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Author: katcom

app/src/main/java/com/katcom/androidFileVault/CustomedCrypto/CustomCipherInputStream.java

@@ -0,0 +1,361 @@
+package com.katcom.androidFileVault.CustomedCrypto;
+
+/*
+ * Copyright (c) 1997, 2014, 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.
+ */
+import java.io.InputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+
+import javax.crypto.AEADBadTagException;
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NullCipher;
+import javax.crypto.ShortBufferException;
+
+/**
+ * A CipherInputStream is composed of an InputStream and a Cipher so
+ * that read() methods return data that are read in from the
+ * underlying InputStream but have been additionally processed by the
+ * Cipher.  The Cipher must be fully initialized before being used by
+ * a CipherInputStream.
+ *
+ * <p> For example, if the Cipher is initialized for decryption, the
+ * CipherInputStream will attempt to read in data and decrypt them,
+ * before returning the decrypted data.
+ *
+ * <p> This class adheres strictly to the semantics, especially the
+ * failure semantics, of its ancestor classes
+ * java.io.FilterInputStream and java.io.InputStream.  This class has
+ * exactly those methods specified in its ancestor classes, and
+ * overrides them all.  Moreover, this class catches all exceptions
+ * that are not thrown by its ancestor classes.  In particular, the
+ * <code>skip</code> method skips, and the <code>available</code>
+ * method counts only data that have been processed by the encapsulated Cipher.
+ *
+ * <p> It is crucial for a programmer using this class not to use
+ * methods that are not defined or overriden in this class (such as a
+ * new method or constructor that is later added to one of the super
+ * classes), because the design and implementation of those methods
+ * are unlikely to have considered security impact with regard to
+ * CipherInputStream.
+ *
+ * @author  Li Gong
+ * @see     java.io.InputStream
+ * @see     java.io.FilterInputStream
+ * @see     javax.crypto.Cipher
+ * @see     javax.crypto.CipherOutputStream
+ *
+ * @since 1.4
+ */
+
+public class CustomCipherInputStream extends FilterInputStream {
+
+    // the cipher engine to use to process stream data
+    private Cipher cipher;
+
+    // the underlying input stream
+    private InputStream input;
+
+    /* the buffer holding data that have been read in from the
+       underlying stream, but have not been processed by the cipher
+       engine. This class change the buffer size from 512 of the original CipherInputStream to 8192 */
+    private byte[] ibuffer = new byte[8192];
+
+    // having reached the end of the underlying input stream
+    private boolean done = false;
+
+    /* the buffer holding data that have been processed by the cipher
+       engine, but have not been read out */
+    private byte[] obuffer;
+    // the offset pointing to the next "new" byte
+    private int ostart = 0;
+    // the offset pointing to the last "new" byte
+    private int ofinish = 0;
+    // stream status
+    private boolean closed = false;
+
+    /**
+     * private convenience function.
+     *
+     * Entry condition: ostart = ofinish
+     *
+     * Exit condition: ostart <= ofinish
+     *
+     * return (ofinish-ostart) (we have this many bytes for you)
+     * return 0 (no data now, but could have more later)
+     * return -1 (absolutely no more data)
+     *
+     * Note:  Exceptions are only thrown after the stream is completely read.
+     * For AEAD ciphers a read() of any length will internally cause the
+     * whole stream to be read fully and verify the authentication tag before
+     * returning decrypted data or exceptions.
+     */
+    private int getMoreData() throws IOException {
+        // Android-changed: The method was creating a new object every time update(byte[], int, int)
+        // or doFinal() was called resulting in the old object being GCed. With do(byte[], int) and
+        // update(byte[], int, int, byte[], int), we use already initialized obuffer.
