to return the length of the digest. Default is to
- return 0. It is concrete for backwards compatibility with JDK1.1
- message digest classes.
-
- @return Length of Digest in Bytes
-
- @since 1.2
- */
- protected int engineGetDigestLength()
- {
- return 0;
- }
-
- /**
- Updates the digest with the specified byte.
-
- @param input the byte to update digest with
- */
- protected abstract void engineUpdate(byte input);
-
-
- /**
- Updates the digest with the specified bytes starting with the
- offset and proceeding for the specified length.
-
- @param input the byte array to update digest with
- @param offset the offset of the byte to start with
- @param len the number of the bytes to update with
- */
- protected abstract void engineUpdate(byte[]input, int offset, int len);
-
- /**
- Computes the final digest of the stored bytes and returns
- them. It performs any necessary padding. The message digest
- should reset sensitive data after performing the digest.
-
- @return An array of bytes containing the digest
- */
- protected abstract byte[] engineDigest();
-
- /**
- Computes the final digest of the stored bytes and returns
- them. It performs any necessary padding. The message digest
- should reset sensitive data after performing the digest. This
- method is left concrete for backwards compatibility with JDK1.1
- message digest classes.
-
- @param buf An array of bytes to store the digest
- @param offset An offset to start storing the digest at
- @param len The length of the buffer
- @return Returns the length of the buffer
-
- @since 1.2
- */
- protected int engineDigest(byte[]buf, int offset, int len)
- throws DigestException
- {
- if (engineGetDigestLength() > len)
- throw new DigestException("Buffer is too small.");
-
- byte tmp[] = engineDigest();
- if (tmp.length > len)
- throw new DigestException("Buffer is too small");
-
- System.arraycopy(tmp, 0, buf, offset, tmp.length);
- return tmp.length;
- }
-
- /**
- Resets the digest engine. Reinitializes internal variables
- and clears sensitive data.
- */
- protected abstract void engineReset();
-
- /**
- Returns a clone of this class.
-
- If cloning is not supported, then by default the class throws a
- CloneNotSupportedException. The MessageDigestSpi provider
- implementation has to overload this class in order to be
- cloneable.
- */
- public Object clone() throws CloneNotSupportedException
- {
- if (this instanceof Cloneable)
- return super.clone();
- else
- throw new CloneNotSupportedException();
- }
-}
projects / msp430-gcc.git / blobdiff