PBKDF2Params.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » Pkcs » C# / CSharp Open Source

using System;

using Org.BouncyCastle.Math;

namespace Org.BouncyCastle.Asn1.Pkcs{
  public class Pbkdf2Params
    : Asn1Encodable
  {
    private readonly Asn1OctetString  octStr;
    private readonly DerInteger      iterationCount;
    private readonly DerInteger      keyLength;

    public static Pbkdf2Params GetInstance(
      object obj)
    {
      if (obj == null || obj is Pbkdf2Params)
        return (Pbkdf2Params)obj;

      if (obj is Asn1Sequence)
        return new Pbkdf2Params((Asn1Sequence)obj);

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

    public Pbkdf2Params(
      Asn1Sequence seq)
    {
      if (seq.Count < 2 || seq.Count > 3)
        throw new ArgumentException("Wrong number of elements in sequence", "seq");

      octStr = (Asn1OctetString)seq[0];
      iterationCount = (DerInteger)seq[1];

      if (seq.Count > 2)
      {
        keyLength = (DerInteger)seq[2];
      }
    }

    public Pbkdf2Params(
      byte[] salt,
      int iterationCount)
    {
      this.octStr = new DerOctetString(salt);
      this.iterationCount = new DerInteger(iterationCount);
    }

    public byte[] GetSalt()
    {
      return octStr.GetOctets();
    }

    public BigInteger IterationCount
    {
      get { return iterationCount.Value; }
    }

    public BigInteger KeyLength
    {
      get { return keyLength == null ? null : keyLength.Value; }
    }

    public override Asn1Object ToAsn1Object()
    {
      Asn1EncodableVector v = new Asn1EncodableVector(
        octStr, iterationCount);

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

      return new DerSequence(v);
    }
  }
}