Jo Shields a575963da9 Imported Upstream version 3.6.0
Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14
2014-08-13 10:39:27 +01:00

277 lines
8.8 KiB
C#

/******************************************************************************
* The MIT License
* Copyright (c) 2003 Novell Inc. www.novell.com
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the Software), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*******************************************************************************/
//
// Novell.Directory.Ldap.Asn1.LBERDecoder.cs
//
// Author:
// Sunil Kumar (Sunilk@novell.com)
//
// (C) 2003 Novell, Inc (http://www.novell.com)
//
using System;
namespace Novell.Directory.Ldap.Asn1
{
/// <summary> This class provides LBER decoding routines for ASN.1 Types. LBER is a
/// subset of BER as described in the following taken from 5.1 of RFC 2251:
///
/// 5.1. Mapping Onto BER-based Transport Services
///
/// The protocol elements of Ldap are encoded for exchange using the
/// Basic Encoding Rules (BER) [11] of ASN.1 [3]. However, due to the
/// high overhead involved in using certain elements of the BER, the
/// following additional restrictions are placed on BER-encodings of Ldap
/// protocol elements:
///
/// <li>(1) Only the definite form of length encoding will be used.</li>
///
/// <li>(2) OCTET STRING values will be encoded in the primitive form only.</li>
///
/// <li>(3) If the value of a BOOLEAN type is true, the encoding MUST have
/// its contents octets set to hex "FF".</li>
///
/// <li>(4) If a value of a type is its default value, it MUST be absent.
/// Only some BOOLEAN and INTEGER types have default values in this
/// protocol definition.
///
/// These restrictions do not apply to ASN.1 types encapsulated inside of
/// OCTET STRING values, such as attribute values, unless otherwise
/// noted.</li>
///
/// [3] ITU-T Rec. X.680, "Abstract Syntax Notation One (ASN.1) -
/// Specification of Basic Notation", 1994.
///
/// [11] ITU-T Rec. X.690, "Specification of ASN.1 encoding rules: Basic,
/// Canonical, and Distinguished Encoding Rules", 1994.
///
/// </summary>
public class LBERDecoder : Asn1Decoder
{
public LBERDecoder()
{
InitBlock();
}
public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
{
}
private void InitBlock()
{
asn1ID = new Asn1Identifier();
asn1Len = new Asn1Length();
}
//used to speed up decode, so it doesn't need to recreate an identifier every time
//instead just reset is called CANNOT be static for multiple connections
private Asn1Identifier asn1ID;
private Asn1Length asn1Len;
/* Generic decode routines
*/
/// <summary> Decode an LBER encoded value into an Asn1Type from a byte array.</summary>
[CLSCompliantAttribute(false)]
public virtual Asn1Object decode(sbyte[] value_Renamed)
{
Asn1Object asn1 = null;
System.IO.MemoryStream in_Renamed = new System.IO.MemoryStream(SupportClass.ToByteArray(value_Renamed));
try
{
asn1 = decode(in_Renamed);
}
catch (System.IO.IOException ioe)
{
}
return asn1;
}
/// <summary> Decode an LBER encoded value into an Asn1Type from an InputStream.</summary>
public virtual Asn1Object decode(System.IO.Stream in_Renamed)
{
int[] len = new int[1];
return decode(in_Renamed, len);
}
/// <summary> Decode an LBER encoded value into an Asn1Object from an InputStream.
///
/// This method also returns the total length of this encoded
/// Asn1Object (length of type + length of length + length of content)
/// in the parameter len. This information is helpful when decoding
/// structured types.
/// </summary>
public virtual Asn1Object decode(System.IO.Stream in_Renamed, int[] len)
{
asn1ID.reset(in_Renamed);
asn1Len.reset(in_Renamed);
int length = asn1Len.Length;
len[0] = asn1ID.EncodedLength + asn1Len.EncodedLength + length;
if (asn1ID.Universal)
{
switch (asn1ID.Tag)
{
case Asn1Sequence.TAG:
return new Asn1Sequence(this, in_Renamed, length);
case Asn1Set.TAG:
return new Asn1Set(this, in_Renamed, length);
case Asn1Boolean.TAG:
return new Asn1Boolean(this, in_Renamed, length);
case Asn1Integer.TAG:
return new Asn1Integer(this, in_Renamed, length);
case Asn1OctetString.TAG:
return new Asn1OctetString(this, in_Renamed, length);
case Asn1Enumerated.TAG:
return new Asn1Enumerated(this, in_Renamed, length);
case Asn1Null.TAG:
return new Asn1Null(); // has no content to decode.
