1 files changed, 155 insertions, 0 deletions
diff --git a/src/main/java/ch/ethz/ssh2/crypto/cipher/CipherOutputStream.java b/src/main/java/ch/ethz/ssh2/crypto/cipher/CipherOutputStream.java
new file mode 100644
index 0000000..27ba410
--- /dev/null
+++ b/src/main/java/ch/ethz/ssh2/crypto/cipher/CipherOutputStream.java
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
+ * Please refer to the LICENSE.txt for licensing details.
+ */
+package ch.ethz.ssh2.crypto.cipher;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * CipherOutputStream.
+ *
+ * @author Christian Plattner
+ * @version $Id: CipherOutputStream.java 11 2011-05-27 14:14:06Z dkocher@sudo.ch $
+ */
+public class CipherOutputStream
+{
+	BlockCipher currentCipher;
+	OutputStream bo;
+	byte[] buffer;
+	byte[] enc;
+	int blockSize;
+	int pos;
+
+	/*
+	 * We cannot use java.io.BufferedOutputStream, since that is not available
+	 * in J2ME. Everything could be improved here alot.
+	 */
+
+	private static final int BUFF_SIZE = 8192;
+	byte[] out_buffer = new byte[BUFF_SIZE];
+	int out_buffer_pos = 0;
+
+	public CipherOutputStream(BlockCipher tc, OutputStream bo)
+	{
+		this.bo = bo;
+		changeCipher(tc);
+	}
+
+	private void internal_write(byte[] src, int off, int len) throws IOException
+	{
+		while (len > 0)
+		{
+			int space = BUFF_SIZE - out_buffer_pos;
+			int copy = (len > space) ? space : len;
+
+			System.arraycopy(src, off, out_buffer, out_buffer_pos, copy);
+
+			off += copy;
+			out_buffer_pos += copy;
+			len -= copy;
+
+			if (out_buffer_pos >= BUFF_SIZE)
+			{
+				bo.write(out_buffer, 0, BUFF_SIZE);
+				out_buffer_pos = 0;
+			}
+		}
+	}
+
+	private void internal_write(int b) throws IOException
+	{
+		out_buffer[out_buffer_pos++] = (byte) b;
+		if (out_buffer_pos >= BUFF_SIZE)
+		{
+			bo.write(out_buffer, 0, BUFF_SIZE);
+			out_buffer_pos = 0;
+		}
+	}
+
+	public void flush() throws IOException
+	{
+		if (pos != 0)
+		{
+			throw new IOException("FATAL: cannot flush since crypto buffer is not aligned.");
+		}
+
+		if (out_buffer_pos > 0)
+		{
+			bo.write(out_buffer, 0, out_buffer_pos);
+			out_buffer_pos = 0;
+		}
+		bo.flush();
+	}
+
+	public void changeCipher(BlockCipher bc)
+	{
+		this.currentCipher = bc;
+		blockSize = bc.getBlockSize();
+		buffer = new byte[blockSize];
+		enc = new byte[blockSize];
+		pos = 0;
+	}
+
+	private void writeBlock() throws IOException
+	{
+		try
+		{
+			currentCipher.transformBlock(buffer, 0, enc, 0);
+		}
+		catch (Exception e)
+		{
+			throw (IOException) new IOException("Error while decrypting block.").initCause(e);
+		}
+
+		internal_write(enc, 0, blockSize);
+		pos = 0;
+	}
+
+	public void write(byte[] src, int off, int len) throws IOException
+	{
+		while (len > 0)
+		{
+			int avail = blockSize - pos;
+			int copy = Math.min(avail, len);
+
+			System.arraycopy(src, off, buffer, pos, copy);
+			pos += copy;
+			off += copy;
+			len -= copy;
+
+			if (pos >= blockSize)
+			{
+				writeBlock();
+			}
+		}
+	}
+
+	public void write(int b) throws IOException
+	{
+		buffer[pos++] = (byte) b;
+		if (pos >= blockSize)
+		{
+			writeBlock();
+		}
+	}
+
+	public void writePlain(int b) throws IOException
+	{
+		if (pos != 0)
+		{
+			throw new IOException("Cannot write plain since crypto buffer is not aligned.");
+		}
+		internal_write(b);
+	}
+
+	public void writePlain(byte[] b, int off, int len) throws IOException
+	{
+		if (pos != 0)
+		{
+			throw new IOException("Cannot write plain since crypto buffer is not aligned.");
+		}
+		internal_write(b, off, len);
+	}
+}