+        if (done) return -1;
+        ofinish = 0;
+        ostart = 0;
+        int expectedOutputSize = cipher.getOutputSize(ibuffer.length);
+        if (obuffer == null || expectedOutputSize > obuffer.length) {
+            obuffer = new byte[expectedOutputSize];
+        }
+        int readin = input.read(ibuffer);
+        if (readin == -1) {
+            done = true;
+            try {
+                // doFinal resets the cipher and it is the final call that is made. If there isn't
+                // any more byte available, it returns 0. In case of any exception is raised,
+                // obuffer will get reset and therefore, it is equivalent to no bytes returned.
+                ofinish = cipher.doFinal(obuffer, 0);
+            } catch (IllegalBlockSizeException | BadPaddingException e) {
+                obuffer = null;
+                throw new IOException(e);
+            } catch (ShortBufferException e) {
+                obuffer = null;
+                throw new IllegalStateException("ShortBufferException is not expected", e);
+            }
+        } else {
+            // update returns number of bytes stored in obuffer.
+            try {
+                ofinish = cipher.update(ibuffer, 0, readin, obuffer, 0);
+            } catch (IllegalStateException e) {
+                obuffer = null;
+                throw e;
+            } catch (ShortBufferException e) {
+                // Should not reset the value of ofinish as the cipher is still not invalidated.
+                obuffer = null;
+                throw new IllegalStateException("ShortBufferException is not expected", e);
+            }
+        }
+        return ofinish;
+    }
+
+    /**
+     * Constructs a CipherInputStream from an InputStream and a
+     * Cipher.
+     * <br>Note: if the specified input stream or cipher is
+     * null, a NullPointerException may be thrown later when
+     * they are used.
+     * @param is the to-be-processed input stream
+     * @param c an initialized Cipher object
+     */
+    public CustomCipherInputStream(InputStream is, Cipher c) {
+        super(is);
+        input = is;
+        cipher = c;
+    }
+
+    /**
+     * Constructs a CipherInputStream from an InputStream without
+     * specifying a Cipher. This has the effect of constructing a
+     * CipherInputStream using a NullCipher.
+     * <br>Note: if the specified input stream is null, a
+     * NullPointerException may be thrown later when it is used.
+     * @param is the to-be-processed input stream
+     */
+    protected CustomCipherInputStream(InputStream is) {
+        super(is);
+        input = is;
+        cipher = new NullCipher();
+    }
+
+    /**
+     * Reads the next byte of data from this input stream. The value
+     * byte is returned as an <code>int</code> in the range
+     * <code>0</code> to <code>255</code>. If no byte is available
+     * because the end of the stream has been reached, the value
+     * <code>-1</code> is returned. This method blocks until input data
+     * is available, the end of the stream is detected, or an exception
+     * is thrown.
+     * <p>
+     *
+     * @return  the next byte of data, or <code>-1</code> if the end of the
+     *          stream is reached.
+     * @exception  IOException  if an I/O error occurs.
+     * @since JCE1.2
+     */
+    public int read() throws IOException {
+        if (ostart >= ofinish) {
+            // we loop for new data as the spec says we are blocking
+            int i = 0;
+            while (i == 0) i = getMoreData();
+            if (i == -1) return -1;
+        }
+        return ((int) obuffer[ostart++] & 0xff);
+    };
+
+    /**
+     * Reads up to <code>b.length</code> bytes of data from this input
+     * stream into an array of bytes.
+     * <p>
+     * The <code>read</code> method of <code>InputStream</code> calls
+     * the <code>read</code> method of three arguments with the arguments
+     * <code>b</code>, <code>0</code>, and <code>b.length</code>.
+     *
+     * @param      b   the buffer into which the data is read.
+     * @return     the total number of bytes read into the buffer, or
+     *             <code>-1</code> is there is no more data because the end of
+     *             the stream has been reached.
+     * @exception  IOException  if an I/O error occurs.
+     * @see        java.io.InputStream#read(byte[], int, int)
+     * @since      JCE1.2
+     */
+    public int read(byte b[]) throws IOException {
+        return read(b, 0, b.length);
+    }
+
+    /**
+     * Reads up to <code>len</code> bytes of data from this input stream
+     * into an array of bytes. This method blocks until some input is
+     * available. If the first argument is <code>null,</code> up to
+     * <code>len</code> bytes are read and discarded.
