BerTaggedObject.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » C# / CSharp Open Source

using System;
using System.Collections;

using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1{
  /**
   * BER TaggedObject - in ASN.1 notation this is any object preceded by
   * a [n] where n is some number - these are assumed to follow the construction
   * rules (as with sequences).
   */
  public class BerTaggedObject
    : DerTaggedObject
  {
    /**
     * @param tagNo the tag number for this object.
     * @param obj the tagged object.
     */
    public BerTaggedObject(
      int        tagNo,
      Asn1Encodable  obj)
      : base(tagNo, obj)
    {
    }

    /**
     * @param explicitly true if an explicitly tagged object.
     * @param tagNo the tag number for this object.
     * @param obj the tagged object.
     */
    public BerTaggedObject(
      bool      explicitly,
      int        tagNo,
      Asn1Encodable  obj)
      : base(explicitly, tagNo, obj)
    {
    }

    /**
     * create an implicitly tagged object that contains a zero
     * length sequence.
     */
    public BerTaggedObject(
      int tagNo)
      : base(false, tagNo, BerSequence.Empty)
    {
    }

    internal override void Encode(
      DerOutputStream derOut)
    {
      if (derOut is Asn1OutputStream || derOut is BerOutputStream)
      {
        derOut.WriteTag((byte)(Asn1Tags.Constructed | Asn1Tags.Tagged), tagNo);
        derOut.WriteByte(0x80);

        if (!IsEmpty())
        {
          if (!explicitly)
          {
            IEnumerable eObj;
            if (obj is Asn1OctetString)
            {
              if (obj is BerOctetString)
              {
                eObj = (BerOctetString) obj;
              }
              else
              {
                Asn1OctetString octs = (Asn1OctetString)obj;
                eObj = new BerOctetString(octs.GetOctets());
              }
            }
            else if (obj is Asn1Sequence)
            {
              eObj = (Asn1Sequence) obj;
            }
            else if (obj is Asn1Set)
            {
              eObj = (Asn1Set) obj;
            }
            else
            {
              throw Platform.CreateNotImplementedException(obj.GetType().Name);
            }

            foreach (Asn1Encodable o in eObj)
            {
              derOut.WriteObject(o);
            }
          }
          else
          {
            derOut.WriteObject(obj);
          }
        }

        derOut.WriteByte(0x00);
        derOut.WriteByte(0x00);
      }
      else
      {
        base.Encode(derOut);
      }
    }
  }
}