1 /* 2 * Copyright 2012, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 package org.jf.dexlib2.dexbacked; 33 34 import org.jf.util.ExceptionWithContext; 35 36 import javax.annotation.Nonnull; 37 38 public class BaseDexBuffer { 39 @Nonnull /* package private */ final byte[] buf; 40 /* package private */ final int baseOffset; 41 42 public BaseDexBuffer(@Nonnull byte[] buf) { 43 this(buf, 0); 44 } 45 public BaseDexBuffer(@Nonnull byte[] buf, int offset) { 46 this.buf = buf; 47 this.baseOffset = offset; 48 } 49 50 public int readSmallUint(int offset) { 51 byte[] buf = this.buf; 52 offset += baseOffset; 53 int result = (buf[offset] & 0xff) | 54 ((buf[offset+1] & 0xff) << 8) | 55 ((buf[offset+2] & 0xff) << 16) | 56 ((buf[offset+3]) << 24); 57 if (result < 0) { 58 throw new ExceptionWithContext("Encountered small uint that is out of range at offset 0x%x", offset); 59 } 60 return result; 61 } 62 63 public int readOptionalUint(int offset) { 64 byte[] buf = this.buf; 65 offset += baseOffset; 66 int result = (buf[offset] & 0xff) | 67 ((buf[offset+1] & 0xff) << 8) | 68 ((buf[offset+2] & 0xff) << 16) | 69 ((buf[offset+3]) << 24); 70 if (result < -1) { 71 throw new ExceptionWithContext("Encountered optional uint that is out of range at offset 0x%x", offset); 72 } 73 return result; 74 } 75 76 public int readUshort(int offset) { 77 byte[] buf = this.buf; 78 offset += baseOffset; 79 return (buf[offset] & 0xff) | 80 ((buf[offset+1] & 0xff) << 8); 81 } 82 83 public int readUbyte(int offset) { 84 return buf[offset + baseOffset] & 0xff; 85 } 86 87 public long readLong(int offset) { 88 byte[] buf = this.buf; 89 offset += baseOffset; 90 return (buf[offset] & 0xff) | 91 ((buf[offset+1] & 0xff) << 8) | 92 ((buf[offset+2] & 0xff) << 16) | 93 ((buf[offset+3] & 0xffL) << 24) | 94 ((buf[offset+4] & 0xffL) << 32) | 95 ((buf[offset+5] & 0xffL) << 40) | 96 ((buf[offset+6] & 0xffL) << 48) | 97 (((long)buf[offset+7]) << 56); 98 } 99 100 public int readLongAsSmallUint(int offset) { 101 byte[] buf = this.buf; 102 offset += baseOffset; 103 long result = (buf[offset] & 0xff) | 104 ((buf[offset+1] & 0xff) << 8) | 105 ((buf[offset+2] & 0xff) << 16) | 106 ((buf[offset+3] & 0xffL) << 24) | 107 ((buf[offset+4] & 0xffL) << 32) | 108 ((buf[offset+5] & 0xffL) << 40) | 109 ((buf[offset+6] & 0xffL) << 48) | 110 (((long)buf[offset+7]) << 56); 111 if (result < 0 || result > Integer.MAX_VALUE) { 112 throw new ExceptionWithContext("Encountered out-of-range ulong at offset 0x%x", offset); 113 } 114 return (int)result; 115 } 116 117 public int readInt(int offset) { 118 byte[] buf = this.buf; 119 offset += baseOffset; 120 return (buf[offset] & 0xff) | 121 ((buf[offset+1] & 0xff) << 8) | 122 ((buf[offset+2] & 0xff) << 16) | 123 (buf[offset+3] << 24); 124 } 125 126 public int readShort(int offset) { 127 byte[] buf = this.buf; 128 offset += baseOffset; 129 return (buf[offset] & 0xff) | 130 (buf[offset+1] << 8); 131 } 132 133 public int readByte(int offset) { 134 return buf[baseOffset + offset]; 135 } 136 137 @Nonnull 138 public BaseDexReader readerAt(int offset) { 139 return new BaseDexReader<BaseDexBuffer>(this, offset); 140 } 141 142 @Nonnull 143 protected byte[] getBuf() { 144 return buf; 145 } 146 147 protected int getBaseOffset() { 148 return baseOffset; 149 } 150 } 151
