ObjectDigestInfo.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » X509 » C# / CSharp Open Source

using System;

namespace Org.BouncyCastle.Asn1.X509{
  /**
   * ObjectDigestInfo ASN.1 structure used in v2 attribute certificates.
   * 
   * <pre>
   *  
   *    ObjectDigestInfo ::= SEQUENCE {
   *         digestedObjectType  ENUMERATED {
   *                 publicKey            (0),
   *                 publicKeyCert        (1),
   *                 otherObjectTypes     (2) },
   *                         -- otherObjectTypes MUST NOT
   *                         -- be used in this profile
   *         otherObjectTypeID   OBJECT IDENTIFIER OPTIONAL,
   *         digestAlgorithm     AlgorithmIdentifier,
   *         objectDigest        BIT STRING
   *    }
   *   
   * </pre>
   * 
   */
  public class ObjectDigestInfo
        : Asn1Encodable
    {
    /**
     * The public key is hashed.
     */
    public const int PublicKey = 0;

    /**
     * The public key certificate is hashed.
     */
    public const int PublicKeyCert = 1;

    /**
     * An other object is hashed.
     */
    public const int OtherObjectDigest = 2;

    internal readonly DerEnumerated      digestedObjectType;
        internal readonly DerObjectIdentifier  otherObjectTypeID;
        internal readonly AlgorithmIdentifier  digestAlgorithm;
        internal readonly DerBitString      objectDigest;

    public static ObjectDigestInfo GetInstance(
            object obj)
        {
            if (obj == null || obj is ObjectDigestInfo)
            {
                return (ObjectDigestInfo) obj;
            }

      if (obj is Asn1Sequence)
            {
                return new ObjectDigestInfo((Asn1Sequence) obj);
            }

      throw new ArgumentException("unknown object in factory: " + obj.GetType().Name, "obj");
    }

    public static ObjectDigestInfo GetInstance(
            Asn1TaggedObject  obj,
            bool        isExplicit)
        {
            return GetInstance(Asn1Sequence.GetInstance(obj, isExplicit));
        }

    /**
     * Constructor from given details.
     * <p>
     * If <code>digestedObjectType</code> is not {@link #publicKeyCert} or
     * {@link #publicKey} <code>otherObjectTypeID</code> must be given,
     * otherwise it is ignored.</p>
     * 
     * @param digestedObjectType The digest object type.
     * @param otherObjectTypeID The object type ID for
     *            <code>otherObjectDigest</code>.
     * @param digestAlgorithm The algorithm identifier for the hash.
     * @param objectDigest The hash value.
     */
    public ObjectDigestInfo(
      int          digestedObjectType,
      string        otherObjectTypeID,
      AlgorithmIdentifier  digestAlgorithm,
      byte[]        objectDigest)
    {
      this.digestedObjectType = new DerEnumerated(digestedObjectType);

      if (digestedObjectType == OtherObjectDigest)
      {
        this.otherObjectTypeID = new DerObjectIdentifier(otherObjectTypeID);
      }

      this.digestAlgorithm = digestAlgorithm; 

      this.objectDigest = new DerBitString(objectDigest);
    }

    private ObjectDigestInfo(
      Asn1Sequence seq)
        {
      if (seq.Count > 4 || seq.Count < 3)
      {
        throw new ArgumentException("Bad sequence size: " + seq.Count);
      }

      digestedObjectType = DerEnumerated.GetInstance(seq[0]);

      int offset = 0;

      if (seq.Count == 4)
            {
                otherObjectTypeID = DerObjectIdentifier.GetInstance(seq[1]);
                offset++;
            }

      digestAlgorithm = AlgorithmIdentifier.GetInstance(seq[1 + offset]);
      objectDigest = DerBitString.GetInstance(seq[2 + offset]);
    }

    public DerEnumerated DigestedObjectType
    {
      get { return digestedObjectType; }
    }

    public DerObjectIdentifier OtherObjectTypeID
    {
      get { return otherObjectTypeID; }
    }

    public AlgorithmIdentifier DigestAlgorithm
    {
      get { return digestAlgorithm; }
    }

    public DerBitString ObjectDigest
    {
      get { return objectDigest; }
    }

    /**
     * Produce an object suitable for an Asn1OutputStream.
     * 
     * <pre>
     *  
     *    ObjectDigestInfo ::= SEQUENCE {
     *         digestedObjectType  ENUMERATED {
     *                 publicKey            (0),
     *                 publicKeyCert        (1),
     *                 otherObjectTypes     (2) },
     *                         -- otherObjectTypes MUST NOT
     *                         -- be used in this profile
     *         otherObjectTypeID   OBJECT IDENTIFIER OPTIONAL,
     *         digestAlgorithm     AlgorithmIdentifier,
     *         objectDigest        BIT STRING
     *    }
     *   
     * </pre>
     */
    public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(digestedObjectType);

      if (otherObjectTypeID != null)
            {
                v.Add(otherObjectTypeID);
            }

      v.Add(digestAlgorithm, objectDigest);

      return new DerSequence(v);
        }
    }
}