1 files changed, 89 insertions, 0 deletions
diff --git a/crypto/src/x509/extension/X509ExtensionUtil.cs b/crypto/src/x509/extension/X509ExtensionUtil.cs
new file mode 100644
index 000000000..845a87bad
--- /dev/null
+++ b/crypto/src/x509/extension/X509ExtensionUtil.cs
@@ -0,0 +1,89 @@
+using System;
+using System.Collections;
+using System.IO;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Security.Certificates;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.X509.Extension
+{
+	public class X509ExtensionUtilities
+	{
+		public static Asn1Object FromExtensionValue(
+			Asn1OctetString extensionValue)
+		{
+			return Asn1Object.FromByteArray(extensionValue.GetOctets());
+		}
+
+		public static ICollection GetIssuerAlternativeNames(
+			X509Certificate cert)
+		{
+			Asn1OctetString extVal = cert.GetExtensionValue(X509Extensions.IssuerAlternativeName);
+
+			return GetAlternativeName(extVal);
+		}
+
+		public static ICollection GetSubjectAlternativeNames(
+			X509Certificate cert)
+		{
+			Asn1OctetString extVal = cert.GetExtensionValue(X509Extensions.SubjectAlternativeName);
+
+			return GetAlternativeName(extVal);
+		}
+
+		private static ICollection GetAlternativeName(
+			Asn1OctetString extVal)
+		{
+			IList temp = Platform.CreateArrayList();
+
+			if (extVal != null)
+			{
+				try
+				{
+					Asn1Sequence seq = DerSequence.GetInstance(FromExtensionValue(extVal));
+
+					foreach (GeneralName genName in seq)
+					{
+                        IList list = Platform.CreateArrayList();
+						list.Add(genName.TagNo);
+
+						switch (genName.TagNo)
+						{
+							case GeneralName.EdiPartyName:
+							case GeneralName.X400Address:
+							case GeneralName.OtherName:
+								list.Add(genName.Name.ToAsn1Object());
+								break;
+							case GeneralName.DirectoryName:
+								list.Add(X509Name.GetInstance(genName.Name).ToString());
+								break;
+							case GeneralName.DnsName:
+							case GeneralName.Rfc822Name:
+							case GeneralName.UniformResourceIdentifier:
+								list.Add(((IAsn1String)genName.Name).GetString());
+								break;
+							case GeneralName.RegisteredID:
+								list.Add(DerObjectIdentifier.GetInstance(genName.Name).Id);
+								break;
+							case GeneralName.IPAddress:
+								list.Add(DerOctetString.GetInstance(genName.Name).GetOctets());
+								break;
+							default:
+								throw new IOException("Bad tag number: " + genName.TagNo);
+						}
+
+						temp.Add(list);
+					}
+				}
+				catch (Exception e)
+				{
+					throw new CertificateParsingException(e.Message);
+				}
+			}
+
+			return temp;
+		}
+	}
+}