/* Asn1 TYPE NOT YET SUPPORTED
case Asn1BitString.TAG:
return new Asn1BitString(this, in, length);
case Asn1ObjectIdentifier.TAG:
return new Asn1ObjectIdentifier(this, in, length);
case Asn1Real.TAG:
return new Asn1Real(this, in, length);
case Asn1NumericString.TAG:
return new Asn1NumericString(this, in, length);
case Asn1PrintableString.TAG:
return new Asn1PrintableString(this, in, length);
case Asn1TeletexString.TAG:
return new Asn1TeletexString(this, in, length);
case Asn1VideotexString.TAG:
return new Asn1VideotexString(this, in, length);
case Asn1IA5String.TAG:
return new Asn1IA5String(this, in, length);
case Asn1GraphicString.TAG:
return new Asn1GraphicString(this, in, length);
case Asn1VisibleString.TAG:
return new Asn1VisibleString(this, in, length);
case Asn1GeneralString.TAG:
return new Asn1GeneralString(this, in, length);
*/
default:
throw new System.IO.EndOfStreamException("Unknown tag"); // !!! need a better exception
}
}
else
{
// APPLICATION or CONTEXT-SPECIFIC tag
return new Asn1Tagged(this, in_Renamed, length, (Asn1Identifier) asn1ID.Clone());
}
}
/* Decoders for ASN.1 simple type Contents
*/
/// <summary> Decode a boolean directly from a stream.</summary>
public System.Object decodeBoolean(System.IO.Stream in_Renamed, int len)
{
sbyte[] lber = new sbyte[len];
int i = SupportClass.ReadInput(in_Renamed, ref lber, 0, lber.Length);
if (i != len)
throw new System.IO.EndOfStreamException("LBER: BOOLEAN: decode error: EOF");
return (lber[0] == 0x00)?false:true;
}
/// <summary> Decode a Numeric type directly from a stream. Decodes INTEGER
/// and ENUMERATED types.
/// </summary>
public System.Object decodeNumeric(System.IO.Stream in_Renamed, int len)
{
long l = 0;
int r = in_Renamed.ReadByte();
if (r < 0)
throw new System.IO.EndOfStreamException("LBER: NUMERIC: decode error: EOF");
if ((r & 0x80) != 0)
{
// check for negative number
l = - 1;
}
l = (l << 8) | r;
for (int i = 1; i < len; i++)
{
r = in_Renamed.ReadByte();
if (r < 0)
throw new System.IO.EndOfStreamException("LBER: NUMERIC: decode error: EOF");
l = (l << 8) | r;
}
return (System.Int64) l;
}
/// <summary> Decode an OctetString directly from a stream.</summary>
public System.Object decodeOctetString(System.IO.Stream in_Renamed, int len)
{
sbyte[] octets = new sbyte[len];
int totalLen = 0;
while (totalLen < len)
{
// Make sure we have read all the data
int inLen = SupportClass.ReadInput(in_Renamed, ref octets, totalLen, len - totalLen);
totalLen += inLen;
}
return octets;
}
/// <summary> Decode a CharacterString directly from a stream.</summary>
public System.Object decodeCharacterString(System.IO.Stream in_Renamed, int len)
{
sbyte[] octets = new sbyte[len];
for (int i = 0; i < len; i++)
{
int ret = in_Renamed.ReadByte(); // blocks
if (ret == - 1)
throw new System.IO.EndOfStreamException("LBER: CHARACTER STRING: decode error: EOF");
octets[i] = (sbyte) ret;
}
System.Text.Encoding encoder = System.Text.Encoding.GetEncoding("utf-8");
char[] dchar = encoder.GetChars(SupportClass.ToByteArray(octets));
string rval = new String(dchar);
return rval;//new String( "UTF8");
}
}
}