1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * https://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 package org.apache.commons.compress.archivers.sevenz; 20 21 import java.util.Arrays; 22 23 /** 24 * Enumerates the (partially) supported compression/encryption methods used in 7z archives. 25 * <p> 26 * All methods with a {@code _FILTER} suffix are used as preprocessors with the goal of creating a better compression ratio with the compressor that comes next 27 * in the chain of methods. 7z will in general only allow them to be used together with a "real" compression method but Commons Compress doesn't enforce this. 28 * </p> 29 * <p> 30 * The {@code BCJ_} filters work on executable files for the given platform and convert relative addresses to absolute addresses in CALL instructions. This 31 * means they are only useful when applied to executables of the chosen platform. 32 * </p> 33 */ 34 public enum SevenZMethod { 35 36 /** No compression at all. */ 37 COPY(new byte[] { (byte) 0x00 }), 38 39 /** LZMA - only supported when reading. */ 40 LZMA(new byte[] { (byte) 0x03, (byte) 0x01, (byte) 0x01 }), 41 42 /** LZMA2. */ 43 LZMA2(new byte[] { (byte) 0x21 }), 44 45 /** Deflate. */ 46 DEFLATE(new byte[] { (byte) 0x04, (byte) 0x01, (byte) 0x08 }), 47 48 /** 49 * Deflate64. 50 * 51 * @since 1.16 52 */ 53 DEFLATE64(new byte[] { (byte) 0x04, (byte) 0x01, (byte) 0x09 }), 54 55 /** BZIP2. */ 56 BZIP2(new byte[] { (byte) 0x04, (byte) 0x02, (byte) 0x02 }), 57 58 /** 59 * AES encryption with a key length of 256 bit using SHA256 for hashes - only supported when reading. 60 */ 61 AES256SHA256(new byte[] { (byte) 0x06, (byte) 0xf1, (byte) 0x07, (byte) 0x01 }), 62 63 /** 64 * BCJ x86 platform version 1. 65 * 66 * @since 1.8 67 */ 68 BCJ_X86_FILTER(new byte[] { 0x03, 0x03, 0x01, 0x03 }), 69 70 /** 71 * BCJ PowerPC platform. 72 * 73 * @since 1.8 74 */ 75 BCJ_PPC_FILTER(new byte[] { 0x03, 0x03, 0x02, 0x05 }), 76 77 /** 78 * BCJ I64 platform. 79 * 80 * @since 1.8 81 */ 82 BCJ_IA64_FILTER(new byte[] { 0x03, 0x03, 0x04, 0x01 }), 83 84 /** 85 * BCJ ARM platform. 86 * 87 * @since 1.8 88 */ 89 BCJ_ARM_FILTER(new byte[] { 0x03, 0x03, 0x05, 0x01 }), 90 91 /** 92 * BCJ ARM Thumb platform. 93 * 94 * @since 1.8 95 */ 96 BCJ_ARM_THUMB_FILTER(new byte[] { 0x03, 0x03, 0x07, 0x01 }), 97 98 /** 99 * BCJ Sparc platform. 100 * 101 * @since 1.8 102 */ 103 BCJ_SPARC_FILTER(new byte[] { 0x03, 0x03, 0x08, 0x05 }), 104 105 /** 106 * Delta filter. 107 * 108 * @since 1.8 109 */ 110 DELTA_FILTER(new byte[] { 0x03 }); 111 112 static SevenZMethod byId(final byte[] id) { 113 for (final SevenZMethod method : SevenZMethod.class.getEnumConstants()) { 114 if (Arrays.equals(method.id, id)) { 115 return method; 116 } 117 } 118 return null; 119 } 120 121 private final byte[] id; 122 123 SevenZMethod(final byte[] id) { 124 this.id = id; 125 } 126 127 byte[] getId() { 128 return Arrays.copyOf(id, id.length); 129 } 130 }