/// <inheritdoc />
/// <inheritdoc cref="EnsureParameter" />
public async Task UnprotectAsync(byte[] encryptedData)
{
this.EnsureParameter(encryptedData);
var decryptedBytes = await _encryptor.DecryptAsync(encryptedData, _key)
.ConfigureAwait(false);
SetBytesToByteArray(
source: decryptedBytes,
target: ref encryptedData);
}
private async Task <byte[]> DecryptAsync(byte[] encryptedBytes, int saltLength, byte[] encryptionKey)
{
var saltedBytes = await _encryptor.DecryptAsync(encryptedBytes, encryptionKey)
.ConfigureAwait(false);
try
{
return(saltedBytes
.Take(saltedBytes.Length - saltLength)
.ToArray());
}
finally
{
if (saltedBytes != null)
{
Array.Clear(saltedBytes, 0, saltedBytes.Length);
}
}
}
/// <inheritdoc />
/// <inheritdoc cref="EnsureByteIsSet"/>
/// <inheritdoc cref="DisposableBase.ThrowIfDisposed"/>
public async Task <byte> RevealDecryptedByteAsync()
{
ThrowIfDisposed();
EnsureByteIsSet();
byte[] byteBuffer = null;
try
{
var encryptedBuffer = new byte[_encryptedByteLength];
try
{
using (var @byte = await _encryptedByte.RevealDecryptedBytesAsync().ConfigureAwait(false))
{
Buffer.BlockCopy(@byte.PlainBytes, 0, encryptedBuffer, 0, _encryptedByteLength);
}
using (var encryptionKey = await _encryptionKey.RevealDecryptedBytesAsync().ConfigureAwait(false))
{
byteBuffer = await _encryptor.DecryptAsync(encryptedBuffer, encryptionKey.PlainBytes)
.ConfigureAwait(false);
}
//Extract the byte from arbitrary bytes
return(byteBuffer[_realBytePosition]);
}
finally
{
Array.Clear(encryptedBuffer, 0, _encryptedByteLength);
}
}
finally
{
if (byteBuffer != null)
{
Array.Clear(byteBuffer, 0, byteBuffer.Length);
}
}
}