| /* |
| * 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.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * 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 Base64InputStream is to DECODE, whereas the default behaviour of the Base64OutputStream |
| * is to ENCODE, 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: Base64InputStream.java 155 2009-09-17 21:00:58Z julius $ |
| * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> |
| * @since 1.4 |
| */ |
| public class Base64InputStream extends FilterInputStream { |
| |
| private final boolean doEncode; |
| |
| private final Base64 base64; |
| |
| private final byte[] singleByte = new byte[1]; |
| |
| /** |
| * Creates a Base64InputStream such that all data read is Base64-decoded from the original provided InputStream. |
| * |
| * @param in |
| * InputStream to wrap. |
| */ |
| public Base64InputStream(InputStream in) { |
| this(in, false); |
| } |
| |
| /** |
| * Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original |
| * provided InputStream. |
| * |
| * @param in |
| * InputStream to wrap. |
| * @param doEncode |
| * true if we should encode all data read from us, false if we should decode. |
| */ |
| public Base64InputStream(InputStream in, boolean doEncode) { |
| super(in); |
| this.doEncode = doEncode; |
| this.base64 = new Base64(); |
| } |
| |
| /** |
| * Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original |
| * provided InputStream. |
| * |
| * @param in |
| * InputStream to wrap. |
| * @param doEncode |
| * true if we should encode all data read from 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 Base64InputStream(InputStream in, boolean doEncode, int lineLength, byte[] lineSeparator) { |
| super(in); |
| this.doEncode = doEncode; |
| this.base64 = new Base64(lineLength, lineSeparator); |
| } |
| |
| /** |
| * Reads one <code>byte</code> from this input stream. |
| * |
| * @return the byte as an integer in the range 0 to 255. Returns -1 if EOF has been reached. |
| * @throws java.io.IOException |
| * if an I/O error occurs. |
| */ |
| public int read() throws IOException { |
| int r = read(singleByte, 0, 1); |
| while (r == 0) { |
| r = read(singleByte, 0, 1); |
| } |
| if (r > 0) { |
| return singleByte[0] < 0 ? 256 + singleByte[0] : singleByte[0]; |
| } |
| return -1; |
| } |
| |
| /** |
| * Attempts to read <code>len</code> bytes into the specified <code>b</code> array starting at <code>offset</code> |
| * from this InputStream. |
| * |
| * @param b |
| * destination byte array |
| * @param offset |
| * where to start writing the bytes |
| * @param len |
| * maximum number of bytes to read |
| * |
| * @return number of bytes read |
| * @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 int read(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) { |
| return 0; |
| } else { |
| if (!base64.hasData()) { |
| byte[] buf = new byte[doEncode ? 4096 : 8192]; |
| int c = in.read(buf); |
| // A little optimization to avoid System.arraycopy() |
| // when possible. |
| if (c > 0 && b.length == len) { |
| base64.setInitialBuffer(b, offset, len); |
| } |
| if (doEncode) { |
| base64.encode(buf, 0, c); |
| } else { |
| base64.decode(buf, 0, c); |
| } |
| } |
| return base64.readResults(b, offset, len); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * @return false |
| */ |
| public boolean markSupported() { |
| return false; // not an easy job to support marks |
| } |
| } |