1 files changed, 67 insertions, 0 deletions
diff --git a/Crypto/src/util/collections/UnmodifiableList.cs b/Crypto/src/util/collections/UnmodifiableList.cs
new file mode 100644
index 000000000..28e49eac3
--- /dev/null
+++ b/Crypto/src/util/collections/UnmodifiableList.cs
@@ -0,0 +1,67 @@
+using System;
+using System.Collections;
+
+namespace Org.BouncyCastle.Utilities.Collections
+{
+	public abstract class UnmodifiableList
+		: IList
+	{
+		protected UnmodifiableList()
+		{
+		}
+
+		public virtual int Add(object o)
+		{
+			throw new NotSupportedException();
+		}
+
+		public virtual void Clear()
+		{
+			throw new NotSupportedException();
+		}
+
+		public abstract bool Contains(object o);
+
+		public abstract void CopyTo(Array array, int index);
+
+		public abstract int Count { get; }
+
+		public abstract IEnumerator GetEnumerator();
+
+		public abstract int IndexOf(object o);
+
+		public virtual void Insert(int i, object o)
+		{
+			throw new NotSupportedException();
+		}
+
+		public abstract bool IsFixedSize { get; }
+
+		public virtual bool IsReadOnly
+		{
+			get { return true; }
+		}
+
+		public abstract bool IsSynchronized { get; }
+
+		public virtual void Remove(object o)
+		{
+			throw new NotSupportedException();
+		}
+
+		public virtual void RemoveAt(int i)
+		{
+			throw new NotSupportedException();
+		}
+
+		public abstract object SyncRoot { get; }
+		
+		public virtual object this[int i]
+		{
+			get { return GetValue(i); }
+			set { throw new NotSupportedException(); }
+		}
+
+		protected abstract object GetValue(int i);
+	}
+}