AuthEnvelopedDataParser.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>
   * AuthEnvelopedData ::= SEQUENCE {
   *   version CMSVersion,
   *   originatorInfo [0] IMPLICIT OriginatorInfo OPTIONAL,
   *   recipientInfos RecipientInfos,
   *   authEncryptedContentInfo EncryptedContentInfo,
   *   authAttrs [1] IMPLICIT AuthAttributes OPTIONAL,
   *   mac MessageAuthenticationCode,
   *   unauthAttrs [2] IMPLICIT UnauthAttributes OPTIONAL }
   * </pre>
  */
  public class AuthEnvelopedDataParser
  {
    private Asn1SequenceParser  seq;
    private DerInteger      version;
    private IAsn1Convertible  nextObject;
    private bool        originatorInfoCalled;

    public AuthEnvelopedDataParser(
      Asn1SequenceParser  seq)
    {
      this.seq = seq;

      // TODO
      // "It MUST be set to 0."
      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 GetAuthEncryptedContentInfo() 
    {
      if (nextObject == null)
      {
        nextObject = seq.ReadObject();
      }

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

      return null;
    }
    
    public Asn1SetParser GetAuthAttrs()
    {
      if (nextObject == null)
      {
        nextObject = seq.ReadObject();
      }

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

      // TODO
      // "The authAttrs MUST be present if the content type carried in
      // EncryptedContentInfo is not id-data."

      return null;
    }
    
    public Asn1OctetString GetMac()
    {
      if (nextObject == null)
      {
        nextObject = seq.ReadObject();
      }

      IAsn1Convertible o = nextObject;
      nextObject = null;

      return Asn1OctetString.GetInstance(o.ToAsn1Object());
    }
    
    public Asn1SetParser GetUnauthAttrs()
    {
      if (nextObject == null)
      {
        nextObject = seq.ReadObject();
      }

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

      return null;
    }
  }
}