1 // NAME
2 // $RCSfile: AsnInteger.java,v $
3 // DESCRIPTION
4 // [given below in javadoc format]
5 // DELTA
6 // $Revision: 3.14 $
7 // CREATED
8 // $Date: 2008/05/27 15:40:14 $
9 // COPYRIGHT
10 // Westhawk Ltd
11 // TO DO
12 //
13
14 /*
15 * Copyright (C) 1995, 1996 by West Consulting BV
16 *
17 * Permission to use, copy, modify, and distribute this software
18 * for any purpose and without fee is hereby granted, provided
19 * that the above copyright notices appear in all copies and that
20 * both the copyright notice and this permission notice appear in
21 * supporting documentation.
22 * This software is provided "as is" without express or implied
23 * warranty.
24 * author <a href="mailto:snmp@westhawk.co.uk">Tim Panton</a>
25 * original version by hargrave@dellgate.us.dell.com (Jordan Hargrave)
26 */
27
28 /*
29 * Copyright (C) 1996 - 2006 by Westhawk Ltd
30 * <a href="www.westhawk.co.uk">www.westhawk.co.uk</a>
31 *
32 * Permission to use, copy, modify, and distribute this software
33 * for any purpose and without fee is hereby granted, provided
34 * that the above copyright notices appear in all copies and that
35 * both the copyright notice and this permission notice appear in
36 * supporting documentation.
37 * This software is provided "as is" without express or implied
38 * warranty.
39 * author <a href="mailto:snmp@westhawk.co.uk">Tim Panton</a>
40 */
41
42 package uk.co.westhawk.snmp.stack;
43
44 /*-
45 * ╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲
46 * SNMP Java Client
47 * ჻჻჻჻჻჻
48 * Copyright 2023 Sentry Software, Westhawk
49 * ჻჻჻჻჻჻
50 * This program is free software: you can redistribute it and/or modify
51 * it under the terms of the GNU Lesser General Public License as
52 * published by the Free Software Foundation, either version 3 of the
53 * License, or (at your option) any later version.
54 *
55 * This program is distributed in the hope that it will be useful,
56 * but WITHOUT ANY WARRANTY; without even the implied warranty of
57 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
58 * GNU General Lesser Public License for more details.
59 *
60 * You should have received a copy of the GNU General Lesser Public
61 * License along with this program. If not, see
62 * <http://www.gnu.org/licenses/lgpl-3.0.html>.
63 * ╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱
64 */
65
66 import java.io.*;
67 import java.util.*;
68
69 /**
70 * This class represents the ASN.1 32-bit signed integer
71 *
72 * @see SnmpConstants#ASN_INTEGER
73 *
74 * @author <a href="mailto:snmp@westhawk.co.uk">Tim Panton</a>
75 * @version $Revision: 3.14 $ $Date: 2008/05/27 15:40:14 $
76 */
77 public class AsnInteger extends AsnObject
78 {
79 private static final String version_id =
80 "@(#)$Id: AsnInteger.java,v 3.14 2008/05/27 15:40:14 birgita Exp $ Copyright Westhawk Ltd";
81
82 /**
83 * The internal value of AsnInteger.
84 */
85 protected int value;
86
87 /**
88 * Constructor.
89 *
90 * @param v The value of the AsnInteger
91 */
92 public AsnInteger(int v)
93 {
94 value = v;
95 type = ASN_INTEGER;
96 }
97
98 /**
99 * Constructor.
100 *
101 * @param in The input stream from which the value should be read
102 * @param len The length of the AsnInteger
103 */
104 public AsnInteger(InputStream in, int len) throws IOException
105 {
106 byte data[] = new byte[len];
107 if (len != in.read(data,0,len))
108 {
109 throw new IOException("AsnInteger(): Not enough data");
110 }
111 int val = bytesToInteger(data);
112 value = val;
113 }
114
115 /**
116 * Returns the value.
117 *
118 * @return The value of the AsnInteger
119 */
120 public int getValue()
121 {
122 return value;
123 }
124
125 /**
126 * Returns the string representation of the AsnInteger.
127 *
128 * @return The string of the AsnInteger
129 */
130 public String toString()
131 {
132 return (String.valueOf(value));
133 }
134
135 /**
136 * Returns the number of bytes the integer occupies.
137 */
138 int size()
139 {
140 int count, empty = 0x00, sign = 0x00;
141
142 if (value < 0)
143 {
144 empty = 0xFF;
145 sign = 0x80;
146 }
147
148 // 32-bit integer.. change to 56 to write 64-bit long
149 // loop through bytes in value while it is 'empty'
150 for(count=24; count>0; count-=8)
151 {
152 if ( ((value >> count) & 0xFF) != empty) break;
153 }
154 // Check sign bit.. make sure negative's MSB bit is 1,
155 // positives is 0
156 // (0x00000080 = 0x00 0x80) 0xFFFFFF01 => 0xFF 0x01
157 // (0x0000007F = 0x7F) 0xFFFFFF80 => 0x80
158 if (((value >> count) & 0x80) != sign) count += 8;
159 return (count>>3)+1;
160 }
161
162
163 /**
164 * Output integer.
165 */
166 void write(OutputStream out, int pos) throws IOException
167 {
168 int count, empty = 0x00, sign = 0x00;
169
170 if (value < 0)
171 {
172 empty = 0xFF;
173 sign = 0x80;
174 }
175
176 // Get count
177 for(count=24; count>0; count-=8)
178 {
179 if ( ((value >> count) & 0xFF) != empty) break;
180 }
181 if (((value >> count) & 0x80) != sign) count += 8;
182
183 // Build header and write value
184 AsnBuildHeader(out, ASN_INTEGER, (count>>3)+1);
185
186 if (debug > 10)
187 {
188 System.out.println("\tAsnInteger(): value = " + value
189 + ", pos = " + pos);
190 }
191
192 for(; count>=0; count-=8)
193 {
194 out.write((byte)((value >> count) & 0xFF));
195 }
196 }
197
198 /**
199 * Changes an array of bytes into an int.
200 * Thanks to Julien Conan (jconan@protego.net) for improving
201 * this method.
202 *
203 * @param data the array of bytes
204 * @return the int representation of the array
205 */
206 protected int bytesToInteger(byte[] data) throws IOException
207 {
208 DataInputStream dis = new DataInputStream(
209 new ByteArrayInputStream(data));
210
211 int val = 0;
212 int size = data.length;
213
214 /*
215 * First byte contains the sign if the number is negative. Do this
216 * only for AsnInteger
217 */
218 val = dis.readByte();
219
220 for (int n=1; n<size; n++)
221 {
222 val = (val << 8) + dis.readUnsignedByte();
223 }
224
225 return val;
226 }
227
228
229 /**
230 * Compares this object to the specified object. The result is
231 * <code>true</code> if and only if the argument is not
232 * <code>null</code> and is an <code>AsnInteger</code> object that
233 * contains the same <code>int</code> value as this object.
234 *
235 * @param obj the object to compare with.
236 * @return <code>true</code> if the objects are the same;
237 * <code>false</code> otherwise.
238 */
239 public boolean equals(Object obj)
240 {
241 if (obj instanceof AsnInteger)
242 {
243 return value == ((AsnInteger)obj).value;
244 }
245 return false;
246 }
247
248
249 /**
250 * Returns a hash code for this <code>AsnInteger</code>.
251 *
252 * @return a hash code value for this object, equal to the
253 * primitive <code>int</code> value represented by this
254 * <code>AsnInteger</code> object.
255 */
256 public int hashCode()
257 {
258 return value;
259 }
260 }