Merge in bc-git to this repo

1 files changed, 160 insertions, 0 deletions

diff --git a/crypto/src/asn1/x509/CertificatePair.cs b/crypto/src/asn1/x509/CertificatePair.cs
new file mode 100644
index 000000000..8baa64719
--- /dev/null
+++ b/crypto/src/asn1/x509/CertificatePair.cs
@@ -0,0 +1,160 @@
+using System;
+
+namespace Org.BouncyCastle.Asn1.X509
+{
+	/**
+	* This class helps to support crossCerfificatePairs in a LDAP directory
+	* according RFC 2587
+	*
+	* <pre>
+	*     crossCertificatePairATTRIBUTE::={
+	*       WITH SYNTAX   CertificatePair
+	*       EQUALITY MATCHING RULE certificatePairExactMatch
+	*       ID joint-iso-ccitt(2) ds(5) attributeType(4) crossCertificatePair(40)}
+	* </pre>
+	*
+	* <blockquote> The forward elements of the crossCertificatePair attribute of a
+	* CA's directory entry shall be used to store all, except self-issued
+	* certificates issued to this CA. Optionally, the reverse elements of the
+	* crossCertificatePair attribute, of a CA's directory entry may contain a
+	* subset of certificates issued by this CA to other CAs. When both the forward
+	* and the reverse elements are present in a single attribute value, issuer name
+	* in one certificate shall match the subject name in the other and vice versa,
+	* and the subject public key in one certificate shall be capable of verifying
+	* the digital signature on the other certificate and vice versa.
+	*
+	* When a reverse element is present, the forward element value and the reverse
+	* element value need not be stored in the same attribute value; in other words,
+	* they can be stored in either a single attribute value or two attribute
+	* values. </blockquote>
+	*
+	* <pre>
+	*       CertificatePair ::= SEQUENCE {
+	*         forward		[0]	Certificate OPTIONAL,
+	*         reverse		[1]	Certificate OPTIONAL,
+	*         -- at least one of the pair shall be present -- }
+	* </pre>
+	*/
+	public class CertificatePair
+		: Asn1Encodable
+	{
+		private X509CertificateStructure forward, reverse;
+
+		public static CertificatePair GetInstance(
+			object obj)
+		{
+			if (obj == null || obj is CertificatePair)
+			{
+				return (CertificatePair) obj;
+			}
+
+			if (obj is Asn1Sequence)
+			{
+				return new CertificatePair((Asn1Sequence) obj);
+			}
+
+			throw new ArgumentException("unknown object in factory: " + obj.GetType().Name, "obj");
+		}
+
+		/**
+		* Constructor from Asn1Sequence.
+		* <p/>
+		* The sequence is of type CertificatePair:
+		* <p/>
+		* <pre>
+		*       CertificatePair ::= SEQUENCE {
+		*         forward		[0]	Certificate OPTIONAL,
+		*         reverse		[1]	Certificate OPTIONAL,
+		*         -- at least one of the pair shall be present -- }
+		* </pre>
+		*
+		* @param seq The ASN.1 sequence.
+		*/
+		private CertificatePair(
+			Asn1Sequence seq)
+		{
+			if (seq.Count != 1 && seq.Count != 2)
+			{
+				throw new ArgumentException("Bad sequence size: " + seq.Count, "seq");
+			}
+
+			foreach (object obj in seq)
+			{
+				Asn1TaggedObject o = Asn1TaggedObject.GetInstance(obj);
+				if (o.TagNo == 0)
+				{
+					forward = X509CertificateStructure.GetInstance(o, true);
+				}
+				else if (o.TagNo == 1)
+				{
+					reverse = X509CertificateStructure.GetInstance(o, true);
+				}
+				else
+				{
+					throw new ArgumentException("Bad tag number: " + o.TagNo);
+				}
+			}
+		}
+
+		/**
+		* Constructor from a given details.
+		*
+		* @param forward Certificates issued to this CA.
+		* @param reverse Certificates issued by this CA to other CAs.
+		*/
+		public CertificatePair(
+			X509CertificateStructure	forward,
+			X509CertificateStructure	reverse)
+		{
+			this.forward = forward;
+			this.reverse = reverse;
+		}
+
+		/**
+		* Produce an object suitable for an Asn1OutputStream.
+		* <p/>
+		* Returns:
+		* <p/>
+		* <pre>
+		*       CertificatePair ::= SEQUENCE {
+		*         forward		[0]	Certificate OPTIONAL,
+		*         reverse		[1]	Certificate OPTIONAL,
+		*         -- at least one of the pair shall be present -- }
+		* </pre>
+		*
+		* @return a DERObject
+		*/
+		public override Asn1Object ToAsn1Object()
+		{
+			Asn1EncodableVector vec = new Asn1EncodableVector();
+
+			if (forward != null)
+			{
+				vec.Add(new DerTaggedObject(0, forward));
+			}
+
+			if (reverse != null)
+			{
+				vec.Add(new DerTaggedObject(1, reverse));
+			}
+
+			return new DerSequence(vec);
+		}
+
+		/**
+		* @return Returns the forward.
+		*/
+		public X509CertificateStructure Forward
+		{
+			get { return forward; }
+		}
+
+		/**
+		* @return Returns the reverse.
+		*/
+		public X509CertificateStructure Reverse
+		{
+			get { return reverse; }
+		}
+	}
+}