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

using System;
using System.Collections;

namespace Org.BouncyCastle.Asn1.X509{
    /**
     * The DigestInfo object.
     * <pre>
     * DigestInfo::=Sequence{
     *          digestAlgorithm  AlgorithmIdentifier,
     *          digest OCTET STRING }
     * </pre>
     */
    public class DigestInfo
        : Asn1Encodable
    {
        private readonly byte[] digest;
        private readonly AlgorithmIdentifier algID;

    public static DigestInfo GetInstance(
            Asn1TaggedObject  obj,
            bool        explicitly)
        {
            return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
        }

    public static DigestInfo GetInstance(
            object obj)
        {
            if (obj is DigestInfo)
            {
                return (DigestInfo) obj;
            }

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

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

    public DigestInfo(
            AlgorithmIdentifier  algID,
            byte[]        digest)
        {
            this.digest = digest;
            this.algID = algID;
        }

    private DigestInfo(
            Asn1Sequence seq)
        {
      if (seq.Count != 2)
        throw new ArgumentException("Wrong number of elements in sequence", "seq");

            algID = AlgorithmIdentifier.GetInstance(seq[0]);
      digest = Asn1OctetString.GetInstance(seq[1]).GetOctets();
    }

    public AlgorithmIdentifier AlgorithmID
    {
      get { return algID; }
    }

    public byte[] GetDigest()
        {
            return digest;
        }

    public override Asn1Object ToAsn1Object()
        {
      return new DerSequence(algID, new DerOctetString(digest));
        }
    }
}