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1
17
18 package org.apache.geronimo.util.asn1;
19
20 import java.io.ByteArrayOutputStream  ;
21 import java.io.IOException ;
22
23 public class DERBitString
24 extends DERObject
25 implements DERString
26 {
27 private static final char[] table = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
28
29 protected byte[] data;
30 protected int padBits;
31
32
36 static protected int getPadBits(
37 int bitString)
38 {
39 int val = 0;
40 for (int i = 3; i >= 0; i--)
41 {
42 if (i != 0)
47 {
48 if ((bitString >> (i * 8)) != 0)
49 {
50 val = (bitString >> (i * 8)) & 0xFF;
51 break;
52 }
53 }
54 else
55 {
56 if (bitString != 0)
57 {
58 val = bitString & 0xFF;
59 break;
60 }
61 }
62 }
63
64 if (val == 0)
65 {
66 return 7;
67 }
68
69
70 int bits = 1;
71
72 while (((val <<= 1) & 0xFF) != 0)
73 {
74 bits++;
75 }
76
77 return 8 - bits;
78 }
79
80
84 static protected byte[] getBytes(int bitString)
85 {
86 int bytes = 4;
87 for (int i = 3; i >= 1; i--)
88 {
89 if ((bitString & (0xFF << (i * 8))) != 0)
90 {
91 break;
92 }
93 bytes--;
94 }
95
96 byte[] result = new byte[bytes];
97 for (int i = 0; i < bytes; i++)
98 {
99 result[i] = (byte) ((bitString >> (i * 8)) & 0xFF);
100 }
101
102 return result;
103 }
104
105
110 public static DERBitString getInstance(
111 Object obj)
112 {
113 if (obj == null || obj instanceof DERBitString)
114 {
115 return (DERBitString)obj;
116 }
117
118 if (obj instanceof ASN1OctetString)
119 {
120 byte[] bytes = ((ASN1OctetString)obj).getOctets();
121 int padBits = bytes[0];
122 byte[] data = new byte[bytes.length - 1];
123
124 System.arraycopy(bytes, 1, data, 0, bytes.length - 1);
125
126 return new DERBitString(data, padBits);
127 }
128
129 if (obj instanceof ASN1TaggedObject)
130 {
131 return getInstance(((ASN1TaggedObject)obj).getObject());
132 }
133
134 throw new IllegalArgumentException ("illegal object in getInstance: " + obj.getClass().getName());
135 }
136
137
146 public static DERBitString getInstance(
147 ASN1TaggedObject obj,
148 boolean explicit)
149 {
150 return getInstance(obj.getObject());
151 }
152
153 protected DERBitString(
154 byte data,
155 int padBits)
156 {
157 this.data = new byte[1];
158 this.data[0] = data;
159 this.padBits = padBits;
160 }
161
162
166 public DERBitString(
167 byte[] data,
168 int padBits)
169 {
170 this.data = data;
171 this.padBits = padBits;
172 }
173
174 public DERBitString(
175 byte[] data)
176 {
177 this(data, 0);
178 }
179
180 public DERBitString(
181 DEREncodable obj)
182 {
183 try
184 {
185 ByteArrayOutputStream bOut = new ByteArrayOutputStream ();
186 DEROutputStream dOut = new DEROutputStream(bOut);
187
188 dOut.writeObject(obj);
189 dOut.close();
190
191 this.data = bOut.toByteArray();
192 this.padBits = 0;
193 }
194 catch (IOException e)
195 {
196 throw new IllegalArgumentException ("Error processing object : " + e.toString());
197 }
198 }
199
200 public byte[] getBytes()
201 {
202 return data;
203 }
204
205 public int getPadBits()
206 {
207 return padBits;
208 }
209
210
211
214 public int intValue()
215 {
216 int value = 0;
217
218 for (int i = 0; i != data.length && i != 4; i++)
219 {
220 value |= (data[i] & 0xff) << (8 * i);
221 }
222
223 return value;
224 }
225
226 void encode(
227 DEROutputStream out)
228 throws IOException
229 {
230 byte[] bytes = new byte[getBytes().length + 1];
231
232 bytes[0] = (byte)getPadBits();
233 System.arraycopy(getBytes(), 0, bytes, 1, bytes.length - 1);
234
235 out.writeEncoded(BIT_STRING, bytes);
236 }
237
238 public int hashCode()
239 {
240 int value = 0;
241
242 for (int i = 0; i != data.length; i++)
243 {
244 value ^= (data[i] & 0xff) << (i % 4);
245 }
246
247 return value;
248 }
249
250 public boolean equals(
251 Object o)
252 {
253 if (o == null || !(o instanceof DERBitString))
254 {
255 return false;
256 }
257
258 DERBitString other = (DERBitString)o;
259
260 if (data.length != other.data.length)
261 {
262 return false;
263 }
264
265 for (int i = 0; i != data.length; i++)
266 {
267 if (data[i] != other.data[i])
268 {
269 return false;
270 }
271 }
272
273 return (padBits == other.padBits);
274 }
275
276 public String getString()
277 {
278 StringBuffer buf = new StringBuffer ("#");
279 ByteArrayOutputStream bOut = new ByteArrayOutputStream ();
280 ASN1OutputStream aOut = new ASN1OutputStream(bOut);
281
282 try
283 {
284 aOut.writeObject(this);
285 }
286 catch (IOException e)
287 {
288 throw new RuntimeException ("internal error encoding BitString");
289 }
290
291 byte[] string = bOut.toByteArray();
292
293 for (int i = 0; i != string.length; i++)
294 {
295 buf.append(table[(string[i] >>> 4) % 0xf]);
296 buf.append(table[string[i] & 0xf]);
297 }
298
299 return buf.toString();
300 }
301 }
302 |
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