private int GenerateInternal(byte b, byte[] salt, ref bool isSaltEncrypted, bool doNotEncrypt = false)
{
var byteBuffer = new byte[salt.Length + 1];
try
{
//Decrypt salt
if (isSaltEncrypted)
{
_memoryProtector.Unprotect(salt);
isSaltEncrypted = false;
}
//Append salt + byte
Array.Copy(salt, byteBuffer, salt.Length);
byteBuffer[salt.Length] = b;
//Hash it
var result = _fastHasher.ComputeFast(byteBuffer);
return(result);
}
finally
{
Array.Clear(byteBuffer, 0, byteBuffer.Length);
//Encrypt the salt
if (!isSaltEncrypted && !doNotEncrypt)
{
_memoryProtector.Protect(salt);
isSaltEncrypted = true;
}
}
}
/// <summary>
/// Appends the specified <see cref="ISafeByte" /> instance to the inner encrypted collection.
/// </summary>
/// <param name="safeByte">The safe byte.</param>
/// <exception cref="System.ArgumentNullException"><paramref name="safeByte" /> is <see langword="null" />.</exception>
/// <exception cref="ObjectDisposedException">Throws if the <see cref="EncryptedSafeByteCollection" /> instance is disposed</exception>
/// <seealso cref="ISafeByte" />
public void Append(ISafeByte safeByte)
{
EnsureNotDisposed();
if (safeByte == null)
{
throw new ArgumentNullException(nameof(safeByte));
}
_memoryProtector.Unprotect(_encryptionKey);
var list = DecryptAndDeserialize(_encryptedCollection, _encryptionKey);
list.Add(safeByte.Id);
_encryptedCollection = SerializeAndEncrypt(list, _encryptionKey);
list.Clear();
_memoryProtector.Protect(_encryptionKey);
Length++;
}
/// <summary>
/// Decrypts and returns the byte that this <see cref="SafeByte" /> instance represents.
/// </summary>
/// <returns></returns>
/// <exception cref="System.InvalidOperationException">Thrown when byte is not set</exception>
public byte Get()
{
EnsureByteIsSet();
byte[] byteBuffer = null;
try
{
_memoryProtector.Unprotect(_encryptionKey);
_memoryProtector.Unprotect(_encryptedByte);
var encryptedBuffer = new byte[_encryptedByteLength];
try
{
Buffer.BlockCopy(_encryptedByte, 0, encryptedBuffer, 0, _encryptedByteLength);
byteBuffer = _encryptor.Decrypt(encryptedBuffer, _encryptionKey);
//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);
}
_memoryProtector.Protect(_encryptionKey);
_memoryProtector.Protect(_encryptedByte);
}
}