Aaru/Aaru.Images/DiskCopy42/Verify.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Verify.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Verifies Apple DiskCopy 4.2 disk images.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library is distributed in the hope that it will be useful, but
//     WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2021 Natalia Portillo
// ****************************************************************************/

using System.IO;
using Aaru.Console;

namespace Aaru.DiscImages
{
    public sealed partial class DiskCopy42
    {
        /// <inheritdoc />
        public bool? VerifyMediaImage()
        {
            byte[] data    = new byte[header.DataSize];
            byte[] tags    = new byte[header.TagSize];
            uint   tagsChk = 0;

            AaruConsole.DebugWriteLine("DC42 plugin", "Reading data");
            Stream dataStream = dc42ImageFilter.GetDataForkStream();
            dataStream.Seek(dataOffset, SeekOrigin.Begin);
            dataStream.Read(data, 0, (int)header.DataSize);

            AaruConsole.DebugWriteLine("DC42 plugin", "Calculating data checksum");
            uint dataChk = CheckSum(data);
            AaruConsole.DebugWriteLine("DC42 plugin", "Calculated data checksum = 0x{0:X8}", dataChk);
            AaruConsole.DebugWriteLine("DC42 plugin", "Stored data checksum = 0x{0:X8}", header.DataChecksum);

            if(header.TagSize <= 0)
                return dataChk == header.DataChecksum && tagsChk == header.TagChecksum;

            AaruConsole.DebugWriteLine("DC42 plugin", "Reading tags");
            Stream tagStream = dc42ImageFilter.GetDataForkStream();
            tagStream.Seek(tagOffset, SeekOrigin.Begin);
            tagStream.Read(tags, 0, (int)header.TagSize);

            AaruConsole.DebugWriteLine("DC42 plugin", "Calculating tag checksum");
            tagsChk = CheckSum(tags);
            AaruConsole.DebugWriteLine("DC42 plugin", "Calculated tag checksum = 0x{0:X8}", tagsChk);
            AaruConsole.DebugWriteLine("DC42 plugin", "Stored tag checksum = 0x{0:X8}", header.TagChecksum);

            return dataChk == header.DataChecksum && tagsChk == header.TagChecksum;
        }
    }
}