1 files changed, 100 insertions, 0 deletions
diff --git a/crypto/src/asn1/DefiniteLengthInputStream.cs b/crypto/src/asn1/DefiniteLengthInputStream.cs
new file mode 100644
index 000000000..4ae803c0e
--- /dev/null
+++ b/crypto/src/asn1/DefiniteLengthInputStream.cs
@@ -0,0 +1,100 @@
+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 void ReadAllIntoByteArray(byte[] buf)
+ {
+ if (_remaining != buf.Length)
+ throw new ArgumentException("buffer length not right for data");
+
+ if ((_remaining -= Streams.ReadFully(_in, buf)) != 0)
+ throw new EndOfStreamException("DEF length " + _originalLength + " object truncated by " + _remaining);
+ SetParentEofDetect(true);
+ }
+
+ 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;
+ }
+ }
+}
|
