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

using System;

namespace Org.BouncyCastle.Asn1.Cms{
  /**
  * Produce an object suitable for an Asn1OutputStream.
  * <pre>
  * EnvelopedData ::= SEQUENCE {
  *     version CMSVersion,
  *     originatorInfo [0] IMPLICIT OriginatorInfo OPTIONAL,
  *     recipientInfos RecipientInfos,
  *     encryptedContentInfo EncryptedContentInfo,
  *     unprotectedAttrs [1] IMPLICIT UnprotectedAttributes OPTIONAL
  * }
  * </pre>
  */
  public class EnvelopedDataParser
  {
    private Asn1SequenceParser  _seq;
    private DerInteger      _version;
    private IAsn1Convertible  _nextObject;
    private bool        _originatorInfoCalled;

    public EnvelopedDataParser(
      Asn1SequenceParser seq)
    {
      this._seq = seq;
      this._version = (DerInteger)seq.ReadObject();
    }

    public DerInteger Version
    {
      get { return _version; }
    }

    public OriginatorInfo GetOriginatorInfo() 
    {
      _originatorInfoCalled = true; 

      if (_nextObject == null)
      {
        _nextObject = _seq.ReadObject();
      }

      if (_nextObject is Asn1TaggedObjectParser && ((Asn1TaggedObjectParser)_nextObject).TagNo == 0)
      {
        Asn1SequenceParser originatorInfo = (Asn1SequenceParser)
          ((Asn1TaggedObjectParser)_nextObject).GetObjectParser(Asn1Tags.Sequence, false);
        _nextObject = null;
        return OriginatorInfo.GetInstance(originatorInfo.ToAsn1Object());
      }

      return null;
    }

    public Asn1SetParser GetRecipientInfos()
    {
      if (!_originatorInfoCalled)
      {
        GetOriginatorInfo();
      }

      if (_nextObject == null)
      {
        _nextObject = _seq.ReadObject();
      }

      Asn1SetParser recipientInfos = (Asn1SetParser)_nextObject;
      _nextObject = null;
      return recipientInfos;
    }

    public EncryptedContentInfoParser GetEncryptedContentInfo()
    {
      if (_nextObject == null)
      {
        _nextObject = _seq.ReadObject();
      }

      if (_nextObject != null)
      {
        Asn1SequenceParser o = (Asn1SequenceParser) _nextObject;
        _nextObject = null;
        return new EncryptedContentInfoParser(o);
      }

      return null;
    }

    public Asn1SetParser GetUnprotectedAttrs()
    {
      if (_nextObject == null)
      {
        _nextObject = _seq.ReadObject();
      }

      if (_nextObject != null)
      {
        IAsn1Convertible o = _nextObject;
        _nextObject = null;
        return (Asn1SetParser)((Asn1TaggedObjectParser)o).GetObjectParser(Asn1Tags.Set, false);
      }
        
      return null;
    }
  }
}