--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/com/sun/crypto/provider/CipherFeedback.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,276 @@
+/*
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.crypto.provider;
+
+import java.security.InvalidKeyException;
+
+/**
+ * This class represents ciphers in cipher-feedback (CFB) mode.
+ *
+ * <p>This mode is implemented independently of a particular cipher.
+ * Ciphers to which this mode should apply (e.g., DES) must be
+ * <i>plugged-in</i> using the constructor.
+ *
+ * <p>NOTE: This class does not deal with buffering or padding.
+ *
+ * @author Gigi Ankeny
+ */
+
+final class CipherFeedback extends FeedbackCipher {
+
+ /*
+ * encrypt/decrypt output buffer
+ */
+ private final byte[] k;
+
+ /*
+ * register value, initialized with iv
+ */
+ private final byte[] register;
+
+ /*
+ * number of bytes for each stream unit, defaults to the blocksize
+ * of the embedded cipher
+ */
+ private int numBytes;
+
+ // variables for save/restore calls
+ private byte[] registerSave = null;
+
+ CipherFeedback(SymmetricCipher embeddedCipher, int numBytes) {
+ super(embeddedCipher);
+ if (numBytes > blockSize) {
+ numBytes = blockSize;
+ }
+ this.numBytes = numBytes;
+ k = new byte[blockSize];
+ register = new byte[blockSize];
+ }
+
+ /**
+ * Gets the name of this feedback mode.
+ *
+ * @return the string <code>CFB</code>
+ */
+ String getFeedback() {
+ return "CFB";
+ }
+
+ /**
+ * Initializes the cipher in the specified mode with the given key
+ * and iv.
+ *
+ * @param decrypting flag indicating encryption or decryption
+ * @param algorithm the algorithm name
+ * @param key the key
+ * @param iv the iv
+ *
+ * @exception InvalidKeyException if the given key is inappropriate for
+ * initializing this cipher
+ */
+ void init(boolean decrypting, String algorithm, byte[] key, byte[] iv)
+ throws InvalidKeyException {
+ if ((key == null) || (iv == null) || (iv.length != blockSize)) {
+ throw new InvalidKeyException("Internal error");
+ }
+ this.iv = iv;
+ reset();
+ // always encrypt mode for embedded cipher
+ embeddedCipher.init(false, algorithm, key);
+ }
+
+ /**
+ * Resets the iv to its original value.
+ * This is used when doFinal is called in the Cipher class, so that the
+ * cipher can be reused (with its original iv).
+ */
+ void reset() {
+ System.arraycopy(iv, 0, register, 0, blockSize);
+ }
+
+ /**
+ * Save the current content of this cipher.
+ */
+ void save() {
+ if (registerSave == null) {
+ registerSave = new byte[blockSize];
+ }
+ System.arraycopy(register, 0, registerSave, 0, blockSize);
+ }
+
+ /**
+ * Restores the content of this cipher to the previous saved one.
+ */
+ void restore() {
+ System.arraycopy(registerSave, 0, register, 0, blockSize);
+ }
+
+ /**
+ * Performs encryption operation.
+ *
+ * <p>The input plain text <code>plain</code>, starting at
+ * <code>plainOffset</code> and ending at
+ * <code>(plainOffset + len - 1)</code>, is encrypted.
+ * The result is stored in <code>cipher</code>, starting at
+ * <code>cipherOffset</code>.
+ *
+ * <p>It is the application's responsibility to make sure that
+ * <code>plainLen</code> is a multiple of the stream unit size
+ * <code>numBytes</code>, as any excess bytes are ignored.
+ *
+ * <p>It is also the application's responsibility to make sure that
+ * <code>init</code> has been called before this method is called.
+ * (This check is omitted here, to avoid double checking.)
