1 files changed, 167 insertions, 0 deletions
diff --git a/luni/src/main/java/javax/crypto/CipherOutputStream.java b/luni/src/main/java/javax/crypto/CipherOutputStream.java
new file mode 100644
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--- /dev/null
+++ b/luni/src/main/java/javax/crypto/CipherOutputStream.java
@@ -0,0 +1,167 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package javax.crypto;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import javax.crypto.NullCipher;
+
+/**
+ * This class wraps an output stream and a cipher so that {@code write} methods
+ * send the data through the cipher before writing them to the underlying output
+ * stream.
+ * <p>
+ * The cipher must be initialized for the requested operation before being used
+ * by a {@code CipherOutputStream}. For example, if a cipher initialized for
+ * encryption is used with a {@code CipherOutputStream}, the {@code
+ * CipherOutputStream} tries to encrypt the data writing it out.
+ */
+public class CipherOutputStream extends FilterOutputStream {
+
+    private final Cipher cipher;
+    private final byte[] arr = new byte[1];
+
+    /**
+     * Creates a new {@code CipherOutputStream} instance for an {@code
+     * OutputStream} and a {@code Cipher}.
+     *
+     * @param os
+     *            the output stream to write data to.
+     * @param c
+     *            the cipher to process the data with.
+     */
+    public CipherOutputStream(OutputStream os, Cipher c) {
+        super(os);
+        cipher = c;
+    }
+
+    /**
+     * Creates a new {@code CipherOutputStream} instance for an {@code
+     * OutputStream} without a cipher.
+     * <p>
+     * A {@code NullCipher} is created to process the data.
+     *
+     * @param os
+     *            the output stream to write the data to.
+     */
+    protected CipherOutputStream(OutputStream os) {
+        this(os, new NullCipher());
+    }
+
+    /**
+     * Writes the single byte to this cipher output stream.
+     *
+     * @param b
+     *            the byte to write.
+     * @throws IOException
+     *             if an error occurs.
+     */
+    @Override
+    public void write(int b) throws IOException {
+        byte[] result;
+        arr[0] = (byte) b;
+        result = cipher.update(arr);
+        if (result != null) {
+            out.write(result);
+        }
+    }
+
+    /**
+     * Writes the buffer of bytes to this cipher output stream.
+     *
+     * @param b
+     *            the buffer of bytes.
+     * @throws IOException
+     *             if an error occurs.
+     */
+    @Override
+    public void write(byte[] b) throws IOException {
+        write(b, 0, b.length);
+    }
+
+    /**
+     * Writes the {@code len} bytes from buffer {@code b} starting at offset
+     * {@code off} to this cipher output stream.
+     *
+     * @param b
+     *            the buffer.
+     * @param off
+     *            the offset to start at.
+     * @param len
+     *            the number of bytes.
+     * @throws IOException
+     *             if an error occurs.
+     */
+    @Override
+    public void write(byte[] b, int off, int len) throws IOException {
+        if (len == 0) {
+            return;
+        }
+        byte[] result = cipher.update(b, off, len);
+        if (result != null) {
+            out.write(result);
+        }
+    }
+
+    /**
+     * Flushes this cipher output stream.
+     *
+     * @throws IOException
+     *             if an error occurs
+     */
+    @Override
+    public void flush() throws IOException {
+        out.flush();
+    }
+
+    /**
+     * Close this cipher output stream.
+     * <p>
+     * On the underlying cipher {@code doFinal} will be invoked, and any
+     * buffered bytes from the cipher are also written out, and the cipher is
+     * reset to its initial state. The underlying output stream is also closed.
+     *
+     * @throws IOException
+     *             if an error occurs.
+     */
+    @Override
+    public void close() throws IOException {
+        byte[] result;
+        try {
+            if (cipher != null) {
+                result = cipher.doFinal();
+                if (result != null) {
+                    out.write(result);
+                }
+            }
+            if (out != null) {
+                out.flush();
+            }
+        } catch (BadPaddingException e) {
+            throw new IOException(e.getMessage());
+        } catch (IllegalBlockSizeException e) {
+            throw new IOException(e.getMessage());
+        } finally {
+            if (out != null) {
+                out.close();
+            }
+        }
+    }
+}
+