DERInteger


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.geronimo.util.asn1;
19  
20  import java.io.IOException  ;
21  import java.math.BigInteger  ;
22  
23  public class DERInteger
24      extends DERObject
25  {
26      byte[]      bytes;
27  
28      /**
29       * return an integer from the passed in object
30       *
31       * @exception IllegalArgumentException if the object cannot be converted.
32       */
33      public static DERInteger getInstance(
34          Object    obj)
35      {
36          if (obj == null || obj instanceof DERInteger)
37          {
38              return (DERInteger)obj;
39          }
40  
41          if (obj instanceof ASN1OctetString)
42          {
43              return new DERInteger(((ASN1OctetString)obj).getOctets());
44          }
45  
46          if (obj instanceof ASN1TaggedObject)
47          {
48              return getInstance(((ASN1TaggedObject)obj).getObject());
49          }
50  
51          throw new IllegalArgumentException  ("illegal object in getInstance: " + obj.getClass().getName());
52      }
53  
54      /**
55       * return an Integer from a tagged object.
56       *
57       * @param obj the tagged object holding the object we want
58       * @param explicit true if the object is meant to be explicitly
59       *              tagged false otherwise.
60       * @exception IllegalArgumentException if the tagged object cannot
61       *               be converted.
62       */
63      public static DERInteger getInstance(
64          ASN1TaggedObject obj,
65          boolean          explicit)
66      {
67          return getInstance(obj.getObject());
68      }
69  
70      public DERInteger(
71          int         value)
72      {
73          bytes = BigInteger.valueOf(value).toByteArray();
74      }
75  
76      public DERInteger(
77          BigInteger     value)
78      {
79          bytes = value.toByteArray();
80      }
81  
82      public DERInteger(
83          byte[]   bytes)
84      {
85          this.bytes = bytes;
86      }
87  
88      public BigInteger   getValue()
89      {
90          return new BigInteger  (bytes);
91      }
92  
93      /**
94       * in some cases positive values get crammed into a space,
95       * that's not quite big enough...
96       */
97      public BigInteger   getPositiveValue()
98      {
99          return new BigInteger  (1, bytes);
100     }
101 
102     void encode(
103         DEROutputStream out)
104         throws IOException  
105     {
106         out.writeEncoded(INTEGER, bytes);
107     }
108 
109     public int hashCode()
110     {
111          int     value = 0;
112 
113          for (int i = 0; i != bytes.length; i++)
114          {
115              value ^= (bytes[i] & 0xff) << (i % 4);
116          }
117 
118          return value;
119     }
120 
121     public boolean equals(
122         Object    o)
123     {
124         if (o == null || !(o instanceof DERInteger))
125         {
126             return false;
127         }
128 
129         DERInteger other = (DERInteger)o;
130 
131         if (bytes.length != other.bytes.length)
132         {
133             return false;
134         }
135 
136         for (int i = 0; i != bytes.length; i++)
137         {
138             if (bytes[i] != other.bytes[i])
139             {
140                 return false;
141             }
142         }
143 
144         return true;
145     }
146 }
147
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