1 files changed, 123 insertions, 0 deletions
diff --git a/crypto/src/x509/X509CertificatePair.cs b/crypto/src/x509/X509CertificatePair.cs
new file mode 100644
index 000000000..fbeba4dc6
--- /dev/null
+++ b/crypto/src/x509/X509CertificatePair.cs
@@ -0,0 +1,123 @@
+using System;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Security.Certificates;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.X509
+{
+	/// <remarks>
+	/// This class contains a cross certificate pair. Cross certificates pairs may
+	/// contain two cross signed certificates from two CAs. A certificate from the
+	/// other CA to this CA is contained in the forward certificate, the certificate
+	/// from this CA to the other CA is contained in the reverse certificate.
+	/// </remarks>
+	public class X509CertificatePair
+	{
+		private readonly X509Certificate forward;
+		private readonly X509Certificate reverse;
+
+		/// <summary>Constructor</summary>
+		/// <param name="forward">Certificate from the other CA to this CA.</param>
+		/// <param name="reverse">Certificate from this CA to the other CA.</param>
+		public X509CertificatePair(
+			X509Certificate	forward,
+			X509Certificate	reverse)
+		{
+			this.forward = forward;
+			this.reverse = reverse;
+		}
+
+		/// <summary>Constructor from a ASN.1 CertificatePair structure.</summary>
+		/// <param name="pair">The <c>CertificatePair</c> ASN.1 object.</param>
+		public X509CertificatePair(
+			CertificatePair pair)
+		{
+			if (pair.Forward != null)
+			{
+				this.forward = new X509Certificate(pair.Forward);
+			}
+			if (pair.Reverse != null)
+			{
+				this.reverse = new X509Certificate(pair.Reverse);
+			}
+		}
+
+		public byte[] GetEncoded()
+		{
+			try
+			{
+				X509CertificateStructure f = null, r = null;
+
+				if (forward != null)
+				{
+					f = X509CertificateStructure.GetInstance(
+						Asn1Object.FromByteArray(forward.GetEncoded()));
+
+					if (f == null)
+						throw new CertificateEncodingException("unable to get encoding for forward");
+				}
+
+				if (reverse != null)
+				{
+					r = X509CertificateStructure.GetInstance(
+						Asn1Object.FromByteArray(reverse.GetEncoded()));
+
+					if (r == null)
+						throw new CertificateEncodingException("unable to get encoding for reverse");
+				}
+
+				return new CertificatePair(f, r).GetDerEncoded();
+			}
+			catch (Exception e)
+			{
+				// TODO
+//				throw new ExtCertificateEncodingException(e.toString(), e);
+				throw new CertificateEncodingException(e.Message, e);
+			}
+		}
+
+		/// <summary>Returns the certificate from the other CA to this CA.</summary>
+		public X509Certificate Forward
+		{
+			get { return forward; }
+		}
+
+		/// <summary>Returns the certificate from this CA to the other CA.</summary>
+		public X509Certificate Reverse
+		{
+			get { return reverse; }
+		}
+
+		public override bool Equals(
+			object obj)
+		{
+			if (obj == this)
+				return true;
+
+			X509CertificatePair other = obj as X509CertificatePair;
+
+			if (other == null)
+				return false;
+
+			return Platform.Equals(this.forward, other.forward)
+				&& Platform.Equals(this.reverse, other.reverse);
+		}
+
+		public override int GetHashCode()
+		{
+			int hash = -1;
+			if (forward != null)
+			{
+				hash ^= forward.GetHashCode();
+			}
+			if (reverse != null)
+			{
+				hash *= 17;
+				hash ^= reverse.GetHashCode();
+			}
+			return hash;
+		}
+	}
+}