| /* |
| * 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 org.apache.kerby.util; |
| |
| import java.io.FilterOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| |
| /** |
| * Provides Base64 encoding and decoding in a streaming fashion (unlimited size). When encoding the default lineLength |
| * is 76 characters and the default lineEnding is CRLF, but these can be overridden by using the appropriate |
| * constructor. |
| * <p> |
| * The default behaviour of the Base64OutputStream is to ENCODE, whereas the default behaviour of the Base64InputStream |
| * is to DECODE. But this behaviour can be overridden by using a different constructor. |
| * </p> |
| * <p> |
| * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose |
| * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein. |
| * </p> |
| * <p> |
| * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode |
| * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc). |
| * </p> |
| * |
| * @author Apache Software Foundation |
| * @version $Id$ |
| * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> |
| * @since 1.4 |
| */ |
| public class Base64OutputStream extends FilterOutputStream { |
| private final boolean doEncode; |
| |
| private final Base64 base64; |
| |
| private final byte[] singleByte = new byte[1]; |
| |
| /** |
| * Creates a Base64OutputStream such that all data written is Base64-encoded to the original provided OutputStream. |
| * |
| * @param out |
| * OutputStream to wrap. |
| */ |
| public Base64OutputStream(OutputStream out) { |
| this(out, true); |
| } |
| |
| /** |
| * Creates a Base64OutputStream such that all data written is either Base64-encoded or Base64-decoded to the |
| * original provided OutputStream. |
| * |
| * @param out |
| * OutputStream to wrap. |
| * @param doEncode |
| * true if we should encode all data written to us, false if we should decode. |
| */ |
| public Base64OutputStream(OutputStream out, boolean doEncode) { |
| super(out); |
| this.doEncode = doEncode; |
| this.base64 = new Base64(); |
| } |
| |
| /** |
| * Creates a Base64OutputStream such that all data written is either Base64-encoded or Base64-decoded to the |
| * original provided OutputStream. |
| * |
| * @param out |
| * OutputStream to wrap. |
| * @param doEncode |
| * true if we should encode all data written to us, false if we should decode. |
| * @param lineLength |
| * If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to |
| * nearest multiple of 4). If {@code lineLength <=0}, the encoded data is not divided into lines. If doEncode is |
| * false, lineLength is ignored. |
| * @param lineSeparator |
| * If doEncode is true, each line of encoded data will be terminated with this byte sequence (e.g. \r\n). |
| * If {@code lineLength <= 0}, the lineSeparator is not used. If doEncode is false lineSeparator is ignored. |
| */ |
| public Base64OutputStream(OutputStream out, boolean doEncode, int lineLength, byte[] lineSeparator) { |
| super(out); |
| this.doEncode = doEncode; |
| this.base64 = new Base64(lineLength, lineSeparator); |
| } |
| |
| /** |
| * Writes the specified <code>byte</code> to this output stream. |
| * |
| * @param i |
| * source byte |
| * @throws java.io.IOException |
| * if an I/O error occurs. |
| */ |
| public void write(int i) throws IOException { |
| singleByte[0] = (byte) i; |
| write(singleByte, 0, 1); |
| } |
| |
| /** |
| * Writes <code>len</code> bytes from the specified <code>b</code> array starting at <code>offset</code> to this |
| * output stream. |
| * |
| * @param b |
| * source byte array |
| * @param offset |
| * where to start reading the bytes |
| * @param len |
| * maximum number of bytes to write |
| * |
| * @throws java.io.IOException |
| * if an I/O error occurs. |
| * @throws NullPointerException |
| * if the byte array parameter is null |
| * @throws IndexOutOfBoundsException |
| * if offset, len or buffer size are invalid |
| */ |
| public void write(byte[] b, int offset, int len) throws IOException { |
| if (b == null) { |
| throw new NullPointerException(); |
| } else if (offset < 0 || len < 0) { |
| throw new IndexOutOfBoundsException(); |
| } else if (offset > b.length || offset + len > b.length) { |
| throw new IndexOutOfBoundsException(); |
| } else if (len > 0) { |
| if (doEncode) { |
| base64.encode(b, offset, len); |
| } else { |
| base64.decode(b, offset, len); |
| } |
| flush(false); |
| } |
| } |
| |
| /** |
| * Flushes this output stream and forces any buffered output bytes to be written out to the stream. If propogate is |
| * true, the wrapped stream will also be flushed. |
| * |
| * @param propogate |
| * boolean flag to indicate whether the wrapped OutputStream should also be flushed. |
| * @throws java.io.IOException |
| * if an I/O error occurs. |
| */ |
| private void flush(boolean propogate) throws IOException { |
| int avail = base64.avail(); |
| if (avail > 0) { |
| byte[] buf = new byte[avail]; |
| int c = base64.readResults(buf, 0, avail); |
| if (c > 0) { |
| out.write(buf, 0, c); |
| } |
| } |
| if (propogate) { |
| out.flush(); |
| } |
| } |
| |
| /** |
| * Flushes this output stream and forces any buffered output bytes to be written out to the stream. |
| * |
| * @throws java.io.IOException |
| * if an I/O error occurs. |
| */ |
| public void flush() throws IOException { |
| flush(true); |
| } |
| |
| /** |
| * Closes this output stream and releases any system resources associated with the stream. |
| * |
| * @throws java.io.IOException |
| * if an I/O error occurs. |
| */ |
| public void close() throws IOException { |
| // Notify encoder of EOF (-1). |
| if (doEncode) { |
| base64.encode(singleByte, 0, -1); |
| } else { |
| base64.decode(singleByte, 0, -1); |
| } |
| flush(); |
| out.close(); |
| } |
| |
| } |