1 files changed, 102 insertions, 0 deletions
diff --git a/crypto/src/asn1/ConstructedOctetStream.cs b/crypto/src/asn1/ConstructedOctetStream.cs
new file mode 100644
index 000000000..1773b22cc
--- /dev/null
+++ b/crypto/src/asn1/ConstructedOctetStream.cs
@@ -0,0 +1,102 @@
+using System.IO;
+
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Asn1
+{
+	internal class ConstructedOctetStream
+		: BaseInputStream
+	{
+		private readonly Asn1StreamParser _parser;
+
+		private bool _first = true;
+		private Stream _currentStream;
+
+		internal ConstructedOctetStream(
+			Asn1StreamParser parser)
+		{
+			_parser = parser;
+		}
+
+		public override int Read(byte[] buffer, int offset, int count)
+		{
+			if (_currentStream == null)
+			{
+				if (!_first)
+					return 0;
+
+				Asn1OctetStringParser s = (Asn1OctetStringParser)_parser.ReadObject();
+
+				if (s == null)
+					return 0;
+
+				_first = false;
+				_currentStream = s.GetOctetStream();
+			}
+
+			int totalRead = 0;
+
+			for (;;)
+			{
+				int numRead = _currentStream.Read(buffer, offset + totalRead, count - totalRead);
+
+				if (numRead > 0)
+				{
+					totalRead += numRead;
+
+					if (totalRead == count)
+						return totalRead;
+				}
+				else
+				{
+					Asn1OctetStringParser aos = (Asn1OctetStringParser)_parser.ReadObject();
+
+					if (aos == null)
+					{
+						_currentStream = null;
+						return totalRead;
+					}
+
+					_currentStream = aos.GetOctetStream();
+				}
+			}
+		}
+
+		public override int ReadByte()
+		{
+			if (_currentStream == null)
+			{
+				if (!_first)
+					return 0;
+
+				Asn1OctetStringParser s = (Asn1OctetStringParser)_parser.ReadObject();
+
+				if (s == null)
+					return 0;
+
+				_first = false;
+				_currentStream = s.GetOctetStream();
+			}
+
+			for (;;)
+			{
+				int b = _currentStream.ReadByte();
+
+				if (b >= 0)
+				{
+					return b;
+				}
+
+				Asn1OctetStringParser aos = (Asn1OctetStringParser)_parser.ReadObject();
+
+				if (aos == null)
+				{
+					_currentStream = null;
+					return -1;
+				}
+
+				_currentStream = aos.GetOctetStream();
+			}
+		}
+	}
+}