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1
19
20 package com.maverick.crypto.asn1;
21
22 import java.io.ByteArrayInputStream  ;
23 import java.io.EOFException ;
24 import java.io.FilterInputStream ;
25 import java.io.IOException ;
26 import java.io.InputStream ;
27
28
33 public class DERInputStream
34 extends FilterInputStream implements DERTags
35 {
36 public DERInputStream(
37 InputStream is)
38 {
39 super(is);
40 }
41
42 protected int readLength()
43 throws IOException
44 {
45 int length = read();
46 if (length < 0)
47 {
48 throw new IOException ("EOF found when length expected");
49 }
50
51 if (length == 0x80)
52 {
53 return -1; }
55
56 if (length > 127)
57 {
58 int size = length & 0x7f;
59
60 length = 0;
61 for (int i = 0; i < size; i++)
62 {
63 int next = read();
64
65 if (next < 0)
66 {
67 throw new IOException ("EOF found reading length");
68 }
69
70 length = (length << 8) + next;
71 }
72 }
73
74 return length;
75 }
76
77 protected void readFully(
78 byte[] bytes)
79 throws IOException
80 {
81 int left = bytes.length;
82
83 if (left == 0)
84 {
85 return;
86 }
87
88 while (left > 0)
89 {
90 int l = read(bytes, bytes.length - left, left);
91
92 if (l < 0)
93 {
94 throw new EOFException ("unexpected end of stream");
95 }
96
97 left -= l;
98 }
99 }
100
101
105 protected DERObject buildObject(
106 int tag,
107 byte[] bytes)
108 throws IOException
109 {
110 switch (tag)
111 {
112 case NULL:
113 return null;
114 case SEQUENCE | CONSTRUCTED:
115 ByteArrayInputStream bIn = new ByteArrayInputStream (bytes);
116 BERInputStream dIn = new BERInputStream(bIn);
117 DERConstructedSequence seq = new DERConstructedSequence();
118
119 try
120 {
121 for (;;)
122 {
123 DERObject obj = dIn.readObject();
124
125 seq.addObject(obj);
126 }
127 }
128 catch (EOFException ex)
129 {
130 return seq;
131 }
132 case SET | CONSTRUCTED:
133 bIn = new ByteArrayInputStream (bytes);
134 dIn = new BERInputStream(bIn);
135
136 ASN1EncodableVector v = new ASN1EncodableVector();
137
138 try
139 {
140 for (;;)
141 {
142 DERObject obj = dIn.readObject();
143
144 v.add(obj);
145 }
146 }
147 catch (EOFException ex)
148 {
149 return new DERConstructedSet(v);
150 }
151 case BOOLEAN:
152 return new DERBoolean(bytes);
153 case INTEGER:
154 return new DERInteger(bytes);
155 case ENUMERATED:
156 return new DEREnumerated(bytes);
157 case OBJECT_IDENTIFIER:
158 return new DERObjectIdentifier(bytes);
159 case BIT_STRING:
160 int padBits = bytes[0];
161 byte[] data = new byte[bytes.length - 1];
162
163 System.arraycopy(bytes, 1, data, 0, bytes.length - 1);
164
165 return new DERBitString(data, padBits);
166 case UTF8_STRING:
167 return new DERUTF8String(bytes);
168 case PRINTABLE_STRING:
169 return new DERPrintableString(bytes);
170 case IA5_STRING:
171 return new DERIA5String(bytes);
172 case T61_STRING:
173 return new DERT61String(bytes);
174 case VISIBLE_STRING:
175 return new DERVisibleString(bytes);
176 case UNIVERSAL_STRING:
177 return new DERUniversalString(bytes);
178 case GENERAL_STRING:
179 return new DERGeneralString(bytes);
180 case BMP_STRING:
181 return new DERBMPString(bytes);
182 case OCTET_STRING:
183 return new DEROctetString(bytes);
184 case UTC_TIME:
185 return new DERUTCTime(bytes);
186 case GENERALIZED_TIME:
187 return new DERGeneralizedTime(bytes);
188 default:
189 if ((tag & TAGGED) != 0)
193 {
194 if ((tag & 0x1f) == 0x1f)
195 {
196 throw new IOException ("unsupported high tag encountered");
197 }
198
199 if (bytes.length == 0) {
201 if ((tag & CONSTRUCTED) == 0)
202 {
203 return new DERTaggedObject(false, tag & 0x1f, new DERNull());
204 }
205 else
206 {
207 return new DERTaggedObject(false, tag & 0x1f, new DERConstructedSequence());
208 }
209 }
210
211 if ((tag & CONSTRUCTED) == 0)
215 {
216 return new DERTaggedObject(false, tag & 0x1f, new DEROctetString(bytes));
217 }
218
219 bIn = new ByteArrayInputStream (bytes);
220 dIn = new BERInputStream(bIn);
221
222 DEREncodable dObj = dIn.readObject();
223
224 if (dIn.available() == 0)
229 {
230 return new DERTaggedObject(tag & 0x1f, dObj);
231 }
232
233 seq = new DERConstructedSequence();
237
238 seq.addObject(dObj);
239
240 try
241 {
242 for (;;)
243 {
244 dObj = dIn.readObject();
245
246 seq.addObject(dObj);
247 }
248 }
249 catch (EOFException ex)
250 {
251 }
253
254 return new DERTaggedObject(false, tag & 0x1f, seq);
255 }
256
257 return new DERUnknownTag(tag, bytes);
258 }
259 }
260
261 public DERObject readObject()
262 throws IOException
263 {
264 int tag = read();
265 if (tag == -1)
266 {
267 throw new EOFException ();
268 }
269
270 int length = readLength();
271 byte[] bytes = new byte[length];
272
273 readFully(bytes);
274
275 return buildObject(tag, bytes);
276 }
277 }
278 |
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