public static Stream Create(Stream encryptedStream, string sharedSecret, string salt, bool leaveOpen)
{
Action <Stream> onDisposingAction = (s) =>
{
s?.Dispose();
if (!leaveOpen)
{
encryptedStream?.Dispose();
}
};
return(ReadOnlyStreamWrapper.Create(async() => await CreateAsync(encryptedStream, sharedSecret, salt).IgnoreContext(), onDisposingAction: onDisposingAction));
}
public static Stream Create(Stream originalStream, string sharedSecret, string salt, bool leaveOpen)
{
var pipeOptions = new PipedStreamOptions()
{
WriteTimeout = TimeSpan.FromMinutes(10)
};
var pipe = new PipedStreamManager(pipeOptions);
var saltBytes = Encoding.UTF8.GetBytes(salt);
var encryptorTask = Task.Run(async() =>
{
try
{
using (var writerStream = pipe.CreateWriter(throwsFailedWrite: true))
using (var aesAlg = new RijndaelManaged())
using (var key = new Rfc2898DeriveBytes(sharedSecret, saltBytes))
{
try
{
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// prepends the IV
await writerStream.WriteAsync(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int))
.IgnoreContext();
await writerStream.WriteAsync(aesAlg.IV, 0, aesAlg.IV.Length)
.IgnoreContext();
// Creates an encryptor to perform the stream transform.
using (var encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV))
using (var cryptoStream = new CryptoStream(writerStream, encryptor, CryptoStreamMode.Write))
{
await originalStream.CopyToAsync(cryptoStream, bufferSize: pipeOptions.BlockSize)
.IgnoreContext();
await cryptoStream.FlushAsync()
.IgnoreContext();
await writerStream.FlushAsync()
.IgnoreContext();
if (!cryptoStream.HasFlushedFinalBlock)
{
cryptoStream.FlushFinalBlock();
}
await writerStream.FlushAsync()
.IgnoreContext();
}
}
catch (Exception ex)
{
pipe.FaultPipe(ex);
}
}
}
finally
{
if (!leaveOpen)
{
originalStream.Dispose();
}
}
});
return(ReadOnlyStreamWrapper.Create(pipe.CreateReader(), onDisposingAction: (Stream s) => s?.Dispose()));
}