+ *
+ * @param plain the buffer with the input data to be encrypted
+ * @param plainOffset the offset in <code>plain</code>
+ * @param plainLen the length of the input data
+ * @param cipher the buffer for the result
+ * @param cipherOffset the offset in <code>cipher</code>
+ * @return the length of the encrypted data
+ */
+ int encrypt(byte[] plain, int plainOffset, int plainLen,
+ byte[] cipher, int cipherOffset)
+ {
+ int i, len;
+ len = blockSize - numBytes;
+ int loopCount = plainLen / numBytes;
+ int oddBytes = plainLen % numBytes;
+
+ if (len == 0) {
+ for (; loopCount > 0 ;
+ plainOffset += numBytes, cipherOffset += numBytes,
+ loopCount--) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ for (i = 0; i < blockSize; i++)
+ register[i] = cipher[i+cipherOffset] =
+ (byte)(k[i] ^ plain[i+plainOffset]);
+ }
+ if (oddBytes > 0) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ for (i=0; i<oddBytes; i++)
+ register[i] = cipher[i+cipherOffset] =
+ (byte)(k[i] ^ plain[i+plainOffset]);
+ }
+ } else {
+ for (; loopCount > 0 ;
+ plainOffset += numBytes, cipherOffset += numBytes,
+ loopCount--) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ System.arraycopy(register, numBytes, register, 0, len);
+ for (i=0; i<numBytes; i++)
+ register[i+len] = cipher[i+cipherOffset] =
+ (byte)(k[i] ^ plain[i+plainOffset]);
+
+ }
+ if (oddBytes != 0) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ System.arraycopy(register, numBytes, register, 0, len);
+ for (i=0; i<oddBytes; i++) {
+ register[i+len] = cipher[i+cipherOffset] =
+ (byte)(k[i] ^ plain[i+plainOffset]);
+ }
+ }
+ }
+ return plainLen;
+ }
+
+ /**
+ * Performs decryption operation.
+ *
+ * <p>The input cipher text <code>cipher</code>, starting at
+ * <code>cipherOffset</code> and ending at
+ * <code>(cipherOffset + len - 1)</code>, is decrypted.
+ * The result is stored in <code>plain</code>, starting at
+ * <code>plainOffset</code>.
+ *
+ * <p>It is the application's responsibility to make sure that
+ * <code>cipherLen</code> is a multiple of the stream unit size
+ * <code>numBytes</code>, as any excess bytes are ignored.
+ *
+ * <p>It is also the application's responsibility to make sure that
+ * <code>init</code> has been called before this method is called.
+ * (This check is omitted here, to avoid double checking.)
+ *
+ * @param cipher the buffer with the input data to be decrypted
+ * @param cipherOffset the offset in <code>cipherOffset</code>
+ * @param cipherLen the length of the input data
+ * @param plain the buffer for the result
+ * @param plainOffset the offset in <code>plain</code>
+ * @return the length of the decrypted data
+ */
+ int decrypt(byte[] cipher, int cipherOffset, int cipherLen,
+ byte[] plain, int plainOffset)
+ {
+ int i, len;
+ len = blockSize - numBytes;
+ int loopCount = cipherLen / numBytes;
+ int oddBytes = cipherLen % numBytes;
+
+ if (len == 0) {
+ for (; loopCount > 0;
+ plainOffset += numBytes, cipherOffset += numBytes,
+ loopCount--) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ for (i = 0; i < blockSize; i++) {
+ register[i] = cipher[i+cipherOffset];
+ plain[i+plainOffset]
+ = (byte)(cipher[i+cipherOffset] ^ k[i]);
+ }
+ }
+ if (oddBytes > 0) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ for (i=0; i<oddBytes; i++) {
+ register[i] = cipher[i+cipherOffset];
+ plain[i+plainOffset]
+ = (byte)(cipher[i+cipherOffset] ^ k[i]);
+ }
+ }
+ } else {
+ for (; loopCount > 0;
+ plainOffset += numBytes, cipherOffset += numBytes,
+ loopCount--) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ System.arraycopy(register, numBytes, register, 0, len);
+ for (i=0; i<numBytes; i++) {
+ register[i+len] = cipher[i+cipherOffset];
+ plain[i+plainOffset]
+ = (byte)(cipher[i+cipherOffset] ^ k[i]);
+ }
+ }
+ if (oddBytes != 0) {
+ embeddedCipher.encryptBlock(register, 0, k, 0);
+ System.arraycopy(register, numBytes, register, 0, len);
+ for (i=0; i<oddBytes; i++) {
+ register[i+len] = cipher[i+cipherOffset];
+ plain[i+plainOffset]
+ = (byte)(cipher[i+cipherOffset] ^ k[i]);
+ }
+ }
+ }
+ return cipherLen;
+ }
+}