1 /* 2 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved. 3 * Please refer to the LICENSE.txt for licensing details. 4 */ 5 package ch.ethz.ssh2.packets; 6 7 import java.io.IOException; 8 import java.math.BigInteger; 9 10 import ch.ethz.ssh2.util.StringEncoder; 11 import ch.ethz.ssh2.util.Tokenizer; 12 13 /** 14 * TypesReader. 15 * 16 * @author Christian Plattner 17 * @version 2.50, 03/15/10 18 */ 19 public class TypesReader 20 { 21 byte[] arr; 22 int pos = 0; 23 int max = 0; 24 25 public TypesReader(byte[] arr) 26 { 27 this.arr = arr; 28 pos = 0; 29 max = arr.length; 30 } 31 32 public TypesReader(byte[] arr, int off) 33 { 34 this.arr = arr; 35 this.pos = off; 36 this.max = arr.length; 37 38 if ((pos < 0) || (pos > arr.length)) 39 throw new IllegalArgumentException("Illegal offset."); 40 } 41 42 public TypesReader(byte[] arr, int off, int len) 43 { 44 this.arr = arr; 45 this.pos = off; 46 this.max = off + len; 47 48 if ((pos < 0) || (pos > arr.length)) 49 throw new IllegalArgumentException("Illegal offset."); 50 51 if ((max < 0) || (max > arr.length)) 52 throw new IllegalArgumentException("Illegal length."); 53 } 54 55 public int readByte() throws IOException 56 { 57 if (pos >= max) 58 throw new IOException("Packet too short."); 59 60 return (arr[pos++] & 0xff); 61 } 62 63 public byte[] readBytes(int len) throws IOException 64 { 65 if ((pos + len) > max) 66 throw new IOException("Packet too short."); 67 68 byte[] res = new byte[len]; 69 70 System.arraycopy(arr, pos, res, 0, len); 71 pos += len; 72 73 return res; 74 } 75 76 public void readBytes(byte[] dst, int off, int len) throws IOException 77 { 78 if ((pos + len) > max) 79 throw new IOException("Packet too short."); 80 81 System.arraycopy(arr, pos, dst, off, len); 82 pos += len; 83 } 84 85 public boolean readBoolean() throws IOException 86 { 87 if (pos >= max) 88 throw new IOException("Packet too short."); 89 90 return (arr[pos++] != 0); 91 } 92 93 public int readUINT32() throws IOException 94 { 95 if ((pos + 4) > max) 96 throw new IOException("Packet too short."); 97 98 return ((arr[pos++] & 0xff) << 24) | ((arr[pos++] & 0xff) << 16) | ((arr[pos++] & 0xff) << 8) 99 | (arr[pos++] & 0xff); 100 } 101 102 public long readUINT64() throws IOException 103 { 104 if ((pos + 8) > max) 105 throw new IOException("Packet too short."); 106 107 long high = ((arr[pos++] & 0xff) << 24) | ((arr[pos++] & 0xff) << 16) | ((arr[pos++] & 0xff) << 8) 108 | (arr[pos++] & 0xff); /* sign extension may take place - will be shifted away =) */ 109 110 long low = ((arr[pos++] & 0xff) << 24) | ((arr[pos++] & 0xff) << 16) | ((arr[pos++] & 0xff) << 8) 111 | (arr[pos++] & 0xff); /* sign extension may take place - handle below */ 112 113 return (high << 32) | (low & 0xffffffffl); /* see Java language spec (15.22.1, 5.6.2) */ 114 } 115 116 public BigInteger readMPINT() throws IOException 117 { 118 BigInteger b; 119 120 byte raw[] = readByteString(); 121 122 if (raw.length == 0) 123 b = BigInteger.ZERO; 124 else 125 b = new BigInteger(raw); 126 127 return b; 128 } 129 130 public byte[] readByteString() throws IOException 131 { 132 int len = readUINT32(); 133 134 if ((len + pos) > max) 135 throw new IOException("Malformed SSH byte string."); 136 137 byte[] res = new byte[len]; 138 System.arraycopy(arr, pos, res, 0, len); 139 pos += len; 140 return res; 141 } 142 143 public String readString(String charsetName) throws IOException 144 { 145 int len = readUINT32(); 146 147 if ((len + pos) > max) 148 throw new IOException("Malformed SSH string."); 149 150 String res = (charsetName == null) ? new String(arr, pos, len) : new String(arr, pos, len, charsetName); 151 pos += len; 152 153 return res; 154 } 155 156 public String readString() throws IOException 157 { 158 int len = readUINT32(); 159 160 if ((len + pos) > max) 161 throw new IOException("Malformed SSH string."); 162 163 String res = StringEncoder.GetString(arr, pos, len); 164 pos += len; 165 166 return res; 167 } 168 169 public String[] readNameList() throws IOException 170 { 171 return Tokenizer.parseTokens(readString(), ','); 172 } 173 174 public int remain() 175 { 176 return max - pos; 177 } 178 179 } 180
