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() { if (_remaining < 2) { if (_remaining == 0) return -1; int num = _in.ReadByte(); if (num < 0) throw new EndOfStreamException("DEF length " + _originalLength.ToString() + " object truncated by " + _remaining.ToString()); _remaining = 0; SetParentEofDetect(); return num; } int num2 = _in.ReadByte(); if (num2 < 0) 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); if (num < 1) throw new EndOfStreamException("DEF length " + _originalLength.ToString() + " object truncated by " + _remaining.ToString()); if ((_remaining -= num) == 0) SetParentEofDetect(); return num; } public override int Read(Span<byte> buffer) { if (_remaining == 0) return 0; int length = System.Math.Min(buffer.Length, _remaining); int num = _in.Read(buffer.Slice(0, length)); if (num < 1) throw new EndOfStreamException("DEF length " + _originalLength.ToString() + " object truncated by " + _remaining.ToString()); if ((_remaining -= num) == 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()); if ((_remaining -= Streams.ReadFully(_in, buf, 0, buf.Length)) != 0) throw new EndOfStreamException("DEF length " + _originalLength.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]; if ((_remaining -= Streams.ReadFully(_in, array, 0, array.Length)) != 0) throw new EndOfStreamException("DEF length " + _originalLength.ToString() + " object truncated by " + _remaining.ToString()); SetParentEofDetect(); return array; } } }