Source for gnu.java.security.ber.BERReader

   1: /* BERReader.java -- basic encoding rules (BER) reader.
   2:    Copyright (C) 2004  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.java.security.ber;
  40: 
  41: import gnu.java.security.der.DERReader;
  42: import gnu.java.security.der.DERValue;
  43: 
  44: import java.io.EOFException;
  45: import java.io.IOException;
  46: import java.io.InputStream;
  47: 
  48: public class BERReader extends DERReader implements BER
  49: {
  50: 
  51:   /**
  52:    * Create a new DER reader from a byte array.
  53:    *
  54:    * @param in The encoded bytes.
  55:    */
  56:   public BERReader(byte[] in)
  57:   {
  58:     super(in);
  59:   }
  60: 
  61:   public BERReader (byte[] in, int off, int len)
  62:   {
  63:     super(in, off, len);
  64:   }
  65: 
  66:   /**
  67:    * Create a new DER readed from an input stream.
  68:    *
  69:    * @param in The encoded bytes.
  70:    */
  71:   public BERReader(InputStream in)
  72:   {
  73:     super(in);
  74:   }
  75: 
  76:   public DERValue read() throws IOException
  77:   {
  78:     in.mark(2);
  79:     int tag = in.read();
  80:     if (tag == -1)
  81:       throw new EOFException();
  82:     int length = in.read();
  83:     if (length == 0)
  84:       {
  85:         if (tag == 0)
  86:           return END_OF_SEQUENCE;
  87:         return new BERValue(tag, CONSTRUCTED_VALUE, new byte[] { (byte) tag, 0 });
  88:       }
  89:     else
  90:       {
  91:         in.reset();
  92:         return super.read();
  93:       }
  94:   }
  95: 
  96:   public int peek() throws IOException
  97:   {
  98:     in.mark(1);
  99:     int ret = in.read();
 100:     in.reset();
 101:     return ret;
 102:   }
 103: }