1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.codec.binary; 19 20 import java.io.InputStream; 21 22 import org.apache.commons.codec.CodecPolicy; 23 24 /** 25 * Provides Base32 encoding and decoding in a streaming fashion (unlimited size). When encoding the default lineLength 26 * is 76 characters and the default lineEnding is CRLF, but these can be overridden by using the appropriate 27 * constructor. 28 * <p> 29 * The default behavior of the Base32InputStream is to DECODE, whereas the default behavior of the Base32OutputStream 30 * is to ENCODE, but this behavior can be overridden by using a different constructor. 31 * </p> 32 * <p> 33 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode 34 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc). 35 * </p> 36 * <p> 37 * You can set the decoding behavior when the input bytes contain leftover trailing bits that cannot be created by a 38 * valid encoding. These can be bits that are unused from the final character or entire characters. The default mode is 39 * lenient decoding. 40 * </p> 41 * <ul> 42 * <li>Lenient: Any trailing bits are composed into 8-bit bytes where possible. The remainder are discarded. 43 * <li>Strict: The decoding will raise an {@link IllegalArgumentException} if trailing bits are not part of a valid 44 * encoding. Any unused bits from the final character must be zero. Impossible counts of entire final characters are not 45 * allowed. 46 * </ul> 47 * <p> 48 * When strict decoding is enabled it is expected that the decoded bytes will be re-encoded to a byte array that matches 49 * the original, i.e. no changes occur on the final character. This requires that the input bytes use the same padding 50 * and alphabet as the encoder. 51 * </p> 52 * @see <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a> 53 * @since 1.5 54 */ 55 public class Base32InputStream extends BaseNCodecInputStream { 56 57 /** 58 * Creates a Base32InputStream such that all data read is Base32-decoded from the original provided InputStream. 59 * 60 * @param inputStream 61 * InputStream to wrap. 62 */ 63 public Base32InputStream(final InputStream inputStream) { 64 this(inputStream, false); 65 } 66 67 /** 68 * Creates a Base32InputStream such that all data read is either Base32-encoded or Base32-decoded from the original 69 * provided InputStream. 70 * 71 * @param inputStream 72 * InputStream to wrap. 73 * @param doEncode 74 * true if we should encode all data read from us, false if we should decode. 75 */ 76 public Base32InputStream(final InputStream inputStream, final boolean doEncode) { 77 super(inputStream, new Base32(false), doEncode); 78 } 79 80 /** 81 * Creates a Base32InputStream such that all data read is either Base32-encoded or Base32-decoded from the original 82 * provided InputStream. 83 * 84 * @param inputStream 85 * InputStream to wrap. 86 * @param doEncode 87 * true if we should encode all data read from us, false if we should decode. 88 * @param lineLength 89 * If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to 90 * the nearest multiple of 4). If lineLength <= 0, the encoded data is not divided into lines. If 91 * doEncode is false, lineLength is ignored. 92 * @param lineSeparator 93 * If doEncode is true, each line of encoded data will be terminated with this byte sequence (e.g. \r\n). 94 * If lineLength <= 0, the lineSeparator is not used. If doEncode is false lineSeparator is ignored. 95 */ 96 public Base32InputStream(final InputStream inputStream, final boolean doEncode, final int lineLength, final byte[] lineSeparator) { 97 super(inputStream, new Base32(lineLength, lineSeparator), doEncode); 98 } 99 100 /** 101 * Creates a Base32InputStream such that all data read is either Base32-encoded or Base32-decoded from the original 102 * provided InputStream. 103 * 104 * @param inputStream 105 * InputStream to wrap. 106 * @param doEncode 107 * true if we should encode all data read from us, false if we should decode. 108 * @param lineLength 109 * If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to 110 * the nearest multiple of 4). If lineLength <= 0, the encoded data is not divided into lines. If 111 * doEncode is false, lineLength is ignored. 112 * @param lineSeparator 113 * If doEncode is true, each line of encoded data will be terminated with this byte sequence (e.g. \r\n). 114 * If lineLength <= 0, the lineSeparator is not used. If doEncode is false lineSeparator is ignored. 115 * @param decodingPolicy 116 * The decoding policy. 117 * @since 1.15 118 */ 119 public Base32InputStream(final InputStream inputStream, final boolean doEncode, final int lineLength, final byte[] lineSeparator, 120 final CodecPolicy decodingPolicy) { 121 super(inputStream, new Base32(lineLength, lineSeparator, false, BaseNCodec.PAD_DEFAULT, decodingPolicy), doEncode); 122 } 123 124 }