Beispiel #1
0
        /// <summary>
        /// Method for decrypting an extracted watermark.
        /// </summary>
        /// <param name="password">The password that was used during encryption.</param>
        public Watermark Decrypt(string password)
        {
            bytes = new Rfc2898DeriveBytes(password, salt);

            this.key      = bytes.GetBytes(Algorithm.KeySize / 8);
            Algorithm.Key = key;

            int ivLength = BitConverter.ToInt32(cryptedData, 0);

            byte[] iv = new byte[ivLength];

            Array.Copy(cryptedData, 4, iv, 0, ivLength);
            Algorithm.IV = iv;

            int cryptDataLength = BitConverter.ToInt32(cryptedData, 4 + ivLength);

            byte[] cryptedData2 = new byte[cryptDataLength];

            Array.Copy(cryptedData, 4 + ivLength + 4, cryptedData2, 0, cryptDataLength);

            byte[] decrypted = Decrypt(cryptedData2, Algorithm);

            byte markType       = decrypted[0];
            int  markDataLength = BitConverter.ToInt32(decrypted, 1);

            byte[] markData = new byte[markDataLength];

            Array.Copy(decrypted, 5, markData, 0, markDataLength);
            Watermark decryptedMark = null;

            switch (markType)
            {
            case 1:
                decryptedMark = TextWatermark.LoadFromBytes(markData);
                break;

            case 2:
                decryptedMark = FileWatermark.LoadFromBytes(markData);
                break;

            case 3:
                decryptedMark = BinaryWatermark.LoadFromBytes(markData);
                break;

            case 4:
                decryptedMark = CompositeWatermark.LoadFromBytes(markData);
                break;

            case 9:
                decryptedMark = EncryptedWatermark.LoadFromBytes(markData);
                break;
            }

            return(decryptedMark);
        }
Beispiel #2
0
        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);
        }