mcs/class/Novell.Directory.Ldap/Novell.Directory.Ldap.Asn1/LBEREncoder.cs

   1 /******************************************************************************
   2 * The MIT License
   3 * Copyright (c) 2003 Novell Inc.  www.novell.com
   4 *
   5 * Permission is hereby granted, free of charge, to any person obtaining  a copy
   6 * of this software and associated documentation files (the Software), to deal
   7 * in the Software without restriction, including  without limitation the rights
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   9 * copies of the Software, and to  permit persons to whom the Software is
  10 * furnished to do so, subject to the following conditions:
  11 *
  12 * The above copyright notice and this permission notice shall be included in
  13 * all copies or substantial portions of the Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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  17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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  21 * SOFTWARE.
  22 *******************************************************************************/
  23 //
  24 // Novell.Directory.Ldap.Asn1.LBEREncoder.cs
  25 //
  26 // Author:
  27 //   Sunil Kumar (Sunilk@novell.com)
  28 //
  29 // (C) 2003 Novell, Inc (http://www.novell.com)
  30 //
  31
  32 using System;
  33
  34 namespace Novell.Directory.Ldap.Asn1
  35 {
  36
  37         /// <summary> This class provides LBER encoding routines for ASN.1 Types. LBER is a
  38         /// subset of BER as described in the following taken from 5.1 of RFC 2251:
  39         ///
  40         /// 5.1. Mapping Onto BER-based Transport Services
  41         ///
  42         /// The protocol elements of Ldap are encoded for exchange using the
  43         /// Basic Encoding Rules (BER) [11] of ASN.1 [3]. However, due to the
  44         /// high overhead involved in using certain elements of the BER, the
  45         /// following additional restrictions are placed on BER-encodings of Ldap
  46         /// protocol elements:
  47         ///
  48         /// <li>(1) Only the definite form of length encoding will be used.</li>
  49         ///
  50         /// <li>(2) OCTET STRING values will be encoded in the primitive form only.</li>
  51         ///
  52         /// <li>(3) If the value of a BOOLEAN type is true, the encoding MUST have
  53         /// its contents octets set to hex "FF".</li>
  54         ///
  55         /// <li>(4) If a value of a type is its default value, it MUST be absent.
  56         /// Only some BOOLEAN and INTEGER types have default values in this
  57         /// protocol definition.
  58         ///
  59         /// These restrictions do not apply to ASN.1 types encapsulated inside of
  60         /// OCTET STRING values, such as attribute values, unless otherwise
  61         /// noted.</li>
  62         ///
  63         /// [3] ITU-T Rec. X.680, "Abstract Syntax Notation One (ASN.1) -
  64         /// Specification of Basic Notation", 1994.
  65         ///
  66         /// [11] ITU-T Rec. X.690, "Specification of ASN.1 encoding rules: Basic,
  67         /// Canonical, and Distinguished Encoding Rules", 1994.
  68         ///
  69         /// </summary>
  70         [CLSCompliantAttribute(true)]
  71         public class LBEREncoder : Asn1Encoder
  72         {
  73
  74                 /* Encoders for ASN.1 simple type Contents
  75                 */
  76                 public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
  77                 {
  78                 }
  79                 /// <summary> BER Encode an Asn1Boolean directly into the specified output stream.</summary>
  80                 public virtual void  encode(Asn1Boolean b, System.IO.Stream out_Renamed)
  81                 {
  82                         /* Encode the id */
  83                         encode(b.getIdentifier(), out_Renamed);
  84
  85                         /* Encode the length */
  86                         out_Renamed.WriteByte((System.Byte) 0x01);
  87
  88                         /* Encode the boolean content*/
  89                         out_Renamed.WriteByte((byte) (b.booleanValue()?(sbyte) SupportClass.Identity(0xff):(sbyte) 0x00));
  90
  91                         return ;
  92                 }
  93
  94                 /// <summary> Encode an Asn1Numeric directly into the specified outputstream.
  95                 ///
  96                 /// Use a two's complement representation in the fewest number of octets
  97                 /// possible.
  98                 ///
  99                 /// Can be used to encode INTEGER and ENUMERATED values.