+     *
+     * @param      b     the buffer into which the data is read.
+     * @param      off   the start offset in the destination array
+     *                   <code>buf</code>
+     * @param      len   the maximum number of bytes read.
+     * @return     the total number of bytes read into the buffer, or
+     *             <code>-1</code> if there is no more data because the end of
+     *             the stream has been reached.
+     * @exception  IOException  if an I/O error occurs.
+     * @see        java.io.InputStream#read()
+     * @since      JCE1.2
+     */
+    public int read(byte b[], int off, int len) throws IOException {
+        if (ostart >= ofinish) {
+            // we loop for new data as the spec says we are blocking
+            int i = 0;
+            while (i == 0) i = getMoreData();
+            if (i == -1) return -1;
+        }
+        if (len <= 0) {
+            return 0;
+        }
+        int available = ofinish - ostart;
+        if (len < available) available = len;
+        if (b != null) {
+            System.arraycopy(obuffer, ostart, b, off, available);
+        }
+        ostart = ostart + available;
+        return available;
+    }
+
+    /**
+     * Skips <code>n</code> bytes of input from the bytes that can be read
+     * from this input stream without blocking.
+     *
+     * <p>Fewer bytes than requested might be skipped.
+     * The actual number of bytes skipped is equal to <code>n</code> or
+     * the result of a call to
+     * {@link #available() available},
+     * whichever is smaller.
+     * If <code>n</code> is less than zero, no bytes are skipped.
+     *
+     * <p>The actual number of bytes skipped is returned.
+     *
+     * @param      n the number of bytes to be skipped.
+     * @return     the actual number of bytes skipped.
+     * @exception  IOException  if an I/O error occurs.
+     * @since JCE1.2
+     */
+    public long skip(long n) throws IOException {
+        int available = ofinish - ostart;
+        if (n > available) {
+            n = available;
+        }
+        if (n < 0) {
+            return 0;
+        }
+        ostart += n;
+        return n;
+    }
+
+    /**
+     * Returns the number of bytes that can be read from this input
+     * stream without blocking. The <code>available</code> method of
+     * <code>InputStream</code> returns <code>0</code>. This method
+     * <B>should</B> be overridden by subclasses.
+     *
+     * @return     the number of bytes that can be read from this input stream
+     *             without blocking.
+     * @exception  IOException  if an I/O error occurs.
+     * @since      JCE1.2
+     */
+    public int available() throws IOException {
+        return (ofinish - ostart);
+    }
+
+    /**
+     * Closes this input stream and releases any system resources
+     * associated with the stream.
+     * <p>
+     * The <code>close</code> method of <code>CipherInputStream</code>
+     * calls the <code>close</code> method of its underlying input
+     * stream.
+     *
+     * @exception  IOException  if an I/O error occurs.
+     * @since JCE1.2
+     */
+    public void close() throws IOException {
+        if (closed) {
+            return;
+        }
+
+        closed = true;
+        input.close();
+
+        // Android-removed: Removed a now-inaccurate comment
+        if (!done) {
+            try {
+                cipher.doFinal();
+            }
+            catch (BadPaddingException | IllegalBlockSizeException ex) {
+                // Android-changed: Added throw if bad tag is seen.  See b/31590622.
+                if (ex instanceof AEADBadTagException) {
+                    throw new IOException(ex);
+                }
+            }
+        }
+        ostart = 0;
+        ofinish = 0;
+    }
+
+    /**
+     * Tests if this input stream supports the <code>mark</code>
+     * and <code>reset</code> methods, which it does not.
+     *
+     * @return  <code>false</code>, since this class does not support the
+     *          <code>mark</code> and <code>reset</code> methods.
+     * @see     java.io.InputStream#mark(int)
+     * @see     java.io.InputStream#reset()
+     * @since   JCE1.2
+     */
+    public boolean markSupported() {
+        return false;
+    }
+}