using System; using Org.BouncyCastle.Math; using Org.BouncyCastle.Utilities; namespace Org.BouncyCastle.Asn1.X509 { public class BasicConstraints : Asn1Encodable { public static BasicConstraints GetInstance(Asn1TaggedObject obj, bool explicitly) { return GetInstance(Asn1Sequence.GetInstance(obj, explicitly)); } public static BasicConstraints GetInstance(object obj) { if (obj is BasicConstraints) return (BasicConstraints)obj; if (obj is X509Extension) return GetInstance(X509Extension.ConvertValueToObject((X509Extension)obj)); if (obj == null) return null; return new BasicConstraints(Asn1Sequence.GetInstance(obj)); } public static BasicConstraints FromExtensions(X509Extensions extensions) { return GetInstance(X509Extensions.GetExtensionParsedValue(extensions, X509Extensions.BasicConstraints)); } private readonly DerBoolean cA; private readonly DerInteger pathLenConstraint; 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. *
         * BasicConstraints := Sequence {
         *    cA                  Boolean DEFAULT FALSE,
         *    pathLenConstraint   Integer (0..MAX) OPTIONAL
         * }
         * 
*/ public override Asn1Object ToAsn1Object() { Asn1EncodableVector v = new Asn1EncodableVector(2); v.AddOptional(cA, pathLenConstraint); // yes some people actually do this when cA is false... return new DerSequence(v); } public override string ToString() { if (pathLenConstraint == null) { return "BasicConstraints: isCa(" + this.IsCA() + ")"; } return "BasicConstraints: isCa(" + this.IsCA() + "), pathLenConstraint = " + pathLenConstraint.Value; } } }