 100                 /// </summary>
 101                 public void  encode(Asn1Numeric n, System.IO.Stream out_Renamed)
 102                 {
 103                         sbyte[] octets = new sbyte[8];
 104                         sbyte len;
 105                         long value_Renamed = n.longValue();
 106                         long endValue = (value_Renamed < 0)?- 1:0;
 107                         long endSign = endValue & 0x80;
 108
 109                         for (len = 0; len == 0 || value_Renamed != endValue || (octets[len - 1] & 0x80) != endSign; len++)
 110                         {
 111                                 octets[len] = (sbyte) (value_Renamed & 0xFF);
 112                                 value_Renamed >>= 8;
 113                         }
 114
 115                         encode(n.getIdentifier(), out_Renamed);
 116                         out_Renamed.WriteByte((byte) len); // Length
 117                         for (int i = len - 1; i >= 0; i--)
 118                         // Content
 119                                 out_Renamed.WriteByte((byte) octets[i]);
 120                         return ;
 121                 }
 122
 123                 /* Asn1 TYPE NOT YET SUPPORTED
 124                 * Encode an Asn1Real directly to a stream.
 125                 public void encode(Asn1Real r, OutputStream out)
 126                 throws IOException
 127                 {
 128                 throw new IOException("LBEREncoder: Encode to a stream not implemented");
 129                 }
 130                 */
 131
 132                 /// <summary> Encode an Asn1Null directly into the specified outputstream.</summary>
 133                 public void  encode(Asn1Null n, System.IO.Stream out_Renamed)
 134                 {
 135                         encode(n.getIdentifier(), out_Renamed);
 136                         out_Renamed.WriteByte((System.Byte) 0x00); // Length (with no Content)
 137                         return ;
 138                 }
 139
 140                 /* Asn1 TYPE NOT YET SUPPORTED
 141                 * Encode an Asn1BitString directly to a stream.
 142                 public void encode(Asn1BitString bs, OutputStream out)
 143                 throws IOException
 144                 {
 145                 throw new IOException("LBEREncoder: Encode to a stream not implemented");
 146                 }
 147                 */
 148
 149                 /// <summary> Encode an Asn1OctetString directly into the specified outputstream.</summary>
 150                 public void  encode(Asn1OctetString os, System.IO.Stream out_Renamed)
 151                 {
 152                         encode(os.getIdentifier(), out_Renamed);
 153                         encodeLength(os.byteValue().Length, out_Renamed);
 154                         sbyte[] temp_sbyteArray;
 155                         temp_sbyteArray = os.byteValue();
 156                         out_Renamed.Write(SupportClass.ToByteArray(temp_sbyteArray), 0, temp_sbyteArray.Length);;;
 157                         return ;
 158                 }
 159
 160                 /* Asn1 TYPE NOT YET SUPPORTED
 161                 * Encode an Asn1ObjectIdentifier directly to a stream.
 162                 * public void encode(Asn1ObjectIdentifier oi, OutputStream out)
 163                 * throws IOException
 164                 * {
 165                 * throw new IOException("LBEREncoder: Encode to a stream not implemented");
 166                 * }
 167                 */
 168
 169                 /* Asn1 TYPE NOT YET SUPPORTED
 170                 * Encode an Asn1CharacterString directly to a stream.
