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1 package com.lowagie.bc.asn1;
2
3 import java.io.ByteArrayInputStream;
4 import java.io.EOFException;
5 import java.io.FilterInputStream;
6 import java.io.IOException;
7 import java.io.InputStream;
8
9
14 public class DERInputStream
15 extends FilterInputStream implements DERTags
16 {
17 public DERInputStream(
18 InputStream is)
19 {
20 super(is);
21 }
22
23 protected int readLength()
24 throws IOException
25 {
26 int length = read();
27 if (length < 0)
28 {
29 throw new IOException("EOF found when length expected");
30 }
31
32 if (length == 0x80)
33 {
34 return -1; }
36
37 if (length > 127)
38 {
39 int size = length & 0x7f;
40
41 length = 0;
42 for (int i = 0; i < size; i++)
43 {
44 int next = read();
45
46 if (next < 0)
47 {
48 throw new IOException("EOF found reading length");
49 }
50
51 length = (length << 8) + next;
52 }
53 }
54
55 return length;
56 }
57
58 protected void readFully(
59 byte[] bytes)
60 throws IOException
61 {
62 int left = bytes.length;
63
64 if (left == 0)
65 {
66 return;
67 }
68
69 while (left > 0)
70 {
71 int l = read(bytes, bytes.length - left, left);
72
73 if (l < 0)
74 {
75 throw new EOFException("unexpected end of stream");
76 }
77
78 left -= l;
79 }
80 }
81
82
86 protected DERObject buildObject(
87 int tag,
88 byte[] bytes)
89 throws IOException
90 {
91 switch (tag)
92 {
93 case NULL:
94 return null;
95 case SEQUENCE | CONSTRUCTED:
96 ByteArrayInputStream bIn = new ByteArrayInputStream(bytes);
97 BERInputStream dIn = new BERInputStream(bIn);
98 DERConstructedSequence seq = new DERConstructedSequence();
99
100 try
101 {
102 for (;;)
103 {
104 DERObject obj = dIn.readObject();
105
106 seq.addObject(obj);
107 }
108 }
109 catch (EOFException ex)
110 {
111 return seq;
112 }
113 case SET | CONSTRUCTED:
114 bIn = new ByteArrayInputStream(bytes);
115 dIn = new BERInputStream(bIn);
116
117 ASN1EncodableVector v = new ASN1EncodableVector();
118
119 try
120 {
121 for (;;)
122 {
123 DERObject obj = dIn.readObject();
124
125 v.add(obj);
126 }
127 }
128 catch (EOFException ex)
129 {
130 return new DERConstructedSet(v);
131 }
132 case BOOLEAN:
133 return new DERBoolean(bytes);
134 case INTEGER:
135 return new DERInteger(bytes);
136 case ENUMERATED:
137 return new DEREnumerated(bytes);
138 case OBJECT_IDENTIFIER:
139 return new DERObjectIdentifier(bytes);
140 case BIT_STRING:
141 int padBits = bytes[0];
142 byte[] data = new byte[bytes.length - 1];
143
144 System.arraycopy(bytes, 1, data, 0, bytes.length - 1);
145
146 return new DERBitString(data, padBits);
147 case UTF8_STRING:
148 return new DERUTF8String(bytes);
149 case PRINTABLE_STRING:
150 return new DERPrintableString(bytes);
151 case IA5_STRING:
152 return new DERIA5String(bytes);
153 case T61_STRING:
154 return new DERT61String(bytes);
155 case VISIBLE_STRING:
156 return new DERVisibleString(bytes);
157 case UNIVERSAL_STRING:
158 return new DERUniversalString(bytes);
159 case GENERAL_STRING:
160 return new DERGeneralString(bytes);
161 case BMP_STRING:
162 return new DERBMPString(bytes);
163 case OCTET_STRING:
164 return new DEROctetString(bytes);
165 case UTC_TIME:
166 return new DERUTCTime(bytes);
167 case GENERALIZED_TIME:
168 return new DERGeneralizedTime(bytes);
169 default:
170 if ((tag & TAGGED) != 0)
174 {
175 if ((tag & 0x1f) == 0x1f)
176 {
177 throw new IOException("unsupported high tag encountered");
178 }
179
180 if (bytes.length == 0) {
182 if ((tag & CONSTRUCTED) == 0)
183 {
184 return new DERTaggedObject(false, tag & 0x1f, new DERNull());
185 }
186 else
187 {
188 return new DERTaggedObject(false, tag & 0x1f, new DERConstructedSequence());
189 }
190 }
191
192 if ((tag & CONSTRUCTED) == 0)
196 {
197 return new DERTaggedObject(false, tag & 0x1f, new DEROctetString(bytes));
198 }
199
200 bIn = new ByteArrayInputStream(bytes);
201 dIn = new BERInputStream(bIn);
202
203 DEREncodable dObj = dIn.readObject();
204
205 if (dIn.available() == 0)
210 {
211 return new DERTaggedObject(tag & 0x1f, dObj);
212 }
213
214 seq = new DERConstructedSequence();
218
219 seq.addObject(dObj);
220
221 try
222 {
223 for (;;)
224 {
225 dObj = dIn.readObject();
226
227 seq.addObject(dObj);
228 }
229 }
230 catch (EOFException ex)
231 {
232 }
234
235 return new DERTaggedObject(false, tag & 0x1f, seq);
236 }
237
238 return new DERUnknownTag(tag, bytes);
239 }
240 }
241
242 public DERObject readObject()
243 throws IOException
244 {
245 int tag = read();
246 if (tag == -1)
247 {
248 throw new EOFException();
249 }
250
251 int length = readLength();
252 byte[] bytes = new byte[length];
253
254 readFully(bytes);
255
256 return buildObject(tag, bytes);
257 }
258 }
259 |
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