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author | Oren Novotny <oren@novotny.org> | 2014-02-26 10:08:50 -0500 |
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committer | Oren Novotny <oren@novotny.org> | 2014-02-26 10:08:50 -0500 |
commit | 176743ab5faec2dd275b5efd3a2dd62c610f237a (patch) | |
tree | 1d2e50c534a479d749c266d7c52434d8f17f86aa /Crypto/src/asn1/DefiniteLengthInputStream.cs | |
parent | Add git files (diff) | |
download | BouncyCastle.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.cs | 90 |
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; + } + } +} |