 171                 * public void encode(Asn1CharacterString cs, OutputStream out)
 172                 * throws IOException
 173                 * {
 174                 * throw new IOException("LBEREncoder: Encode to a stream not implemented");
 175                 * }
 176                 */
 177
 178                 /* Encoders for ASN.1 structured types
 179                 */
 180
 181                 /// <summary> Encode an Asn1Structured into the specified outputstream.  This method
 182                 /// can be used to encode SET, SET_OF, SEQUENCE, SEQUENCE_OF
 183                 /// </summary>
 184                 public void  encode(Asn1Structured c, System.IO.Stream out_Renamed)
 185                 {
 186                         encode(c.getIdentifier(), out_Renamed);
 187
 188                         Asn1Object[] value_Renamed = c.toArray();
 189
 190                         System.IO.MemoryStream output = new System.IO.MemoryStream();
 191
 192                         /* Cycle through each element encoding each element */
 193                         for (int i = 0; i < value_Renamed.Length; i++)
 194                         {
 195                                 (value_Renamed[i]).encode(this, output);
 196                         }
 197
 198                         /* Encode the length */
 199                         encodeLength((int)output.Length, out_Renamed);
 200
 201                         /* Add each encoded element into the output stream */
 202                         sbyte[] temp_sbyteArray;
 203                         temp_sbyteArray = SupportClass.ToSByteArray(output.ToArray());
 204                         out_Renamed.Write(SupportClass.ToByteArray(temp_sbyteArray), 0, temp_sbyteArray.Length);;;
 205                         return ;
 206                 }
 207
 208                 /// <summary> Encode an Asn1Tagged directly into the specified outputstream.</summary>
 209                 public void  encode(Asn1Tagged t, System.IO.Stream out_Renamed)
 210                 {
 211                         if (t.Explicit)
 212                         {
 213                                 encode(t.getIdentifier(), out_Renamed);
 214
 215                                 /* determine the encoded length of the base type. */
 216                                 System.IO.MemoryStream encodedContent = new System.IO.MemoryStream();
 217                                 t.taggedValue().encode(this, encodedContent);
 218
 219                                 encodeLength((int)encodedContent.Length, out_Renamed);
 220                                 sbyte[] temp_sbyteArray;
 221                                 temp_sbyteArray = SupportClass.ToSByteArray(encodedContent.ToArray());
 222                                 out_Renamed.Write(SupportClass.ToByteArray(temp_sbyteArray), 0, temp_sbyteArray.Length);;;;
 223                         }
 224                         else
 225                         {
 226                                 t.taggedValue().encode(this, out_Renamed);
 227                         }
 228                         return ;
 229                 }
 230
 231                 /* Encoders for ASN.1 useful types
 232                 */
 233                 /* Encoder for ASN.1 Identifier
 234                 */
 235
 236                 /// <summary> Encode an Asn1Identifier directly into the specified outputstream.</summary>
 237                 public void  encode(Asn1Identifier id, System.IO.Stream out_Renamed)
 238                 {
 239                         int c = id.Asn1Class;
 240                         int t = id.Tag;
 241                         sbyte ccf = (sbyte) ((c << 6) | (id.Constructed?0x20:0));
 242
 243                         if (t < 30)
 244                         {
 245                                 /* single octet */
 246                                 out_Renamed.WriteByte((System.Byte) (ccf | t));
 247                         }
 248                         else
 249                         {
 250                                 /* multiple octet */
 251                                 out_Renamed.WriteByte((System.Byte) (ccf | 0x1F));
 252                                 encodeTagInteger(t, out_Renamed);
 253                         }
 254                         return ;
 255                 }
 256
 257                 /* Private helper methods
 258                 */
 259
 260                 /*
 261                 *  Encodes the specified length into the the outputstream
 262                 */
 263                 private void  encodeLength(int length, System.IO.Stream out_Renamed)
 264                 {
 265                         if (length < 0x80)
 266                         {
 267                                 out_Renamed.WriteByte((System.Byte) length);
 268                         }
 269                         else
 270                         {
 271                                 sbyte[] octets = new sbyte[4]; // 4 bytes sufficient for 32 bit int.
 272                                 sbyte n;
 273                                 for (n = 0; length != 0; n++)
 274                                 {
 275                                         octets[n] = (sbyte) (length & 0xFF);
 276                                         length >>= 8;
 277                                 }
 278
 279                                 out_Renamed.WriteByte((System.Byte) (0x80 | n));
 280
 281                                 for (int i = n - 1; i >= 0; i--)
 282                                         out_Renamed.WriteByte((byte) octets[i]);
 283                         }
 284                         return ;
 285                 }
 286
 287                 /// <summary> Encodes the provided tag into the outputstream.</summary>
 288                 private void  encodeTagInteger(int value_Renamed, System.IO.Stream out_Renamed)
 289                 {
 290                         sbyte[] octets = new sbyte[5];
 291                         int n;
 292                         for (n = 0; value_Renamed != 0; n++)
 293                         {
 294                                 octets[n] = (sbyte) (value_Renamed & 0x7F);
 295                                 value_Renamed = value_Renamed >> 7;
 296                         }
 297                         for (int i = n - 1; i > 0; i--)
 298                         {
 299                                 out_Renamed.WriteByte((System.Byte) (octets[i] | 0x80));
 300                         }
 301                         out_Renamed.WriteByte((byte) octets[0]);
 302                         return ;
 303                 }
 304         }
 305 }