8187443: Forest Consolidation: Move files to unified layout

Reviewed-by: darcy, ihse

src/java.base/share/classes/com/sun/crypto/provider/CounterMode.java

@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2002, 2017, 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;
+import java.util.Objects;
+
+import jdk.internal.HotSpotIntrinsicCandidate;
+
+/**
+ * This class represents ciphers in counter (CTR) 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 Andreas Sterbenz
+ * @since 1.4.2
+ */
+class CounterMode extends FeedbackCipher {
+
+    // current counter value
+    final byte[] counter;
+
+    // encrypted bytes of the previous counter value
+    private final byte[] encryptedCounter;
+
+    // number of bytes in encryptedCounter already used up
+    private int used;
+
+    // variables for save/restore calls
+    private byte[] counterSave = null;
+    private byte[] encryptedCounterSave = null;
+    private int usedSave = 0;
+
+    CounterMode(SymmetricCipher embeddedCipher) {
+        super(embeddedCipher);
+        counter = new byte[blockSize];
+        encryptedCounter = new byte[blockSize];
+    }
+
+    /**
+     * Gets the name of the feedback mechanism
+     *
+     * @return the name of the feedback mechanism
+     */
+    String getFeedback() {
+        return "CTR";
+    }
+
+    /**
+     * 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, counter, 0, blockSize);
+        used = blockSize;
+    }
+
+    /**
+     * Save the current content of this cipher.
+     */
+    void save() {
+        if (counterSave == null) {
+            counterSave = new byte[blockSize];
+            encryptedCounterSave = new byte[blockSize];
+        }
+        System.arraycopy(counter, 0, counterSave, 0, blockSize);
+        System.arraycopy(encryptedCounter, 0, encryptedCounterSave, 0,
+            blockSize);
+        usedSave = used;
+    }
+
+    /**
+     * Restores the content of this cipher to the previous saved one.
+     */
+    void restore() {
+        System.arraycopy(counterSave, 0, counter, 0, blockSize);
+        System.arraycopy(encryptedCounterSave, 0, encryptedCounter, 0,
+            blockSize);
+        used = usedSave;
+    }
+
+    /**
+     * 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);
+    }
+
+    /**
+     * 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>.
+     *
+     * @param in the buffer with the input data to be encrypted
+     * @param inOff the offset in <code>plain</code>
+     * @param len the length of the input data
+     * @param out the buffer for the result
+     * @param outOff the offset in <code>cipher</code>
+     * @return the length of the encrypted data
+     */
+    int encrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {
+        return crypt(in, inOff, len, out, outOff);
+    }
+
+    // CTR encrypt and decrypt are identical
+    int decrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {
+        return crypt(in, inOff, len, out, outOff);
+    }
+
+    /**
+     * Increment the counter value.
+     */
+    private static void increment(byte[] b) {
+        int n = b.length - 1;
+        while ((n >= 0) && (++b[n] == 0)) {
+            n--;
+        }
+    }
+
+    /**
+     * Do the actual encryption/decryption operation.
+     * Essentially we XOR the input plaintext/ciphertext stream with a
+     * keystream generated by encrypting the counter values. Counter values
+     * are encrypted on demand.
+     */
+    private int crypt(byte[] in, int inOff, int len, byte[] out, int outOff) {
+        if (len == 0) {
+            return 0;
+        }
+        Objects.checkFromIndexSize(inOff, len, in.length);
+        Objects.checkFromIndexSize(outOff, len, out.length);
+        return implCrypt(in, inOff, len, out, outOff);
+    }
+
+    // Implementation of crpyt() method. Possibly replaced with a compiler intrinsic.
+    @HotSpotIntrinsicCandidate
+    private int implCrypt(byte[] in, int inOff, int len, byte[] out, int outOff) {
+        int result = len;
+        while (len-- > 0) {
+            if (used >= blockSize) {
+                embeddedCipher.encryptBlock(counter, 0, encryptedCounter, 0);
+                increment(counter);
+                used = 0;
+            }
+            out[outOff++] = (byte)(in[inOff++] ^ encryptedCounter[used++]);
+        }
+        return result;
+    }
+
+}