private void Load(ChunkLookup.IChunkVariantInfo chunkVariantInfo, Stream output)
{
using (var file = MemoryMappedFile.CreateFromFile(chunkVariantInfo.DataPath, FileMode.Open))
using (var input = file.CreateViewStream(chunkVariantInfo.Offset, chunkVariantInfo.Size.Align(16)))
{
if (chunkVariantInfo.CryptoInfo.HasValue == false)
{
output.WriteFromStream(input, chunkVariantInfo.Size);
return;
}
var keyId = chunkVariantInfo.CryptoInfo.Value.KeyId;
byte[] keyBytes;
if (this._CryptoKeys.TryGetValue(keyId, out keyBytes) == false)
{
throw new ChunkCryptoKeyMissingException(keyId);
}
using (var aes = Aes.Create())
{
aes.Key = keyBytes;
aes.IV = keyBytes; // yes, it's that stupid
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
using (var decryptor = aes.CreateDecryptor())
using (var cryptoStream = new CryptoStream(input, decryptor, CryptoStreamMode.Read))
{
output.WriteFromStream(cryptoStream, chunkVariantInfo.Size);
}
}
}
}
public void Load(ChunkLookup.IChunkVariantInfo chunkVariantInfo, long size, Stream output)
{
if (chunkVariantInfo == null)
{
throw new ArgumentNullException("chunkVariantInfo");
}
if (chunkVariantInfo.Size == size)
{
Load(chunkVariantInfo, output);
}
else
{
using (var temp = new MemoryStream())
{
Load(chunkVariantInfo, temp);
if (temp.Length != chunkVariantInfo.Size)
{
throw new InvalidOperationException();
}
temp.Position = 0;
Decompress(temp, output, size);
}
}
}
