using System.IO; namespace Org.BouncyCastle.Asn1 { internal class IndefiniteLengthInputStream : LimitedInputStream { private int _lookAhead; private bool _eofOn00 = true; internal IndefiniteLengthInputStream(Stream inStream, int limit) : base(inStream, limit) { _lookAhead = RequireByte(); if (_lookAhead == 0) CheckEndOfContents(); } internal void SetEofOn00(bool eofOn00) { _eofOn00 = eofOn00; if (_eofOn00 && _lookAhead == 0) CheckEndOfContents(); } private void CheckEndOfContents() { if (RequireByte() != 0) throw new IOException("malformed end-of-contents marker"); _lookAhead = -1; SetParentEofDetect(); } public override int Read(byte[] buffer, int offset, int count) { if (_eofOn00 || count <= 1) return base.Read(buffer, offset, count); if (_lookAhead < 0) return 0; int num = _in.Read(buffer, offset + 1, count - 1); if (num <= 0) throw new EndOfStreamException(); buffer[offset] = (byte)_lookAhead; _lookAhead = RequireByte(); return num + 1; } public override int ReadByte() { if (_eofOn00 && _lookAhead <= 0) { if (_lookAhead == 0) CheckEndOfContents(); return -1; } int lookAhead = _lookAhead; _lookAhead = RequireByte(); return lookAhead; } private int RequireByte() { int num = _in.ReadByte(); if (num < 0) throw new EndOfStreamException(); return num; } } }