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

using System;

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

namespace Org.BouncyCastle.Asn1.X509{
    public class BasicConstraints
        : Asn1Encodable
    {
        private readonly DerBoolean  cA;
        private readonly DerInteger  pathLenConstraint;

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

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

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

      if (obj is X509Extension)
      {
        return GetInstance(X509Extension.ConvertValueToObject((X509Extension) obj));
      }

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

    private BasicConstraints(
            Asn1Sequence seq)
        {
      if (seq.Count > 0)
      {
        if (seq[0] is DerBoolean)
        {
          this.cA = DerBoolean.GetInstance(seq[0]);
        }
        else
        {
          this.pathLenConstraint = DerInteger.GetInstance(seq[0]);
        }

        if (seq.Count > 1)
        {
          if (this.cA == null)
            throw new ArgumentException("wrong sequence in constructor", "seq");

          this.pathLenConstraint = DerInteger.GetInstance(seq[1]);
        }
      }
        }

    public BasicConstraints(
            bool cA)
        {
      if (cA)
      {
        this.cA = DerBoolean.True;
      }
        }

    /**
         * create a cA=true object for the given path length constraint.
         *
         * @param pathLenConstraint
         */
        public BasicConstraints(
            int pathLenConstraint)
        {
            this.cA = DerBoolean.True;
            this.pathLenConstraint = new DerInteger(pathLenConstraint);
        }

    public bool IsCA()
        {
            return cA != null && cA.IsTrue;
        }

    public BigInteger PathLenConstraint
        {
            get { return pathLenConstraint == null ? null : pathLenConstraint.Value; }
        }

    /**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * BasicConstraints := Sequence {
         *    cA                  Boolean DEFAULT FALSE,
         *    pathLenConstraint   Integer (0..MAX) OPTIONAL
         * }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector();

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

            if (pathLenConstraint != null)  // yes some people actually do this when cA is false...
            {
                v.Add(pathLenConstraint);
            }

      return new DerSequence(v);
        }

    public override string ToString()
        {
            if (pathLenConstraint == null)
            {
        return "BasicConstraints: isCa(" + this.IsCA() + ")";
            }

      return "BasicConstraints: isCa(" + this.IsCA() + "), pathLenConstraint = " + pathLenConstraint.Value;
        }
    }
}