|
1
17
18 package org.apache.geronimo.util.asn1;
19
20 import java.io.ByteArrayOutputStream  ;
21 import java.io.EOFException ;
22 import java.io.IOException ;
23 import java.io.InputStream ;
24 import java.util.Vector ;
25
26
29 public class BERInputStream
30 extends DERInputStream
31 {
32 private DERObject END_OF_STREAM = new DERObject() {
33 void encode(
34 DEROutputStream out)
35 throws IOException
36 {
37 throw new IOException ("Eeek!");
38 }
39 public int hashCode()
40 {
41 return 0;
42 }
43 public boolean equals(
44 Object o)
45 {
46 return o == this;
47 }
48 };
49 public BERInputStream(
50 InputStream is)
51 {
52 super(is);
53 }
54
55
58 private byte[] readIndefiniteLengthFully()
59 throws IOException
60 {
61 ByteArrayOutputStream bOut = new ByteArrayOutputStream ();
62 int b, b1;
63
64 b1 = read();
65
66 while ((b = read()) >= 0)
67 {
68 if (b1 == 0 && b == 0)
69 {
70 break;
71 }
72
73 bOut.write(b1);
74 b1 = b;
75 }
76
77 return bOut.toByteArray();
78 }
79
80 private BERConstructedOctetString buildConstructedOctetString()
81 throws IOException
82 {
83 Vector octs = new Vector ();
84
85 for (;;)
86 {
87 DERObject o = readObject();
88
89 if (o == END_OF_STREAM)
90 {
91 break;
92 }
93
94 octs.addElement(o);
95 }
96
97 return new BERConstructedOctetString(octs);
98 }
99
100 public DERObject readObject()
101 throws IOException
102 {
103 int tag = read();
104 if (tag == -1)
105 {
106 throw new EOFException ();
107 }
108
109 int length = readLength();
110
111 if (length < 0) {
113 switch (tag)
114 {
115 case NULL:
116 return null;
117 case SEQUENCE | CONSTRUCTED:
118 BERConstructedSequence seq = new BERConstructedSequence();
119
120 for (;;)
121 {
122 DERObject obj = readObject();
123
124 if (obj == END_OF_STREAM)
125 {
126 break;
127 }
128
129 seq.addObject(obj);
130 }
131 return seq;
132 case OCTET_STRING | CONSTRUCTED:
133 return buildConstructedOctetString();
134 case SET | CONSTRUCTED:
135 ASN1EncodableVector v = new ASN1EncodableVector();
136
137 for (;;)
138 {
139 DERObject obj = readObject();
140
141 if (obj == END_OF_STREAM)
142 {
143 break;
144 }
145
146 v.add(obj);
147 }
148 return new BERSet(v);
149 default:
150 if ((tag & TAGGED) != 0)
154 {
155 if ((tag & 0x1f) == 0x1f)
156 {
157 throw new IOException ("unsupported high tag encountered");
158 }
159
160 if ((tag & CONSTRUCTED) == 0)
164 {
165 byte[] bytes = readIndefiniteLengthFully();
166
167 return new BERTaggedObject(false, tag & 0x1f, new DEROctetString(bytes));
168 }
169
170 DERObject dObj = readObject();
174
175 if (dObj == END_OF_STREAM) {
177 return new DERTaggedObject(tag & 0x1f);
178 }
179
180 DERObject next = readObject();
181
182 if (next == END_OF_STREAM)
187 {
188 return new BERTaggedObject(tag & 0x1f, dObj);
189 }
190
191 seq = new BERConstructedSequence();
195
196 seq.addObject(dObj);
197
198 do
199 {
200 seq.addObject(next);
201 next = readObject();
202 }
203 while (next != END_OF_STREAM);
204
205 return new BERTaggedObject(false, tag & 0x1f, seq);
206 }
207
208 throw new IOException ("unknown BER object encountered");
209 }
210 }
211 else
212 {
213 if (tag == 0 && length == 0) {
215 return END_OF_STREAM;
216 }
217
218 byte[] bytes = new byte[length];
219
220 readFully(bytes);
221
222 return buildObject(tag, bytes);
223 }
224 }
225 }
226 |
Popular Tags |
Java API By Example, From Geeks To Geeks.