/// <summary>
/// Initializes a new instance of the <see cref="PbdfFile"/> class from the given <paramref name="stream"/>.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> to load data from.</param>
public PbdfFile(Stream stream, object parameter = null)
{
Parameter = parameter;
// Retrieve encryption secrets.
Key = Pbdf.RetrieveKey(stream);
stream.Position = 0;
BlockSize = Pbdf.RetrieveBlockSize(stream, Key);
stream.Position = 0;
// Decrypt header and data into a temporary stream.
byte[] buffer = new byte[stream.Length - (stream.Length / BlockSize * sizeof(uint))];
using (MemoryStream decStream = new MemoryStream(buffer))
{
Pbdf.Decrypt(stream, decStream, Key, BlockSize);
// Read the header and adjusted offsets.
decStream.Position = 0;
Offsets = Pbdf.ReadHeader(decStream, BlockSize);
int headerSize = (int)decStream.Position;
// Create a stream view on the data excluding the header.
using (MemoryStream dataStream = new MemoryStream(buffer, headerSize, buffer.Length - headerSize))
LoadData(dataStream);
}
}
/// <summary>
/// Saves the data of the instance in the given <paramref name="stream"/>.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> to save data in.</param>
public void Save(Stream stream)
{
// Compose the decrypted file contents in a temporary stream.
using (MemoryStream decStream = new MemoryStream())
{
// Write out the file data into a temporary stream.
Offsets = new List <int>();
using (MemoryStream dataStream = new MemoryStream())
{
SaveData(dataStream);
Pbdf.WriteHeader(decStream, BlockSize, Offsets, (int)dataStream.Position);
dataStream.Position = 0;
dataStream.CopyTo(decStream);
}
// Encrypt the data into the provided stream.
decStream.Position = 0;
Pbdf.Encrypt(decStream, stream, Key, BlockSize);
}
}
