Source for gnu.java.security.der.DERValue

   1: /* DERValue.java -- a value read or written to a DER encoding.
   2:    Copyright (C) 2003 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.der;
  40: 
  41: import java.io.ByteArrayOutputStream;
  42: import java.io.IOException;
  43: 
  44: public class DERValue implements DER
  45: {
  46: 
  47:   // Fields.
  48:   // ------------------------------------------------------------------------
  49: 
  50:   private final int tagClass;
  51:   private final boolean constructed;
  52:   private final int tag;
  53:   private int length;
  54:   private final Object value;
  55:   private byte[] encoded;
  56: 
  57:   // Constructor.
  58:   // ------------------------------------------------------------------------
  59: 
  60:   public DERValue(int tag, int length, Object value, byte[] encoded)
  61:   {
  62:     tagClass = tag & 0xC0;
  63:     this.tag = tag & 0x1F;
  64:     constructed = (tag & CONSTRUCTED) == CONSTRUCTED;
  65:     this.length = length;
  66:     this.value = value;
  67:     if (encoded != null)
  68:       this.encoded = (byte[]) encoded.clone();
  69:   }
  70: 
  71:   public DERValue(int tag, Object value)
  72:   {
  73:     this(tag, 0, value, null);
  74:   }
  75: 
  76:   // Instance methods.
  77:   // ------------------------------------------------------------------------
  78: 
  79:   public int getExternalTag()
  80:   {
  81:     return tagClass | tag | (constructed ? 0x20 : 0x00);
  82:   }
  83: 
  84:   public int getTag()
  85:   {
  86:     return tag;
  87:   }
  88: 
  89:   public int getTagClass()
  90:   {
  91:     return tagClass;
  92:   }
  93: 
  94:   public boolean isConstructed()
  95:   {
  96:     return constructed;
  97:   }
  98: 
  99:   public int getLength()
 100:   {
 101:     if (encoded == null)
 102:       {
 103:         try
 104:           {
 105:             ByteArrayOutputStream out = new ByteArrayOutputStream();
 106:             length = DERWriter.write(out, this);
 107:             encoded = out.toByteArray();
 108:           }
 109:         catch (IOException ioe)
 110:           {
 111:             encoded = new byte[0];
 112:           }
 113:       }
 114:     return length;
 115:   }
 116: 
 117:   public Object getValue()
 118:   {
 119:     return value;
 120:   }
 121: 
 122:   public Object getValueAs (final int derType) throws IOException
 123:   {
 124:     byte[] encoded = getEncoded ();
 125:     encoded[0] = (byte) derType;
 126:     return DERReader.read (encoded).getValue ();
 127:   }
 128: 
 129:   public byte[] getEncoded()
 130:   {
 131:     if (encoded == null)
 132:       {
 133:         try
 134:           {
 135:             ByteArrayOutputStream out = new ByteArrayOutputStream();
 136:             length = DERWriter.write(out, this);
 137:             encoded = out.toByteArray();
 138:           }
 139:         catch (IOException ioe)
 140:           {
 141:             encoded = new byte[0];
 142:           }
 143:       }
 144:     return (byte[]) encoded.clone();
 145:   }
 146: 
 147:   public int getEncodedLength()
 148:   {
 149:     if (encoded == null)
 150:       {
 151:         try
 152:           {
 153:             ByteArrayOutputStream out = new ByteArrayOutputStream();
 154:             length = DERWriter.write(out, this);
 155:             encoded = out.toByteArray();
 156:           }
 157:         catch (IOException ioe)
 158:           {
 159:             encoded = new byte[0];
 160:           }
 161:       }
 162:     return encoded.length;
 163:   }
 164: 
 165:   public String toString()
 166:   {
 167:     return "DERValue [ tag=" + tag + ", class=" + tagClass + ", constructed="
 168:       + constructed + ", value=" + value + " ]";
 169:   }
 170: }