Initial Commit

iTechSharp/srcbc/asn1/x509/GeneralSubtree.cs

@@ -0,0 +1,177 @@
+using System;
+
+using Org.BouncyCastle.Math;
+
+namespace Org.BouncyCastle.Asn1.X509
+{
+	/**
+	 * Class for containing a restriction object subtrees in NameConstraints. See
+	 * RFC 3280.
+	 *
+	 * <pre>
+	 *
+	 *       GeneralSubtree ::= SEQUENCE
+	 *       {
+	 *         baseName                    GeneralName,
+	 *         minimum         [0]     BaseDistance DEFAULT 0,
+	 *         maximum         [1]     BaseDistance OPTIONAL
+	 *       }
+	 * </pre>
+	 *
+	 * @see org.bouncycastle.asn1.x509.NameConstraints
+	 *
+	 */
+	public class GeneralSubtree
+		: Asn1Encodable
+	{
+		private readonly GeneralName	baseName;
+		private readonly DerInteger		minimum;
+		private readonly DerInteger		maximum;
+
+		private GeneralSubtree(
+			Asn1Sequence seq)
+		{
+			baseName = GeneralName.GetInstance(seq[0]);
+
+			switch (seq.Count)
+			{
+				case 1:
+					break;
+				case 2:
+				{
+					Asn1TaggedObject o = Asn1TaggedObject.GetInstance(seq[1]);
+					switch (o.TagNo)
+					{
+						case 0:
+							minimum = DerInteger.GetInstance(o, false);
+							break;
+						case 1:
+							maximum = DerInteger.GetInstance(o, false);
+							break;
+						default:
+							throw new ArgumentException("Bad tag number: " + o.TagNo);
+					}
+					break;
+				}
+				case 3:
+				{
+					minimum = DerInteger.GetInstance(Asn1TaggedObject.GetInstance(seq[1]));
+					maximum = DerInteger.GetInstance(Asn1TaggedObject.GetInstance(seq[2]));
+					break;
+				}
+				default:
+					throw new ArgumentException("Bad sequence size: " + seq.Count);
+			}
+		}
+
+		/**
+		 * Constructor from a given details.
+		 *
+		 * According RFC 3280, the minimum and maximum fields are not used with any
+		 * name forms, thus minimum MUST be zero, and maximum MUST be absent.
+		 * <p>
+		 * If minimum is <code>null</code>, zero is assumed, if
+		 * maximum is <code>null</code>, maximum is absent.</p>
+		 *
+		 * @param baseName
+		 *            A restriction.
+		 * @param minimum
+		 *            Minimum
+		 *
+		 * @param maximum
+		 *            Maximum
+		 */
+		public GeneralSubtree(
+			GeneralName	baseName,
+			BigInteger	minimum,
+			BigInteger	maximum)
+		{
+			this.baseName = baseName;
+			if (minimum != null)
+			{
+				this.minimum = new DerInteger(minimum);
+			}
+			if (maximum != null)
+			{
+				this.maximum = new DerInteger(maximum);
+			}
+		}
+
+		public GeneralSubtree(
+			GeneralName baseName)
+			: this(baseName, null, null)
+		{
+		}
+
+		public static GeneralSubtree GetInstance(
+			Asn1TaggedObject	o,
+			bool				isExplicit)
+		{
+			return new GeneralSubtree(Asn1Sequence.GetInstance(o, isExplicit));
+		}
+
+		public static GeneralSubtree GetInstance(
+			object obj)
+		{
+			if (obj == null)
+			{
+				return null;
+			}
+
+			if (obj is GeneralSubtree)
+			{
+				return (GeneralSubtree) obj;
+			}
+
+			return new GeneralSubtree(Asn1Sequence.GetInstance(obj));
+		}
+
+		public GeneralName Base
+		{
+			get { return baseName; }
+		}
+
+		public BigInteger Minimum
+		{
+			get { return minimum == null ? BigInteger.Zero : minimum.Value; }
+		}
+
+		public BigInteger Maximum
+		{
+			get { return maximum == null ? null : maximum.Value; }
+		}
+
+		/**
+		 * Produce an object suitable for an Asn1OutputStream.
+		 *
+		 * Returns:
+		 *
+		 * <pre>
+		 *       GeneralSubtree ::= SEQUENCE
+		 *       {
+		 *         baseName                    GeneralName,
+		 *         minimum         [0]     BaseDistance DEFAULT 0,
+		 *         maximum         [1]     BaseDistance OPTIONAL
+		 *       }
+		 * </pre>
+		 *
+		 * @return a DERObject
+		 */
+		public override Asn1Object ToAsn1Object()
+		{
+			Asn1EncodableVector v = new Asn1EncodableVector(baseName);
+
+			if (minimum != null && minimum.Value.SignValue != 0)
+			{
+				v.Add(new DerTaggedObject(false, 0, minimum));
+			}
+
+			if (maximum != null)
+			{
+				v.Add(new DerTaggedObject(false, 1, maximum));
+			}
+
+			return new DerSequence(v);
+		}
+	}
+}