summaryrefslogtreecommitdiff
path: root/libjava/classpath/gnu/java/security/der/DERReader.java
blob: cd552c8beddc00a47358f2ac9025af4067903415 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
/* DERReader.java -- parses ASN.1 DER sequences
   Copyright (C) 2003 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package gnu.java.security.der;

import gnu.java.lang.CPStringBuilder;

import gnu.java.security.OID;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

/**
 * This class decodes DER sequences into Java objects. The methods of
 * this class do not have knowledge of higher-levels of structure in the
 * DER stream -- such as ASN.1 constructions -- and it is therefore up
 * to the calling application to determine if the data are structured
 * properly by inspecting the {@link DERValue} that is returned.
 *
 * @author Casey Marshall (csm@gnu.org)
 */
public class DERReader implements DER
{

  // Fields.
  // ------------------------------------------------------------------------

  protected InputStream in;

  protected final ByteArrayOutputStream encBuf;

  // Constructor.
  // ------------------------------------------------------------------------

  /**
   * Create a new DER reader from a byte array.
   *
   * @param in The encoded bytes.
   */
  public DERReader(byte[] in)
  {
    this(new ByteArrayInputStream(in));
  }

  public DERReader (byte[] in, int off, int len)
  {
    this (new ByteArrayInputStream (in, off, len));
  }

  /**
   * Create a new DER readed from an input stream.
   *
   * @param in The encoded bytes.
   */
  public DERReader(InputStream in)
  {
    if (!in.markSupported())
      this.in = new BufferedInputStream(in, 16384);
    else
      this.in = in;
    encBuf = new ByteArrayOutputStream(2048);
  }

  // Class methods.
  // ------------------------------------------------------------------------

  /**
   * Convenience method for reading a single primitive value from the
   * given byte array.
   *
   * @param encoded The encoded bytes.
   * @throws IOException If the bytes do not represent an encoded
   * object.
   */
  public static DERValue read(byte[] encoded) throws IOException
  {
    return new DERReader(encoded).read();
  }

  // Instance methods.
  // ------------------------------------------------------------------------

  public void skip (int bytes) throws IOException
  {
    in.skip (bytes);
  }

  /**
   * Decode a single value from the input stream, returning it in a new
   * {@link DERValue}. By "single value" we mean any single type in its
   * entirety -- including constructed types such as SEQUENCE and all
   * the values they contain. Usually it is sufficient to call this
   * method once to parse and return the top-level structure, then to
   * inspect the returned value for the proper contents.
   *
   * @return The parsed DER structure.
   * @throws IOException If an error occurs reading from the input
   * stream.
   * @throws DEREncodingException If the input does not represent a
   * valid DER stream.
   */
  public DERValue read() throws IOException
  {
    int tag = in.read();
    if (tag == -1)
      throw new EOFException();
    encBuf.write(tag);
    int len = readLength();
    DERValue value = null;
    if ((tag & CONSTRUCTED) == CONSTRUCTED)
      {
        in.mark(2048);
        byte[] encoded = new byte[len];
        in.read(encoded);
        encBuf.write(encoded);
        value = new DERValue(tag, len, CONSTRUCTED_VALUE, encBuf.toByteArray());
        in.reset();
        encBuf.reset();
        return value;
      }
    switch (tag & 0xC0)
      {
        case UNIVERSAL:
          value = new DERValue(tag, len, readUniversal(tag, len),
            encBuf.toByteArray());
          encBuf.reset();
          break;
        case CONTEXT:
          byte[] encoded = new byte[len];
          in.read(encoded);
          encBuf.write(encoded);
          value = new DERValue(tag, len, encoded, encBuf.toByteArray());
          encBuf.reset();
          break;
        case APPLICATION:
          // This should not be reached, since (I think) APPLICATION is
          // always constructed.
          throw new DEREncodingException("non-constructed APPLICATION data");
        default:
          throw new DEREncodingException("PRIVATE class not supported");
      }
    return value;
  }

  protected int readLength() throws IOException
  {
    int i = in.read();
    if (i == -1)
      throw new EOFException();
    encBuf.write(i);
    if ((i & ~0x7F) == 0)
      {
        return i;
      }
    else if (i < 0xFF)
      {
        byte[] octets = new byte[i & 0x7F];
        in.read(octets);
        encBuf.write(octets);
        return new BigInteger(1, octets).intValue();
      }
    throw new DEREncodingException();
  }

