--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/crypto/MacSpi.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,153 @@
+/*
+ * Copyright 1998-2007 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.crypto;
+
+import java.security.*;
+import java.security.spec.*;
+
+import java.nio.ByteBuffer;
+
+/**
+ * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
+ * for the <code>Mac</code> class.
+ * All the abstract methods in this class must be implemented by each
+ * cryptographic service provider who wishes to supply the implementation
+ * of a particular MAC algorithm.
+ *
+ * <p> Implementations are free to implement the Cloneable interface.
+ *
+ * @author Jan Luehe
+ *
+ * @since 1.4
+ */
+
+public abstract class MacSpi {
+
+    /**
+     * Returns the length of the MAC in bytes.
+     *
+     * @return the MAC length in bytes.
+     */
+    protected abstract int engineGetMacLength();
+
+    /**
+     * Initializes the MAC with the given (secret) key and algorithm
+     * parameters.
+     *
+     * @param key the (secret) key.
+     * @param params the algorithm parameters.
+     *
+     * @exception InvalidKeyException if the given key is inappropriate for
+     * initializing this MAC.
+     * @exception InvalidAlgorithmParameterException if the given algorithm
+     * parameters are inappropriate for this MAC.
+     */
+    protected abstract void engineInit(Key key,
+                                       AlgorithmParameterSpec params)
+        throws InvalidKeyException, InvalidAlgorithmParameterException ;
+
+    /**
+     * Processes the given byte.
+     *
+     * @param input the input byte to be processed.
+     */
+    protected abstract void engineUpdate(byte input);
+
+    /**
+     * Processes the first <code>len</code> bytes in <code>input</code>,
+     * starting at <code>offset</code> inclusive.
+     *
+     * @param input the input buffer.
+     * @param offset the offset in <code>input</code> where the input starts.
+     * @param len the number of bytes to process.
+     */
+    protected abstract void engineUpdate(byte[] input, int offset, int len);
+
+    /**
+     * Processes <code>input.remaining()</code> bytes in the ByteBuffer
+     * <code>input</code>, starting at <code>input.position()</code>.
+     * Upon return, the buffer's position will be equal to its limit;
+     * its limit will not have changed.
+     *
+     * <p>Subclasses should consider overriding this method if they can
+     * process ByteBuffers more efficiently than byte arrays.
+     *
+     * @param input the ByteBuffer
+     * @since 1.5
+     */
+    protected void engineUpdate(ByteBuffer input) {
+        if (input.hasRemaining() == false) {
+            return;
+        }
+        if (input.hasArray()) {
+            byte[] b = input.array();
+            int ofs = input.arrayOffset();
+            int pos = input.position();
+            int lim = input.limit();
+            engineUpdate(b, ofs + pos, lim - pos);
+            input.position(lim);
+        } else {
+            int len = input.remaining();
+            byte[] b = new byte[CipherSpi.getTempArraySize(len)];
+            while (len > 0) {
+                int chunk = Math.min(len, b.length);
+                input.get(b, 0, chunk);
+                engineUpdate(b, 0, chunk);
+                len -= chunk;
+            }
+        }
+    }
+
+    /**
+     * Completes the MAC computation and resets the MAC for further use,
+     * maintaining the secret key that the MAC was initialized with.
+     *
+     * @return the MAC result.
+     */
+    protected abstract byte[] engineDoFinal();
+
+    /**
+     * Resets the MAC for further use, maintaining the secret key that the
+     * MAC was initialized with.
+     */
+    protected abstract void engineReset();
+
+    /**
+     * Returns a clone if the implementation is cloneable.
+     *
+     * @return a clone if the implementation is cloneable.
+     *
+     * @exception CloneNotSupportedException if this is called
+     * on an implementation that does not support <code>Cloneable</code>.
+     */
+    public Object clone() throws CloneNotSupportedException {
+        if (this instanceof Cloneable) {
+            return super.clone();
+        } else {
+            throw new CloneNotSupportedException();
+        }
+    }
+}