/// <summary>
/// Opens an existing stream and optionally verifies the stream
/// </summary>
/// <param name="stream">The stream to open</param>
/// <param name="mode">The verification to use</param>
public AssuredStream(Stream stream, VerificationMode mode)
: this(stream, false)
{
_header = new AssuredStreamHeader(stream, mode);
if (mode == VerificationMode.Full)
{
if (!_seekable)
{
throw new InvalidOperationException("Can't fully verify unseekable streams");
}
_basePosition = stream.Position;
if (!_header.VerifyHash(stream))
{
throw new CryptographicException("Invalid hash value");
}
stream.Position = _basePosition;
}
else
{
_basePosition = stream.CanSeek ? stream.Position : 0;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="AssuredStream"/> class.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="args">The args.</param>
public AssuredStream(Stream stream, AssuredStreamCreateArgs args)
: this(stream, true)
{
if (args == null)
{
throw new ArgumentNullException("args");
}
args.VerifyArgs("args");
long pos = stream.Position;
_header = new AssuredStreamHeader(args);
_header.WriteHeader(stream);
_basePosition = stream.Position;
}
