diff -r fd16c54261b3 -r 90ce3da70b43 jdk/src/share/classes/com/sun/crypto/provider/PKCS5Padding.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/crypto/provider/PKCS5Padding.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,128 @@
+/*
+ * Copyright 1997-2007 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 com.sun.crypto.provider;
+
+import javax.crypto.ShortBufferException;
+
+/**
+ * This class implements padding as specified in the PKCS#5 standard.
+ *
+ * @author Gigi Ankeny
+ *
+ *
+ * @see Padding
+ */
+final class PKCS5Padding implements Padding {
+
+ private int blockSize;
+
+ PKCS5Padding(int blockSize) {
+ this.blockSize = blockSize;
+ }
+
+ /**
+ * Adds the given number of padding bytes to the data input.
+ * The value of the padding bytes is determined
+ * by the specific padding mechanism that implements this
+ * interface.
+ *
+ * @param in the input buffer with the data to pad
+ * @param off the offset in in
where the padding bytes
+ * are appended
+ * @param len the number of padding bytes to add
+ *
+ * @exception ShortBufferException if in
is too small to hold
+ * the padding bytes
+ */
+ public void padWithLen(byte[] in, int off, int len)
+ throws ShortBufferException
+ {
+ if (in == null)
+ return;
+
+ if ((off + len) > in.length) {
+ throw new ShortBufferException("Buffer too small to hold padding");
+ }
+
+ byte paddingOctet = (byte) (len & 0xff);
+ for (int i = 0; i < len; i++) {
+ in[i + off] = paddingOctet;
+ }
+ return;
+ }
+
+ /**
+ * Returns the index where the padding starts.
+ *
+ *
Given a buffer with padded data, this method returns the
+ * index where the padding starts.
+ *
+ * @param in the buffer with the padded data
+ * @param off the offset in in
where the padded data starts
+ * @param len the length of the padded data
+ *
+ * @return the index where the padding starts, or -1 if the input is
+ * not properly padded
+ */
+ public int unpad(byte[] in, int off, int len) {
+ if ((in == null) ||
+ (len == 0)) { // this can happen if input is really a padded buffer
+ return 0;
+ }
+
+ byte lastByte = in[off + len - 1];
+ int padValue = (int)lastByte & 0x0ff;
+ if ((padValue < 0x01)
+ || (padValue > blockSize)) {
+ return -1;
+ }
+
+ int start = off + len - ((int)lastByte & 0x0ff);
+ if (start < off) {
+ return -1;
+ }
+
+ for (int i = 0; i < ((int)lastByte & 0x0ff); i++) {
+ if (in[start+i] != lastByte) {
+ return -1;
+ }
+ }
+
+ return start;
+ }
+
+ /**
+ * Determines how long the padding will be for a given input length.
+ *
+ * @param len the length of the data to pad
+ *
+ * @return the length of the padding
+ */
+ public int padLength(int len) {
+ int paddingOctet = blockSize - (len % blockSize);
+ return paddingOctet;
+ }
+}