Add java.security.MessageDigest class

java/cldc1.1.1/java/security/MessageDigest.java

@@ -0,0 +1,159 @@
+/*
+ *   
+ *
+ * Copyright  1990-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
+ * 
+ * This program 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.
+ * 
+ * This program 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 at /legal/license.txt).
+ * 
+ * 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 or visit www.sun.com if you need additional
+ * information or have any questions.
+ */
+
+package java.security;
+
+/**
+ * This MessageDigest class provides applications 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>A <code>MessageDigest</code> object starts out initialized. The data is 
+ * processed through it using the <code>update</code>
+ * method. At any point {@link #reset() reset} can be called
+ * to reset the digest. Once all the data to be updated has been
+ * updated, the <code>digest</code> method should 
+ * be called to complete the hash computation.
+ *
+ * <p>The <code>digest</code> method can be called once for a given number 
+ * of updates. After <code>digest</code> has been called, 
+ * the <code>MessageDigest</code>
+ * object is reset to its initialized state.
+ */
+
+public abstract class MessageDigest  {
+
+    /**
+     * Message digest implementation.
+     */
+    com.sun.midp.crypto.MessageDigest messageDigest;
+
+    /**
+     * Creates a message digest with the specified algorithm name.
+     * 
+     * @param algorithm the standard name of the digest algorithm. 
+     * See Appendix A in the
+     * Java Cryptography Architecture API Specification &amp; Reference 
+     * for information about standard algorithm names.
+     */
+    MessageDigest(String algorithm) {
+    }
+
+    /**
+     * Generates a <code>MessageDigest</code> object that implements
+     * the specified digest
+     * algorithm. 
+     *
+     * @param algorithm the name of the algorithm requested. 
+     * See Appendix A in the 
+     * Java Cryptography Architecture API Specification &amp; Reference
+     * for information about standard algorithm names.
+     *
+     * @return a MessageDigest object implementing the specified
+     * algorithm.
+     *
+     * @exception NoSuchAlgorithmException if the algorithm is
+     * not available in the caller's environment.  
+     */
+    public static MessageDigest getInstance(String algorithm) 
+        throws NoSuchAlgorithmException {
+
+        try {
+            return new MessageDigestImpl(algorithm,
+                com.sun.midp.crypto.MessageDigest.getInstance(algorithm));
+        } catch (com.sun.midp.crypto.NoSuchAlgorithmException e) {
+            throw new NoSuchAlgorithmException(e.getMessage());
+        }
+    }
+
+
+    /**
+     * Updates the digest using the specified array of bytes, starting
+     * at the specified offset.
+     * 
+     * @param input the array of bytes.
+     *
+     * @param offset the offset to start from in the array of bytes.
+     *
+     * @param len the number of bytes to use, starting at 
+     * <code>offset</code>.  
+     */
+    public void update(byte[] input, int offset, int len) {
+        messageDigest.update(input, offset, len);
+    }
+
+
+    /**
+     * Completes the hash computation by performing final operations
+     * such as padding. The digest is reset after this call is made.
+     *
+     * @param buf output buffer for the computed digest
+     *
+     * @param offset offset into the output buffer to begin storing the digest
+     *
+     * @param len number of bytes within buf allotted for the digest
+     *
+     * @return the number of bytes placed into <code>buf</code>
+     * 
+     * @exception DigestException if an error occurs.
+     */
+    public int digest(byte[] buf, int offset, int len) throws DigestException {
+        try {
+            return messageDigest.digest(buf, offset, len);
+        } catch (com.sun.midp.crypto.DigestException e) {
+            throw new DigestException(e.getMessage());
+        }
+    }
+
+    /**
+     * Resets the digest for further use.
+     */
+    public void reset() {
+        messageDigest.reset();
+    }
+}
+
+/**
+ * The non-abstract MessageDigest.
+ */
+class MessageDigestImpl extends MessageDigest {
+
+    /**
+     * Creates a message digest with the specified algorithm name.
+     *
+     * @param algorithm the standard name of the digest algorithm.
+     * See Appendix A in the
+     * Java Cryptography Architecture API Specification &amp; Reference
+     * for information about standard algorithm names.
+     * @param messageDigest MessageDigest implementation
+     */
+    MessageDigestImpl(String algorithm,
+                      com.sun.midp.crypto.MessageDigest messageDigest) {
+        super(algorithm);
+        this.messageDigest = messageDigest;
+    }
+}