/// <summary>
/// Initializes a new instance of the <see cref="BlobReader"/> class.
/// </summary>
/// <param name="input">The input stream to process.</param>
protected BlobReader(Stream input)
: this()
{
if (!input.CanRead || !input.CanSeek)
{
throw new ArgumentException("Input stream must be readable and seekable.");
}
this.input = new PeekableStream(input);
this.length = input.Length;
}
/// <summary>
/// Initializes a new instance of the <see cref="BlobReader"/> class.
/// </summary>
/// <param name="input">The input stream to process.</param>
protected BlobReader(Stream input)
: this()
{
if ( !input.CanRead || !input.CanSeek )
throw new ArgumentException( "Input stream must be readable and seekable." );
this.input = new PeekableStream(input);
this.length = input.Length;
}
private bool TryReadBlob()
{
if (!CanRead(BlobHeaderLength))
return false;
ECacheState cachestate;
EAutoPreprocessCode process;
Int32 serialized, spare;
Mark(BlobHeaderLength);
try
{
cachestate = (ECacheState)input.ReadByte();
process = (EAutoPreprocessCode)input.ReadByte();
serialized = input.ReadInt32();
spare = input.ReadInt32();
}
catch (Exception)
{
Reset();
throw new InvalidDataException( "Corrupted blob" );
}
if (!BlobUtil.IsValidCacheState(cachestate) || !BlobUtil.IsValidProcess(process) ||
serialized < 0 || spare < 0 ||
!CanReadMarked(serialized))
{
Reset();
return false;
}
serialized -= BlobHeaderLength;
if (process != EAutoPreprocessCode.eAutoPreprocessCodePlaintext)
{
PeekableStream originalStream = input;
object extendedData = null;
input = HandleProcessCode(process, ref serialized, out extendedData);
bool result = TryReadBlob();
input.ReadBytes( 40 ); // read and dispose HMACs
// todo: validate them?
input.Close();
input = originalStream;
return result;
}
if(Blob != null)
Blob(process, cachestate);
ProcessFields(serialized);
if (spare > 0)
{
byte[] spareData = new byte[spare];
input.Read(spareData, 0, spare);
if(Spare != null)
Spare(spareData);
}
if(EndBlob != null)
EndBlob();
return true;
}
private bool TryReadBlob(UInt32 lengthHint)
{
if (!CanRead(BlobHeaderLength) || lengthHint < BlobHeaderLength)
{
return(false);
}
ECacheState cachestate;
EAutoPreprocessCode process;
Int32 serialized, spare;
Mark(BlobHeaderLength);
try
{
cachestate = (ECacheState)input.ReadByte();
process = (EAutoPreprocessCode)input.ReadByte();
serialized = input.ReadInt32();
spare = input.ReadInt32();
}
catch (Exception)
{
Reset();
throw new InvalidDataException("Corrupted blob");
}
if (!BlobUtil.IsValidCacheState(cachestate) || !BlobUtil.IsValidProcess(process) ||
serialized < 0 || spare < 0 ||
!CanReadMarked(serialized))
{
Reset();
return(false);
}
serialized -= BlobHeaderLength;
if (process != EAutoPreprocessCode.eAutoPreprocessCodePlaintext)
{
PeekableStream originalStream = input;
object extendedData = null;
input = HandleProcessCode(process, ref serialized, out extendedData);
bool result = TryReadBlob((uint)serialized);
input.ReadBytes(40); // read and dispose HMACs
// todo: validate them?
input.Close();
input = originalStream;
return(result);
}
if (Blob != null)
{
Blob(process, cachestate);
}
ProcessFields(serialized);
if (spare > 0)
{
byte[] spareData = new byte[spare];
input.Read(spareData, 0, spare);
if (Spare != null)
{
Spare(spareData);
}
}
if (EndBlob != null)
{
EndBlob();
}
return(true);
}
