1 files changed, 147 insertions, 0 deletions
diff --git a/libjava/java/security/MessageDigestSpi.java b/libjava/java/security/MessageDigestSpi.java
new file mode 100644
index 0000000..ce9e54d
--- /dev/null
+++ b/libjava/java/security/MessageDigestSpi.java
@@ -0,0 +1,147 @@
+/* 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.
+
+As a special exception, if you link this library with other files to
+produce an executable, this library does not by itself cause the
+resulting executable to be covered by the GNU General Public License.
+This exception does not however invalidate any other reasons why the
+executable file might be covered by the GNU General Public License. */
+
+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();
+  }
+}