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

using System;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Math;

namespace Org.BouncyCastle.Asn1.Pkcs{
    public class MacData
        : Asn1Encodable
    {
        internal DigestInfo  digInfo;
        internal byte[]    salt;
        internal BigInteger  iterationCount;

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

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

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

    private MacData(
            Asn1Sequence seq)
        {
            this.digInfo = DigestInfo.GetInstance(seq[0]);
            this.salt = ((Asn1OctetString) seq[1]).GetOctets();

      if (seq.Count == 3)
            {
                this.iterationCount = ((DerInteger) seq[2]).Value;
            }
            else
            {
                this.iterationCount = BigInteger.One;
            }
        }

    public MacData(
            DigestInfo  digInfo,
            byte[]    salt,
            int      iterationCount)
        {
            this.digInfo = digInfo;
            this.salt = (byte[]) salt.Clone();
            this.iterationCount = BigInteger.ValueOf(iterationCount);
        }

    public DigestInfo Mac
    {
      get { return digInfo; }
    }

    public byte[] GetSalt()
        {
            return (byte[]) salt.Clone();
        }

    public BigInteger IterationCount
    {
      get { return iterationCount; }
    }

    /**
     * <pre>
     * MacData ::= SEQUENCE {
     *     mac      DigestInfo,
     *     macSalt  OCTET STRING,
     *     iterations INTEGER DEFAULT 1
     *     -- Note: The default is for historic reasons and its use is deprecated. A
     *     -- higher value, like 1024 is recommended.
     * </pre>
     * @return the basic DERObject construction.
     */
    public override Asn1Object ToAsn1Object()
        {
      Asn1EncodableVector v = new Asn1EncodableVector(digInfo, new DerOctetString(salt));

      if (!iterationCount.Equals(BigInteger.One))
      {
        v.Add(new DerInteger(iterationCount));
      }

      return new DerSequence(v);
        }
    }
}