  // Own methods.
  // ------------------------------------------------------------------------

  private Object readUniversal(int tag, int len) throws IOException
  {
    byte[] value = new byte[len];
    in.read(value);
    encBuf.write(value);
    switch (tag & 0x1F)
      {
        case BOOLEAN:
          if (value.length != 1)
            throw new DEREncodingException();
          return Boolean.valueOf(value[0] != 0);
        case NULL:
          if (len != 0)
            throw new DEREncodingException();
          return null;
        case INTEGER:
        case ENUMERATED:
          return new BigInteger(value);
        case BIT_STRING:
          byte[] bits = new byte[len - 1];
          System.arraycopy(value, 1, bits, 0, bits.length);
          return new BitString(bits, value[0] & 0xFF);
        case OCTET_STRING:
          return value;
        case NUMERIC_STRING:
        case PRINTABLE_STRING:
        case T61_STRING:
        case VIDEOTEX_STRING:
        case IA5_STRING:
        case GRAPHIC_STRING:
        case ISO646_STRING:
        case GENERAL_STRING:
        case UNIVERSAL_STRING:
        case BMP_STRING:
        case UTF8_STRING:
          return makeString(tag, value);
        case UTC_TIME:
        case GENERALIZED_TIME:
          return makeTime(tag, value);
        case OBJECT_IDENTIFIER:
          return new OID(value);
        case RELATIVE_OID:
          return new OID(value, true);
        default:
          throw new DEREncodingException("unknown tag " + tag);
      }
  }

  private static String makeString(int tag, byte[] value)
    throws IOException
  {
    switch (tag & 0x1F)
      {
        case NUMERIC_STRING:
        case PRINTABLE_STRING:
        case T61_STRING:
        case VIDEOTEX_STRING:
        case IA5_STRING:
        case GRAPHIC_STRING:
        case ISO646_STRING:
        case GENERAL_STRING:
          return fromIso88591(value);

        case UNIVERSAL_STRING:
          // XXX The docs say UniversalString is encoded in four bytes
          // per character, but Java has no support (yet) for UTF-32.
          //return new String(buf, "UTF-32");
        case BMP_STRING:
          return fromUtf16Be(value);

        case UTF8_STRING:
          return fromUtf8(value);

        default:
          throw new DEREncodingException("unknown string tag");
      }
  }

  private static String fromIso88591(byte[] bytes)
  {
    CPStringBuilder str = new CPStringBuilder(bytes.length);
    for (int i = 0; i < bytes.length; i++)
      str.append((char) (bytes[i] & 0xFF));
    return str.toString();
  }

  private static String fromUtf16Be(byte[] bytes) throws IOException
  {
    if ((bytes.length & 0x01) != 0)
      throw new IOException("UTF-16 bytes are odd in length");
    CPStringBuilder str = new CPStringBuilder(bytes.length / 2);
    for (int i = 0; i < bytes.length; i += 2)
      {
        char c = (char) ((bytes[i] << 8) & 0xFF);
        c |= (char) (bytes[i+1] & 0xFF);
        str.append(c);
      }
    return str.toString();
  }

