DefiniteLengthInputStream
using Org.BouncyCastle.Utilities.IO;
using System;
using System.IO;
namespace Org.BouncyCastle.Asn1
{
internal class DefiniteLengthInputStream : LimitedInputStream
{
private static readonly byte[] EmptyBytes = new byte[0];
private readonly int _originalLength;
private int _remaining;
internal int Remaining => _remaining;
internal DefiniteLengthInputStream(Stream inStream, int length, int limit)
: base(inStream, limit)
{
if (length <= 0) {
if (length < 0)
throw new ArgumentException("negative lengths not allowed", "length");
SetParentEofDetect();
}
_originalLength = length;
_remaining = length;
}
public override int ReadByte()
{
int originalLength;
if (_remaining < 2) {
if (_remaining == 0)
return -1;
int num = _in.ReadByte();
if (num < 0) {
originalLength = _originalLength;
throw new EndOfStreamException("DEF length " + originalLength.ToString() + " object truncated by " + _remaining.ToString());
}
_remaining = 0;
SetParentEofDetect();
return num;
}
int num2 = _in.ReadByte();
if (num2 < 0) {
originalLength = _originalLength;
throw new EndOfStreamException("DEF length " + originalLength.ToString() + " object truncated by " + _remaining.ToString());
}
_remaining--;
return num2;
}
public override int Read(byte[] buf, int off, int len)
{
if (_remaining == 0)
return 0;
int count = System.Math.Min(len, _remaining);
int num = _in.Read(buf, off, count);
int num2;
if (num < 1) {
num2 = _originalLength;
throw new EndOfStreamException("DEF length " + num2.ToString() + " object truncated by " + _remaining.ToString());
}
num2 = (_remaining -= num);
if (num2 == 0)
SetParentEofDetect();
return num;
}
internal void ReadAllIntoByteArray(byte[] buf)
{
if (_remaining != buf.Length)
throw new ArgumentException("buffer length not right for data");
if (_remaining != 0) {
int limit = Limit;
if (_remaining >= limit)
throw new IOException("corrupted stream - out of bounds length found: " + _remaining.ToString() + " >= " + limit.ToString());
int num = _remaining -= Streams.ReadFully(_in, buf, 0, buf.Length);
if (num != 0) {
num = _originalLength;
throw new EndOfStreamException("DEF length " + num.ToString() + " object truncated by " + _remaining.ToString());
}
SetParentEofDetect();
}
}
internal byte[] ToArray()
{
if (_remaining == 0)
return EmptyBytes;
int limit = Limit;
if (_remaining >= limit)
throw new IOException("corrupted stream - out of bounds length found: " + _remaining.ToString() + " >= " + limit.ToString());
byte[] array = new byte[_remaining];
int num = _remaining -= Streams.ReadFully(_in, array, 0, array.Length);
if (num != 0) {
num = _originalLength;
throw new EndOfStreamException("DEF length " + num.ToString() + " object truncated by " + _remaining.ToString());
}
SetParentEofDetect();
return array;
}
}
}