1 files changed, 133 insertions, 0 deletions
diff --git a/crypto/src/asn1/x509/BasicConstraints.cs b/crypto/src/asn1/x509/BasicConstraints.cs
new file mode 100644
index 000000000..522cb61cc
--- /dev/null
+++ b/crypto/src/asn1/x509/BasicConstraints.cs
@@ -0,0 +1,133 @@
+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;
+        }
+    }
+}