  private static String fromUtf8(byte[] bytes) throws IOException
  {
    CPStringBuilder str = new CPStringBuilder((int)(bytes.length / 1.5));
    for (int i = 0; i < bytes.length; )
      {
        char c = 0;
        if ((bytes[i] & 0xE0) == 0xE0)
          {
            if ((i + 2) >= bytes.length)
              throw new IOException("short UTF-8 input");
            c = (char) ((bytes[i++] & 0x0F) << 12);
            if ((bytes[i] & 0x80) != 0x80)
              throw new IOException("malformed UTF-8 input");
            c |= (char) ((bytes[i++] & 0x3F) << 6);
            if ((bytes[i] & 0x80) != 0x80)
              throw new IOException("malformed UTF-8 input");
            c |= (char) (bytes[i++] & 0x3F);
          }
        else if ((bytes[i] & 0xC0) == 0xC0)
          {
            if ((i + 1) >= bytes.length)
              throw new IOException("short input");
            c = (char) ((bytes[i++] & 0x1F) << 6);
            if ((bytes[i] & 0x80) != 0x80)
              throw new IOException("malformed UTF-8 input");
            c |= (char) (bytes[i++] & 0x3F);
          }
        else if ((bytes[i] & 0xFF) < 0x80)
          {
            c = (char) (bytes[i++] & 0xFF);
          }
        else
          throw new IOException("badly formed UTF-8 sequence");
        str.append(c);
      }
    return str.toString();
  }

  private Date makeTime(int tag, byte[] value) throws IOException
  {
    Calendar calendar = Calendar.getInstance();
    String str = makeString(PRINTABLE_STRING, value);

    // Classpath's SimpleDateFormat does not work for parsing these
    // types of times, so we do this by hand.
    String date = str;
    String tz = "";
    if (str.indexOf("+") > 0)
      {
        date = str.substring(0, str.indexOf("+"));
        tz = str.substring(str.indexOf("+"));
      }
    else if (str.indexOf("-") > 0)
      {
        date = str.substring(0, str.indexOf("-"));
        tz = str.substring(str.indexOf("-"));
      }
    else if (str.endsWith("Z"))
      {
        date = str.substring(0, str.length()-2);
        tz = "Z";
      }
    if (!tz.equals("Z") && tz.length() > 0)
      calendar.setTimeZone(TimeZone.getTimeZone(tz));
    else
      calendar.setTimeZone(TimeZone.getTimeZone("UTC"));
    if ((tag & 0x1F) == UTC_TIME)
      {
        if (date.length() < 10)  // must be at least 10 chars long
          throw new DEREncodingException("cannot parse date");
        // UTCTime is of the form "yyMMddHHmm[ss](Z|(+|-)hhmm)"
        try
          {
            int year = Integer.parseInt(str.substring(0, 2));
            if (year < 50)
              year += 2000;
            else
              year += 1900;
            calendar.set(year,
              Integer.parseInt(str.substring( 2,  4))-1,  // month
              Integer.parseInt(str.substring( 4,  6)),    // day
              Integer.parseInt(str.substring( 6,  8)),    // hour
              Integer.parseInt(str.substring( 8, 10)));   // minute
            if (date.length() == 12)
              calendar.set(Calendar.SECOND,
                Integer.parseInt(str.substring(10, 12)));
          }
        catch (NumberFormatException nfe)
          {
            throw new DEREncodingException("cannot parse date");
          }
      }
    else
      {
        if (date.length() < 10)  // must be at least 10 chars long
          throw new DEREncodingException("cannot parse date");
        // GeneralTime is of the form "yyyyMMddHH[mm[ss[(.|,)SSSS]]]"
        // followed by "Z" or "(+|-)hh[mm]"
        try
          {
            calendar.set(
              Integer.parseInt(date.substring(0, 4)),      // year
              Integer.parseInt(date.substring(4, 6))-1,    // month
              Integer.parseInt(date.substring(6, 8)),      // day
              Integer.parseInt(date.substring(8, 10)), 0); // hour, min
            switch (date.length())
              {
                case 19:
                case 18:
                case 17:
                case 16:
                  calendar.set(Calendar.MILLISECOND,
                    Integer.parseInt(date.substring(15)));
                case 14:
                  calendar.set(Calendar.SECOND,
                    Integer.parseInt(date.substring(12, 14)));
                case 12:
                  calendar.set(Calendar.MINUTE,
                    Integer.parseInt(date.substring(10, 12)));
              }
          }
        catch (NumberFormatException nfe)
          {
            throw new DEREncodingException("cannot parse date");
          }
      }
    return calendar.getTime();
  }
}