public T Decrypt <T>(string password)
{
Watermark m = Decrypt(password);
T retVal = default(T);
try
{
retVal = (T)Convert.ChangeType(m, typeof(T));
}
catch (Exception ex) { }
return(retVal);
}
internal static CompositeWatermark LoadFromBytes(byte[] data)
{
CompositeWatermark comp = new CompositeWatermark();
MemoryStream ms = new MemoryStream(data);
byte[] type = new byte[1];
byte[] dword = new byte[4];
byte[] markData;
while (ms.Position < ms.Length)
{
ms.Read(type, 0, 1);
ms.Read(dword, 0, 4);
markData = new byte[BitConverter.ToInt32(dword, 0)];
ms.Read(markData, 0, markData.Length);
Watermark mark = null;
switch (type[0])
{
case 1:
mark = TextWatermark.LoadFromBytes(markData);
break;
case 2:
mark = FileWatermark.LoadFromBytes(markData);
break;
case 3:
mark = BinaryWatermark.LoadFromBytes(markData);
break;
case 4:
mark = CompositeWatermark.LoadFromBytes(markData);
break;
case 9:
mark = EncryptedWatermark.LoadFromBytes(markData);
break;
}
comp.watermarks.Add(mark);
}
return(comp);
}
/// <summary>
/// Constructor for an encrypted watermark.
/// </summary>
/// <param name="mark">The watermark to encrypt.</param>
/// <param name="password">The password which is used to derive the encryption key.</param>
public EncryptedWatermark(Watermark mark, string password)
{
/*if (mark.GetMarkType() == this.GetMarkType())
* {
* throw new ArgumentException("You cannot next encrypted watermarks!");
* }*/
// get the base marks bytes
byte[] markBytes = mark.GetBytes();
bytes = new Rfc2898DeriveBytes(password, 8);
this.salt = bytes.Salt;
key = bytes.GetBytes(Algorithm.KeySize / 8);
if (Algorithm.IV == null)
{
Algorithm.IV = bytes.GetBytes(Algorithm.BlockSize);
}
Algorithm.Key = key;
byte[] iv = Algorithm.IV;
byte[] cryptData = Encrypt(markBytes, Algorithm);
MemoryStream ms = new MemoryStream();
byte[] ivLength = BitConverter.GetBytes(iv.Length);
ms.Write(ivLength, 0, ivLength.Length);
ms.Write(iv, 0, iv.Length);
byte[] dataLength = BitConverter.GetBytes(cryptData.Length);
ms.Write(dataLength, 0, dataLength.Length);
ms.Write(cryptData, 0, cryptData.Length);
cryptedData = ms.ToArray();
}
public void RemoveWatermark(Watermark mark)
{
watermarks.Remove(mark);
}
public void AddWatermark(Watermark mark)
{
watermarks.Add(mark);
}
