| /* |
| * 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); |
| } |
| } |