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authorOren Novotny <oren@novotny.org>2014-02-26 10:08:50 -0500
committerOren Novotny <oren@novotny.org>2014-02-26 10:08:50 -0500
commit176743ab5faec2dd275b5efd3a2dd62c610f237a (patch)
tree1d2e50c534a479d749c266d7c52434d8f17f86aa /Crypto/src/asn1/DefiniteLengthInputStream.cs
parentAdd git files (diff)
downloadBouncyCastle.NET-ed25519-654c26abd79e9451e5a9bd108f1358bc2849fdbf.tar.xz
Add BouncyCastle PCL files v1.7.0
Diffstat (limited to 'Crypto/src/asn1/DefiniteLengthInputStream.cs')
-rw-r--r--Crypto/src/asn1/DefiniteLengthInputStream.cs90
1 files changed, 90 insertions, 0 deletions
diff --git a/Crypto/src/asn1/DefiniteLengthInputStream.cs b/Crypto/src/asn1/DefiniteLengthInputStream.cs
new file mode 100644
index 000000000..cfea89f21
--- /dev/null
+++ b/Crypto/src/asn1/DefiniteLengthInputStream.cs
@@ -0,0 +1,90 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Asn1
+{
+    class DefiniteLengthInputStream
+        : LimitedInputStream
+    {
+		private static readonly byte[] EmptyBytes = new byte[0];
+
+		private readonly int _originalLength;
+		private int _remaining;
+
+        internal DefiniteLengthInputStream(
+            Stream	inStream,
+            int		length)
+            : base(inStream, length)
+        {
+			if (length < 0)
+				throw new ArgumentException("negative lengths not allowed", "length");
+
+			this._originalLength = length;
+			this._remaining = length;
+
+			if (length == 0)
+			{
+				SetParentEofDetect(true);
+			}
+        }
+
+		internal int Remaining
+		{
+			get { return _remaining; }
+		}
+
+		public override int ReadByte()
+        {
+			if (_remaining == 0)
+				return -1;
+
+			int b = _in.ReadByte();
+
+			if (b < 0)
+				throw new EndOfStreamException("DEF length " + _originalLength + " object truncated by " + _remaining);
+
+			if (--_remaining == 0)
+			{
+				SetParentEofDetect(true);
+			}
+
+			return b;
+        }
+
+		public override int Read(
+			byte[]	buf,
+			int		off,
+			int		len)
+		{
+			if (_remaining == 0)
+				return 0;
+
+			int toRead = System.Math.Min(len, _remaining);
+			int numRead = _in.Read(buf, off, toRead);
+
+			if (numRead < 1)
+				throw new EndOfStreamException("DEF length " + _originalLength + " object truncated by " + _remaining);
+
+			if ((_remaining -= numRead) == 0)
+			{
+				SetParentEofDetect(true);
+			}
+
+			return numRead;
+		}
+
+		internal byte[] ToArray()
+		{
+			if (_remaining == 0)
+				return EmptyBytes;
+
+			byte[] bytes = new byte[_remaining];
+			if ((_remaining -= Streams.ReadFully(_in, bytes)) != 0)
+				throw new EndOfStreamException("DEF length " + _originalLength + " object truncated by " + _remaining);
+			SetParentEofDetect(true);
+			return bytes;
+		}
+    }
+}