PBES2Parameters.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » Pkcs » C# / CSharp Open Source

using System;
using System.Collections;

namespace Org.BouncyCastle.Asn1.Pkcs{
    public class PbeS2Parameters
        : Asn1Encodable
    {
        private readonly KeyDerivationFunc func;
        private readonly EncryptionScheme scheme;

    public static PbeS2Parameters GetInstance(
      object obj)
    {
      if (obj == null || obj is PbeS2Parameters)
        return (PbeS2Parameters) obj;

      if (obj is Asn1Sequence)
        return new PbeS2Parameters((Asn1Sequence) obj);

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

    public PbeS2Parameters(
            Asn1Sequence seq)
        {
      if (seq.Count != 2)
        throw new ArgumentException("Wrong number of elements in sequence", "seq");

      Asn1Sequence funcSeq = (Asn1Sequence)seq[0];

      // TODO Not sure if this special case is really necessary/appropriate
      if (funcSeq[0].Equals(PkcsObjectIdentifiers.IdPbkdf2))
            {
        func = new KeyDerivationFunc(PkcsObjectIdentifiers.IdPbkdf2,
          Pbkdf2Params.GetInstance(funcSeq[1]));
      }
            else
            {
                func = new KeyDerivationFunc(funcSeq);
            }

      scheme = new EncryptionScheme((Asn1Sequence) seq[1]);
        }

    public KeyDerivationFunc KeyDerivationFunc
    {
      get { return func; }
    }

    public EncryptionScheme EncryptionScheme
    {
      get { return scheme; }
    }

    public override Asn1Object ToAsn1Object()
        {
      return new DerSequence(func, scheme);
        }
    }
}